NATIONAL ALUMINIUM COMPANY LIMITED - Rites

i) Gallery Trusses
Span / 400
ii) Top of End portal of gallery truss H / 325 where H =Height of portal above beams
iii) Traverse deflection of top of Trestle H/1000 where H = Height of trestle above foundation
18.6 FABRICATION OF STEEL STRUCTURES
18.6.1 Drawings
The Contractor shall prepare fabrication drawings, erection drawings, bill of materials,
drawing office despatch lists / shipping documents, schedule of bolts and nuts and as built
drawings. All drawing work shall be in metric system and all writing work shall be in English.
The work shall be carried out as described in General Technical Specifications for s sstructural
works.
18.6.2 Material of Construction
18.6.2.1All steel and other materials used for steelwork and in association with steelwork shall
conform to appropriate Indian standards. Only tested materials shall be used unless written
authority is obtained for the use of untested materials for certain secondary structural
members.
Unless otherwise specified in the drawings
i. All rolled sections and plates upto 20 mm thk. Shall conform to Grade Grade-E250 & quality
A of IS: 2062-2006 2006 and shall generally be of tested quality.
ii. Plates above 20 mm thk. and plated structures subjected to dynamic loading shall
conform to Grade Grade-E 250 & quality B as per IS: 2062-2006.
iii. For High Tensile steel requirements, material conforming to IS: 8500 or SAIL SAIL- MA
(HYA or HYB) shall be used.
18.6.2.2 Steel sheets shall conform to IS: 1079.
18.6.2.3 Steel tubes for structural purpose shall conform to IS: 1161 (of Grade Yst 240)
18.6.2.4 Corrugated Galvanised Sheets shall conform to IS: 277 with appropriate Zinc coating for
the selected thickness of sheet on roof and sides. (1.0mm thk for roof and 0.8mm thk for
sides)
18.6.2.5 Aluminium industrial troughed sheets conforming to IS: 1254 shall be used as follows:
i) On roof - 0.91mm thick ii) On side walls - 0.71mm thick
18.6.2.6 Translucent sheets shall be fibre glass reinforced polyester sheets of matching profile as
per IS: 12866.
18.6.2.7 Colour coated sheets shall be as per appropriate standard.
18.6.2.8 Gutters shall be of copper bearing steel conforming to Grade "A" as per IS:2062.
18.6.2.9 Rails shall conform to IS: 3443.
18.6.2.10 All black bolts, nuts and locknuts shall conform to IS: 1363 and IS: 1364 (for precision and
semi precision hexagonal bolts) of property class 6.4unless otherwise specified. Washers
shall conform to IS: 6610
Technical Specification:Sec-4,System System Parameters, Operation & Control Philosophy
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