Research & Development Information

PCA R&D Serial No. SN2860

Life Cycle Benefit of Concrete Slab Track

by Sunil K. Kondapalli & David N. Bilow

©Portland Cement Association 2008 All rights reserved

5420 Old Orchard Road Skokie, Illinois 60077-1083 847.966.6200 Fax 847.966.9481

www.cement.org

1

KEYWORDS Concrete, heavy axle freight, high speed rail, railroad track, shared corridor, slab track. ABSTRACT This report summarizes the economic benefit of concrete slab track as compared to ballasted tie track when used on railroad track in heavy freight traffic and combined freight and high speed rail service. The benefit analysis is performed using the EcoSlab computer program developed by ZETA-TECH Associates, Inc. for the Portland Cement Association. The EcoSlab economic analysis model provides for the development of an accurate and detailed life cycle cost analysis for the comparison of ballastless concrete slab track with alternate railroad track systems. The user has the ability to vary significant track characteristics, track maintenance frequency and cost, and train operating parameters. The software also allows the user to perform sensitivity analysis of several important variables. REFERENCE Kondapalli, Sunil K.1 and Bilow, David N.2, Life Cycle Benefit of Concrete Slab Track, SN2860, Portland Cement Association, Skokie, Illinois, USA, 2008, 62 pages.

1 Project Manager, ZETA‐TECH Associates, Inc., 900 Kings Highway N., Cherry Hill, NJ  08034 2 Director, Engineered Structures, Portland Cement Association, 5420 Old Orchard Road,    Skokie, IL 60077 

2

3

TABLE OF CONTENTS Executive Summary 4 Introduction 5 Life Cycle Cost Analysis Methodology 7

Route Profile 9 Component Life 10 Determination of Costs 10

Track Construction 10 Track Maintenance 10 Operating Costs 16 Derailment Risk/Costs 18

Model Utility and Ease of Use 18 EcoSlab Input Date 19

Source of Data 20 Route Profile Selection and Definition 20 Slab Track Construction 21 Component Life 31 Cost Data Input 33 Track Construction Costs 34 Track Maintenance 35 Operating Costs 43 Derailment Risk/Costs 46 Model Data Input and Ease of Use 47 Factors That Affect Data Input Values 47

Conclusion 48 Acknowledgement 49 References 49 Appendix 51

4

EXECUTIVE SUMMARY Slab track, also called ballastless track, consists of rails fastened directly to a continuous concrete slab which is placed on a prepared subgrade, tunnel invert, or aerial structure. Up until 2000, only a small amount of slab track had been constructed on North American railroads. In 1977, the Long Island Railroad constructed 1.3 miles of concrete slab track on the Massapequa Line. In Canada, in 1984, the Canadian Pacific Railway constructed a test section of slab track on-grade and subsequently a slab track through 10 miles of tunnels in the Canadian Rockies. Because of the increasing weight of freight cars and the need for a reliable track for shared freight and high speed rail, the Portland Cement Association (PCA) in 2000 studied the potential for concrete slab track as a replacement for conventional ballasted track.

For shared freight and high speed rail, the challenge is to design and construct a track system that provides the required ride quality for high speed passenger trains and the strength to withstand 39-ton axle loads from freight cars while keeping track maintenance to a minimum. To address this challenge, the Portland Cement Association (PCA) created the Cooperative Concrete Slab Track Research and Demonstration Program for Shared Freight and High Speed Passenger Service and in 2002, the Federal Railroad Administration (FRA) agreed to cosponsor together with PCA the design, construction, and testing of a slab track test section on the High Tonnage Loop (HTL) at the Transportation Technology Center (TTC) in Pueblo, Colorado.

The objectives of the cooperative research and demonstration program are to

advance concrete slab track technology, validate slab track design methodology, and demonstrate the capability of slab track to provide a low maintenance and safe track structure on high axle load freight track and track shared by high speed rail and freight in the United States. The research and demonstration program includes development of the design methodology, conducting laboratory tests on slab track specimens at the Construction Technology Laboratories, Inc. (CTL), design and construction of the slab track test section at TTC, operating the Heavy Axle Load train over the test section at TTC, and development of slab track life cycle cost software.

This report summarizes the economic benefit of concrete slab track as compared

to ballasted tie track when used on railroad track in heavy freight and combined freight and high speed rail service. The benefit analysis was performed using the EcoSlab computer program developed by ZETA-TECH Associates, Inc. for the Portland Cement Association. The EcoSlab economic analysis model provides for the development of an accurate and detailed life cycle cost analysis for the comparison of ballastless concrete slab track with alternate railroad track systems. The user has the ability to vary significant track characteristics, track maintenance frequency and cost, and train operating parameters. The software also allows the user to perform sensitivity analysis of several important variables. Analysis of three prototype systems in this report illustrate a life cycle cost savings of from 7% to 11% when slab track is compared to ballasted track.

5

Life Cycle Benefit of Concrete Slab Track

by Sunil K. Kondapalli & David N. Bilow

INTRODUCTION A slab track consists of a continuously reinforced concrete (CRC) slab placed over a stabilized subbase that is placed over a prepared subgrade. Continuous welded rails are normally used on the slab track. Up until 2000, only a small amount of slab track research had been conducted in North America. In the United States, in 1977, the Long Island Railroad constructed 1.3 miles of concrete slab track on the Massapequa Line. In Canada, in 1984, the Canadian Pacific Railway constructed a test section of slab track on-grade to evaluate the performance characteristics of a concrete slab track. Following the successful test, the Canadian Pacific Railway constructed slab track through 10 miles of tunnels in the Canadian Rockies (Hanna 1981, Hanna 1982, Longi 1990, Longi 1993, Tayabji and Bilow 2001). Starting in early 2000, the Portland Cement Association (PCA) studied the potential for concrete slab track as a replacement for conventional ballasted track. The challenge is to design and construct a track system that provides the required ride quality for high speed passenger trains and the strength to withstand 39-ton axle loads at freight train speeds. To address this challenge, PCA created the Cooperative Concrete Slab Track Research and Demonstration Program for Shared Freight and High Speed Passenger Service. PCA provides the management for this program. The objectives of the overall cooperative research and demonstration program created by PCA are to advance concrete slab track technology, validate slab track design procedures, and demonstrate the capability of slab track to provide a low maintenance and safe track structure. The research and demonstration program includes development of design methodology, design of the slab track test sections, preparation of a design guide, life cycle cost studies, laboratory tests, and field tests.

Many different types of slab track are in use in railroads and transit systems in North America, Europe, South Africa, South America, and Asia. Types of slab track include precast/prestressed concrete, cast-in place concrete, and a combination of precast ties and cast-in-place concrete. As a part of the cooperative research and demonstration program, two types of slab track were tested under simulated heavy freight car loads in the structural laboratory of Construction Technology Laboratories, Inc. (CTL) and on the High Tonnage Loop at the Transportation Technology Center in Pueblo, Colorado. One type of track is the Direct Fixation Slab Track (named DFST slab track), shown in

6

Figures 3, 4, and 5, and the other type is the Independent Dual Block Track (named IDBT slab track), also called Low Vibration Track (LVT), shown in Figures 6, 7, and 8. These two types of slab track were selected for testing because both types of slab track have been widely used and both could be upgraded to accommodate heavy axle loads. However, it is recognized that properly designed precast/prestressed concrete slab track can also be used to withstand high traffic of heavy axle load trains while maintaining track alignment and surface.

This report summarizes the economic benefit of concrete slab track as compared

to ballasted tie track when used on railroad track in freight and combined freight and high speed rail service. The benefit analysis was performed using the EcoSlab computer program developed by ZETA-TECH Associates, Inc. for the Portland Cement Association. The EcoSlab economic analysis model provides for the development of an accurate and detailed life cycle cost and benefits analysis for the comparison of ballastless concrete slab track with alternate railroad track systems. The model is used to compute the total life cycle costs for alternate track systems and the user has the ability to vary significant track characteristics, track maintenance frequency and cost, and train operating parameters. The software also allows the user to perform sensitivity analysis of several important variables.

The following four track systems are described in various details in this report:

Concrete Slab Track • Direct fixation concrete slab track without ballast • Individual dual block concrete slab track without ballast

(also referred to as low vibration track, LVT). Conventional Ballasted Track • Concrete tie track in ballast • Wood tie track in ballast

Track systems are analyzed in freight service only and combined high speed

passenger and heavy freight traffic service on a Class I railroad. The life cycle costs are calculated using track construction and maintenance costs

including labor, equipment, and material costs, and railroad operation costs including fuel, train delays, and derailment costs.

The report is divided into the following sections: 1) Life Cycle Cost Analysis Methodology 2) Input Data for the Model 3) Appendix - Prototype System Analysis A hands-on demonstration of the EcoSlab economic analysis model software can

be arranged by contacting PCA.

7

The first section of this report covers the development of life cycle cost analysis methodology for the EcoSlab model. The methodology involved in the development of life cycle costs for both ballasted track and concrete slab track are discussed in detail. The different combinations of track system that can be analyzed are listed in this section. Topics discussed include the track structure, maintenance practices, and track component lives. Also, cost items related to track construction, maintenance, and railroad operations that influence the life cycle costs of track systems are discussed.

The next section covers the input data for populating the EcoSlab model. The

track construction costs, maintenance costs, and railroad operation costs including costs for train delays and derailment are discussed. The construction methods for slab and ballasted tracks are summarized to identify differences in track systems and their track components. It should be noted that construction costs for a slab track are higher than for a ballast track, but slab track has a longer service life and requires much less maintenance than ballasted track. Also, slab track can accommodate traffic of higher track classes (up to Track Class 9) for high speed passenger trains (200 mph) and increased freight tonnage (such as 125 ton freight cars) without increased track maintenance costs.

The Appendix covers the preparation of life cycle cost analyses and parametric

studies for three prototype systems. The analysis and parametric studies are calculated using EcoSlab. The total life cycle present value cost comparison of slab track with conventional track is based on the input data and the calculations performed by the EcoSlab software.

The default input data values used in the model were obtained from several

different sources by ZETA-TECH. The default values may be used directly, or new values provided by railroad management can be input to the model. For input variables where there is some uncertainty in the correct value to use in the analysis, parametric sensitivity analysis is performed by the software to determine the input’s effect on total life cycle costs. By evaluating the sensitivity analysis graphs, the relative importance of the variable can be determined and “break even” points established.

8

LIFE-CYCLE COST ANALYSIS METHODOLOGY The EcoSlab economic model’s primary function is to evaluate the overall economics of a concrete slab track system1 as compared to a typical ballasted track system. This economic analysis is performed over a user defined route where the route is divided into multiple segments of track based on defined track and operating characteristics. The individual segments are analyzed to determine component life cycles for various track components (rail, tie, fastener, etc.) taking into account track geometry, maintenance, and operating characteristics of the segment. Maintenance and replacement costs of track components are evaluated using equipment, material, and labor unit costs along with maintenance production rates. These future costs are then transformed to a present value using the remaining life, defined life cycle, and interest rate and are then compared for each track system to determine the comparative track system economics.

The EcoSlab economic model is illustrated as a flowchart in Figure 1.

Figure 1 EcoSlab model

The EcoSlab model uses the default or input variables to calculate the total cost of construction, maintenance, and operation in each year of train operation over the specified route. Using the default or input interest rate, the model then applies discounting formulas to convert each year’s cost to a present value and sums up all the present values to obtain the total present value in cost per mile of track. This process is performed for two types of track simultaneously by the model so that the total present 1 Note that two types of ballastless concrete slab tracks are considered in this analysis – direct fixation slab track and individual dual block track.

Track Construction: material, labor, equipment costs

EcoSlab Economic Life Cycle Cost Model of Railroad

Track

Route Profile and Operating Data

Track Maintenance parameters

Track Component Life Data

Mainten-ance costs

Operation

costs

Derailment

costs

Present Value of Life Cycle Cost of Railroad

Track

9

value of costs for one type of track can be compared to the total present value of costs for the other type of track.

EcoSlab helps the user properly analyze the benefits of concrete slab track such as

lower track maintenance cost, longer life, and extended rail life versus lower track construction costs of ballasted track. Also, the impact of future increases in traffic and car loading, and the addition of passenger trains can be quantified using EcoSlab. The model can also help optimize track design by selecting components which can lower the life cycle cost. To assist in track optimization, the EcoSlab model includes sensitivity graphs for variables, e.g., million gross tons, which have a major impact on life cycle cost.

The user can perform a comparative analysis of either direct fixation or dual block

slab track against either or concrete tie or wood tie ballasted track. In addition, the user can compare the two types of slab track against each other. However, the difference in present value cost between the two types of slab track is very small.

The default case life cycle cost analysis is performed in a combined high speed

passenger and heavy freight traffic corridor within a Class I railroad. The user has the option to input different cost numbers or use default cost values which are based on economies of scale. The track construction, maintenance, and operation parameters used for the default case analysis are as follows:

• Track corridor length – 200 miles • Track construction tolerances – equivalent to Amtrak MW 1000 (Track Class 9) • Total traffic of 50 million gross tons (MGT) per year • Freight loads – 39-ton axle load • Passenger operations – maximum speed of 200 mph • Track maintenance tolerances – equivalent to Amtrak MW 1000 (Track Class 9)

Route Profile The route profile of a track system is defined in terms of individual segments to allow for variation in key track and operating characteristics. The user has the option of creating several segments, up to 20, to define the route profile. The data input for each segment includes segment length, grade/curvature profile, maximum operating speed for freight and passenger traffic, traffic tonnage (or number of trains per day), FRA class, and climate type. There are three climate types that have wood tie decay hazard values based on decay risk associated with each climate type. The three different climate types are Hot/Dry, Moderate, and Wet/Cold.

10

Component Life The route profile of a track system is analyzed to determine various track and operating variables that define each segment. These variables govern the lives of track components such as rail, tie, slab, fastener, pad, etc. The component lives are expressed either in years, or in million gross tons (MGT) of traffic. Table 3 shows sample default component life values for track components of both slab track and concrete tie track systems. The actual default values will be calculated by an internal model which accounts for key conditions that define this life (e.g. climate, traffic density, speed, etc.) The user has the option of either specifying different track component life values or using the default numbers. Determination of Costs Once the track structure, maintenance practices, and component lives are defined, costs can be calculated. The following are cost items related to track construction, maintenance, and railroad operations that influence the life cycle costs of track systems. Some of these cost items apply to all types of track, or only to one or two types of track. Costs are grouped into four distinct categories as follows:

Track Construction Track Maintenance Operating Costs Derailment Costs

A brief description of each cost category is presented below.

Track Construction. Track construction costs are incurred during new construction or complete replacement of existing track. Construction cost does not include the case of existing track that is in a state of ongoing maintenance. Track Maintenance. Track maintenance costs are those costs associated with the ongoing maintenance of an existing segment of track and usually deal with replacement of specific components. A key input into the calculation of track maintenance cost is the maintenance cycle itself, i.e., the interval between component replacement activities. Different combinations of high speed passenger and heavy freight traffic can generate different track degradation rates for each track component. Thus, rail is affected by wear, internal fatigue, and surface fatigue where the latter two modes, surface fatigue and internal fatigue, will increase exponentially with axle load. Ties are subject to mechanical wear and crushing by heavy trains as well as to environmental decay and degradation. Similarly, tie pads and rail pads (slab track) deteriorate under combined traffic. Ballast and subgrade are affected by repeated cyclic loading.

The relevant track maintenance activities include: • Basic Labor Force • Rail Replacement

11

• Tie Installation • Fastener Replacement • Concrete Abrasion Repair • Surfacing • Undercutting • Rail Grinding • Gaging • Anchor Adjustment • Track Buckling • Track Pull-apart

Not all of the above activities are relevant to all of the track types or to all operating or maintenance environments.

A brief description of each individual activity is presented below. Basic labor force. The personnel responsible for inspection and maintenance of the track constitute the Basic Labor Force. The size of the Force depends on the railroad property and the type of track structure and operating environment. In comparison to ballasted track system, fewer personnel will be required for basic maintenance of slab track system. Note: These are annual costs. As such, the final present value calculation is based on an annual cost of the basic labor force costs for each type of track. Rail replacement. The total cost involved in rail replacement is computed separately for each type of track. The variables considered in each analysis are as follows:

1) Equipment cost 2) Labor cost 3) Productivity rates 4) Rail material cost 5) Costs for other material which is replaced at the same time as the rail

including OTM, pads, insulators, and perhaps fasteners. 6) Rail life cycle The total cost of the rail replacement is based on the amount of material required

and either the rail replacement cost (per mile) or the daily cost of equipment and labor. If the latter, the daily costs are in turn divided by the productivity rate to get the replacement cost per mile. Based on the respective rail life cycles (there may be a difference in rail life between the different track types), the total cost is converted to present value by calculating the remaining life and using the interest rate to facilitate the comparison between the two systems.

Table 5 shows a sample rail replacement cost per mile for a concrete tie track and

a slab track, based on the curvature of the track segment. The material cost, installation cost, salvage credit, and total cost are shown for different sections of track. It should be

12

evident from the table that rail replacement costs for a slab track are slightly lower than for a concrete tie track system.

Table 5 Rail Replacement Cost per Mile

Item Slab track Concrete tie track

Material cost Tangent Moderate curve Severe curve

$256,000 $269,000 $282,000

$256,000 $269,000 $282,000

Installation cost Tangent Moderate curve Severe curve

$276,662 $301,545 $327,464

$291,224 $317,416 $344,699

Salvage credit $26,700 $26,700 Total cost (per mile) Tangent Moderate curve Severe curve

$505,962 $543,845 $582,764

$520,524 $559,716 $599,999

Tie installation. The tie installation activity is one of the major cost items for ballasted track. The variables governing tie installation cost analysis are:

1) Tie replacement cycle 2) Number of ties replaced per cycle 3) Percentage of fasteners replaced (if included as part of tie installation) 4) Equipment cost 5) Labor costs 6) Productivity rate

The calculation of total cost is carried out separately for wood tie track and

concrete tie track. Due to the nature of this cost analysis and the life cycle for concrete ties, it is assumed that concrete ties are replaced completely at the end of their life cycle. The fasteners replaced during wood tie installation might include cut spikes, plates, and anchors. The fasteners for wood tie track can be either cut spikes or elastic fasteners, and for concrete tie track, they are always elastic fastening systems. Fastener replacement. Fastener replacement activity is carried out for both concrete tie track and slab track. (In the case of wood tie track, fastener work is generally included as part of the tie replacement or gaging activities and as such is usually not performed separately.) The various items considered include clips, pads, and insulators for concrete tie track, as well as rail pads, under-tie pads, and boots for IDBT slab track and fasteners for DFST slab track. The total cost is dependent on material cost, installation cost, and percentage of fasteners replaced. The installation cost for rail pads is the same as rail installation cost (and as noted previously, may be performed as part of the rail installation activity).

13

Tie abrasion repair. Rail seat abrasion of concrete ties is a degradation problem that has been experienced by concrete tie track under North American heavy axle loadings. The depth of degradation can be significant enough to cause loss of fastener hold down force (clip toe load) and corresponding loss of fastener longitudinal restraint. As such, it usually requires in-site repair of the damaged concrete. The cost of this rail seat abrasion repair must be included for concrete tie track. Because of the elastomeric fasteners used on slab track, rail seat abrasion is unlikely. The analysis includes the probability and extent of rail seat abrasion, based on historical performance (for concrete tie track). Based on North American experience, the percentage of ties subjected to rail seat abrasion and the time for the abrasion to develop (the abrasion “life”) is dependent on the curvature as well as the traffic on a track segment. An annualized cost is assigned based on the cost of the tie abrasion repair and the number of ties repaired in a segment. Surfacing. Surfacing is performed only on ballasted track. The same gang composition and equipment is usually used for both the concrete and wood tie track systems. Thus, the primary difference between the costs of surfacing wood versus concrete tie track is the surfacing cycle and the productivity rate. In general, the surfacing cycle is somewhat longer on concrete tie track than on wood tie track. Also, due to the more uniform spacing of the concrete ties and lower number of ties per mile compared to wood tie track, the productivity rate for surfacing is somewhat higher for the concrete tie track. In addition, the amount of ballast will usually vary with concrete tie track requiring a greater depth of ballast than wood tie track. Undercutting maintenance. Undercutting represents a second order level of ballast maintenance, where the ballast is cleaned after an extended period of time in track. Again it applies only to wood and concrete tie track. The undercutting maintenance activity is introduced here to account for the cost of periodic ballast cleaning, through track undercutting, necessary to maintain track performance and avoid decreases in the surfacing cycle as the ballast becomes fouled. In this activity the labor, equipment, and material costs are introduced in the same manner as the previous maintenance operations and are used in a present value cost analysis based on the undercutting cycle. Rail grinding. Rail grinding is the grinding of the surface of the railhead to maintain a proper wheel/rail profile and to reduce the development of rail surface fatigue defects. Generally, concrete tie track has been found to require somewhat more frequent grinding than wood tie track. Spot corrective rail grinding every 100 to 150 mgt is performed at the Transportation Technology Center (TTC). The concrete slab track in the five degree curve test section at TTC has not required any rail grinding in five years of operation.

14

This maintenance activity is influenced by the following track and traffic characteristics:

1) Curvature 2) Traffic tonnage 3) Track stiffness

The grinding cycle is also governed by the method of grinding, whether maintenance profile or corrective grinding. This is generally an annual cost, with several grinding cycles per year (based on curvature and annual tonnage). The annualized present worth cost is calculated, and the difference between the different track systems is presented in the economic summary results. Gaging. Gaging refers to the correction of the track gage independent of any other maintenance activity. This activity is carried out only on wood tie track with cut spikes, which can experience a higher rate of gage widening, particularly on sharp curves, than track with elastic fasteners and as such requires correction before other required tie maintenance activities.

The different parameters influencing this activity are as follows: 1) Gaging cycle (function of curvature, annual tonnage, etc.) 2) Cost of equipment 3) Labor cost 4) Amount of material replaced (sometimes cut spikes are replaced or added)

Note: The gaging cycle is also a staggered cycle occurring out of phase with the tie gang (tie replacement) cycle. The total cost is calculated based on the sum of the labor and equipment cost divided by the productivity rates. The cost of material replaced (if any) is calculated, and the total for labor, equipment, and material is calculated. The total present value of all costs is then calculated. Anchor adjustment. Like gaging, this maintenance activity is used only for wood tie track. It is most common on track with severe grades or where there is extensive rail movement (longitudinal).

As in the case of gaging, the different variables governing the anchor adjustment activity are as follows:

1) Anchor adjustment cycle (function of track and traffic parameters) 2) Labor cost 3) Equipment cost 4) Productivity rate

Note: As in most of the component cycles, the user has the ability to change the anchor adjustment cycle.

15

Track buckling. Track buckling refers to the lateral deformation of the track structure, usually under high thermal and mechanical longitudinal loading. Track buckling costs can be divided into two major subcategories:

• Buckling maintenance and repair, where the buckle is found prior to a derailment and is repaired (usually occurs 100 times as often as actual track buckle derailments).

• Buckle derailment, where there is a significant cost due to the actual derailment of a train at a track buckle. This is an FRA reported derailment category and as such frequency and cost data is available from FRA public records.

Track buckling generally is expected to occur only on ballasted track. Slab track uses continuously reinforced concrete pavement which is also used for highway pavement on many interstate routes and horizontal buckling never occurs on highway pavement. Also, because of the weight of the concrete slab and the resistance to bending of the longitudinal reinforcement and rails, buckling in the vertical direction is highly unlikely. The cost of track buckling derailments can be determined based on the probability of a track buckle derailment per billion gross ton-mile (BGTM), which can then be calculated on a route specific basis (see discussion under derailments). The cost of track buckling repair – non-derailment - can be calculated based on the risk of a non-track buckle and the corresponding cost of restoring the track per buckle.

Note: The probability of track buckling is higher for wood tie track than for a concrete tie track system. However, the cost of a track buckle derailment is higher for concrete tie track than wood tie track.

Track pull-apart. Track pull-apart refers to the separation of rail ends in a rail joint or a break at a weld or the rail itself, usually under high thermal tensile forces. Pull-aparts are most likely to occur in the early winter when there is a sudden drop in the temperature or during extreme cold weather. This phenomenon is exactly opposite to track buckling. Track pull-apart can take place on both ballasted and ballastless track systems.

Track pull-apart costs include: • Pull-apart maintenance and repair, where the pull-apart is found prior to a

derailment. • Pull-apart derailment, where there is a significant cost due to the actual

derailment of a train at a pull-apart.

The cost of track pull-apart derailments can be determined based on the probability of a track pull-apart derailment per billion gross ton-mile (BGTM), which can then be calculated on a route specific basis (see discussion under derailments). The cost of track pull-apart repair, non-derailment, can be calculated based on the risk of a non-

16

derailment track pull-apart and the corresponding cost of restoring the track per track pull-apart. Operating Costs The type of track structure can affect several Operating Cost areas including:

• Fuel consumption • Vehicle maintenance • Train delays (including slow orders and rerouting costs)

These costs are generally related to the stiffness/resiliency of the track.

Fuel consumption. Studies by AREMA and other organizations show that there is a relationship between track stiffness, track deflection, and corresponding rolling resistance of a vehicle over the track. Decreasing the rolling resistance results in lower fuel consumption. This effect has been incorporated into the EcoSlab economic model to give it the ability to calculate fuel consumption for given traffic over a specific route. The model has an internal fuel consumption calculator which evaluates route characteristics and traffic data to estimate total fuel consumption. The user specified traffic data include the number of passenger trains per day, tonnage (MGT) of freight traffic, and operating speed limits. The model evaluates the annual number of passenger and freight trains in a segment based on the traffic characteristics defined for that segment. A typical passenger train will have a default value corresponding to a train consisting of one locomotive and six passenger cars with a total train weight of 550 tons. A freight train has a default value corresponding to a train consisting of 2 locomotives and 45 freight cars with a total train weight of 6,000 tons. Note: These variables can be set by the user with different values for each segment. The model’s internal calculator uses relative stiffness values to examine the effect of the track structure on rolling resistance and fuel consumption. Fuel consumption is then developed as a function of grade and curvature profile, operating speed limit, and available horsepower at the rail. ZETA-TECH fuel consumption models, calibrated to the AAR-developed Train Energy Model (TEM), are used to determine fuel consumption rates.

Thus, the reduction in fuel consumption achieved by trains running on a concrete tie or concrete slab track over a ballasted track will be calculated by a ZETA-TECH derived mathematical equation relating the track modulus values of both track systems and the corresponding effect on fuel consumption. The user can input the track modulus values for different track systems. Vehicle maintenance. Since the dynamic wheel/rail impact forces generated as a function of different track structures can affect the level of loading and corresponding

17

vehicle maintenance, the model addresses the relative cost of vehicle maintenance for different track types. These vehicle maintenance costs are calculated for each train based on the number of locomotives and cars in the train, noting that the maintenance costs of passenger and freight cars are different. The annual vehicle maintenance costs are based on the number of trains operated over a segment in a year. The difference in annual vehicle maintenance costs between track systems is based on their track strength (stiffness). The reduction in vehicle maintenance costs of trains operating on a concrete tie track in comparison to a ballasted track system is obtained by a ZETA-TECH derived mathematical equation relating the track modulus values of both track systems. Similarly the vehicle maintenance savings by trains operating over a slab track are calculated by using track modulus values of a slab track and a ballasted track. The user can edit the track modulus values. Train delays. A railroad track is subjected to periodic maintenance activities in order to maintain the track to that required for normal operations. There are certain track maintenance activities during which a track is taken out of service, resulting in train delays. Track maintenance activities such as rail, tie, and fastener replacement can cause trains to remain idle on a track, resulting in an operating loss for the railroad. This loss can be calculated from an average train delay cost, and used in the life cycle analysis.

The train delay cost is based on the number of hours lost by a train and the hourly cost of train delay. The number of hours lost due to train delay is dependent on the traffic density as well as the productivity rate of a rail gang working on a particular segment. Since the productivity rate of a maintenance gang is often higher on a slab track than a wood tie track system, this results in reduced train delay costs for slab track. Table 6 presents an example comparison of train delay costs per mile between slab track and wood tie track due to rail gang operations. The productivity rate used for the rail gang for a slab track and a wood tie track is 0.55 and 0.5 miles per hour respectively. The rail gang’s work window consists of six hours. The train delay cost for this example is $450 per hour.

Table 6 Train Delay Costs per Mile

Item Wood tie track Slab track Productivity rate (rail gang) 0.5 miles/hr 0.55 miles/hr Distance worked/day 3 miles 3.3 miles Number of trains Per day Per hour

17 0.7

17 0.7

Delay hours/day 12.8 hrs 12.8 hrs Delay hours per mile worked 4.3 hrs 3.9 hrs Delay cost per mile $1,935 $1, 755

Similar delay costs are incorporated into the model but can be modified by the user.

18

Derailment Risk/Costs The final area to be addressed in the analysis is that of derailment costs. As was already noted under track buckling and track pull-apart, certain categories of train derailment, particularly track-caused train derailment, can have different probability of occurrence rates for different track systems. This is clearly the case for gage widening/rail rollover derailments, which are significantly lower for concrete tie track than for wood ties with cut spike fastenings.

The approach that will be used is a probability of derailment (derailment risk) approach that has been used by ZETA-TECH in similar types of analyses. This approach uses publicly available derailment statistics from the FRA accident/derailment data bases to calculate a derailment risk or probability of a derailment per billion gross ton-miles (BGTM) and the corresponding average cost per derailment cause category. These costs are then applied to each defined segment, since the number of ton-miles on that segment is defined by the user to determine the number and total cost of derailments on the segment. These values are generally based on wood tie track because 90% of all track today is wood tie track.

Corresponding derailment rates and costs are then calculated for concrete tie track, based on available industry experience. Derailment rates and costs for slab track will be inferred based on expected system performance.

In general, the probability of a derailment for relevant tie and fastener related derailments is higher for wood tie track than for both concrete tie track and slab track. However, the cost per derailment is generally somewhat higher for concrete tie track, though it still must be determined if that is also the case for concrete slab track.

Based on the above approach, annual derailment costs are calculated for each track type under analysis and a corresponding total present value of costs is calculated. Model Utility and Ease of Use The computer model is a user-friendly, easy-to-use Windows format model written in Visual Basic (VB) that allows for detailed specification of all input variables, modification of these variables, sensitivity analyses, and what-if scenario analysis. ZETA-TECH’s experience with user-friendly models has shown that VB based models are easier to use and understand than spreadsheet based models which were extensively used in earlier versions of ZETA-TECH benefit analysis models. VB based models also offer more control to the owner of the model since they allow for better protection against unauthorized user modification than spreadsheet models.

The model is designed to be intuitive in appearance to allow for ease of application and use. While full flexibility in inputting performance and cost data is built

19

into the model, the model is provided with industry average default values for all inputs to allow for application, even when specific cost or performance variables are unknown. ECOSLAB INPUT DATA The EcoSlab economic model requires several input data sets to evaluate the overall economics of concrete slab track as compared to a ballasted track. Input data include: route profile and operating data, track component lives, track maintenance parameters, and cost information. The track component life data include the life of different track components in either years or in terms of traffic density (MGT). The track maintenance parameters data address the maintenance cycles/thresholds of track components in terms of number of years, traffic density (MGT), or track wear limits. The costing information specifies cost data for track construction, material, labor, and equipment/machinery costs. The flowchart of the model as shown in Figure 1 illustrates the type of data used for input into the model.

The input data required for the model was obtained from several different sources including the Portland Cement Association (PCA), ZETA-TECH Associates, railroads, transit systems, contractors, and railroad/transit suppliers. The data obtained may be used directly or extrapolated to similar track systems.

The EcoSlab model contains a data set of default values. The user has the option to use the default values or input different values. The default values may not be appropriate for smaller scale activities, limited construction, or maintenance activities since the default values are from large scale railroad maintenance activities and are based on economies of scale.

The economic analysis is performed over a user-defined route where the route is divided into multiple homogeneous segments of track based on defined track and operating characteristics. The individual segments are analyzed to determine component life cycles for various track components (rail, tie, fastener, etc.) taking into account different track, maintenance, and operating characteristics of the segment. Maintenance and replacement costs of different track components are evaluated using appropriate equipment, material, and labor costs along with maintenance production rates. These costs are then transformed to a present worth value (using the remaining life, defined life cycle, and interest rate), for each track type to determine the comparative track economics.

The following sections list the sources of data and present various data inputs for

different areas of the model. These sections also describe construction methods of slab track and ballasted track systems, and track construction costs.

20

Source of Data The data required to populate the model are taken from several sources. The majority of data related to a typical ballasted track including track construction, maintenance, and operational costs are collected from ZETA-TECH’s library which contains an extensive collection of projects and field studies performed in the past by ZETA-TECH Associates, Inc., as well as from railroad, transit, and supply industry sources. The track construction, material, and component, and other input data for the slab track were collected from a diverse group of sources including PCA, railroads, suppliers, contractors, consultants, and published papers. The different sources of slab track information are listed as follows:

1) William P. Kucera, David N. Bilow, Claire G. Ball, “Laboratory Test Results of Heavy Axle Loads on Concrete Slab Track for Shared High-Speed Passenger and Freight Train,” AREMA, September, 2002

2) William P. Kucera, David N. Bilow, Claire G. Ball, D. Li, “Laboratory Test Results and Field Test Status of Heavy Axle Loads on Concrete Slab Track Designed for Shared High-Speed Passenger and Freight Train Corridors,” AREMA, October, 2003

3) William Moorhead, The Permanent Way Corporation 4) John Zuspan, Marta Track Constructors/Balfour Beatty 5) William Osler, Advance Track Products 6) Bernard Sonneville, Sonneville International Corporation 7) Arthur S. Kretzmann, Consultant (formerly with Spoornet/COALlink, South

Africa) 8) M.S. Longi, “Concrete Slab Track on the Long Island Railroad” 9) Tetsuhisa Kobayashi, Katsutoshi Ando, “State-of-the-Art Slab Track in

Shinkansen,” Rail Tech Europe, 2001 10) Katsutoshi Ando, Makoto Sunaga, Hifumi Aoki, Osamu Haga, “Development of

Slab Tracks for Hokuriku Shinkansen Line,” QR of RTRI, Vol. 42, No.1, March 2001

11) Katsutoshi Ando, Shigeru Miura, Kainen Watanabe, “Twenty Years Experience on Slab Track,” QR of RTRI, Vol. 35, No.1, February 1994

12) Katsutoshi Ando, Takahiro Horiike, Kouichi Kubomura, Masanori Hansaka, Takaharu Nagafuji, “Present Status on Slab Track and Environmental Countermeasure,” QR of RTRI, Vol. 37, No.4, December 1996

13) Li, Dingqing, “Slab Track Field Test and Demonstration Program for Shared Freight and High-Speed Passenger Service,” PCA R&D Serial No. 2988, 2007

Route Profile Selection and Definition

The grade and curvature profile describes a range of values for both grade and curvature which is selected to match as closely as possible the actual grade and curvature of each route segment. Table 1 shows the various combinations of grade and curvature found in typical track. The user can select a grade/curvature combination for a particular segment

21

of the route. The four different grades shown in the table are tangent (<1%), mild grade (1%-1.5%), moderate grade (1.5%-2%), and severe grade (>2%). Similarly the four curvatures are tangent (<1 degree), mild curvature (1-3 degrees), moderate curvature (3-6 degrees), and severe curvature (>6 degrees). Table 1 Segment Grade and Curvature

Item Tangent Mild grade Moderate grade Severe grade

Tangent Grade <1% Curve < 1deg

Grade 1-1.5% Curve <1 deg

Grade 1.5-2% Curve <1 deg

Grade >2% Curve <1 deg

Mild curvature

Grade <1% Curve 1-3 deg

Grade 1-1.5% Curve 1-3 deg

Grade 1.5-2% Curve 1-3 deg

Grade >2% Curve 1-3 deg

Moderate curvature

Grade <1% Curve 3-6 deg

Grade 1-1.5% Curve 3-6 deg

Grade 1.5-2% Curve 3-6 deg

Grade >2% Curve 3-6 deg

Severe curvature

Grade <1% Curve >6 deg

Grade 1-1.5% Curve >6 deg

Grade 1.5-2% Curve >6 deg

Grade >2% Curve >6 deg

The route characteristics for a sample track system are illustrated in Table 2. A

total of five segments are created to define the track profile. The total length of the route is 200 miles. The data shown in the table represent track and operating characteristics for each segment. The traffic on the route can be expressed either as million gross tons (MGT) or as number of trains per day (with defined train weights). The FRA class and climate zone of each segment are also listed in the table. Table 2 Route Characteristics Segment No. 1 2 3 4 5 Length (miles) 30 40 60 40 30 Axle load (freight-ton) 39 39 39 39 39

Trains/day (freight) 18 17 18 18 19

Trains/day (passenger) 7 7 8 8 4

MGT (total) 50.2 47.4 50.4 50.4 52.3 Grade/Curve Grade <1%

Curve 1-3deg Grade <1%

Curve 1-3degGrade <1%

Curve 1-3degGrade <1%

Curve 3-6deg Grade <1%

Curve 1-3degRail size (lb/yd) 136 136 136 136 136

FRA class 9 9 9 9 9 Climate type Moderate Moderate Moderate Moderate Moderate Slab Track Construction Slab track is a ballastless track that uses a reinforced concrete slab to which rails are attached for support. A concrete slab is typically supported on a subbase over a prepared subgrade. Slab track can be precast, cast in place, or slip formed. The rails are attached to

22

the track by fasteners that are anchored to the slab or by the use of individual concrete block ties which are embedded in the concrete slab.

The following describes the steps involved in the construction of two types of slab

track which have been tested on the High Tonnage Loop (HTL) at the Transportation Technology Center (TTC) in Pueblo, Colorado. One type of slab track is the direct fixation concrete slab track (DFST), and the other type is the individual dual block concrete slab track (IDBT). The IDBT track is also referred to as low vibration track (LVT). The two types of slab track selected are designed for operation in a combined high-speed passenger train and heavy freight traffic corridor on a Class I railroad. Slab track is capable of maintaining FRA safety class 9 tolerance for high-speed passenger trains at a speed of 200 mph while carrying freight cars with 39 ton axle loads as demonstrated at TTC.

The tests at TTC were undertaken as part of a cooperative research program titled,

“Cooperative Concrete Slab Track Research and Demonstration Program For Shared Freight and High-Speed Passenger Service,” which was sponsored by the Federal Railroad Administration (FRA) and PCA.

Two 250-ft slab track test sections were constructed at TTC. The existing

ballasted track structure on section 38 of the HTL was removed to build the two test sections of slab track. Section 38 is on a bypass track section with a curve of 5 degrees, and a super elevation of 4 in. The slab track sections were constructed in accordance with Amtrak Standard MW 1000 and FRA safety standards for Class 9 track.

After removal of the existing track work and ballast, the subgrade was graded to

the proper line and elevation. The subgrade was then compacted and a mixture of soil and portland cement was compacted to a 6-in. thickness to be used as a subbase under the concrete slab. The subbase provided a working platform for construction, reduced settlement of the subgrade, reduced pumping at cracks and joints, and will minimize frost damage.

The two slab track sections were built on the subbase using the top-down

construction and manual methods. The top-down construction method was chosen because of its inherent low cost and ease of attaining the strict tolerances required for high-speed rail track systems. A standard formwork with tie rods was used for both slab track sections. The sections of slab track were not long enough to use a slip form paver, a more efficient construction method for long sections of slab track. Direct Fixation Slab Track (DFST). The DFST is 10 ft wide, 1 ft thick, and 250 ft long and is placed directly on the soil cement subbase. Two mats of bar reinforcement were placed within the side forms. Each mat had longitudinal and transverse bars.

Iron Horse rail alignment fixtures were used to provide support and maintain rails and fasteners at the proper elevation, gage, and cant during slab construction. The

23

Acoustical Loadmaster rail fasteners supplied by Advanced Track Products and embedment inserts supplied by PTC Fastening, Inc. were attached to the alignment fixtures. The fasteners were spaced at two feet apart to support a standard RE136 lb rail at a standard gage of 56.5 in. with a gage tolerance of +1/16 to –3/32 in. The welded 80-ft rail sections were held to the fastener with Pandrol e-clips. A standard 5,000 psi concrete mix was placed and finished to form the concrete slab. The DFST slab track is shown in Figures 2, 3 and 4.

As concrete placement was progressing, the surveying team checked elevation and alignment to ensure that the track would meet the specified tolerances. Curing consisted of the application of a curing compound supplemented by placement of an insulating blanket that further reduced moisture loss and helped maintain constant temperatures.

The slab width of 10 ft 6 in. was selected to keep subgrade pressures lower than 20 psi (as per recommendation of AREMA, Chapter 8, part 27). The subgrade pressure was measured after the slab track construction, and the maximum subgrade pressure was only 12 psi.

The slab track construction at TTC experienced temperature variations of about

30 degrees for ambient temperature and 70 degrees for rail temperature in a typical 24-hour period. The following measures were taken to control the temperature variation effect on construction operations:

a) Quick release clips replaced the e-clips during construction. These clips were released after the initial set of the concrete, thus allowing the rail to expand and contract as needed without dragging the fastener and inserts along with it before the concrete attained sufficient strength.

b) Wire braces were installed every 10 feet to hold the rail in proper position as well as to prevent the jig from racking and the rail from walking toward the inside of the curve.

c) Placement of concrete within a “pour window” enabled the maximum amount of time to place concrete with minimal rail temperature differentials. Historical ambient and rail temperature data collected by TTCI gave a predictable window of opportunity regarding when the temperature range would be within 15 degrees.

24

Figure 2 DFST track layout

Figure 3 DFST slab track – concrete placement

25

Figure 4 DFST slab track – fastener removal

Individual Dual Block Track (IDBT). The individual dual block track was constructed in two phases. The first phase involved placing concrete directly on the soil cement subbase and over two bar reinforcement mats to create a 7.75-in. thick “U” shaped slab. The second phase used self-compacting concrete (SCC) placed around and under the individual dual blocks ties. The block ties are delivered assembled with fasteners, under tie pads, and rubber boots. The phase 1 concrete slab, has a width of 10 ft-6 in. and length of 250 ft. A standard 5,000 psi concrete mix was placed to form the concrete slab. The phase 1 reinforced IDBT slab track is shown in Figure 5. The top surface of the curb was trowel finished while the surface of the slab was raked to ensure a rough finish for bonding with the phase 2 concrete slab. The phase 1 concrete slab was cured for 5 days by the application of a curing compound (1100 Sealtight water-base). The curing was supplemented by placement of a plastic coated insulative blanket that further reduced moisture loss and helped to maintain constant temperatures.

The second phase construction of IDBT track started after the phase 1 concrete slab had cured. The top-down construction procedure was used for the second phase construction. The individual dual blocks (supplied by The Permanent Way Corporation) were attached to the rail at 2-ft centers to support a standard 136RE rail at a standard gage of 56.5 in. with a gage tolerance of +1/16 to –3/32 in. The welded 80-ft rail sections were held to dual blocks by STL rail fastenings (supplied by Sonneville International

26

Corporation) and tensioned by a shoulder and lock combination. Rail pads and insulators were also installed.

Iron Horse rail alignment fixtures provided support to the rails and maintained the

rails and dual blocks at their proper elevation, gage, and cant as the phase 2 concrete was placed. A self-compacting concrete mix (SCC – supplied by Axim Concrete Technologies) with good flowability characteristics was used to properly fill the small space between the top of the phase 1 slab and the bottom of the boot block. There was no reinforcement in the phase 2 slab. The phase 2 concrete placement of the IDBT slab track is shown in Figure 6. The two phases resulted in a 15-in.-thick concrete slab. As concrete pouring was progressing, the surveying team checked elevation and alignment to ensure that the track would meet the specified tolerances. The same curing procedure discussed earlier was adopted to reduce moisture loss and maintain constant temperatures.

The temperature variations at TTCI as discussed earlier were a major concern during the construction of IDBT track. The following measures were implemented to control the temperature variation effect during construction operations:

27

a) Steel braces were installed every 10 feet to hold the rail in proper position. The brace was fitted with a structural angle at each end, one to bear on the toe of the rail and the other to bear against the top inside corner of the concrete curb poured in phase 1. The system provided the necessary lateral resistance to maintain rail alignment during concrete placement and curing. The braces were needed for phase 2 concrete placement only.

b) Placement of concrete within a “pour window” enabled the maximum amount

of time to place concrete with minimal rail temperature differentials. Historical ambient and rail temperature data collected by TTCI gave a predictable window of opportunity when the temperature range would be within 15 degrees.

Figure 5 IDBT slab track – phase 1 layout

28

Figure 6 IDBT slab track – phase 2 concrete placement Ballasted Track Construction. In order to compare ballasted track with a slab track, a ballasted track should be constructed to the same track class standards as the slab track. The ballasted track must accommodate high-speed passenger trains at a maximum speed of 200 mph and be capable of carrying freight cars with 39 ton axle load (125 ton freight car). There are numerous techniques available to build new track ranging from new track construction machines to track renewal machines which are designed to pick up old track and replace it with new track, such as in going from wood to concrete tie track. Alternately, smaller systems or combinations of independent machines can be used.

For new track construction, one such system is the HARSCO Model NTC New Track Construction Machine (see Figure 7). This machine lays new track on a previously prepared roadbed in a continuous operation.

The unit consists of a truss frame supported at one end by a specially modified

flatcar running on the newly laid track and, at the other end, by a non-powered crawler running on the roadbed. The truss frame contains a conveyor system for carrying the crossties down to the tie laying mechanism, which places them on the roadbed at a precise and predetermined spacing. A self-propelled gantry, requiring one operator, keeps the ties supplied to the conveyor systems. The tie handling cars are equipped with auxiliary rails which form a continuous running rail for the gantry. Pivoting extensions between the cars allow the gantry to operate on curves. After being deposited by the

29

gantry, the ties move via the conveyor system to the tie drop area. Prior to being positioned on the roadbed, cushioning pads are placed on the ties to cushion the effect of steel rail on concrete ties. The entire consist is pulled by a crawler-type auxiliary power unit. Rail, which has been previously distributed along the roadbed, is threaded through guides located at the rear of the tow unit. It is then guided inward to a gaging station. Final placement of the rail on the new ties is controlled by an operator who guides the rail onto the tie seat. The operator is also responsible for the proper alignment of the track. Steering of the machine is accomplished by hydraulically controlling the non-powered crawler under the front of the truss beam in reference to a plumb line previously laid out to indicate the path of the new track.

FIGURE 7 HARSCO model NTC new track construction machine

Track renewal systems like the P-811 (Figure 8) and Pony Express (Figure 9)

systems remove old ties and rails, level and prepare the ballast, lay new ties, and thread in new rails…all in just one continuous pass. These units utilize specially modified rail cars to transport new ties to the job site. A gantry unit feeds new ties into the machine and loads old ties removed from the track onto the same rail cars for ecology-minded disposal.

The units generally include a work car, conveyorized tie handling cars - designed

for easy transport and fast cut-in/cut-out at the job site, and articulated frames for the feeding in of new ties and rail and the feeding out of old ties and rail. They also carry mechanisms for the removal of old ties and the laying of new ties, with a ballast preparation mechanism in between. These units can remove and replace wood, concrete, or steel ties in any combination. They prepare a new tie bed with an undercutting ballast chain mechanism that lowers and levels the ballast surface and moves the excess material to the outside of the track. It also precisely spaces new ties and lays them accurately - at an average rate of 14 ties-per-minute, this equals more than 10,000 ties in a 12-hour shift

30

- and returns the old rails to the ties or threads in new ones from the side of the track or from rail storage racks on the cars that carry the ties.

The final product is a completely renewed track structure (Figure 10).

FIGURE 8 HARSCO P811 track renewal machine

FIGURE 9 HARSCO pony express track renewal machine

31

FIGURE 10 Recently renewed track

Conventional Track Maintenance. Wood and concrete tie track are often maintained by partial component replacement, i.e. rail replacement, tie replacement, ballast surfacing, etc. These techniques are well known to the railroad industry and will not be discussed in detail. Component Life The route profile of a track system is analyzed to determine various track and operating variables that define each segment. These variables govern the lives of track components such as rail, tie, slab, fastener, pad, etc. The component lives are expressed either in years or in million gross tons (MGT) of traffic. Table 9 shows sample default component life values for track components of both slab track and wood tie track systems. The actual default values will be calculated by an internal model that accounts for key conditions that define this life (e.g., climate, traffic density, speed, etc.). The user has the option of either specifying different track component life values or using the default values.

It should be observed from the table that rail life is normally expressed in MGT, since rail life is generally accepted as being linear with MGT. However, a maximum rail life in years will also be defined to avoid excessively long lives, e.g., for an annual tonnage of 1 MGT, the 1200 MGT rail life would give a life of 1200 years, which is highly excessive. To avoid this effect, a maximum rail life, in years, usually 100 years, will be defined. Note that rail life is dependent on the curvature profile of the track

32

segment, with a shorter life in sharper curves. Also, note that premium rail has longer life than the standard carbon rail for a given curvature.

The life for other components such as concrete slab, rail pad, and slab fastener is

expressed in years. However, as already noted, the life of many components is sensitive to key variables such as annual tonnage, climate, etc.

The track component lives together with track maintenance parameters such as

rail replacement (e.g., criterion for use of premium versus standard carbon rail) and tie replacement criterion (e.g., ties replaced per mile) are used to calculate maintenance cycles. These cycles are calculated using proprietary models developed by ZETA-TECH Associates, a simplified version of which is incorporated into this model. It should be noted that maintenance cycles are calibrated to United States average industry values. Implementation of maintenance cycles results in maintenance and replacement costs of track components. These costs are determined using various equipment, material, and labor costs along with maintenance production rates.

The sample track component life values shown in Table 9 are based on the

following assumptions: • Premium rail installed on moderate and severe curves • Moderate lubrication on moderate and severe curves • 100% CWR, 136 lb/yd rail • Track Class 9 • Annual traffic of 50 MGT • Rail grinding is performed where necessary • Moderate climate (decay hazard value)

In Table 9 the value for the life of the Direct Fixation Slab Track pad is

conservatively shown as nine years. However, the DFST fastener has been installed on Amtrak’s Northeast Corridor at Trenton for 20 years without any maintenance. Also, Battelle Institute tested a 30 ton fastener model under 40 ton axle loads to 4500 MGT.

33

Table 9 Track Component Life

Component/Activity Slab track - DFST MGT

Concrete tie track, Years MGT Years

Rail life – Standard tangent

606

594

Rail life – Premium moderate curve

Severe curve

308 175

302 172

Surfacing cycle Class 5 Class 6 Class 7 Class 8 Class 9

3.2 2.4 2.2 1.7 1.2

Geometry Adj cycle Class 5 Class 6 Class 7 Class 8 Class 9

13 10 9 7 5

Tie life 42 Undercutting cycle 12 Rail grinding cycle 0.1

Slab life 50

DFST track Fastener plate Fastener clip Fastener pad

47 24 9

IDBT track Boot/Under tie pad

15

Cost Data Input

Costs represent a key input into the model and as such must be input as accurately as possible. While the model does include realistic default cost values for each variable, these are generally generic type values which can vary significantly between railways, applications, and conditions. As such, users are strongly encouraged to examine the default costs in light of their own experience and if there is a significant difference to input revised costs.

It should be noted here that costs related to turnouts and tunnels are not addressed

since they are beyond the scope of this report. Turnout costs for a slab track might be high but maintenance costs could be low. In most railroad tracks, there is about one turnout per mile of track.

The following is a list of the cost items related to track construction, maintenance,

and railroad operations that influence the life cycle costs of track systems. Some of these

34

cost items apply to all types of track, others only to one or two types. Costs are grouped into four distinct categories as follows:

Track Construction Track Maintenance Operating Costs (including delays and rerouting costs) Derailment Risk and Costs

The input data for each cost category is presented below.

Track Construction Costs The track construction costs include items such as subgrade preparation, subballast, ballast, and track superstructure components. The subgrade cost should include cost for the preparation of subgrade without extensive earthwork (i.e., deep cut, blasting rock, and earth fill) and drainage costs. The ballast cost is influenced to a larger extent by the cost of transporting ballast to a track construction site. The material costs of different types of ballast are almost identical. The track component costs include material and installation (labor and machinery) costs for rails, ties, fastener components, and slab track. Track construction costs are necessary for new construction or complete replacement of existing track. They are not used in the case of an existing track that is in a state of ongoing maintenance (e.g., for existing wood tie track). The track construction costs in 2007 for slab track and ballast track are shown in Tables 10A and 10B respectively. These costs assume moderate subgrade preparation (without extensive subgrade or grading preparation).

The track construction costs for both DFST and IDBT slab track are shown in Table 10A. The costs for each component are listed as costs per mile. Table 10A shows the construction costs for slab tracks. It can be observed from the table that total cost for new track construction for slab track is $1,292,000.

Table 10B presents the track construction costs for concrete tie track. The cost

items for concrete tie track include rail material, tie/fastener/clip, ballast, and labor/equipment. The construction costs for track components are shown as costs per mile. It can be observed from the table that total construction cost for concrete tie track is $1,166,000.

35

Table 10A Slab Track Construction Cost per Mile

Component Slab track Rail (material) $256,000

DFST Fastener/pads (material) $724,000

Total labor, equipment, machinery, OH and profit

$312,000

Total new construction cost $1,292,000

Table 10B Ballasted Track Construction Cost per Mile

Component Concrete tie track

Rail (material cost) $256,000

Tie, fasteners, clips, etc; (material) $325000

Ballast (material) $130,000

Total labor, equipment, machinery, OH and contractor profit $455,000

Total new construction cost $1,166,000

Track Maintenance Track maintenance costs are those costs associated with the ongoing maintenance of an existing segment of track. As such, they usually deal with specific component replacement. Additional track maintenance is required to maintain tracks to a higher class of track for high-speed passenger operation. The track maintenance activities carried out on both ballasted track as well as slab track are discussed below. The rail and other track materials that are replaced can be salvaged either for sale as scrap or reuse elsewhere. Some track components will have a substantial value either for reuse (depending on condition) or for scrap. The salvage value of a track component is computed where applicable and used as a credit to the track maintenance costs.

The relevant track maintenance activities include: • Basic labor force • Rail replacement • Tie installation • Fastener replacement • Concrete abrasion repair • Surfacing • Maintenance undercutting • Rail grinding • Track buckling

36

• Track pull-apart Not all of the above activities are relevant to all of the track types or to all operating and maintenance environments. Basic labor force. The personnel responsible for inspection and maintenance of the track constitute the Basic Labor Force. The size of the force depends on the railroad property and the type of track structure and operating environment. In comparison to a ballasted track system, fewer personnel will be generally required for maintenance of slab track. Table 11 shows input data for the size and cost of the force. The daily labor costs are divided by productivity rates to obtain labor costs per mile.

Table 11 Basic Labor Force

Item Slab track Concrete tie track

Laborer group 2 4

Daily wage $135 $135

Daily labor cost $270 $540

Daily productivity rate (miles) 0.25 $0.19

Labor cost per mile $1,080 $2,842

Rail replacement. The total costs involved in rail replacement are computed separately for a wood tie track system, concrete tie track system, and slab track system. The variables considered in each analysis are as follows:

1) Equipment cost 2) Labor costs 3) Productivity rates 4) Material cost, in the form of rail 5) Other material costs replaced at the same time (e.g., pads, insulators, etc.)

[May be included here or under fastener component replacement] 6) Rail life cycles The total cost of the rail replacement is based on the amount of material required

and either the per mile rail replacement cost or the daily cost of equipment and labor. If the latter, the daily costs are in turn divided by the productivity rate to get the cost per mile replacement cost. Based on the respective rail life cycles (there may be a small difference in rail life between the different track types), the total costs are converted to present worth values (evaluating the remaining life and interest rate) to facilitate the comparison between the two systems.

Table 12 shows rail replacement costs per mile for both slab track and ballasted

track. The material and installation costs are listed based on the curvature profile of the

37

track. Train delay cost due to the rail replacement activity as well as other activities is shown under the operating cost category. The salvage credit is applied to replacement costs to derive the total rail replacement costs for both types of track.

Table 12 Rail Replacement Cost per Mile

Cost Category Slab Track Concrete Tie Track

Material cost Tangent Moderate curve Severe curve

$256,000 $269,000 $282,000

$256,000 $269,000 $282,000

Installation cost Tangent Moderate curve Severe curve

$276,662 $301,545 $327,464

$291,224 $317,416 $344,699

Salvage credit $26,700 $26,700

Total cost (per mile) Tangent Moderate curve Severe curve

$505,962 $543,845 $582,764

$520,524 $559,716 $599,999

Tie installation. Tie installation activity is one of the major cost items for ballasted track. The calculation of total costs is carried out separately for wood tie track and concrete tie track. Table 13 shows the tie replacement costs for concrete tie track. The material costs include the cost of ties, fasteners, and other track material. The fasteners for a concrete tie track system are always elastic fastening systems. The salvage credit is applied to determine the total tie replacement cost per mile. The variables governing tie installation cost analysis are:

1) Tie replacement cycle 2) Number of ties replaced per cycle 3) Percentage of fasteners replaced (if included as part of tie installation) 4) Equipment cost 5) Labor costs 6) Productivity rate

Table 13 Tie Replacement Cost (per Mile)

Component Concrete Tie Track Material cost (includes fasteners, clips, etc.) $150,000

Installation cost $198,000

Salvage credit $1,250

Total cost (per mile) $346,750

38

Fastener replacement. Fastener replacement activity is carried out for both concrete tie track and slab track. In the case of wood tie track, fastener work is generally included as part of the tie replacement or gaging activities and as such is usually not performed separately. The various items considered include clips, pads, and insulators for concrete tie track, as well as rail pads, under-tie pads, and boots for IDBT slab track and fasteners for DFST slab track. The total cost is dependent on material cost, installation cost, and percentage of fasteners replaced.

The installation cost for rail pads is the same as rail installation cost (and as noted previously, may be performed as part of the rail installation activity). The material cost and installation costs are shown in Table 14. Train delay cost due to the fastener replacement activity as well as other activities is shown under the operating cost category.

Table 14 Fastener Replacement Cost per Mile

Component Slab track Concrete tie track Material cost (rail pad, boot, fasteners, insulators, etc.) $185,000 $40,000

Installation cost $240,576 $25,000

Salvage credit $50,000 $750

Total cost (per mile) $375,576 $64,250

Tie abrasion repair. Rail seat abrasion of concrete ties is a degradation mode that has been experienced by concrete tie track in curves under North American heavy axle loadings. The depth of the abrasion can be significant enough to cause loss of fastener hold down force (clip toe load) and corresponding loss of fastener longitudinal restraint. As such, it usually requires on a site repair of the damaged concrete.

Based on North American experience, the percentage of ties subjected to rail seat

abrasion is dependent on the curvature as well as on the traffic on a track segment. Similarly the time for the abrasion to develop (the abrasion “life”) is affected by these factors. An annualized cost is assigned based on the cost of the tie abrasion repair and the number of ties repaired in a segment. The model internally calculates the number of ties that need to be repaired. The cost of rail seat abrasion repair is included in the maintenance of concrete tie track. The model includes the probability and extent of rail seat abrasion, based on historical performance (for concrete tie track). An annualized cost is assigned based on the cost of the tie abrasion repair and the number of ties repaired in a segment. Because of the elasticity in the fasteners, the slab track test section at TTC has not experienced rail seat abrasion and therefore this cost is not included in the slab track maintenance cost. The cost of the abrasion repair is $25 per tie and the user has the option to modify this cost.

39

Surfacing. Surfacing is performed only on ballasted track. The same gang composition and equipment is usually used for both the concrete and wood tie track systems. Thus the primary difference between the costs of surfacing on wood versus concrete tie track is the surfacing cycle and the productivity rate. The surfacing costs per mile and productivity rates for concrete tie track are listed in Table 15. The productivity rate for surfacing is somewhat higher for the concrete tie track due to the more uniform spacing of the concrete ties and lower number of ties per mile compared to wood tie track. Also, the material (ballast) cost is slightly higher since the concrete tie track requires a greater depth of ballast than wood tie track.

Table 15 Surfacing Cost per Mile

Component Concrete tie track

Surfacing cost $10,000

Material cost (addition of ballast) $8,250

Total cost (per mile) $18,250

Productivity rate (miles/day) 2.5

Undercutting (maintenance). Undercutting represents a second order level of ballast maintenance, where the ballast is cleaned after an extended period of time in track. Again it applies only to wood and concrete tie track. The undercutting maintenance activity is introduced here to account for the cost of periodic ballast cleaning, via track undercutting, necessary to maintain track performance and avoid decreases in the time between surfacing cycles as the ballast becomes fouled. Table 16 lists undercutting cost (labor and machinery), material costs, and productivity rates.

Table 16 Undercutting Cost per Mile

Component Concrete tie track Undercutting cost (labor & machinery) $12,500

Material cost (ballast) $11,250

Total cost (per mile) $23,750

Productivity rate (miles/day) 0.6

40

Geometry adjustment. While ballastless concrete slab track does not require conventional surfacing, it may require some amount of fastener adjustment to compensate for local settlement or degradation. The slab track test section has not required geometry adjustment even though it has experienced over 268 MGT of heavy freight traffic over a five year period. The fastener system has the capability for lateral and vertical adjustments. The vertical adjustment can be achieved by addition of shims and/or a polyethylene pad. The cost for geometry adjustment of slab track is included in EcoSlab. Rail grinding. Rail grinding is the grinding of the surface of the railhead to maintain a proper wheel/rail profile and to reduce the development of rail surface fatigue defects. Table 17 lists grinding costs and productivity rates for both ballast and slab track. Concrete tie track requires more frequent grinding than wood tie track. It is assumed that slab track requires the same frequency of grinding as concrete tie track.

This maintenance activity is influenced by the following track and traffic characteristics:

1) Curvature 2) Traffic tonnage 3) Track stiffness

The grinding cycle is also governed by the method of grinding, whether maintenance profile or corrective grinding. This is generally an annual cost, with several grinding cycles per year (based on curvature and annual tonnage). The annualized present value cost is calculated.

Table 17 Rail Grinding Cost per Mile

Component All Types of Track

Equipment cost per day $20,000

Total grinding cost (per mile) $1,667

Productivity rate (miles/day) 12

Gaging. Gaging refers to the correction of the track gage independent of any other maintenance activity. This activity is carried out only on wood tie track with cut spikes, which can experience a higher rate of gage widening, particularly on sharp curves, than track with elastic fasteners, and as such requires correction before other required tie maintenance activities. The different parameters influencing this activity are as follows:

1) Gaging cycle (function of curvature, annual tonnage, etc.) 2) Cost of equipment 3) Labor cost 4) Amount of material replaced (sometimes cut spikes are replaced or added)

41

The gaging cycle is also a staggered cycle occurring out of phase with the tie gang (tie replacement) cycle. The total cost is calculated based on the sum of the labor and equipment cost divided by the productivity rates. The cost of material replaced (if any) is then calculated and the total for labor, equipment, and material is calculated. The total present value of all costs is then calculated. Anchor adjustment. Like gaging, this maintenance activity is used only for wood tie track. It is most common on track with severe grades or where there is extensive rail movement (longitudinal). As in the case of gaging, the different variables governing the anchor adjustment activity are as follows:

1) Anchor adjustment cycle (function of track and traffic parameters) 2) Labor cost 3) Equipment cost 4) Productivity rate

As in most of the component cycles, the user has the ability to change the anchor

adjustment cycle. Track buckling. Track buckling refers to the lateral deformation of the track structure, usually under high thermal and mechanical longitudinal loading. Track buckling costs can be divided into two major subcategories:

• Buckling maintenance and repair, where the buckle is found prior to a derailment and is repaired (usually occurs 100 times as often as actual track buckle derailments).

• Buckle derailment, where there is a significant cost due to the actual derailment of a train at a track buckle. This is an FRA reported derailment category and as such, frequency and cost data are available from FRA public records.

Track buckling occurs only on ballasted track systems. The cost of track buckling derailments can be determined based on the probability of a track buckle derailment per billion gross ton-mile (BGTM) which can then be calculated on a route specific basis using traffic characteristics. The cost of track buckling repair – non-derailment – can be calculated based on the probability of a track buckle and the corresponding cost of restoring the track. Table 18 shows the data related to track buckling. It can be observed from the table that the probability of track buckling is higher for wood tie track than for a concrete tie track system. However, the cost of a track buckle derailment is higher for concrete tie track than a wood tie track system.

42

Table 18 Track Buckling Cost

Item Wood Tie Track Concrete Tie Track

Probability of track buckling per BGTM 0.03 0.02

Cost per track buckle • Derailment cost • Track buckle repair

$300,000 $12,000

$330,000 $13,200

Total cost (prior to multiplying by the probability) $312,000 $343,200

Track pull-apart. Track pull-apart refers to the separation of rail ends in a rail joint or a break at a weld or the rail itself, usually under high thermal tensile forces. Pull-aparts are most likely to occur in the early winter when there is a sudden drop in the temperature or during extreme cold weather. This phenomenon is exactly opposite to track buckling. Track pull-apart can take place on both ballasted and ballastless track systems. The first failure of a thermite weld on the slab track test section which is in a 5 degree curve at TTC occurred after 227 MGT of 39 ton axle freight traffic. For comparison, thermite welds in curves in ballasted track only last about 80 MGT at TTC.

Track pull-apart costs include: • Pull-apart maintenance and repair, where the pull-apart is found prior to a

derailment. • Pull-apart derailment, where there is a significant cost due to the actual

derailment of a train at a pull-apart. The cost of track pull-apart derailments can be determined based on the probability of a track pull-apart derailment per billion gross ton-mile (BGTM), which can then be calculated on a route specific basis (see discussion under derailments). The cost of track pull-apart repair for the non-derailment case can be calculated based on the risk of a track pull-apart and the corresponding cost of restoring the track per each track pull-apart. Table 19 shows the data related to track pull-apart. It can be observed from the table that the probability of track buckling is higher for wood tie track than for a concrete tie track system. It is assumed that the probability of track pull-apart on a slab track is smaller than a concrete track. The user has the option to modify the values for probability as well as cost for each track pull-apart.

43

Table 19 Track Pull-apart

Item Wood tie track

Concrete tie track Slab track

Probability of track pull-apart per BGTM 0.03 0.02 0.007

Cost per track pull-apart • Derailment cost • Track pull-apart repair

$150,000 $8,000

$200,000 $8,800

$200,000

$8,800

Total cost (prior to multiplyingby the probability)

$158,000

$208,800

208,800

Operating Costs The type of track structure can affect several Operating Cost areas including:

• Fuel Consumption • Vehicle Maintenance • Train Delays (including slow orders and rerouting costs)

The first two costs are related to the stiffness/resiliency of the track structure and

the corresponding effect on the train response. The third item is related to the frequency and duration of maintenance and repairs of buckles and pull-aparts. Fuel consumption. Studies by AREMA and other organizations show that there is a relationship between track stiffness and track deflection, and corresponding rolling resistance of a vehicle over the track and thus fuel consumption. This effect has been incorporated into the EcoSlab economic model to give it the ability to calculate fuel consumption for given traffic over a specific route. The model has an internal fuel consumption calculator which will evaluate route profile characteristics (see discussion on Route Profile) and traffic data to estimate total fuel consumption. The user specified traffic data include the number of passenger trains per day, tonnage (MGT) of freight traffic, and operating speed limits. Table 20 lists the data for fuel consumption. The train consist data for passenger as well as freight trains are listed in the table. The model evaluates the annual number of passenger and freight trains in a segment based on the traffic characteristics defined for that segment. The different characteristics considered include total train weights and annual tonnage. The user can specify different values for these variables for each defined segment. Fuel consumption is then developed as a function of grade/curvature profile, operating speed limit, and available horsepower at rail. ZETA-TECH fuel consumption models, calibrated to the AAR-developed Train Energy Model (TEM), are used to

44

determine fuel consumption rates. The fuel cost per gallon is listed in the table. The user can modify these values.

The fuel savings or reduction in fuel consumption achieved by trains running on a concrete tie or concrete slab track over a wood tie track system will be evaluated by a ZETA-TECH derived mathematical equation relating the track modulus values of both track systems and the corresponding effect on fuel consumption. The user can input the track modulus values for different track systems as shown in the table. Track modulus values for slab track were obtained from newly constructed slab tracks at TTC, Colorado but can be varied during the selection of the elastomeric pad.

Table 20 Fuel Consumption Costs

Item Data

Train data Passenger:

Number of locos Number of cars

Freight: Number of locos Number of cars

1 6

2 45

Fuel cost per gallon $3.00

Track modulus (lb/in/in) Wood tie track

Concrete tie track Slab track (DFST) Slab track (IDBT)

2,500 3,500 3,000 3,000

Vehicle maintenance. Since the dynamic wheel/rail impact forces generated as a function of different track structures can affect the level of loading and corresponding vehicle maintenance, the model addresses the relative cost of vehicle maintenance for different track types. These vehicle maintenance costs are calculated for each train based on the number of locomotives and cars in the train consist. The maintenance costs of passenger cars are different than those for freight cars. Table 21 lists train consist data for passenger and freight trains, and vehicle maintenance costs for different vehicles. The annual vehicle maintenance costs will be based on the number of trains operated over a segment in a year. The difference in annual vehicle maintenance costs between track systems will be based on their track stiffness. The reduction in vehicle maintenance costs of trains operating on a concrete tie track in comparison to a wood tie track system is obtained by a ZETA-TECH derived mathematical equation relating the track modulus values of both track systems. Similarly the vehicle maintenance savings by trains operating over a slab track system is calculated by using track modulus values of a slab track and a wood tie track system. The user can edit the track modulus values, which are shown in Table 21.

45

Table 21 Vehicle Maintenance Costs

Item Data

Train data Passenger:

Number of locos Number of cars

Freight: Number of locos Number of cars

1 6

2 45

Maintenance cost (per mile) Passenger:

Locomotive Passenger car

Freight: Locomotive Freight car

$0.95 $0.25

$1.00 $0.05

Train delays. A railroad track is subjected to periodic maintenance activities in order to maintain the track to standards required for normal operations. There are certain track maintenance activities during which a track is taken out of service, resulting in train delays. Track maintenance activities such as surfacing and rail, tie, and fastener replacement can result in train delays, which cause trains to remain idle on a track leading to an operating loss for the railroad. This loss can be calculated from an average train delay cost which will be used in the life cycle analysis of track systems. The train delay cost is based on the number of hours lost by a train and the hourly cost of train delay. The number of hours lost due to train delay is dependent on the traffic density as well as the productivity rate of a rail gang working on a particular segment. Since the productivity rate of a maintenance gang is often higher on a slab track than a wood tie track system, this results in reduced train delay costs for the slab track system. The EcoSlab model computes train delay costs associated with different track maintenance activities and presents a total train delay cost. Table 22 presents an example comparison of train delay costs per mile between a slab track system and a wood tie track system due to rail gang operations. The productivity rate used for the rail gang for a slab track and a wood tie track is 0.65 and 0.5 miles per hour respectively. The rail gang’s work window consists of six hours. The train delay cost is shown in the table.

46

Table 22 Train Delay Costs per Mile

Item Wood tie track

change to concrete tie track

Slab track

Productivity rate (rail gang) 0.5 miles/hr 0.65 miles/hr

Distance worked/day 3 miles 3.9 miles

Number of trains Per day Per hour

17 0.7

17 0.7

Delay hours/day 12.8 hrs 12.8 hrs Delay hours per mile worked 4.3 hrs 3.3 hrs

Delay cost per hour $2,500 $2,500

Delay cost per mile $10,750 $8,250

Derailment Risk/Costs The final area to be addressed in the analysis is that of derailment costs. As was already noted under track buckling and track pull-apart, certain categories of train derailment, particularly track-caused train derailment can have different probability of occurrence rates for different track systems. This is clearly the case for gage widening/rail rollover derailments, which are significantly lower for concrete tie track and slab track than for wood ties with cut spike fastenings. The approach to evaluation of the derailment costs was discussed in detail in the first task of this report. The approach that is used is a probability of derailment (derailment risk) approach that has been used by ZETA-TECH in similar types of analyses. This approach uses publicly available derailment statistics from the FRA accident/derailment data bases to calculate a derailment risk or probability of a derailment per billion gross ton miles (BGTM) and the corresponding average cost per derailment category. To determine the number and total cost of derailments on the segment, the number of ton-miles on that segment is multiplied by the derailment probability and then by the expected costs. These values are generally based on wood tie track because 90% of all track today is wood tie track. Corresponding derailment rates and costs are then calculated for concrete tie track, based on available industry experience. Derailment rates and costs for slab track will be inferred based on expected system performance. Based on the above approach, annual derailment costs are calculated for each track type under analysis and a corresponding total present value of costs is calculated.

47

Table 23 shows probability of derailments per billion gross ton miles (BGTM) and derailment costs for different track systems. The probability of a derailment for is higher for a wood tie track system than for both a concrete tie track and a slab track system. However, the cost per derailment is generally somewhat higher for concrete tie track due to track repair cost. Because there is little data on the repair cost of slab track, it is conservatively assumed that the cost per derailment for concrete slab track is the same as that of concrete tie track. As with other cost data, the user has the ability to modify these values.

Table 23 Derailment Costs

Item Wood tie track Concrete track Slab track

Probability of derailments per BGTM 0.27 0.20 0.01

Cost per track derailment $100,000 $110,000 $110,000

Model Data Input and Ease of Use The computer model is a user-friendly, easy-to-use Windows format model written in Visual Basic (VB) that allows for detailed specification of all input variables, modification of these variables, sensitivity analyses, and what-if scenario analysis. The model is designed to be intuitive in appearance to allow for ease of application and use. While full flexibility in inputting performance and cost data is built into the model, the model is provided with industry average default values for all inputs to allow for application, even when specific costs or performance variables are not known. Thus the user has the ability either to enter specific values or allow the model to use default numbers. Factors that Affect Data Input Values The various data inputs and track costs used in the model are subject to market influences and trends in the cost of labor and material. The different factors that could influence various sets of cost data required by the model are as follows:

- Size of a railroad/transit agency - Number of suppliers/contractors - Location of track site - Trend of raw material prices for track components - Labor skills and productivity The size of a railroad system can have an impact on the cost of a track system.

The bigger railroads can obtain better prices from suppliers due to large purchase orders. The number of suppliers/contractors available for a particular track component or a contract job can impact the cost of a track system. A better price can be obtained when

48

multiple suppliers are available for a particular track component. As an example, the use of a nonstandard rail section such as 100 lb rail can drive up the total cost since very few steel companies manufacture this rail section. Railroad historical data exhibits different trends in the costs of labor and material. The unit costs of most track components and materials have risen over the years, while costs of some have remained the same when adjusted for inflation. The location of the track construction site can have a significant influence on the material cost of track components. As an example, the ballast cost is influenced to a larger extent by the cost of transporting ballast than the material cost. A track site in the northeastern part of America can have lower transportation cost of ballast than a track location in the south. The unit cost of labor has risen steadily over the years. However, the usage of modern machinery had contributed to higher worker productivity. The higher productivity has more than compensated for the rise in the cost of labor and has kept the total cost of labor down. The size of a railroad can influence the total labor cost per track mile. The bigger railroad systems use modern machinery which results in higher worker productivity. The smaller railroads use contractors to handle any large jobs and might result in higher unit costs. Thus it is important that the user of EcoSlab identify as closely as possible the actual costs to be used as inputs to this model. The model is sensitive to key cost values. While the default values used in EcoSlab are realistic industry values, they are generic and as such may not be applicable to specific cases. CONCLUSION As shown in this report, there are many variables which impact the total economic cost of constructing, maintaining, and operating today’s large and complex rail transportation system. Identifying and quantifying the major variables related to track economics is essential to performing a thorough cost analysis of alternate track systems. Use of the present value algorithm to evaluate the entire service life of track components and future maintenance and operation costs allows the calculation of a fairly accurate estimate of the total present value cost of each track system.

The EcoSlab software has the capability to accommodate unique route characteristics, different magnitudes of axle load and traffic volumes, and different combinations of freight and passenger trains. EcoSlab also has the flexibility to include a wide range of track component service lives and unit costs. In addition, the software includes provisions for rail pull-aparts, track buckling, and train delay costs due to track maintenance. The sensitivity analysis feature of EcoSlab is a powerful tool to help the user determine how the variation in a variable impacts the total savings when slab track is used in place of ballasted track.

49

The Prototype System Analysis described in the Appendix demonstrates the life cycle benefit analysis of three prototype systems. The results of the analysis are as follows:

Prototype A, freight only, indicates a savings of 7% when slab track is used instead of ballasted track. Prototype B, freight and 125 mph passenger, indicates a savings of 8% when slab track is used instead of ballasted track. Prototype C, freight and 200 mph passenger, indicates a present value savings of 11% when slab track is used instead of ballasted track.

The life cycle savings are greater than the initial construction cost of the slab track. Conservative values of construction, maintenance, and operating variables were used in the EcoSlab analysis, including the load from 286,000 pound freight cars now commonly in service. It is probable that within the next 50 years, 315,000 pound cars will become common for transporting bulk products and will increase the benefit of slab track on high volume routes. ACKNOWLEDGEMENTS The research reported in this paper (PCA R&D Serial No. 2860) was conducted by ZETA-TECH Associates, Inc. with the sponsorship of the Portland Cement Association (PCA Project Index No. 01-06c). The contents of this paper reflect the views of the authors, who are responsible for the facts and accuracy of the data presented. The contents do not necessarily reflect the views of the Portland Cement Association. REFERENCES American Railway Engineering and Maintenance-of-Way Association, Manual for Railway Engineering, Landover, Maryland, USA, 2002. Ball, G. B., “Slab Track Laboratory Test Program,” Report to PCA, Construction Technology Laboratories, Inc., Skokie, Illinois, USA, 2004. Esveld, C., Modern Railway Track, 2nd Edition, MRT-Productions, The Netherlands, 2001. Longi, M. S., “Concrete Slab Track on the Long Island Rail Road,” Publication SP 93-20, American Concrete Institute, 1993. Lotfi, H. R. and Oesterle, R. G., “Analysis and Design of DFST and IDBT Laboratory Specimens,” Report to PCA, Construction Technology Laboratories, Inc., Skokie, Illinois, USA, 2005.

50

Selig, E. T. and Waters, J. M., Track Geotechnology and Substructure Management, Thomas Telford Publications, London, 1994. Tayabji, S. D. and Bilow, D. N., “Concrete Slab Track For Freight and High Speed Service Applications, A Survey of Practice,” TRB Paper Number 01-0240, 2001. Li, Dingqing, Slab Track Field Test and Demonstration Program for Shared Freight and High Speed Passenger Service, Portland Cement Association, Skokie, Illinois, 60077, 118 pages.

51

Appendix

Prototype System Analysis This section demonstrates the economic analysis using the EcoSlab software. The analysis is conducted for the following three prototype rail systems:

• Prototype A is a heavy haul high volume route with 36 ton axle loads and 130 car trains.

• Prototype B is a heavy haul moderate volume route with 36 ton axle loads and 130 car trains combined with 125 MPH passenger trains.

• Prototype C is a heavy haul lighter volume route with 36 ton axle loads and 80 car trains combined with a maximum of 200 MPH high-speed passenger trains.

The EcoSlab software input data for the route characteristics for the three prototype

systems is shown in Table A1. A total of five segments define the track profile for each prototype. Three segments have mild curves and mild grades, and two segments have moderate curves and moderate grades. All five segments in each prototype are exposed to the same traffic. For each prototype the total length of the route is 200 miles, the rail size is 136 lb/yard, and the climate is moderate. Also, EcoSlab default values for other variables including labor cost, component life and component replacement, as well as maintenance, delay, and derailment costs are used in the analysis of the prototypes.

The EcoSlab software analyses results for the three prototypes are shown in Table A2 for track constructed of concrete slab track and track constructed of typical ballasted track with concrete ties. The table shows the present value of construction, maintenance, operation, and derailment costs and the total present value of all costs. All costs are per mile of track.

The net financial benefit of using slab track instead of ballasted track on each of the

prototype systems amounts to a savings of from $970,000 to $1,702,000 per mile of track or 7% to 11% of the present value cost of ballasted track as shown in the bottom line of Table A2. Exhibits A, B, and C illustrate the category costs and total cost for slab track and ballasted track in a bar chart form. It can be observed from these bar charts that the operations category is the largest part of the total present value cost while maintenance is also a substantial part of the total cost. It is also evident that the construction cost of track is a relatively small part of the total lifecycle cost.

In order to help decision makers get a feel for how the total present value cost is affected by changes in major input variables, EcoSlab sensitivity analysis is performed for traffic tonnage, train delay cost, interest rate, slab track life, and slab track construction cost. The sensitivity analysis for these variables for Prototype C is shown in Exhibits D through H. EcoSlab performs sensitivity analysis by changing the variable under investigation while keeping all other variables constant. The net benefit of slab

52

track is calculated by subtracting the total present value cost of slab track from that of ballasted track. The following discusses results of the sensitivity analysis.

1. The net benefit of slab track increases linearly with an increase in traffic tonnage. The input value of traffic for prototype A of 436 MGT/year is at the high end of the plot. A decrease in tonnage by 8% decreases the net benefit of slab track by 5%.

2. The net benefit of slab track also increases linearly with the train delay cost. The input value of the train delay cost of $2,500/hour is at the high end of the plot. A decrease in train delay cost of 11% decreases the net benefit of slab track by 6%.

3. The net benefit of slab track decreases nonlinearly with the increase in net interest rate. The input value of the net interest rate of 7% per year is toward the middle of the plot. In discount calculations, lower interest rates result in future events having more importance.

4. The net benefit of slab track increases with an increase in the slab track life up to about 40 years and then starts to level out. This happens because the cost of events which occur after 40 years have little impact on the present value due to discounting the future cost to present value.

5. The net benefit of slab track decreases with an increase in the slab track cost of

construction. The input value of slab track construction cost of $1,292,000 per mile is toward the center of the plot. If slab track construction cost increases 20%, the net benefit of slab track decreases 16%.

53

Table A1 Route Characteristics for Three Prototypes

Three Prototypes

Route characteristic A. Heavy high volume freight

B. Heavy moderate volume freight + 125

MPH passenger

C. Moderate freight + 200 MPH high speed

passenger

Freight trains/day 60 30 30

Freight train axle load in tons 36 36 36

Number of freight cars 130 130 80

Number of locomotives 6 6 3

Passenger trains/day 0 6 8

Number of passenger cars 0 6 8

Number of locomotives 0 1 1

FRA class 6 7 9

Total MGT per year 436 220 135

Table A2 Present Value of Costs in Dollars per Mile for Three Prototypes

Three Prototypes

Cost category

A. Heavy high volume freight

B. Heavy moderate volume freight + 125

MPH passenger

C. Moderate freight + 200 MPH high

speed passenger

Ballasted track

Slab track

Ballasted track

Slab track

Ballasted track

Slab track

Track construction 1,166,000 1,292,000 1,166,000 1,292,000 1,166,000 1,292,000

Track maintenance 8,057,000 6,926,000 4,551,000 3,894,000 4,880000 4,057,000

Operating cost 13,836,000 13,269,000 6,969,000 6,595,000 7,021,000 6,304,000

Derailment cost 137,000 7,000 69,000 3,000 42,000 2,000

Total present value 23,196,000 21,494,000 12,755,000 11,785,000 13,110,000 11,656,000

Net benefit of slab track

$1,702,000 7% Savings

$970,000 8% Savings

$1,454,000 11% Savings

54

Exhibit A Cost summary for Prototype A

Exhibit B Cost summary for Prototype B

55

Exhibit C Cost summary for Prototype C

Exhibit D Sensitivity analysis for slab track life

56

Exhibit E Sensitivity analysis for slab track construction cost

Exhibit F Sensitivity analysis for traffic

57

Exhibit G Sensitivity analysis for interest rate

Exhibit H Sensitivity analysis for train delay cost