PROVIDING HIGH MAST LIGHTS IN GREEN BELT A B BACKSIDE H.NO. 249-300, SECTOR 51, CHANDIGARH

Supply, erection, testing & commissioning of 12.5 Meter High Mast with 3 rope sysem based on the following parameters/ requirements of the Deptt. Height of Mast: 12.5 Meter with power tool based. The power tool 3 phase motorized 1.1 KW complete in all respect should be installed in the pole Reputed ISI marked only. Wind speed: 180 Km/hour as per IS-875 (Part-III).The High Mast & head frame shall be structurally suitable to accommodate the 8 Nos.LED flood light fittings & its control gear boxes.

Construction of the Mast: The mast shaft shall be manufactured from high tensile steel plates confirming to BS EN 10025 having minimum yield strength of 355N/Sq. mm. Each mast shaft section shall be without any circumferential weld joint except base flange. The mast base flange shall be free from any lamination or incursion and provided with supplementary gussets between the bolt-holes to ensure elimination of helical stress concentration. The minimum A/F dimension of top shall be 150 mm (min.) and bottom 360 mm (min.). The mast should have two sections and the sections shall be joined at site by slip-stress-fit method and the sections shall be joined at site by slip-stress-fit method and minimum overlap distance shall be 1.5 times the diameter at penetration. A door reinforced with welded steel section, vandal resistant, weather proof with Allen bolts and pad locking facility of dimension not less than 1200 mm x 250 mm shall be provided at a height 2 times the width of door from the base of mast to provide clear access to base compartment Equipments winch, motor, cable, connector etc. For the environmental protection of the mast, the entire fabricated mast shall be hot dip galvanized internally and externally in single dip having a uniform average thickness of 85 microns for plates more than 5 mm and 70 microns for 5 mm and less thickness.

Code No.: I.S. 875 (Part III) 1987 Amended up to date Title: Code and practice for design loads for structures under Code No.: BSEN 10025 Title: Grades of M.S. plates Code No.: BS 5135/AWS D 1.1 Title: Welding Code No.: BSEN ISO 1461 Title: Hot dip galvanizing Code No.: TR. No. 7 (2000 addition) of ILE, UK. Title: Specification of Mast and foundation. Code No.: IS 3459 / 2266 Title: Stainless steel Wire rope Code No.: IS 9968 Part – 1 Title: Trailing Cable Code No. IS 325 Title: Motor

Dynamic Loading for the Mast: The mast structure shall be suitable to sustain an assumed maximum reaction arising from a wind speed as per IS 875 (three second gust), and shall be measured at a height of 10 meters above ground level. The design life of the mast shall be 25 years. The force co-efficient taken for design of the twenty sided polygonal structure is to be established from the wind tunnel test data.

Luminaries Carriage: A fabricated Lantern Carriage shall be provided for fixing and holding the flood light fitting and control gear boxes. The Lantern Carriage shall be of special design and shall be of steel tube construction, the tubes acting as conduits for wire, with holes fully protected by grommets. The Lantern Carriage shall be so designed and fabricated to hold the required number of flood light fitting and control gear boxes, and also have a perfect self balance. The Lantern Carriage shall be fabricated in two / three halves and joined by bolted flanges with steel nuts to enable easy installation or removal from the erected mast. The entire lantern carriage shall be hot dip galvanized after fabrication. The inner lining of the carriage shall be provided with protective PVC arrangement, so that no damage is caused to the surface of the mast during raising and lowering operation of the carriage. Weather proof junction box, made of cast Aluminum shall be provided on the Carriage Assembly as required, from which the inter-connections to the designed number of the flood light luminaries and associated control gears fixed on the carriage shall be made.

RAISING AND LOWERING MECHANISM: For the installation and maintenance of the luminaries and lamps, it shall be necessary to lower and raise the Lantern Carriage Assembly. To enable this, a suitable Winch Arrangement shall be provided, with the winch fixed at the base of the mast the specially designed head frame assembly at the top Winch: The winch shall be of “Integral Power Tool” type with motor. The winch shall have provision for manual operation in case of failure of the motor. The winch shall be double drum and completely self sustaining type, without the need for brake shoe, springs or clutches. Each driving spindle of the winch shall be positively locked when not in use. The capacity, operating speed, safe working load, recommended lubrication and serial number of the winch shall be clearly marked on each winch. The winch drums shall be grooved to ensure perfect seat for stable and tidy rope lay, with no chances of rope slippage. The rope termination in the winch shall be such that distortion or twisting is eliminated and at least 5 to 6 turns of rope remains on the drum even when the lantern carriage is fully lowered and rested on the rest pads. It shall be possible to remove the hoisting mechanism after dismantling through the door opening provided at the base of the mast. The winch shall be type tested at a reputed institution and the test certificate shall be furnished before supply of materials. The test certificate shall include the maximum load operated by the winch.

Head Frame: The head frame is to be designed as a capping unit of the mast, shall be of welded steel construction, galvanized both internally and externally after assembly. The top pulley shall be of appropriate diameter, large enough to accommodate the steel wire ropes and the multi-core electric cable. The pulley block shall be made of no corrodible material, and shall be of die cast Aluminum Alloy (LM-6). Pulley made of synthetic materials such as plastic or PVC are not acceptable. Self-lubricating bearings and steel shaft shall be provided to facilitate smooth and maintenance free operation for a long period. The pulley assembly shall be fully protected by a canopy galvanized internally and externally. The head frame shall be provided with guides and stops with PVC buffer for docking the lantern carriage.

Stainless Steel Wire Ropes: The stainless steel wire ropes shall be in AISI 316 grade, 7/19 construction with central core in the same material of diameter and the breaking load of rope shall not be less than 2x1450 Kg. giving a factor of safety of over 5 for the system at full load as per the TR7 referred to in the beginning of this specification. The end construction of rope for the winch drum shall be fitted with talurit and for two continuous ropes the end termination in luminary’s carriage shall be with stainless steel thimble and copper splicing and for others with stainless steel thimble and bull dog grips.

Electrical System, Cable and Cable Connections: Suitable terminal box shall be provided as part of the contract at the base compartment of the high mast for terminating the incoming cable. The electrical connections from the bottom to the top shall be made by special trailing cable. The cable shall be EPR / PVC insulated and PCP sheathed to get flexibility and endurance. At the top there shall be weather proof junction box to terminate the trailing cable. The system shall have in-built facilities for testing the luminaries while in lowered position. Also, suitable provision shall be made at the base compartment of the mast to facilitate the operation of internally mounted, electrically operated power tool for raising and lowering of the lantern carriage assembly. The trailing cables of the lantern carriage rings shall be terminated by means of specially designed, metal clad, multi pin plug and socket provided in the base compartment to enable easy disconnection when required

Power Tool for the Winch: Three phase, motor suitable to lift the load mounted on adjustable plate to adjust the length of winch motor coupling chain is to be provided in base compartment. Mechanical torque limiter is to be mounted on motor shaft to stop transmission of motion from motor to winch in case of excess load and thus prevent the damage to winch and breakage of rope.