NATIONAL ALUMINIUM COMPANY LIMITED - Rites

high accuracy real time clock. It shall be set from 6 PM to 6 AM or any other intermediate
time. The tendered shall indicate the controls offered by him clearl clearly y in the offer.
p. The successful Bidder shall submit design and preliminary data for the design of foundation
of the high mast tower indicating the requirements of embedded inserts etc. The
foundation shall be designed and provided by the purchaser. Bidder to include foundation
bolts etc which shall be embedded in the foundation. Grouting of the bolts shall be done by
the Bidder.
q. The high mast shall be provided with lightning protection with air air- termination and down-
comers as per requirements of BIS and aviation warning lamps as per statutory and civil
aviation requirements. All metallic portions of the high mast shall be effectively earthed
and provided with two earth pits near the base. Effective earthing for luminaries shall be
provided during normal ooperation
and in lowered position.
r. Mast structure is designed to withstand wind velocity conforming to IS 875 (Part (Part-III)-1987.
Mast Design Criteria
The high mast and the lowering system with the required number of floodlights and lamp
controls gears etc. tc. In place shall be capable of withstanding a sustained basic wind speed of
180 Km/ hrs.
The design shall be in such a manner that it is capable of withstanding external forces exerted
by wind pressure and should have a minimum wind load factor of 1.25 and material factor of
1.15. Design life of mast shall be 25 years.
CONSTRUCTIONAL FEATURES OF MAST
The mast shaft shall be made with the best steel grade, in compliance with MS IS IS- 2062/BSEN
10025 having adequate characteristics w.r.t. minimum yield strength, tensile strength and
minimum elongation for thickness.
The steel grade for accessories shall also be MS IS 2062 or equivalent, having adequate
characteristics w.r.t. minimum yield strength, tensile strength and minimum elongation for
thickness.
Each mast section to be delivered to site shall have a minimum length of 10.7 Mtrs. The Mast
sections shall have Single longitudinal weld from Bottom to Top.
The base shall have a flange plate for high mast onto the concrete foundation by anchor bolts.
The mast shall be fabricated and welded longitudinally to form a tapered section with
telescopic friction on slip joints. All welding shall be to IS 816 / 82 having the following basic
requirements.
Technical Specification:Sec-6, Electrical
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