bids are invited for boq total quantity : 1--ladder, aluminium self supporting folding, height 6feet, made from high tensile aluminium alloy non-slip corrugated steps with aluminium firm rigid and chequered plateform on top with four legs and rubber shoes enabling one person to handle. side channel section 2-5 / 8 inches x 1-1 / 4inches, one side steps and on other side rungs 1in dia non-slip corrugated tubing, at 12inch centre fitted, aluminium alloy used for channels section / pipes / tubes / rounds / steps for manufacturing ladder shall confirm to is 733 / 1983 & 1285 / 2002, tolerance of + / ( - ) 3 inch allowed on overall length and width of ladder., collapsible aluminium ladder, open height 10feet, collapsible height 11feet 2inches with side channel section 1-3 / 4 inch x 1 inch or 44.4mm x 25.4 mm and rungs 1 inch dia or 25.4 mm x 16g alloy non slip corrugated tubing at 12inch or 304 mm apart centre to centre and with rubber shoes, overall width in open position 12-1 / 4 inch and width in closed position 1-3 / 4 inch x 2 inch approx. , minimum two nos. locking devices at suitable places to be provided for safe transport of ladder during working in closed position, aluminium alloy used for channels section / pipes / tubes / rounds for manufacturing ladder shall confirm to is 733 / 1983 & 1285 / 2002, tolerance of + / ( - ) 3 inch shall be allowed on overall length and + / ( - ) 1 inch on overall width of ladder., aluminium single ladder made with high tensile aluminium c-section channel size 2-5 / 8inch ( 66.7mm ) x 1-1 / 4 inch ( 31.75mm ) x 3mm thick; having non slip corrugated tubing / rung of 1inch ( 25.4mm ) dia with centre to centre distance of 10 to 12 inches between two rungs & centre width of 14inch ( 0.35mtr. ) , non-skidding thick rubber shoes and caps shall be provided in the ladder, height: 12 feet ( 3.65mtr ) ( + / - 04 inch ) aluminium alloy used for channels section / pipes / tubes / rounds for manufacturing ladder shall confirm to is 733 / 1983 & 1285 / 1975, tolerance of + / ( - ) 01 inch shall be allowed on overall width of ladder.