SULTANATE OF OMAN OMAN TELECOMMUNICATIONS … · 2. Omantel reserves the right to issue work order...

VZ3457 - SOW and Spec. 1

SULTANATE OF OMAN )ECOMMUNICATIONS COMPANY (S.A.O.GOMAN TEL

II –VOLUME

SCOPE OF WORK &

BILL OF QUANTITIES

TENDER DOCUMENT FOR

DESIGN, SUPPLY & INSTALLATION OF TELECOM TOWER WITH RKS AT MAHOOT & AL MECHANICAL WO-ALLIED CIVIL & ELECTRO

ASHKARA EXCHANGES IN THE SULTANATE OF OMAN

TENDER_1225


NOTICE TO TENDERERS

1. The successful Tenderer shall obtain Omantel approval on the Tower / Monopole and all associated

materials, manufacturer and supplier within 14 days from contract awarding. This period includes manufacturing factory visit etc….

2. Omantel reserves the right to issue work order for one or more sites at a time.

3. Omantel reserves the right to split the scope of work as per the demand i.e. Omantel reserves the right to issue the work order of only tower / monopole supply, or only foundation construction or only tower / monopole erection and /or combined all the 3 items.

4. Omantel reserves the right to Supply the tower to the contractor which will be procured directly by Omantel.

5. Omantel reserves to right to issue work order for one or more items of the Bill of Unit Rates for each site.

6. Detailed drawings with design calculations for the tower of each site shall be submitted separately for approval within fourteen days (14) days from contract signature and foundation design within seven days (7) days from the date of receipt of work order if the delivery of the tower is from Omantel.

7. Detailed drawings with design calculations for the tower foundation of each site shall be submitted separately for approval within three (3) days from the date of receipt of either the soil investigation report or the soil bearing capacity value from Omantel if the tower is supplied by the contractor.

8. The sites may be anywhere in the Sultanate of Oman, for which access (access means access for 4WD vehicles) shall be made available by Omantel. Omantel shall be responsible to provide helicopter/ferry service in case required.

9. This tender is for a fixed contract as turnkey basis; therefore, the Contractor does not have the right to claim any additional costs from Omantel in any circumstances.

10. Contractor should submit the copy of document / agreement entered with tower manufacturer stating that they are the local distributor of the tower for the manufacturer proposed in tender.

11. Contractor should not subcontract services more than 40% of value of work and subject to approval from Omantel

12. Contractor should use available local materials for this work which meet the Omantel specifications.

13. Omantel reserves the right to split the contract to more than one contractor.

14. Completion periods shall be: Towers & Monopoles:

a. Tower: Total twelve (12) weeks from the commencement date mentioned in the work order for that specific site including design, manufacturing, transportation, permits acquisition & erection. In case separate Engineer’s Instructions are issued for material and/or allied services; then the tower delivery shall be within four (4) weeks, permits acquisition shall be within four (4) weeks, tower foundation completion shall be within two (2) weeks and tower erection shall be within two (2) weeks.

15. The life-time of towers & monopoles shall be minimum 30 years. The contractor will be solely responsible for any failure due to design, structure, construction & erection within this period. Furthermore, galvanizing of all the steel structures including tower, monopoles, chain link fencing, etc. shall be under warranty for 30 years. In case of any failure due to any of the above, Omantel reserves the right to ask for replacement of the failed item(s) according to the nature of the failure.


DESIGN, SUPPLY & INSTALLATION OF TELECOM TOWER WITH ALLIED MECHANICAL WORKS AT MAHOOT & AL ASHKARA -CIVIL & ELECTRO

IN THE SULTANATE OF OMAN EXCHANGES

ummaryrice SPTotal

Description Amount in R.O.

Total Tender Value for Mahoot Exchange & Al Ashkara Exchange

(Rials Omani ________________________________________________________)

_____________________________________ SEAL AND SIGNATURE OF TENDERER


DESIGN, SUPPLY & INSTALLATION OF TELECOM TOWER WITH ALLIED CIVIL & ELECTRO-MECHANICAL WORKS AT MAHOOT & AL ASHKARA EXCHANGES

IN THE SULTANATE OF OMAN

BILL OF QUANTITIES

Item Description Qty.

(nos.) Rate Total

A MAHOOT EXCHANGE

1. Design and supply of 65 meter four - legged tower including lightning protection, aircraft warning light system according to Omantel Specifications. Anchor bolts for foundation and templates shall be supplied along with the tower.

1

2. Design and construction of foundation for 65 meter - four legged tower including excavation, PCC concreting, reinforcement steel preparation, shuttering, ready mix concrete supply to the site, damp proofing, curing and backfilling with proper compaction as specified in specs in any soil condition. Omantel will either provide soil investigation report when required or a value of soil bearing capacity for foundation design. This item includes obtaining the building permit from the concerned authorities and preparation of As Built Drawings in soft and A-3 size paper hard copy.

1

3. Transportation and erection of 65 meter - four legged tower including installation of grounding system as per the specification mentioned and as specified in the attached Specification, installation of aircraft warning light system (including installation of the control panel inside the shelter or room) and painting the tower. This item also includes the supply and installation of the hot dip galvanized cable ladder (400 mm) between the tower and the shelter/room.

1

Total


FOR

DESIGN, SUPPLY & INSTALLATION OF TELECOM TOWER WITH ALLIED CIVIL & MECHANICAL WORKS AT MAHOOT & AL ASHKARA EXCHANGES -ELECTRO

IN THE SULTANATE OF OMAN

BILL OF QUANTITIES

Item Description Qty.

(nos.) Rate Total

B AL ASHKARA EXCHANGE

1. Design and supply of 50 meter four - legged tower including lightning protection, aircraft warning light system according to Omantel Specifications. Anchor bolts for foundation and templates shall be supplied along with the tower.

1

2. Design and construction of foundation for 50 meter - four legged tower including excavation, PCC concreting, reinforcement steel preparation, shuttering, ready mix concrete supply to the site, damp proofing, curing and backfilling with proper compaction as specified in specs in any soil condition. Omantel will either provide soil investigation report when required or a value of soil bearing capacity for foundation design. This item includes obtaining the building permit from the concerned authorities and preparation of As Built Drawings in soft and A-3 size paper hard copy.

1

3. Transportation and erection of 50 meter - four legged tower including installation of grounding system as per the specification mentioned and as specified in the attached Specification, installation of aircraft warning light system (including installation of the control panel inside the shelter or room) and painting the tower. This item also includes the supply and installation of the hot dip galvanized cable ladder (400 mm) between the tower and the shelter/room.

1

Total


DESIGN, SUPPLY AND INSTALLATION OF TELECOM TOWER WITH ALLIED CIVIL & EM WORKS AT MAHOOT EXCHANGE AND AL ASHKARA EXCHANGE

BRIEF SOW &SPECIFICATIONS

A. INTRODUCTION.

The Project is required to be implemented on urgent basis in order to obtain E1 connectivity. Necessary precautions shall be taken during the construction period for the minimum disturbance to the surrounding areas. B. SCOPE OF WORKS FOR TOWERS & MONOPOLES

1. Fabricate/Import and transport telecom towers & monopoles of various heights to sites spread

throughout the Sultanate of Oman. 2. Customs clearance, warehousing and transport of Towers and monopoles to the required locations. 3. Provide implementation plan (schedule) for each tower and progress committed to the same. 4. Provide tower design & related calculations for the towers based on Omantel specifications within

14 days of contract awarding. 5. Obtain all the required permits & clearances from any local or central authority such as but not

limited to municipalities, Ministry of Environment, Civil Aviation, ROP, MHEW, etc. required for building the sites. Furthermore, the Contractor is obliged to acquire any additional approval or no objections for building the sites in case introduced by Omantel and/or any related authority.

6. Follow up the progress of the applied approvals/no objections from the authorities and report Omantel on daily basis.

7. Provide foundation design based on the soil investigation report or a specific soil bearing capacity value provided by Omantel.

8. All structure design (Tower & Foundation) should be checked & approved by Local consultant 9. Level the area for excavation of the tower foundation for the sites that does not require access road. 10. Make excavation on the site according to the approved foundation design regardless to the soil

characteristics of the site. Additional claims will not be entertained by Omantel due to site specific soil characteristics.

11. Construct civil foundation for the tower according to the approved foundation design. Ready-mix concrete shall be provided for all the foundations. In case ready-mix concrete is not available at a specific site for any reason, Contractor shall justify the reason & seek official approval from Omantel for supplying any other type of concrete.

12. Any additional requirement such as curing compound, epoxy painted reinforcement steel, etc. shall be provided according to site specific condition for the foundation in case requested by Omantel.

13. Provide grounding ring around the tower foundation which consists of a pair of 25mm x 3mm copper strips interconnected to each other at each corner & enough number of earthing rods shall be installed in order to provide a maximum earthing resistance of 3Ω for the tower. (Max 10Ω for passive repeater towers.)

14. Backfill the foundation compacting by layers of max 40cm with proper tools & machinery. Contractor shall seek approval from Omantel in order to utilize the existing excavation material for backfilling. Imported fill material shall be utilized if the existing excavation material is not approved by Omantel engineer during steel inspection.

15. Erection of the tower & monopole complying with the safety rules, regulations & procedures. Specific safety rules, regulations & procedures of the local companies or government offices such as


petroleum companies (i.e. PDO, Occidental, etc.) or government offices such as military or Diwan shall be followed.

16. Provide grounding system according to Omantel specifications. Grounding system will consist of a lightning arrestor at the top of the tower, a down conductor which is directly connected to the grounding ring, grounding ring and earth pit. The down conductor shall run on one leg of the tower while the other three legs shall be connected to the grounding ring via 25mm x 3mm copper strips. All grounding connections under the ground shall be Cad Weld welding connections rather than mechanical joints.

17. Paint the towers according to Omantel Specifications & rules and regulations of the related authorities such as Civil Aviation or ROP.

18. Supply and install aircraft warning light system according to the Omantel Specifications (one duty lamp, one stand-by lamp, and photocell & control panel with required alarms extensions).

19. Supply & install hot dip galvanized horizontal cable ladder (400mm width) with enough number of hot dip galvanized vertical supports (max distance in-between the supports shall be 3 meters) having pre-cast concrete foundations between tower and telecom containers/rooms.

20. Provide gravel to a thickness of minimum 50mm spread around and beneath the tower (minimum 2m from the sides of the tower).

21. 9nos GSM antenna mounting brackets (brackets shall consist of 2nos 0.5meter angle offsets, 1no 2” diameter GI Pipe of 3meter length) shall be provided free of charge along with each tower.

22. The required 7 Nos microwave mounting brackets shall be provided free of charge along with the towers (brackets shall consist of 2nos 0.5meter angle offsets, 1no 4” diameter GI Pipe of 1meter length).

23. Supply & Installation of fall arrest system consisting of Harness, aluminium rail and trolley. 24. Contractor who Design & Supply the tower with associated accessories will be responsible for

giving 30 years warranty against tower failure due to Design defects, Materials defects or workmanship / fabrication defects. Contractor who provide services will be responsible for giving 30 years’ warranty against tower / foundation failure due to foundation design or Construction defects, tower erection defects. The foundation should be designed for the leg reactions / forces provided by tower supplier & Soil bearing capacity given by Omantel. Contractor who Design & Supply the tower should visit the site on completion of tower erection to check & verify that the tower erection works is carried out as per drawings & specification & certificate for the same should be issued by tower contractor for each site.


C. GENERAL SPECIFICATIONS. The Omantel’s Standard Specifications, Terms and Conditions for Towers, GI Poles, Chain link fencing and access roads are attached and shall be followed accordingly. The Towers for both Mahoot Exchange and Al ashkara Exchange shall be designed for the below Antenna loading Criteria. Mahoot Exchange S/N Antenna Type Number of Antennas Antenna Dimensions (m) Antenna Height (m)

1 GSM Antenna 2 1.5 Top.

2 MW 1.2dia 1 1.1314286

3 sector antenna 3 2.25

4 MW 1.2dia 1 1.1314286

5 MW 0.6dia 1 0.2828571

6 sector antenna OT 3 2.25

7 sector antenna Ooredoo 3 2.25

8 MW 2.4dia 1 4.5257143

9 OMNI 2 1.5

10 MW 1.2dia 1 1.1314286


12 MW 2.4dia 1 4.5257143

13 MW 0.6dia Ooredoo 1 0.2828571

Total load to be considered in new tower 40 sq mt

Al ashkara Exchange S/N Antenna Type Number of Antennas Antenna Dimensions (m) Antenna Height (m)

1 GSM Antenna 4 3 Top.

2 MW 2.4 dia 1 4.5257143


4 MW 1.2dia ooredoo 1 1.1314286

5 MW 1.2dia 1 1.1314286

6 MW 2.4 dia 1 4.5257143

7 MW 1.2 dia ooredoo 1 1.1314286

8 MW .3dia 1 0.0707143

9 MW 1.2 dia ooredoo 1 1.1314286


10 MW 0.6 1 0.2828571

11 MW 1.2dia 1 1.1314286


Quantites Calculation and Evaluation Criteria:- 1. QUANTITIES This Tender is for a FIXED Contract; therefore, Quantities of the involved Works form a part of this Tender. Omantel will issue Work Orders (WO) to the successful Tenderer(s) for any of the items in the Bill of Unit Rates according to the requirement at that point of time. Oman tel does not and will not commit any quantity or utilization of any item in the tendering stage or during the Contract Period. However an estimated quatity has been given against each unit in the BOQ to reach a tender value only. 2. CALCULATION OF TENDER VALUE In order to reach a Tender Value for defining the value of the Tender Bond, the Tenderers shall take the quantity of each unit in the Bill of Unit Rates and take the sum of all the rates to reach a Tender Value. The Tender Value shall be stated in “APPENDIX "B" TO THE FORM OF AGREEMENT” of the Volume I – Prime Document and “. 3. EVALUATION CRITERIA Due to the nature of this Tender for a Unit Rate Frame Contract, the offers of the Tenderers will be evaluated according to their technical abilities, experiences, commercial compliances and prices. The evaluation will be done only as per the information which will be available in the submitted offers of the Tenderers. According the nature of the work, the evaluation criteria will be Technical –100%, Pricing (100% for the lowest).


TECHNICAL COMPLIANCE

MAJOR CRITERIA

S.N. Items Marks

1 Company profile & Organizational Structure. 10

2 Specific Experience in similar projects in size and nature. 15

3 Compliance to the specification, Design documents, Tower & Foundation details. 35

4 Program schedule and Project Management. 10

5 Quality Assurance statement & HSE Manual 10

6 The list of sub-contractors & suppliers 10

7 Registrations & Financial information 10 TOTAL MARKS: 100

TECHNICAL COMPLIANCE

SUB CRITERIA

S.N. Item Marks

1 Company profile & Organizational Structure 1.1 General Information & Type of Business 2

1.2 Management of the company 2 1.3 Company Organization chart with number of staff 4 1.4 List of Facilty / assets available with the company. 2

Sub-total of 1 10

2 Specific Experience in similar projects size and nature

2.1 List of contracts ( As Main contractor ) for the similar works carried out in Oman during the last 3 years

5

2.2 List the ongoing similar projects in Oman 5

2.3 Submission of end to end site documents / report along with photographs for Tower works (foundation and tower erection works) carried out in Oman

2

2.4 Submission of copies of certificates issued by the clients about their performance, quality and timely completion of the project.

1

2.5 Previous similar Experience with telecom in Oman. 2

Sub-total of 2 15


3 Compliance to the specification, items delivery, implementation and Project Management.

3.1

Compliance to the specification of the materials as per the tender documents.

Compliance statement should be submitted without any pre conditions. – (2 marks)

Sources / procurement of all materials required for work to be submitted with details of supplier / manufacturer (2 marks)

Details of Local civil consultant who have experience in tower design works. (1 marks)

letter from local consultant to review & certify the design documents as per Omantel specification & Obtain the approvals from Local Municipality / PDO / MOD etc. with copy of registration (1 marks)

Submit the copy of relevant codes / specs followed in tower design as per industry standards (1 marks )

15

3.2

Design Documents as a Sample. Contractor should submit the tower & foundation design with all calculations & drawing for 65 MT height & 50 MT height towers as per the tender specification. 200 KPA to be considered as SBC of soil to design the foundation

15

3.3

Tower & Foundation details. For the above 4 legged 65 mt height & 50 mt height tower the following details should be submitted.

1. Weight of tower. 2. Anchor bolt size & shape. 3. Surface area for tower painting. 4. Volume of excavation. 5. PCC volume. 6. RCC volume for tower footing 7. RCC volume for columns.

5

Sub-total of 3 35

4 Program schedule and Project Management.

4.1

Delivery, Implementation period of the sites as per the given time line in the Work Order. Programmed schedule shall include the following but not limited to these items only.

A. Submission & Approval of Tower & Foundation design. B. Procurement of tower materials. C. Implementation works Survey works Land acquisition works Civil works Tower works Fencing works Obtaining NOC from local municipality D. Labor & Equipment histograms corresponding to the work

programme.

5


4.2

Efficient Project Management including appointment of dedicated project team for the work and attend meetings with the client, follow-up for payments, PAC etc…

- Monthly target for billing / submission of PAC - Submission of the list of staff resources (own staff) with

minimum experience Project Manager civil – 1 with min 10 years’ experience Accounts manager – 1 with min 7 years’ experience Project Engineer civil – min 2 with min 7 years’ experience Civil Site Engineer – 2 with min 5 years’ experience Safety officer 1 with min 5 years’ experience QA & QC Inspector 2 with min 5 years’ experience PRO – 2 Drivers 4 Civil team – min 8 no’s ( 4 own, 4 sub-contractor )

Each team consist of minimum 7 members (Carpenter, Steel fitter, Masson, helper etc. )

Tower erection team – min 4 nos Own team each team consist of min 8 members

5

Sub-total of 4

10

5 Quality Assurance statement & HSE Manual

5.1 Health & safety policy provided by statement including HSE set up and having HSE officer’s periodic visits to the site. 2

5.2 Company’s Quality Assurance and workmanship policy with checklist. All Materials should be tested in Oman laboratory to ensure that the materials are in line with specifications

4

5.3 Methodology statement for Tower, GI pipe works including procedures with checklist. 4

Sub-total of 5 10

6 Site visit certificate (sample work) and the list of sub-contractors

6.1 Submission of site visit certificate to Omantel sites 2

6.2 Submission of company policy on the preventive measure to provide security of the Omantel premises during construction. 4

6.3 Submission of the details of sub-contractors who are experienced in tower works min 4 years

4

Sub-total of 6 10

7 Registrations & Financial information Documents requested in item no 4, 5, 6, &16 of enclosed document “ Information of prospective contractor

7.1 Compliance to the Standard Terms & Conditiions of the Tender 4

7.2 Submission of Registeration Certificates & all other Relevant documents as per the Tender requirements 2

7.3 Submission of last 3 years Audited Financial Statements of the Company 4 10 Sub-total of 7


DESIGN, SUPPLY AND INSTALLATION OF TELECOM TOWER WITH ALLIED CIVIL & EM WORKS AT MAHOOT EXCHANGE AND AL ASHKARA EXCHANGE

TELECOM TOWER

TECHNICAL SPECIFICATIONS


LATTICE TOWERS

TECHNICAL SPECIFICATIONS


INTRODUCTION These specifications refer to general technical requirements for purpose made prefabricated angular, lattice type, self-support towers intended for telecommunications use.

1. INTERNATIONAL CODES OF DESIGN There are different international standards that specify towers according to the following:

• Materials e.g. steel structure & locking devices. • Loads e.g. Dead load, wind load and appurtenances. • Tower stress e.g. structure force.

Oman tel follows the British Standards in general; however, there are some other codes & criteria that are only specific to the use, and are hence used to customize the towers.

2. TOWER TYPES Four Legged Angular Self Support Towers

The specifications for this type of antenna support structures are covered in this document.

3. TOWER DESIGN STANDARDS & CODES Design of the towers shall comply with British Standard (BS) 5950. These shall cover the following:

4.1. Tower Foundation a) Foundation reinforcement should comply with British Standard (BS) 4449. The minimum grade of concrete shall

be C30 as per British Standard (BS) 8110. b) Omantel is obliged to either provide “soil investigation report” or define the characteristics of the soil by

specifying the “soil bearing capacity”. Which is Ranging from 100KPA to 200 KPA . Contractor is obliged to provide the foundation design for approval based on the supplied information.The foundation shall be designed for each site specifically & the site specific foundation design shall be submitted to Omantel for approval prior to the commencement of the civil works at sites. c) Design and construction of foundations for the different height of the towers shall be for any type of soil or rock

conditions. The foundation to be designed as per recommendations of Omantel or soil investigation report and relevant ACI code. No additional amount will be entertained for the excavation in rock, cemented gravel, etc.

d) The contractor is solely responsible for the structural stability of the supplied tower in all aspects and Oman tel

approval does not release the contractor from the responsibility for any unfortunate contingent adverse occurrence in the future.

e) To ensure quick curing of the foundation concrete, the contractor is obliged to utilize proper curing compounds.

The contractor shall seek approval of Omantel for the curing compounds that are going to be utilized. f) Epoxy coated reinforcement steel shall be utilized for the sites within 2km range from the sea. g) All tests required including cylinder test, pile integrity test, concrete core test (in case of unsatisfactory cylinder

test results) etc. shall be carried out for all piles/foundations.


h) Non-shrink cementatious grout “CONBEXTRA GP” or equivalent to be placed below the base plates of the tower legs. (Minimum thickness 50mm).

i) The concrete surface below ground level shall be protected by two coats of approved bituminous coating

‘NITACOAT ET550’ or equivalent. Above ground level, the concrete surface shall be protected by crack accommodating elastomearic protective coating topcoat “DECKGUARD E2000” or equivalent.

j) All foundation work including excavation and backfilling shall be carried out as per relevant ASTM standard. The

reinforcement steel should be as per the relevant British Standards.

k) The contractor shall provide ready mix concrete certified by the manufacturing plant to all the sites unless special approval is acquired from Omantel for some exceptional sites. The certificates from the ready mix concrete manufacturing plant shall be submitted to Omantel for each delivery. In case the contractor is preparing the concrete at site, cube crash test results from accredited laboratories shall be submitted to Omantel. Omantelapproval is required for the number & location of samples that will be taken from the foundation.

l) The backfilling shall be done in layers not exceeding 40cm & each layer shall be compacted properly by watering & utilizing the required compaction machinery. Progress photos shall be submitted to Oman Mobile for each layer of compaction.

m) Vibrators shall be provided & utilized properly during the casting of the concrete at site to ensure the proper concrete settlement.

n) Omantel shall be notified officially by the contractor at least 5 working days prior to steel inspection. The foundation will be rejected if the concrete casting is done without Omantel inspection and approval for the reinforcement steel.

4.2. Steel Grade & Steel Elements

a) All structural angle sections, plates and other sections shall comply with relevant British Standards.

b) Sections used in the fabrication of members shall be cut from single piece of material (no welded pieces).

c) Grades of the steel to comply with BS EN 10025 Grade 275 JR/355 JR or equivalent ASTM standards.

d) Materials used in production of steel work shall be provided free from blisters, mill scale, laminations and other defects.

e) The minimum yield and tensile strength of steel to be used for manufacture of steel work will be in accordance with the design calculations.

f) Tower legs to be high grade steel and manufacturer shall identify clearly the grades of the steel in writing to the Employer.

g) The necessary holes needed for the ground connection on the tower legs close to the base plates must be designed & drilled prior to galvanizing.

h) The Contractor shall inform the Engineer of the date on which fabrication will commence, shall keep the Engineer informed of the fabrication programme and shall permit the Engineer or his representative full access to his factory at all reasonable hours for the purpose of inspecting the steelwork at any stage of its manufacture. Contractor must clearly understand that any material and workmanship not complying with this specification shall upon inspection whether at his works, the site or in erected position be rejected and replaced to the entire satisfaction of the Engineer.

i) Member usage allowed is maximum 85% in comp & Tension

j) Oman climatic conditions should be considered while designing the tower.

Temperature -5 to 55 degreeC,

High Humidity climate ,

Exposed to Sand storm


Note: Manufacturers' certificates and test sheets including chemical composition as required in respect of all

steel sections and plates to be used in the works to be provided by the contractors.

4.3. Tower Heights Heights of Square self support towers shall be in an increment of 5 meters(i.e. 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65,70, 80 & 90m. Heights of Triangular self support towers shall be in an increment of 5 meters(i.e. 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 & 60m If specific site conditions demand deviation from the above-mentioned height increment, detailed technical justification must be specified. The towers shall be designed for at least for a life time of 30 years.

4.4. Tower Dimensions

a) Contractor shall make his own survey of the sites and shall be responsible for obtaining all dimensions and level necessary for the proper fabrication of the steelworks.

b) The Contractor shall be responsible for every piece being made to the correct form and size.

4.5. Definition of Wind Speed Since the wind force on a structure depends on the square of the wind speed, the specification of wind speed is critical in determining the weight, rigidity, and cost of a mast or tower. Every effort should be made to specify the realistic maximum wind speed for the location based on a 3 second gust value. There are two wind speeds which are important for the design: the maximum wind speed in which twist and sway shall be maintained within the specified limits (operational wind speed); and the survival wind speed in which the twist and sway specification shall be temporarily exceeded during extreme gusts but the structure shall return to normal afterwards. These correspond to the 10 and 50 year maximums, respectively. In this case, the towers shall be capable of sustaining survival wind speed of 55.56 m/sec or 200 km/h at 3 second gusting and the operational wind speed shall be 44.44 m/sec or 160 km/h.

4.6. Wind Pressure (Loads) The wind load on a tower or mast is the combined effect of the wind pressure on its structural components and on the antennas which it supports. Antenna manufacturers will normally indicate the wind load for their products at an indicated wind speed. A grid has approximately 65 to 70% less exposed area than a solid dish of the same diameter whilst a Radom fitted to a solid dish improves the dynamic wind flow and hence reduces wind pressure. The contractor is responsible for combining the total load and for any recalculation of the antenna load at the specified wind speed according to the antenna loading criteria for the structure. Wind pressure on the structural members, ladders, antenna mounts, etc. shall be calculated in accordance with British Standard (BS) 8100 on open areas without obstruction. Consider Topography category 2 with minimum 10 mt crest height. Expose category D as per ANSI / TIA / EIA / RS -222-G Factored load should be considered at survival wind speed for Design check


4.7. Twist & Sway All structures move in the wind to some extent. The directivity of the antennas shall determine the allowable twist and sway. In the absence of specific requirements it is normal to limit these values to ±0.5 degrees which should give adequate performance of most radio systems under extreme wind conditions. Twisting of guyed masts can be reduced by using spreader bars or anti-torque devices between the mast structure and the upper end of the guy wires.

4.8. Safety Factor for Overturning The safety factor for overturning shall be 1.7 at survival wind speed.

5. TOWER STRUCTURE DESIGN SPECS

5.1 Antenna Loading A) Mahoot Exchange

S/N Antenna Type Number of Antennas Antenna Dimensions (m) Antenna Height (m)

1 GSM Antenna 2 1.5 Top.

2 MW 1.2dia 1 1.1314286


4 MW 1.2dia 1 1.1314286

5 MW 0.6dia 1 0.2828571


7 sector antenna Ooredoo 3 2.25

8 MW 2.4dia 1 4.5257143

9 OMNI 2 1.5

10 MW 1.2dia 1 1.1314286


12 MW 2.4dia 1 4.5257143

13 MW 0.6dia Ooredoo 1 0.2828571



b) Al ashkara Exchange

S/N Antenna Type Number of Antennas Antenna Dimensions (m) Antenna Height (m)

1 GSM Antenna 4 3 Top.

2 MW 2.4 dia 1 4.5257143


4 MW 1.2dia ooredoo 1 1.1314286

5 MW 1.2dia 1 1.1314286

6 MW 2.4 dia 1 4.5257143

7 MW 1.2 dia ooredoo 1 1.1314286

8 MW .3dia 1 0.0707143

9 MW 1.2 dia ooredoo 1 1.1314286

10 MW 0.6 1 0.2828571

11 MW 1.2dia 1 1.1314286


Note: In addition to the above mentioned loading details, all towers shall have a provision for

future extension by 5 meters by considering all the above mentioned antennae loading will apply to the extended portion and tower design should cover the same.

5.1 Cable Ladders 5.2.1 Horizontal Cable Ladder

A hot dipped galvanized steel cable ladder should be installed between the tower and the container or outdoor cabinets to support the coaxial cables. Steel cable ladders should be delivered & installed between the shelter and tower. The cable ladder shall be 400mm minimum width with horizontal rungs spaced at 500mm maximum. The cable ladder profile shall be of shape and size to provide fixing arrangement for standard cable clamps such as Andrew, FEMA, RBS or other acceptable clamps for cable sizes of ½” through 1⅝”.

The cable ladder shall be delivered complete with all nuts, bolts, and clamps. The cable ladder shall be supported by hot dipped galvanized steel vertical adjustable (telescopic) supports having precast reinforced concrete foundations on the ground with minimum 20cm buried under the ground.

If requested by Omantel, the cable ladder shall be covered with a hot dipped galvanized steel cover, (to prevent damage to the cable) suitably fixed to the cable ladder.

The distance between the tower & the container is normally kept minimum; however the contractor is obliged to provide cable ladder in-between the tower & container regardless of the distance. In addition, the cable ladder should be designed, manufactured & installed in such a way that the unsupported length shall not exceed 3 meters in order to avoid bending under the weight of the cables.

5.2.2 Vertical Cable Support on Tower The vertical feeder supports shall be provided adjacent to the climbing ladder capable of supporting maximum number of feeders for the ultimate system. The spacing between feeder support bars shall not exceed 0.8 meter. The vertical cable support shall not obstruct the feet of the climbing person; therefore the minimum distance from the climbing ladder to the support shall be 0.25 meter.


5.2 Climbing Ladder Climbing ladders (and vertical cable supports) shall be fixed at the nearest leg of the tower to the shelter and it should comply with local & international safety standards and specifications with regard to their dimensions, mounting, material, etc.

a) The climbing ladders shall be fixed to either horizontal bracings or legs but should be adjacent to the vertical feeder support. The design of the access ladder shall be according to BS 4211.

b) Ladder shall not be less than 450 millimetres wide with rungs fixed at not more than 200 mm spacing. Galvanizing to be at least 610 gram of zinc coating per square meter.

c) Ladders shall have a continuous safety cage, constructed of loops separated by not more than 1 meter, and with not less than three vertical back strips. Construction design should be such that the safety cage is rigid.

d) The ladder top piece must extend at least 1 meter beyond the top working platform so that a secure access from

the ladder to the platform is possible. Sharp edges that could lead to injuries should be avoided.

e) The ladder rungs must be able to withstand a concentrated load of 1.5kN.

f) Rest platforms shall be provided along the climbing ladder with intervals not exceeding 15 meters. Rest Platforms shall be strong enough to withstand 2kN concentrated load.

g) The platform floor shall be textured metal sheet or similar and shall be rigidly supported.

h) The platforms shall be fitted with a metal to board and guard rail at one meter level with a maximum free vertical spacing of 400mm.

i) The entire tower height shall be provided with anti fall arrest system consisting of rail, harness and trolley.

5.3 Fasteners a) Bolts, nuts and washers The connection bolts, nuts and washers will be according to any of the following standards (or equivalent):

Mechanical properties of fasteners

prEN 781/2 Hexagon bolts for high strength structural bolting prEN 784/5 Plain washers for high strength structural bolting

Bolts EN 24014 Hexagon head Strength class 8.8

Plain washers ISO 7089 Galvanizing Hot dipped Nut lock The nuts will be locked so that they won’t get loose during the operation. The proper

tightening torque will be defined in the document

b) Dimensional standards for fasteners

Bolts DIN 7990, 6914, 933, 607, 6921, 931, 960 961 Nuts DIN 555, 7967, 934, 6915, 439-2 Washers DIN 7989, 6916, 126, 434 Spring Washers DIN 127, 128 Anchor Bolts As per requirements


5.4 Safety Railing The work platform should be equipped with a top handrail of tubular or angle profile, galvanized steel. The safety railing is capable of carrying a 1kN concentrated load. There is an intermediate rail at a height of 0.6m. A kick plate (toe board) 0.1m in height is installed around the platform to prevent tools or other objects from falling from the tower.

5.5 Aircraft Warning System The Aircraft Warning System of the tower should be designed, supplied & installed according to Oman tel AWL Standards & Specifications that are described in documents OM- ND – QM – 002 – 05.

6. TOWER INSTALLATION & ALLIED WORKS The Contractor shall be responsible for taking extra precaution and all necessary measures to protect existing structure, all existing dish antennae and any other accessories thereof during handling, erection or carrying out any other related works at site. Also, the Contractor shall submit his proposed measures for protection of all existing works to the Omantel engineer for his comments before proceeding with any works at site.

6.1 Tower Erection

a) The proposed implementation plan, erection sequence and procedures shall be submitted to Omantel engineer for approval prior to any civil works.

b) Fabricated parts shall be handled and stacked in such a manner that components are not damaged in any way.

c) All work shall be protected from damage in transportation & storing. Particular care shall be taken to stiffen free ends, prevent distortion and adequately protect surfaces. All bolts, nuts, washers, screws, small plates and small articles generally shall be suitably packed and identified.

d) Erection of the steel work shall be strictly in accordance with the recommendations of relevant British Standard.

e) Throughout the erection of the structure, the steel work shall be securely bolted or fastened in order to ensure that it can adequately withstand all loading liable to be encountered during erection including where necessary those from erection plant and its operations. Any temporary bracing shall be left in position until such time as erection is sufficiently advanced as to allow its safe removal.

f) All connections for temporary bracing, bolts, members etc. to be provided for erection purposes shall be made in such a manner as not to weaken the permanent structure or to impair serviceability in any way.

g) All plant used by contractor shall be sufficient for the purpose of erecting the steel work.

h) The contractor is solely responsible for acquiring any required permissions and authorizations from any local or national authority including but not limited to Environment, Civil Aviation, ROP, Civil Defence, Omantel approvals, Building Permit, etc. The contractor is obliged to pay any fees involved in the process.

i) Details of the weight and location of any lifting, erection or other machinery shall be submitted to the engineer for approval prior to such machinery being brought on to site.

j) The contractor is solely obliged to take all the temporary & permanent safety measures prior or during the construction phase of the sites. Moreover, the contractor is responsible to take all the necessary precautions in order to supply the safety of the inhabitants within the environment.

k) The contractor is responsible for applying all HSE procedures of the local authorities such as but not limited to PDO, civil defence, etc.

l) All equipment and personnel shall be suitable and enough in number with respect to Oman tel’s work flow for transportation and installation.

m) All kinds of equipment and work machines used during installation and transportation will be in conformance with the local legal regulations and they will have enough capacity with respect to the specifications of the


materials to be transported. Contractor is responsible for checking the periodic maintenances of the work machines used.

n) Supplying all & any kind of required work machines and equipments during installation are under contractor’s responsibility.

o) Personnel working at various stages of the tower installation shall be qualified and authorized in their works. An experienced team leader shall be present as the head of each team at all stages of the tower installation. The contractor shall submit a complete organizational chart & CVs in detail for Omantel approval prior to commencement of the works.

p) Any kind of damage on the materials, that may occur during the loading – deploying and transportation of the material, like harming a galvanized surface, are under the installation contractor’s responsibility. Repairing these damages can only be done by the special approval of Oman tel. This approval will be related with only the specific site. In case Oman tel will not approve, the contractor is solely responsible for replacing the material from the direct manufacturer.

q) No mechanical operations can be performed on any part of the galvanized materials for any purpose.

r) All kinds of damages that may occur on the surrounding (buildings, structures, utilities, roads, etc.) during the site works are solely under the contractor’s responsibility and the contractor shall compensate any damage.

s) If the excavated soil is not suitable for backfilling according to the satisfaction of the Engineer, the contractor shall bring imported filling soil to the site regardless of the material availability distance.

t) Anchorage bolts and nuts must be protected while concreting.

u) The contractor shall be entirely responsible for stability of the structure during erection and shall arrange that sufficient tack bolts are used to ensure that work will remain rigid until final bolt tightening.

v) Fabrication shall be such that all parts can be accurately assembled and erected. Alignment of each part of the structure shall be carried out as soon as possible after it has been erected. Permanent connections shall not be made between members sufficient of the structure is aligned, levelled, plumbed and temporarily connected to ensure that members will not be displaced during subsequent erection or alignment of the structure.

w) Verticality Tolerance: The distortion of the mast from the vertical axis can not exceed 0.5% of the tower length.

x) When the steel work has been finally levelled and plumbed the space under all base or bearing plates shall be thoroughly cleaned, dampened and then grouted.

y) The bolts that will be used in tower installation will not be screwed up to the extend of harming the galvanizing of the materials. After the whole tower erection is completed, the tightening of the bolts will be checked according to the submitted & approved torqueing table.

z) The contractor is obliged to clean the site & remove any left-over material after completion of works.

6.2 Tower Painting

a) Entire tower shall be painted to fully meet the requirements of Directorate General of Civil Aviation (DGCA) i.e. with alternate bands of aviation orange and aviation white.

b) The width of each band shall be 1/7th of the height of the structure and the top band shall be aviation orange.

c) Painting works shall be strictly carried out in accordance with the details given below and as per the recommendations of the manufacturer:

Remove all the existing dust including de-rusting, degrease and cleaning with water thoroughly and allow to dry.

Apply one coat of wash/Etch primer at 7-10 microns to the galvanized steel structure, one coat of High build Epoxy paint at 100 microns and one coat of polyurethane top coat at 50 microns and as per the manufacturer’s instruction.


6.3 Tower Welding, Drilling & Modifications on Tower Welding, drilling & any mechanical modification on tower is strictly not allowed after galvanization. Not complying to this clause may result in having the whole structure rejected by the engineer.

6.4 Tower Galvanizing

Except where otherwise specified all iron and steel used in the construction of the tower shall be hot dipped galvanised after fabrication is complete. The zinc coating shall be uniform clean, smooth and as free from spangle as possible. The galvanising should have the following standards.

a) Galvanising shall be applied by hot dip process and shall consist of either a coating of at least 610 grammas of zinc per square meter or minimum thickness of 120microns for all parts. For bolts and nuts the coating shall not be less than 305 grammas per square meter.

b) All galvanizing work shall be strictly in accordance with latest relevant British Standard and would be confirmed in writing by the manufacturer.

c) All hardware (nuts, bolts, washers, etc.) shall be galvanised in accordance to ASTM B695 Class 50 (Mechanical) and the galvanizing shall be as per BS 729 – 120 microns.

d) For Shanna Port the tower galvanizing shall be 160 microns and for Qarn Gazal galvanizing shall be 120 microns.

7. LIGHTNING PROTECTION SYSTEM & GROUNDING

e) On the top of the tower, a vertical lightning bar (lightning arrestor) made of copper with sufficient height (minimum 1.2m) to protect the antennas, assuming a cone of 90° with the vertex at the top of the bar, will be directly bolted on the structure.

f) Lightning arrestor shall be connected to a down conductor copper wire (no joints will be allowed on the down conductor) with a sectional area of at least 50mm2 to the earthing pit at the bottom of the tower. Proper fixing arrangement is required along with clamps & fasteners for the down conductor to be properly fixed on the tower leg.

g) In addition, the tower shall be grounded from all four legs directly to a single ground rod by using a bare copper cord of 50mm2 sectional area.

h) The base plates of the tower must have a dedicated hole (drilled prior to galvanizing) to allow this connection.

i) All ground bars (rods) under the ground will be connected to each other forming a ring made of bare copper cord of 50mm2 sectional area.

j) When using different conductor materials (e.g. steel, aluminum or copper) special connectors must be used to avoid corrosion problems.

k) The earth system shall conform to section 12 of EIA-TIA RS-222-E standard.

l) The maximum allowed earthing resistance for the tower is 10Ohms.

m) All the underground connections of the earthing system shall be made with Cadweld method.

8. DOCUMENTATION & DRAWINGS a) Complete Auto CAD general arrangement, assembly and foundation drawings shall be provided. b) Test certificates shall be supplied for the materials used in manufacturing of steel work. These certificates shall

cover mechanical and / or chemical properties of materials. c) Tower analysis and design details shall be provided which shall include following information:


Joints geometry and secondary joints details, joint positions and rotations, joint support reactions, joint displacements, load and member forces on joints, equilibrium joint positions and rotations.

Steel material properties including modulus of elasticity, yield stress, ultimate stress, members stress and rupture and bearing.

Angle properties including angle groups, angle size, long leg, short leg, thickness, unit weight, gross area, weight to thickness ratio, radius of gyration, number of angles, wind width, long and short edge distance and section modulus, aggregate angel information (angle type, size, material, total length, total surface area and weight), angle forces for all load cases.

Sections details including adjacent factors, angle member connectivity, member capacities, section loads ultimate & service, section loads wind ultimate & service.

Section and joint elevation information.

Ultimate and service load cases including dead load, wind load, strength factor, allowable stress increase factor, basic wind speed, wind direction, temperature, point loads and joint displacement.

Group summaries for compression portion, tension portion and maximum usage by load case.

d) Each Tower structure should be allocated a dedicated file. This file should contain: The structure's specification; Any contract, or extracts from any contract pertaining to the structure; Design information including:

i. Stress calculations, ii. Permissible head loads,

iii. Guy tensions (for guyed masts), iv. Foundation design, v. Soil test results,

vi. Foundation test results - cement tests, vii. Earth resistance test results,

viii. Acceptance inspection form;

9. TESTING & APPROVAL

9.1 Galvanizing Test The two properties of the hot-dip galvanized coating that are closely scrutinized after galvanizing are coating thickness and coating appearance. A variety of simple physical and laboratory tests may be performed to determine thickness, uniformity, adherence and appearance & the test reports signed and approved by the manufacturer shall be submitted to Oman tel.

9.2 Mechanical Testing

Dimensions and tolerances of raw materials are inspected for their conformity with relevant DIN, EN and/or ISO standards. Materials which dimensionally do not conform to the standards shall be rejected.

10. QUALITY ASSURANCE All materials will be of quality in accordance with EN 10025, as detailed below:

Mild Steel EN 10025 Grade Fe 360B ( = S235JRG2 ) EN 10025 Grade Fe 430B ( = S275JR )

High Tensile EN 10025 Grade Fe 510C ( = S355JO )

Fasteners, Washers, Structural Steel, Spring Washers, Spring Steel ISO 898/1-2

Anchor Bolts AISI 1020, 1030, 1040, 1050

SULTANATE OF OMAN OMAN TELECOMMUNICATIONS … · 2. Omantel reserves the right to issue work order...

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Transcript of SULTANATE OF OMAN OMAN TELECOMMUNICATIONS … · 2. Omantel reserves the right to issue work order...