OO-C-2763 Cranes, Hydraulic, Carrier Mounted \(S/S By A-A-59218\)

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00-C-2763

3.10 Crane. The crane assembly, designed for the carrier mounting, shall

consist of a fully revolving superstructure with boom support, hydraulically

operated telescoping type boom, main and auxiliary winches with wire rope, hook

block, cab, controls, and necessary accessories.

" 3.10.1

Superst ructure. The superstructure shall be mounted on the carrier

and shall

be designed to withstand the forces caused by lifting, swinging, and

with the safe loads. The superstructure shall_provide stable

traveling

retention

of the boom in all positions and, with its base, shall rotate on ball

or roller

bearings of sufficient number, size, and capacity to support working

loads.

3.10.2 Boom. The boom shall be of alloy steel and of the hydraulically

operated telescoping type, consisting of a base section and sliding section(s).

The boom shall be capable of elevation from the horizontal to a vertical angle

of not less than 72 degrees. A digital or dial type boom angle indicator shall

be furnished, An anti two-block device with audio-visual warning and function

lockout shall be installed to prevent the hook block from contacting the boom

tip.

3.10.2.1 Boom drift. Boom drift, the vertical dropping of the boom due to

inadvertent retraction of the boom hoist and/or boom extension cylinders, shall

be kept to a minimum. Drift shall take place in gradual, imperceptible steps or

degrees. The crane load, under all operating conditions, shall not drop in a

sharp or sudden manner at any time during crane operation.

3.10.3 Boom jib. A self-storing boom jib or swing away boom extension shall

be provided. Length of the boom jib or extension shall be as specified (see

6.1). Boom Jib shall be provided with the necessary risers, overhaul ball with

swivel hook, and ropes. Boom jibs shall be readily attachable to the tip of

boom with the capability of withstanding the maximum jib load without

malfunctions.

3.10.4 Hook block. The rated capacity of the crane hook block shall be not

less than the rated capacity of the crane for witch it is furnished. The hook

shall be of the forged steel, swivel type with an ultimate breaking strength at

least four times the maximum rated capacity of the crane and shall include a

safety latch. The block assembly shall have adequate weight to insure payout of

the hook in any position. The hook block shall permit disassembly for visual

and nondestructive testing. The hook shall not be painted.

3.10.5 Rope. Load hoist ropes shall be improved plow steel, IWRC,

independent wire rope center, with a safety factor of not less than 3.5, The

main and auxiliary winches shall be furnished with the manufacturer's standard

length rope. The contractor shall provide a signed certification with each

crane identifying the crane serial number, wire rope manufacturer, type of wire

rope construction, type of wire rope material, and the minimum breaking strength

of the wire rope provided. .

3.10.6 Sheaves. Sheaves shall have a pitch diameter at least 18 times the

rope diameter. The hook block pitch diameter shall be at least 16 times the

rope diameter. Sheaves shall be adequately guarded to prevent the wire rope

from leaving the sheave during operation. All sheaves shall be smooth and the