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AA_BPG_37500100 (10 August2011).doc

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AA BEST PRACTICE GUIDELINE 375001

CONVEYOR GUARDINGISSUE 0

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CONTENTS PAGE

1

SCOPE 2

2 DEFINITIONS 23 RISK MANAGEMENT 34 GUARDING OF CONVEYOR BELTS 64.1 FIVE HUMAN MOTIONS 64.2 PHYSICAL HAZARDS (DANGER POINTS) 84.3 SAFETY BARRIERS 94.4 TYPICAL INSTALLATION REQUIREMENTS 155 MATERIAL SPECIFIATIONS 326 MAITENANCE 357 REMOVAL OF GUARDS 35

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1 SCOPE

This document serves to provide the necessary guidelines on the safeguarding of beltconveyor equipment. It outlines the interface between general human motion and knowndanger points on a belt conveyor installation.

2 DEFINITIONS

HIRA : Hazard Identification and Risk Assessment

Danger Points This is identified as nip points and any rotating machinesor parts thereof that are a threat to the health and safetyof persons in the vicinity of belt conveyors.

Primary Safety Barrier : A guard installed to prevent human contact with a source

of danger created by a rotating pulley or idler andeliminate the possibility of any person being drawn intothe nip point. Such guards include nip guards.

Secondary Safety Barrier : A guard, fence or barrier structure designed,manufactured and installed of such material and strengthas to afford the necessary protection against inadvertenthuman contact with a moving or rotating component of aconveyor belt system.

Tertiary Safety Measures : Such measures cover personal protective equipment(PPE).

Indirect Safety Measures : Such measures will include operator and personneltraining which is likely to move in the vicinity of aconveyor belt.

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3 RISK MANAGEMENT

All exposed machinery which, when in motion, may be dangerous to any person shall besecurely fenced off or effectively guarded. Efficient guards shall be provided to such partsof any machinery as may be a source of danger to any person.

The wording may be dangerous to any person and may be a source of danger to anyperson clearly implies that at places where persons may reasonably be expected to workor move about, machinery must be guarded of fenced off. It does not matter whether aperson has or has not any right to approach such items of machinery, for should anaccident result, the plea of safety by position will not normally be accepted in a court oflaw unless at least certain minimum requirements were complied with. Also implicit in thestatutory requirements, is the fact that it is not sufficient to act with hindsight but, as far asis humanly possible hazards must be identified before danger arises. Guards or fences

must therefore be constructed to protect against unforeseen contingencies, not merelyagainst normally expected operational hazards.

The employer must take reasonably practicable measures to prevent persons from beinginjured as a result of them, the clothes being worn by them or any equipment being heldby them coming into contact with or being drawn into any moving part of any machine.

The measures to be taken by the employer to prevent any person from coming intocontact with any moving part of machinery or any equipment attached thereto, mustinclude:

effective physical barriers at the machinery such as screening, guarding or fencing;or

failsafe electric or electronic barriers interlocked with the machinery in such a waythat the machinery would be stopped before persons come into contact with movingmachinery or parts thereof; or

effective barriers at a safe distance away from any machinery.

Key Words: All Exposed; In motion; All sources of danger; Efficiently guarded, Source ofdanger

Hazard is the Source of or exposure to danger

Risk is The likelihood that occupational injury or harm to a person will occur

Ergonomics is the Study of the relationship between man, the equipment with which heworks, and the physical environment in which this man-machine system operates.

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Safety Objectives are:

Prevent any person from being injured at any belt conveyor installation

Guards must be adequately designed and installed

Do adequate maintenance on and around guards to prevent guard from beingineffective due to its design or any external influence such as spillage, impactdamage, etc.

Only persons authorised by the employer may start, operate and maintain beltconveyors.

Only persons permitted by the employer may be in the vicinity of any belt conveyorinstallation.

Belt conveyors may only operate if ALL safety guards, as determined by legislationand Risk Assessment for the particular conveyor, is installed correctly andeffectively maintained for safety.

Persons may not wear loose clothing, or anything else that can be caught in theevent that the moving parts of a conveyor are exposed.

All stored mechanical, electrical, hydraulic, chemical or other forms of energy will beremoved from the conveyor installation before any safe guard is removed.

Barriers must be installed and so positioned at a safe distance away from movingmachinery or their parts.

The following serves to establish the requirements of effective guarding:

IDENTIFY all the danger points with regards to the belt conveyor installation.

DESIGN - Determine the extent to which the danger point is to be safe guarded.

CONSTRUCT the guard to the required dimension using the correct material toensure and maintain safe guarding.

ISOLATE the belt conveyor installation following the correct lockout procedure andINSTALL the constructed guards.

MAINTAIN the safe guards according to correct installation, deterioration ofguards.

REPLACE guards when they become ineffective in its function as a safety barrier.

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ISOLATION & LOCKOUT When any repairs, maintenance, routine cleaning andcleaning of spillage is done on or in the vicinity of conveyor belt installation the

power supply of a conveyor belt installation shall be removed and when the beltconveyor has become stationary this stationary conveyor belt installation shall be

locked out.

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4 GUARDING OF CONVEYOR BELTS

4.1 FIVE HUMAN MOTIONSMechanical danger points around the conveyor are identified by a risk assessmentprocess. Each of these danger points must be addresses in terms of the extent to whichthe danger point is to be guarded and followed by the specified materials used to safeguard such danger point. The extent to which such danger points are safe guarded isdependent on the five physical motions of a human being when in the vicinity of operatingmachines.

For a guard or a fence to be effective it must be so constructed that a person is preventedfrom reaching the danger point. A person may normally be regarded as capable ofreaching upward, over, into, around or through a guard or fence and all five these aspectsmust be taken into account when considering the effectiveness of a guard or fence:

Reaching Upwards - Any rotating or moving equipment or machinery,including pulleys and idlers which are installed and operated at a height above 3,5m from the ground or a working platform where persons might be positioned willbe regarded as positionally safe and need not to be guarded. The possiblereduction of this minimum safe clearance, due to a build-up of spillage ordischarge of material, must be taken into account in the design of the guards.Risk Assessments must be routinely conducted within the workplace to identifysuch areas of change.

Reaching Over Head and tail pulleys must be guarded on at least the twosides and the top unless the guards or fences on the sides are carried to such aheight that it is impossible to reach over it into the nip point. If the side guards onlyare provided with a very small clearance between the edge of the carry belt and

the side guard, this may perhaps be regarded as adequate to prevent reachingover the guard and touching the nip point but this will not necessarily prevent toolsor clothing from being caught in the nip point. If the head end is provided with atop guard it must be high enough above the belt to ensure that the moving loadwill not impact and damaged the guard. Tail pulleys in addition to the sides mustbe guarded across the rear end from the end of the one side-guard to the end ofthe other side-guard. Such guard must not be installed closer than 150 mm fromthe tail pulley circumference.

Reaching Into The distance that the guard or fence is away from the side ofthe belt will really determine the distance the guard or fence must be extendedaway from the nip point along the length of the belt. The distance from the guardto the edge of the belt must be a minimum of 150 mm while the side guard

extends at least 850 mm away from the position of the nip guard along the beltline.

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Reaching Around This really has the same meaning as into as far as theconveyor pulley guard is concerned but may also be applied to determine the

length of the top section of the guard. The same minimum distance of 850mmmust apply.

If there is a V-belt or chain drive associated with the conveyor installation a verycommon defect is often found where the V-belts or chains are perfectly guardedaround the perimeter and on one side, but the guard is so installed that the nippoints can easily be contacted by reaching around the section forming theperimeter guard.

Reaching Through - The protection afforded against injury by reachingthrough the guard will be determined by the shape and size of openings in thematerial used for construction of the guard or fence and is governed by thisdocument.

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4.2 PHYSICAL HAZARDS (DANGER POINTS)

The following exposed hazards require ONLY a Secondary Safety Barrier

Electric motor shaft

Gearbox in- and output shaft

Gearbox external fan

High speed coupling and associated in-and output shafts (such as FluidCouplings or Semi-flexible Coupling)

Pulley shafts extending past the outside of both plummer blocks to which personscould be exposed to (could be idle or driving shafts)

Take-up carriage area

Take-up counterweight tower

Take-up rope, sheaves and winches

Belt turnover(s)

The following exposed hazards require ONLY a Primary Safety Barrier

Return Idler nip points When the belt is moving onto the face of the return idlerrolls and when access underneath the conveyor is possible, exposing such nippoints.

Where idlers are specifically designed and installed to restrict the upwardmovement of a conveyor belt during a start-up or run-down procedure

When the belt tension is such that the additional normal force and belt weightpressing down on idlers in a convex curve posses a significant risk to safety ofpersons.

In areas where idler sets or impact cradles are installed below a bunker, feeder-bin, silo hopper or transfer chute to support a belt, eliminate spillage and improvethe loading profile onto the belt and also applies, even more so, to belt on whichhand sorting is performed.

The following exposed hazards require a Primary AND Secondary Safety Barrier

Pulley nip points Where belt moves onto the pulley face

The following point DO NOT require a Primary or Secondary Safety Barrier

Carry Idler nip point Where the belt is moving onto the carry wing idler rollsurface.

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4.3 SAFETY BARRIERS

4.3.1 Primary Safety barriers

Definition

A nip point is created when a belt moves onto a rotating pulley or return idler and require aprimary safety barrier and is positioned with respect to the rotation of a pulley or returnidler. This guard extends over the whole width of the pulley or idler and may be regardedas a reasonable solution to prevent access to danger points. A person is not completelyprevented from reaching around it and therefore cannot, by itself, be regarded assufficient protection and it is therefore essential that guarded pulley nip points be furtherguarded or fenced off with a secondary safety barrier.

The nip point created by a carry idler cannot in all circumstances be regarded as a threatto life or limb. The mass of the belt, load and convex curve normal force will affect the

decision on whether or not carry idlers required guarding. This will be installation specificand each engineer must determine the necessity of such guards.

Positioning

At the point where a moving belt moves onto the pulley face of a rotating pulley or whereaccess underneath a conveyor is possible and the nip point, created by the belt movingonto a return idler(s), is exposed/reachable:

Belt onto Pulley- The entry point of the belt onto the pulley is known as a dangerousnip point. Any object making contact with any nip point while the belt is in motion willresult in the object being drawn into the nip point. An effective means to safe guardthis nip point is to install a primary AND secondary safety barrier.

Figure 1

HeadPulley

TailPulley

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Belt onto Idlers - The entry point of the belt onto the return idler is known as adangerous nip point. A dangerous condition exists when access underneath the run

of conveyor is possible and such nip point is less than 3, 5 m and more than 1 mabove the walking platform or ground where persons may be positioned or moving.Any object making contact with this nip point while the belt is in motion will result inthe object being drawn into the nip point. An effective means to safe guard this nippoint is to install a primary OR secondary safety barrier. This will include a nip pointguard, fully or semi-enclosed guard or barricading the dangerous portion on bothsides of the conveyor to prevent access underneath the conveyor. Barricadinginclude cross bracing two or three 8 gauge galvanized steel wire rope with No-Entry signs on such bracing.

Figure 2

The positioning of pulley nip guards is illustrated in Figure 3. The belt running awayfrom the pulley surface is not shown in the figure. The figure therefore shows

different variations of angles at which the belt runs onto the pulley surface for allangles around the pulley and how the nip guard should be positioned. The tail pulleynip guard shown in green is the exception to the general orientation as indicated inblue.

Figure 3 is as illustration of pulleys rotating in the counterclockwise rotation, butequivalent requirements will apply for clockwise rotation.

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Figure 3 Position of Nip guard when belt run onto pulley surface

General

On its own a nip guard is not regarded as sufficient or effective protection and it is arequirement that all pulleys must be further guarded, barricaded or fenced off with asecondary safety barrier.

90

270

0180

Third Quadrant (180 - 270) Forth Quadrant (270 - 360)

45

225

180

270

90

0

Second Quadrant (90 - 180) First Quadrant (0 - 90)

PULLEY

Tail pulley nipguard

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4.3.2 Secondary Safety barriers

Definition

Such barriers consist of a guard or fence and is designed, manufactured and installed ofsuch material and strength as to provide the necessary protection against inadvertenthuman contact with moving or rotating components of a conveyor system.

Positioning

Figure 4 illustrates the specific areas along a conveyor system which is most likely to beequipped with secondary safety barriers. The following locations typically requiresecondary safety barriers depending on the conveyor design layout:

A Head/Discharge Endcomprising of a driving or idling pulley(s)

Drivearea which is located either at the Head End, Intermediately or Tail End

Return belt Take-up systemsituated behind the intermediate or head drive

The Loading Pointwhere material is loaded onto the belt

Run Of Conveyor consists of a conveyor stringer (structure) with the carry andreturn idler brackets and normal run of belt and are typically situated between:

o The Head and Intermediate Drive, And/Or

o The Head Drive and following Take-up, And/Or

o The following Take-up and the last Loading Point

o Between Loading Points

o First Loading Point and Tail End

A Tail Endcomprising of a driving or idling pulley

For clear understanding and purpose, this specification will address each of theselocations in the following paragraphs in an attempt to understand the requirements ofprimary and secondary safety barriers.

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Figure 4 Secondary Barriers

4.3.3 Tertiary Safety measures

Such safety measures are defined as personal protective equipment(PPE) and each person will atall times wear the appropriate PPE applicable to the conveyor installations and other machineswhich the person will be exposed to. Persons in close proximity of moving parts of machinery must

not wear clothing or anything else that may be caught in such moving parts.

4.3.4 Indirect Safety measures

Such safety measures include the necessary personnel training and management required tosafely manage, operate and maintain belt conveyor installations. The following measures must beadhered to:

Only authorised persons may start, operate and maintain belt conveyors

When moving parts of a conveyor belt installation or other such conveyor equipmentsposes a significant risk to any person, such movement will only be done under the direct

supervision of a competent person. Only persons authorised to do so may enter the area where belt conveyor operate.

Persons in close proximity of moving parts of machinery must not wear clothing or anythingelse that may be caught in such moving parts.

Head EndAnd/OrHead- Drivelocation

IntermediateDrivelocation

FollowingTake-uplocation

Loadingpoint (s)

Tail EndAnd/OrTail-Take-uplocation

And/OrTail-Drive

Run ofConveyor

4.2.1 / 4.2.2

4.2.2 4.2.3

4.2.4 4.2.5

4.2.6 / 4.2.3

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A properly guarded belt conveyor installation is not, in itself, inherently safe but with adequatetraining and proper awareness of dangers, an operator may use it with perfect safety.

Operator training is usually the personal responsibility of the person in charge of the properoperation and running of the machinery. He must guard against the fact that over familiarity withthe machines on his part and an over estimation of operator skills and knowledge does not result inand under estimation of the amount of instruction and degree of supervision necessary for the safeexecution of tasks. Comprehensive training schemes to ensure that operators are made familiarwith the equipment with which they will be associated, (which includes re-training) are essential.

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4.4 TYPICAL INSTALLATION REQUIREMENTS

4.4.1 Head End

The head end of a conveyor installation typically consists of a head pulley and in some cases asnub pulley. The head pulley can either be driven or idling depending on operational and designrequirements.

In cases where the design of the head end is such that persons can move underneath the headend, it is required that all pulleys, belting, material trajectory and material flow be effectivelyguarded to prevent inadvertent contact with such moving equipment or material flow and theconstruction of such guards will be such as to minimise or prevent the build-up of fugitive materialon such guards. Due to the general elevation of the head end, it is, in most installations, notpossible to access the pulleys and belting from beneath the head end as the chute and supportingstructure generally covers this area. No gaps and opening may exist that would allow a finger or

any part of limb of any person to reach any danger points associated with the head end.

For the purpose of inspection and maintenance, a walkway platform is typically constructed tomove around the head end. Guarding around the head end must therefore adhere to the followinggeneral requirements as referred tofigure 5.

Dimension A1 The guard covering the sides of head and snub pulley shall extend upwardabove the head pulley circumference enough so that no person standing on the workingplatform next to the head end is able to reach over the guard and touch the nip point of thehead pulley. If the top of the head end is guarded, the height of the side guards can bereduced such that this top guard will not be closer than 900 mm from the head pulleycircumference.

Dimension B1 The guard in front of the head pulley must be situated such that thematerial trajectory will not impact directly onto the guard cover, unless the guard structurehas been designed with impact plates in order to ensure that safety guards are notdamaged by the impact from the trajectory.

Dimension C1 The guard covering the sides of head and snub pulley shall extenddownward up to the walking platform level in such a manner that it would be impossible toreach the nip point of any pulley in the vicinity of the head end.

Dimension D1 - The guard covering the sides of head end shall extend a minimum of 850mm along the belt line (Figure 5):

o As measured from the circumference of the head pulley if the head end only consistof on head pulley.

o As measured from the circumference of the snub pulley if the head end is equippedwith such a snub pulley out-bye of the head pulley.

Dimension E1 - The guards covering the sides of the head and snub pulleys shall not becloser than 50 mm from the edge of the pulley shell.

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Dimension F1 - The shaft of the head pulley and any other shaft extending through themain guard side panels shall be guarded such that the gap between the rotating shaft and

the side guard panels are inaccessible to any persons standing or moving on the workingplatform. Where the primary and secondary belt cleaning scraper frame-shaft extendsthrough these side guard panels, the gap between the scraper frame-shaft and the guardpanels is inaccessible to any persons standing or moving on the working platform.

Figure 5 Guarding at the Head End

WORKING PLATFORM

C1

B1D1

A1

D1

B1

E1

F1

SIDE VIEW

PLAN VIEW

Primary Safety Barriers(Nip guards)

Pulleys

Conveyor Belt

ChuteStructure

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4.4.2 Drive

The drive can be located either at the head end, intermediately at a point along the length of theconveyor, at the tail or a combination of these locations. The location(s) of the drive largelydepends on the conveyor design and geometry.

The drive typically consists of the drive pulley(s) and associated snub pulleys to achieve thenecessary drive pulley wrap angle(s).

The electric motor output shaft is mechanically connected to the gear reduction unit with a highspeed coupling and in a lot of cases this high speed coupling unit serves as a start-up controldevice, better known as hydraulic (fluid) couplings. The output shaft of the gear reduction unit isthen connected to the drive pulley shaft with a low speed coupling.

Primary safety barriers are required for the drive and snub pulleys whereas secondary safetybarriers are required to cover all pulleys, the low and high speed couplings, all exposed shafts and

cooling fans of both the electric motor and gear reducer.

The guarding of drive bend pulleys in the vicinity of walkways will be covered in the section dealingwith similar take-up bend pulleys.

Driving belts, chains and couplings between driving motors and gearboxes or drive pulleys must beeffectively guarded. Experience has shown that even when transmissions are apparentlyinaccessible they can still be a hazard. If the driving mechanism or any other part is fenced offcompletely in such a way that access thereto can only be obtained through a gate or door formingpart of the fencing, then this gate or door should be interlocked so that the conveyor is stoppedwhen this gate or door is opened.

Head Drives

The head chute structure is generally considered as the secondary safety barrier guarding thepulleys and primary safety barriers (nip guards) will be installed accordingly. The drive unit(s)(motor, couplings & gear unit) will be either base plate mounted or shaft-hung mounted with atorque arm connected to the supporting structure and such units are located on the outside of thehead chute structure in the walkway area and safe guarding of these drive units are thereforeimperative. Figure 6 is a plan view of drive units in the head area and where guarding is required.

For installations where access is required around the power drive unit(s) of a head pulley, it isnecessary to ensure:

The electric motor cooling fan is effective guarded to prevent contact with the blades orshaft of the fan.

The high speed coupling located between the electric motor and reducer is effectivelyguarded. This guard shall not consist of any holes or openings and shall be constructed ofplate metal. No inspection doors or openings shall be allowed as part of the design of theguard.

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The cooling fan on the gear reduction unit is effectively guarded to prevent contact with theblades or shaft of the fan.

The low speed coupling located between the reducer and head pulley shall be effectivelyguarded to prevent contact with any part of the coupling.

All shafts forming part of the drive unit and pulley system shall be effectively guarded as toprevent any contact with any part of such shafts. A guard shall be installed to cover the gapbetween the pulley shaft and the chute when the minimum gap between the plummerblockand the bearing exceeds 100 mm.

If the head or any other pulley is equipped with an external low speed holdback (back stop)this unit will be guarded in such a manner that is would be impossible to contact any part ofthe unit including its torque arm.

In the event of a V-belt or chain drive associated with the conveyor installation, such drives

must be guarded on its perimeter and both sides that will prevent persons from reachingaround the perimeter guard and contacting the danger nip points on such a drive.

All of these above mentioned guards will be secure to the component or supporting baseplate. The guard of any fluid coupling will be bolted on all four corners to maintain safety inthe event that a fusible plug is blown.

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Figure 6 Guarding of pulleys and power drive unit

Motor Gear Unit

Couplings

WalkwayPlatform

Legend: Guarding Required

Conveyor Belt

Bearing

Bearing

Chute

Structure

Pulleys

Cooling Fans

>100 mm

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Intermediate Drives

In some installations where the entire OR secondary drives and pulleys are situated at a pointalong the run of conveyor, specific guarding requirements apply. There are two methods ofeffective guarding of such drive areas:

1. Independent Guarding

This guarding method comprises of one guard frame to safeguard all drive pulleys and associatedsnub pulleys independent from the power drive unit. In this case the drive pulley shaft will extendthrough the guarding toward the power drive units situated outside the guarded drive pulleysystem.

In this case, power drive units will be guarded in the same manner as explained above.

It will be required to install primary safety barriers (nip guards) on each pulley whether they are

accessible or inaccessible to human contact and such nip guards will be positioned in accordancewith figure 3.

When any person, standing or moving on ground level or on any elevated working platform, arerequired to move next to such pulleys, the following requirements apply with regards to secondarysafety barriers in order to safe guard persons from such pulleys (refer to figure 7):

Dimension A2 - The height of the side guard panels shall be such that no portion of anypulley or belting can be touch when standing on the ground level or working platforms.These side guard panels will be constructed from ground or working platform level in orderto prevent any person reaching underneath the guard and touching any part any pulley orbelting. The height of these guards will be restricted to a minimum height of 2, 5 m, unlessthese guards have reached the bottom of the conveyor stringer. In such cases the side ofthe return stand will also be guarded up to the carry deck and a deck plate will beconstructed between the carry and return strand long enough to extend at least 850 mmpast the nip point of any reachable pulley in both directions of belt line.

Dimension B2 In most cases, this rear guard panel is not installed due to the integrationof the drive guarding with the take-up system guards. In the event that this drive pulleysystem is guarded independently from the take-up system, it is recommended to install thisguard not closer than 150 mm as measured from the closest pulleys circumference to thisguard. The height of this rear guard will be restricted to a minimum height of 2, 5 m unlessthe guard has reached the bottom of a stringer.

Dimension C2 This front guard shall not be closer than 150 mm to any of the pulleyscircumference. The height of this guard will be restricted to a minimum height of 2, 5 munless the guard has reached the bottom of a stringer but will be have sufficient as to

prevent any person contacting any part of the pulley or belt while standing on the groundlevel or working platform.

Dimension D2 Guards in this area are generally constructed on the outside of supportstructural members, but these side guard panels must not be closer than 150 mm asmeasured from the edge of the pulley shell.

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Figure 7

If any pulley shaft extends through the guards, such portion of the shaft will be effectivelyguarded so that it would be impossible for any person to contact any part of that shaft.

In the event of a V-belt or chain drive associated with the conveyor installation, such drivesmust be guarded on its perimeter and both sides that will prevent persons from reachingaround the perimeter guard and contacting the danger nip points on such a drive.

SecondaryDrive Primary Drive

Ground level or working platform

A2B2 C2

SIDE VIEW

D2

B2 C2

Conveyor Belt

Pulleys

FrontGuard

panel

RearGuard

panel

Example of drive pulley layout

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2. Fully Enclosed Guarding

Fully enclosed guarding involves fencing off the entire drive area. All associated drive pulleys,power drive units and in some cases take-up systems are fenced off and access to the area canonly be made through a door(s) or gate(s) and such doors and gates must each be interlockedsuch that power is removed from the power drive units once the door or gate of the fencing isopened. The opening of such gates or doors will be such that they hinge on the sides and swingoutwardly.

It will be required to install primary safety barriers (nip guards) on each pulley whether they areaccessible or inaccessible to human contact and such nip guards will be positioned in accordancewith figure 3.

When any person, standing or moving on ground level, the following requirements will apply tofenced-off guarding which forms part of secondary safety barriers:

The height of the fence shall be such that no portion of any pulley, belt, drive unit or take-upmoving parts can be touch when standing on such ground level outside the fenced-off area.These side guard panels will be constructed from ground level in order to prevent anyperson reaching underneath or over the guard. The height of these guards will be restrictedto a minimum height of 2, 5 m.

This guard shall not be closer than 150 mm to any of the pulleys circumference and anypart of the power drive unit(s) or take-up system.

The gate(s) or door(s) constructed to access such areas shall hinge on the sides of thepanel and shall swing away from the fenced off area.

The guards covering the fan of both the motor and gear box will be present and secure. In

the event that a fluid coupling is used as the start-up control device, the entire fluid couplingwill be guarded as explained previously.

Tail Drives

In the event that the tail end consists of a power drive unit, the same independent guardingrequirements will apply with regards to the power drive unit and pulleys. Primary andsecondary safety barriers will comply as stipulated in the section covering guarding of the TailEnd of conveyor installations. The nip point of associated snub pulley will also be equippedwith a nip guard.

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4.4.3 Take-up Area

The take-up system design of a belt conveyor largely depends on what the belt conveyor requirefor successful operation under starting, running and stopping conditions. For this reason, thefollowing list of typical take-up design layout exists:

Vertical Gravity Consist of a pulley-counterweight system moving vertically in a tower.

Horizontal Gravity Consists of a pulley- carriage system moving horizontally on rails and acounterweight moving vertically in a tower.

Horizontal Automatic/Manual Winch Consist of a pulley-carriage system movinghorizontally on rails and an automatic or manual winch system also acting in the horizontalplane.

Horizontal Screws Consists of a pulley plummer block arrangement which is manually

locked in position with screws acting on the plummer blocks in the horizontal plane.

Due to the variety of take-up designs as mentioned, the specification will deal with guarding ofcounterweight towers, take-up carriages, screws, associated bend pulleys as well ancillary take-upequipments such as rope, sheaves and winches.

1. Counterweight towers

The counterweight tower can facilitate the operation of a counterweight box or a combination of acounterweight box with a pulley.

It will be required to install primary safety barriers (nip guards) on all pulleys whether they areaccessible or inaccessible to human contact and such nip guards will be positioned in accordancewith figure 3.

For counterweight boxes operating less than 5 m from ground level, it will be required to installguarding around the tower starting from ground level to a minimum height of 3m or until it isimpossible to reach over the guard and touch the counterweight. For counterweight boxesoperating higher than 5 m from ground level, it will be required to install guarding around the towerstarting from ground level to a minimum height of 2,5m or until it is impossible to reach over theguard and touch the counterweight.

The guard shall not be closer than 250 mm as measured from the counterweight box, pulley, guiderolls or belt. If such guards consist of gates, such gates will be kept locked and interlock switch willbe installed that will remove power from the conveyor installation once the gate is opened. Thearea inside and outside the counterweight tower shall be kept clean to avoid damage to guards asa result of build-up material.

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For installations where elevated walkways provided movement next to such counterweight towersit will be required to install guarding on that portion of the counterweight tower to a minimum height

of 3 m as measured from the elevated walkway level or until it is impossible to reach over theguard and touch the counterweight and shall proceed around the tower to such extend as toprevent contact with any part of the counterweight box, pulley, guide rolls or belt inside the tower. Ifelevated platform levels exist around such a counterweight tower it will be required to install suchguards all around the tower to a minimum height of 3m or until it is impossible to reach over theguard and touch the counterweight.

2. Take-up Carriages

Take-up carriages consist of a moving trolley unit which supports the take-up pulley and this unitwill move on rails in a horizontal or inclined angle depending on the conveyor layout design.

In the case where the top of the carriage remain unguarded, it is recommended that the guardssurrounding the carriage extend from ground or working platform level to a minimum height of 2,5 m or until it is impossible to reach over the guard and touch any moving part of the carriagesystem. If the top of the carriage is guarded it is recommended that the guard be at least 500 mmabove the circumference of the pulley and these guards shall be kept clean from material build-up.The side guards of the carriage will not be closer than 150 mm as measured from the carriagewheels. The guard at tail portion of the carriage system (upper limit of carriage movement) shallnot be closer than 3 times sheave outer diameter or 1m to this upper limit, whichever is greatestand the height of this guard will be similar to the height of the side guards.

The gap where steel ropes move through the guard will be covered such that no contact with thisgap is possible while the conveyors power drive unit(s) is energised.

3. Manual Screws

If the take-up tension is maintained through the application of a manual screw, it will be requiredthat the screw and take-up pulley be fully enclosed. If the top of the take-up pulley remainsunguarded the guards will extend around the pulley to a maximum height of 2, 5 m. If the top of thepulley is guarded, this top guard shall not be closer than 500 mm above the pulley circumferenceand these guards shall be kept clean from material build-up. The side guards will not be closerthan 150 mm from the screw. The guard at the back of the pulley shall not be closer than 150 mmto the pulley circumference.

4. Take-up and Drive Bend pulleys

It will be required to install primary safety barriers (nip guards) on all pulleys whether they areaccessible or inaccessible to human contact and such nip guards will be positioned in accordancewith figure 3.

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On installations where walkways or platforms are constructed next to incline elevated conveyors, itis often found that drive or take-up snub pulley are in a reachable distance from such walkways or

platforms. Guards must be constructed such as to extend at least 850 mm before and after suchsnub pulleys in the direction of belt line. Guards must not be closer than 150 mm from the pulleyshaft edge and if for some reason it is required that a pulley shaft extend through the guard it mustbe guarded such that contact with such shaft is impossible. The extension of such pulley shaftthrough guarding will not cause any tripping hazard for persons walking on such elevatedwalkways.

For the portion where walkways are situated next to these snub pulleys it is required to install deckplates beneath the carry and return belt strand to prevent persons standing on the walkway toreach over guards an contact pulley danger points.

5. Ancillary Take-up Equipment

Such equipment includes winches, ropes and sheaves. Danger points associated with suchinstalled equipment is:

Nip point between rope and sheaves

Nip point between rope and winch

Nip point between rope and surrounding structure, guards or brackets.

For the purpose of simplicity it can be stated that such equipment and associated danger pointsshall be guarded such that it will be impossible to contact any such equipment or danger pointsunless energy has been removed from the power drive unit of that conveyor installation. Theguards will be so constructed such that it will not contact the rope or sheave during operation.

If mesh guarding is to be used, such guarding will be at least 150 mm away from such equipmentto prevent finger contact with danger points. Caution should be taken as material build-up insidesuch guards will render the take-up system ineffective and compromise safety of the installation.

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4.4.4 Run of Conveyor

The run of conveyor can be defined as the normal conveyor comprising of the carry- and returnbelt, idlers and structure and does not include the head, drive, take-up, loading or tail section.

The danger points associated with regards to the run of conveyor becomes evident when personsare required to cross over or underneath the belt conveyor structure, when the belt is pressingdown on rolls in a convex curve or when pressing rolls are used to prevent belt liftout in specifiecareas.

Trip Wire & Switches

When faults, accidents or blockages occur, it is normally necessary to bring the conveyor to animmediate halt. A continuous trip-wire stretching over the whole length of the conveyor, toactuate the stop switch of the conveyor, is an effective and essential safety device. With such afacility available the operator will be less tempted to try and rectify faults with the conveyor turning.

It must however stretch the full length of the conveyor. If the belt conveyor is so installed thatpersons can walk along the conveyor on either side of it then a trip-wire must be installed on bothsides of the conveyor. It is also recommended that a lockout facility be provided on this trip wirearrangement.

Carry Belt Convex Curves

When the profile of the belt shapes in a convex curve, the tension in the belt will further increasethe force exerted on a carry idler roll in the convex curve and when excessive, can cause severeharm to a human hand when caught in the nip point between the belt and carry idler. When it isknown the curve could/will experience high belt tensions and material loads resulting in the nippoints causing harm, it will be required to guard such idlers for the length necessary to safeguardpersons in that vicinity of the conveyor installation.

Carry Belt Pressing Rolls

Although it was stated that it is essential that head tail and snub pulleys of belt conveyorinstallations, which are within reach, should be guarded, accidents have happened on carryingidlers with serious consequences, particularly where the distance the belt can lift off the idlers isrestricted. The danger at idlers is even more evident when fixed hoppers or skirt plates underwhich the hand can be trapped, are fitted directly above the idlers. If this is the case the dangerpoints must be very carefully guarded or completely enclosed. This also applies, even more so, tobelts on which hand-sorting is performed.

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Some conveyor installations incline upward and the conveyor structure will form a concave curve.Under some operating tensions the conveyor belt could lift-out of the curve. When such lift-out

occurs in the vicinity of the loading points or fixed hoppers or where some other structural memberor equipment is situated above the belt, it becomes necessary to press the belt down in order toprevent such lift-out. This is done by installing pressing rolls on the sides of the conveyor belt.These rolls then present dangerous nip-points and will cause severe harm to limbs. In such casesit is recommended to install guards along the portion of the conveyor equipped with such pressingrolls and such guards must extend at least 850 mm outside the first and last pressing rolls. Theguards must be such that it will be impossible to reach over such guards and make contact withsuch nip points under any belt running condition, whether starting, running or stopping.

Elevated walkways

In cases where walkways are fitted on elevated conveyors, adequate hand and knee rails must beinstalled on the outside of such walkways. Kick/toe boards shall be provided on the hand rail andconveyor stringer side to keep movement of feet restricted to the walkway platform. Walkwaysmust have and even, non-slip surface, be properly drained and free from obstructions.

Inclined shafts

Another condition exists on the walkways next to inclined shaft conveyors. Spillage on walkwayscan cause persons to slip or loose footing and to prevent such person grabbing hold of theconveyor structure or other dangerous equipment, it is imperative that some form of handrail beconstructed to aid persons walking on such walkways.

Cross-Over Bridges

It is often necessary for an attendant to cross a conveyor at various points. It is dangerous toclimb over any belt. Where it is impossible to establish safe passageways underneath the belt,

cross over bridges with handrails, must be provided. The position of these bridges will depend onconditions at the belt conveyor installations but, unless a sufficient number are installed they willnot always be used. Access to the cross over bridge must be provided by means of stairsequipped with handrails. Vertical ladders should be avoided. The cross over bridge should alsobe equipped with a toe-board and an intermediate or knee rail.

Such structures must be adequately designed and constructed of steel members and includesuitably inclined access stairs of non-slip platforms made from steel grid plate and fitted withhandrails on both sides to a minimum height of 1,2 m.

The handrails and stanchions must be bolted to the support steel members. Kick/toe boards andand intermediate or knee rail must be fitted on both sides of the walking platform. The number andposition of such bridges must be determined by a Risk Assessment and based on the maintenanceand inspection requirements for such belt. Vertical ladders must be avoided. The cross over bridge

must elevate to a minimum height of 1, 4 m above the ground or working platform level on whichthe conveyor is supported, before extending across the conveyor.

Crossing Underneath Belts

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On belt conveyors, the return belt and idlers may also present a hazard especially at specificplaces where persons regularly pass through or works underneath the belt. At such places it is

recommended that the underside should be guarded.

In areas where persons or mobile machinery are permitted to cross underneath conveyor beltinstallations, the following must be complied with:

a) All passageways and roadways shall be conspicuously sign-posted to indicate their purposei.e. men and/or machinery.

b) Height restrictions through such passageways and roadways must be prominently displayedon both sides.

c) If the return idler or any pulley is less than 3,5 m from the ground or working platform level,such return idlers or pulleys must be guarded such to provide safe passage to any person ormachine operator whilst crossing below such conveyor belt. The passageway must extend to

a minimum of 1 m beyond both sides of the conveyor structure. Crossing at other placeswhich are not properly guarded must prevented with No-Entry signs on a barricade, even ifonly two or three strands of 8 gauge galvanized wire is used along the outside of thesupporting framework to achieve this purpose. For the purpose of complete safeguarding, itis recommended to construct a canopy over the road/walkway below the return belt to protectpersons and vehicles whenever belt sags, snaps or for cases of spillage which falls from thebelt onto the road.

Under no circumstances will the crossing under or over conveyor belts be permitted at anypoint along its length unless via the approved passageway referred to above.

Belt Turnovers

On some conveyor installations it is required to turn-over the return belt in order to run the non-carry side of the belt in contact with return idler sets in order to reduce spillage and material build-up known as carry-back.

Mangle rolls are typically double flat idler rolls which gradually changes the twisting angle of thebelt in order to turn the belt over 180. These turnover sections must be fully enclosed andeffectively guarded to prevent any contact with any of these mangle roll sets. Side guard panelsmust extend to a minimum height of at least 2, 5 m and must not be closer than 150 mm from therolls end disk.

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4.4.5 Loading Point

At the loading point material is fed onto the conveyor by means of a transfer chute. Danger pointassociated with the loading point is:

Point(s) of impact in the transfer chute

Point of impact on the moving conveyor belt

Material settling zone

Nip point between conveyor belt and chute structure

Maintenance and inspection doors on the transfer chute

To safeguard persons in the vicinity of the loading point it is required that the flow of material be

guarded with a transfer chute in a manner that no person can contact the flowing stream ofmaterial in the chute while standing next to the conveyor installation, whether on ground level orother designated walkways or platforms. The construction of the chute will also prevent the escapeof material from the chute and any rapid deterioration of the chute due to material flow will be re-engineered to prevent such rapid deterioration.

The loading portion of the chute shall act as the safe guarded to prevent persons from reaching thematerial impact zone on the belt and the chute shall extend in the direction of belt travel for thedistance required for material to settle in order to prevent unsettled lumps from falling off the beltdue to loading conditions.

The chute nip point is the gap that exists between the rear end of the chute and the carry beltsurface. This gap shall be minimized to not more than 50 mm.

The design of the conveyor shall prevent belt lift-out in the loading area.

Maintenance and inspection doors shall be positioned outside the normal trajectory of material flowand such doors shall be kept closed and secured under belt starting, running and stoppingconditions.

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4.4.6 Tail End

Non-Driven

The tail end will always be situated behind the loading point and will redirect the belt run from thereturn run direction to the carry run direction.

For any tail end constituting only of an idling pulley, the following danger points exist:

Nip point between the return belt and the tail pulley.

Rotating shafts

It will be required to install primary safety barriers (nip guards) on each pulley whether they areaccessible or inaccessible to human contact and such nip guards will be positioned in accordancewith figure 3.

Figure 8

C3

B3D3

A3

B3

E3

SIDE VIEW

PLAN VIEW

Primary Safety Barriers(Nip guards)

Conveyor Belt

Secondary SafetyBarrier

D3

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A secondary guard will be constructed around the rear end of the pulley starting at least 850 mm(B3) in front of the tail pulley or snub pulley nip guard, whichever is closes to the loading point, and

will cover all around the rear end of the pulley to the other side of the pulley to a distance of 850mm (B3) in front of the tail pulley or snub pulley nip guard. These guards shall extend verticallyground or working platform level to a minimum height where the guard covering the pulley will be atleast 400 mm (A3) above the circumference of the pulley, whichever is closes to the loading point.The vertical guard on the rear end of the pulley shall not be closer than 150 mm (D3) from thecircumference of the pulley. The side guards will be constructed not closer than 150 mm (E3) fromthe edge of the pulley shell. This is illustrated in Figure 8.

If shaft extend through any of the above mentioned guards, such shaft shall be guarded in such amanner that will prevent any contact with any part of such rotating shaft.

In the event that the tail end is integrated with the take-up system, the associated pulleys and take-up equipment shall be guarded in accordance with the take-up guarding requirements as stipulatedin section 4.4.3.

Driven

Tail ends which are equipped with power drive units will be guarded in accordance to therequirements as stipulated in section 4.4.2 in the paragraph covering tail drives.

4.4.7 Belt Cleaning Devices

Lateral movement of the belt is usually caused by a build-up of material at the head and tailpulleys, the carrying idlers or snub pulleys. The manual removal of build-up is slow, complicatedand often dangerous. In order to keep the pulleys and rollers clean, suitable mechanical devicesmust be installed. The manual removal of build-up should not be permitted whilst the belt conveyoris in motion.

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5 MATERIAL SPECIFIATIONSPrimary and secondary safety barriers will comply with the following materialspecifications:

d) Manufactured from a non-corrosive material or galvanized steel to prevent acorrosive environment from rendering the guard ineffective due to excessivematerial loss during operation.

e) The completed guard must be manufactured from a material of adequate strengthand design to safely support the mass of an 85kg person distributed over an area of2m.

f) A guard must not weigh in excess of 30 kg to ensure that one person will capable of

removing or installing such a guard. If guard weigh in excess of 30 kg, they must bea permanent feature to the structure with hinges on the side that will allow theopening of such guard by swinging it outwardly.

g) Colour-coded such guards with ORANGE paint to create an awareness that if suchguard is not in its correct position it will be conspicuous by its absence and alertpersons that it has been inadvertently removed.

h) Guards shall be securely fixed in position with fasteners or other suitable devices,and which ensures that the guard cannot be altered or detached without the aid of atool or key.

i) Guards must be installed such that adjustments will not allow a loss of protection orthe modification of guards.

j) Guards must be such that they do not need to be removed for inspection.

k) The design, material and construction of guards must be such that they present noburrs, sharp edges or pinch points that may be a hazard to safety.

Primary Safety Barrier

The minimum material dimensions for all nip guards must be 120mm x 120mm x 10mmgalvanized angle members.

With regards to the tail pulley, the guard must be secured to the base of the plummer

blocks in order to ensure that they follow the pulleys when repositioned.

These guards must be bolted to the conveyor structure so as to create a minimumclearance of 8 mm from the pulley circumference and 20 mm from the belt. No welding willbe allowed to remove or replace such nip guards.

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Secondary Safety Barrier

It may be assumed that there is no reach through an opening of 10 mm x 10 mm or lessas fingers cannot normally be admitted. If the opening is such that it will admit one, two orthree fingers the reach is restricted by the roots of the fingers, a distance normally notexceeding 150 mm.

When the opening is sufficient to admit the whole arm and the small portion of theshoulder the reasonable safe distance is based on the distance from the fingertips to thearmpit, which may be assumed to be 850 mm.

Screening material with openings in excess of 80 mm x 80 mm should not be used in theconstruction of guards or fences. Preference should be given to materials with openingsnot exceeding 25 mm x 25 mm.

ELONGATED OPENINGS (Openings with parallel sides):

a) Openings up to 6 mm wide may be disregarded. The guard or fence soconstructed may virtually be regarded as a sheet and a working clearance ofapproximately 25 mm is all that is required.

b) Openings greater that 6 mm but less that 13 mm will admit part of a fingerand requires at least 50 mm clearance from danger points.

c) Openings in excess of 13 mm but not greater than 80 mm are subject to thefollowing formula:

X = 10Y where X = reasonable safe distance from danger point

in mm.

Y = width of opening in mm.

Power Drive Unit

Driving belts (V-belts), chains, high and slow speed couplings installed between electricmotors and gearboxes or transmission assemblies fall into the category of exposedmachinery and must be effectively guarded. All such exposed machinery must be totallyenclosed on all sides with guards manufactured from solid steel plate with a minimumthickness of 3mm. They must be bolted securely in position.

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Holdback or brakes can be guarded with mesh guarding but such guards will not be closerthan 150 mm to any part of the hold back or brake and the extend of such guards will be

such that no part of the holdback or brake can be touched.

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6 MAINTENANCE

Safety at belt conveyor installations may be further enhanced by creating the optimumworking environment including not only adequate ventilation, illumination, absence ofundue noise and adequate dust control, but also sufficient clearance around theinstallation and along walkways. Walkways should have an even non-slip surface, beproperly drained and free from obstructions.

Any build-up of spillage material on guards must be removed to prevent deflection of suchguard that would compromise its position relative to the danger point and thereby presentpossible human contact with such danger points. Dimensions given in the best practicemust be maintained at all times.

Primary barrier guards which have been damaged, corroded or bent in any way that wouldyield the barrier ineffective shall be replaced with a new guard.

If secondary barrier guards are in any way damaged, corroded or bent or mesh openingsor any other openings increased to sizes greater than stipulated in this document, suchguards shall be replaced immediately to cover the danger points and present a safeconditions for persons positioned or walking in the vicinity.

Maintenance, travelling and access ways along, around, over or under conveyor belt driveand tail-end installations must be adequately illuminated, kept dry and free of obstructionsor tripping hazards and allow sufficient clearance for routine maintenance and inspectionsto be conducted in a safe manner.

Minimum clearances of 1 m must be maintained for the above purpose. Areas where suchclearances cannot be maintained must be suitably barricaded to prevent the unsafe entryof maintenance personnel.

The COP as required by the Inspectorate for the Operation and Maintenance all ConveyorSystems at any Mine or Plant must be reviewed and updated annually to ensure thesafety of all persons who are required to work in close proximity to such equipment.

Every person who by the nature of his/her work requires training to be competent in theoperation or maintenance of conveyor systems must at all times be briefed and updatedon the requirements of this BPG and subsequent revisions.

Man-riding of conveyor belts are strictly prohibited.

7 REMOVAL OF GUARDS

Under no circumstances may any guard be removed, repositioned or modified unless thebelt conveyor has come to a COMPLETE stand still, power to the drive has been removedand the correct lock-out procedure completed.

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