12M Galvanized Tubular Steel Post Class 7 1340daN Safety Factor 2.0

This specification provides for the design, manufacture, testing in factory, supply, and delivery to site for the Galvanized Steel Tubular Poles.

It shall be the responsibility of the Contractor to furnish equipment, which shall meet in all respects the performance specification and will have satisfactory durability for the prevailing site conditions.

The Contractor shall furnish all material and labour not herein specifically mentioned or included, but which may be necessary to complete any part of the work or work as whole, in compliance with the requirements of this specification.

The detailed design arrangement of the equipment shall be the responsibility of the Contractor subject to the approval of the RREA Engineer.

The Hard Drawn Copper and Aluminium Conductors supplied shall also fully comply with the following RREA specifications, namely:

• RREA General System Conditions

• RREA Packing and Shipment Requirements

• RREA Submittal Requirements

• Standards and Codes

Except where modified all equipment and materials shall be in full accordance with IEC (International Electrotechnical Commission) and ISO (International Standards Organisation) standards and recommendations. If relevant IEC or ISO standards and recommendations are not available in any case or cases then relevant British Standards or National Standards shall apply if available.

When IEC, ISO, BSI or National Standards are referred to the edition used shall be that current at the date of Tender, together with any amendment issued to that date.

Further to that above additional standards order of preference is listed below: IEC International Electrotechnical Commission

ISO International Standards Organisation

BSI British Standards

NS National Standards (where available) ANSI American National Standards Institute

Where the use of a standard other than IEC, ISO or BSI is agreed then this standard shall be used, where applicable. Where other standards are proposed in place of IEC, ISO or BSI Standards, confirmation shall be provided that the provisions of the standards are equivalent to or exceed those of the equivalent IEC, ISO or BSI standards.

Copies of any standards proposed in substitution for IEC, ISO or BSI standards must be submitted with the Tender accompanied where necessary by English translations of the appropriate sections.

Notwithstanding any descriptions, drawings or illustrations which may have been submitted with the Tender, all details other than those shown in the ‘Deviation from the Technical Specification Schedule’ and approved by the RREA Engineer shall be deemed to be in accordance with the Specification and the standard specifications and codes referred to therein.

No departures from the specification except those shown in the ‘Deviation from the Technical Specification Schedule’ and approved by the RREA Engineer are to be made without the written approval of the RREA Engineer.

2.1 Scope

This Technical Specification covers the design, material, fabrication, protective coating, tests, inspection, packing and delivery of welded round conical steel monopoles used in overhead distribution systems. The reference to specifications or organizations together with any drawings or loading diagrams shall be considered part of the specification. The pole manufacturer has to be ISO 9001 certified.

2.2 Reference Standards

Reference to standards and/or specifications herein shall be interpreted to mean the latest revision unless noted.

Design, materials and fabrication of steel poles shall be in accordance with latest edition of international Codes and Standards listed hereafter:

EN 10149: Hot-rolled flat products made of high yield strength for cold forming

EN 10025: Hot-rolled products made of non- alloy structural steels Technical delivery conditions

ISO 898: Mechanical properties of fasteners

ACI 318: Building Code Requirements for Structural Concrete

ASTM A123: Standard Specification for zinc (hot galvanized) Coating on Products Fabricated from Rolled, Pressed, and Forged Steel Shapes, Plates, Bars and Strips

ASCE N°. 72: Design of Steel Transmission Pole Structures (for reference only) ASCE (SE) 48-05: Design of Steel Transmission Pole Structures

AWS: American Welding society for welding and related processes

2.3 Design

• The poles shall be round-conical with a gradual and constant taper.

• Longitudinal welding should be kept to a minimum depending on the fabrication process. Circumferential welding not allowed for shafts assemblies.

• The design will preferably uses non-linear analysis and follows the guidelines and principles described in ASCE manuals and Report on Engineering Practice n° 72 and ASCE(SE) 48-05

· Pole shafts shall be one piece to the maximum length possible within shipping and/or fabrication limitations. Pole shafts exceeding limitations shall be designed in several sections.

Adjacent sections shall be joined by slip joints. Poles shall be designed with a minimum number of joints. Slip joints shall be designed for a minimum overlap of 1- 1/2 times the inside diameter of the female section at the joint, as per ASCE "Report No 72, Design of Steel Transmission Pole Structures" and ASCE(SE) 48-05

· A removable plastic top cap to be fitted on the top of the pole shall be supplied.

· One brass nut will be positioned at the top of the pole and another brass nut at the ground level.

· Deflection limitation at service load shall be 4% of the height above ground.

· Top diameter limitation to be applied during the design is:

o minimum ..................................................... 200 mm

o maximum ..................................................... 240 mm

· Safety factor used for calculation shall be:

2.0………….for transversal loads

1.5 ………….for vertical loads.

· Poles shall be equipped by anchor base. Anchor base shall be designed to transfer the loads from the pole to the foundation. The base plate shall be welded to the pole at factory. The embedded length shall be determined by the anchor bolt design load and the ultimate bond stress for 3000 psi concrete (f c) as specified in the American Concrete Institute Building Code (ACI 318). Anchor bolts shall be delivered together with poles. One upper template per pole type and one lower template per pole (if required) shall be provided. Templates and anchor bolts will be furnished unassembled.

2.4 General standardization

2.4.1 Poles shall be designed for standardized range in the following load classes:

Fmax……………………maximum working load at 600 mm from top of pole

2.4.2 Poles shall be designed for standardized lengths in following range:

8 m, 9 m,10 m, 11 m, 12 m, 13 m and 14 m.

2.5 Material

All material shall be in accordance with relevant standards referred to within this specification.

Steel to be used will be of grade S500MC according to EN 10149. Steel parameters (t<10):

Minimum Yield Stress Fy ………………………... 500.00 (N/mm2) Minimum Tensile Stress Fu ...............................550.00 (N/mm2)

Alternative steel to be used should be of grade S355MC or S315MC according to EN 10149.

2.6 Manufacture

All parts forming the structure shall be fabricated in accordance with drawings approved by the RREA Engineer.

Sections of poles are made from sheets of steel, cut to trapezium, then cold formed to shape the round conical cross section or twelve (12) sided regular polygonal cross section.

Formed plate shall be bent to a radius sufficiently large so as not to produce cracking of the material.

Drilling or punching of holes shall be done before galvanizing in such a manner as to produce cylindrical holes normal to the plane of the material (throughout holes).

2.7 Tolerances

The permitted variation (tolerance) from a stated dimension, the length of elements, outside diameter, straightness, etc shall be as follows:

2.8 Welding

All welding shall, as much as is practicable, follow the AWS Standard.

Longitudinal welds will have sixty (60 %) per cent penetration minimum except within the female part of the slip joint area where the percentage of penetration will be one hundred (100 %) per cent. Other welds shall be fillet welds for all thickness.

2.9 Galvanizing

After the fabrication has been entirely completed, steel poles shall be hot dip galvanized to minimum of 630 g/m2.

All hollow members shall be galvanized both inside and outside surfaces. No double dip galvanizing process is allowed.

Anchor bolts shall be galvanized to full length to minimum 320 g/m2.

Nuts may be re-tapped after galvanizing and then shall be suitably protected from rust by grease. Galvanizing shall be performed in accordance with ASTM standard A 123.

2.10 Marking

All parts of poles shall be appropriately marked. All marking shall be indelible and clearly visible after galvanizing. Pieces which are part of a structure shall be marked with structure type number, followed by the proper assembly item and other identification marks.

2.11 Bituminous protection

An additional bituminous protection from anchor plate to +1.5 from ground level of pole may be required.146 Section VI. Employer’s Requirements

3. INSPECTION AND TESTS

3.1 Inspection - general

Purchaser reserves the right to witness the manufacturing process, any type tests specifically performed on the equipment to be supplied to RREA and any routine tests required in the manufacture and supply of such equipment. Supplier shall provide free access to Purchaser to any site where such manufacturing process, or tests, either type or routine tests are taking place. Supplier shall bear the in plant costs of such witness. Supplier shall provide the Purchaser of a schedule of manufacture and tests at least two weeks before the events are to occur.

3.2 Type tests

Supplier shall provide documentary proof in the form of Certified Test Certificates that the steel pole or parts have been successfully type-tested by an independent testing authority in accordance with the ASCE(SE) 48-05 or BS IEC 60652. Test Certificates as evidence of successful completion of type tests shall be submitted as a part of the Tender.

3.3 Examination and inspection

• Visual Examination

• Verification of Dimensions

• Check of Welds

• Check of Zinc Thickness

4. PACKING AND SHIPPING

The Supplier shall prepare, pack, and load all materials and equipment for shipment in such a manner that they are protected from damage during shipment and shall be responsible for and make good any and all damage resulting from improper packing until final acceptance of the Supply. Items subject to open storage for several months at the sites shall be suitably protected from weather damage.

Each shipment shall be accompanied by a list of all parts, identifiable by pole type and number.