. Railway track and track work . ons. The crane has a radius of 14 to 20 ft.,and is designed to hoist 25 tons at 16 ft. radius, either in front or at theside, outrigger supports being used in the latter case. The. powerful- 30 to40-ton derrick or steam crane is a most economical wrecking tool, al-though some few roads do all the work by lines and jacks, smashing upfreight cars if necessary in order to clear the track, and using small der-rick cars only for picking up the wreckage and freight. This, however, isnot a commendable practice. Derrick cars may be fitted with hoisting en-gines, as in
. Railway track and track work . ons. The crane has a radius of 14 to 20 ft.,and is designed to hoist 25 tons at 16 ft. radius, either in front or at theside, outrigger supports being used in the latter case. The. powerful- 30 to40-ton derrick or steam crane is a most economical wrecking tool, al-though some few roads do all the work by lines and jacks, smashing upfreight cars if necessary in order to clear the track, and using small der-rick cars only for picking up the wreckage and freight. This, however, isnot a commendable practice. Derrick cars may be fitted with hoisting en-gines, as in Fig. 222, or may have the hauling rope attached to a locomotive,the former being the better plan as a rule. The Chicago, Burlington &Quincy Ry. uses a heavy 40-ft. derrick car having two masts, one operatedas a derrick by hand gear, and the other having the rope led down throughthe floor and between the sills to the rear of the car, the end of the ropehaving a shackle by which it can be attached to a locomotive. Hoisting can. Fig. 222.—Wrecking Car. be done much more effectively by a wrecking crane than by a rope attachedtc a locomotive. All parts of the derrick and machinery should be designed with a highfactor of safety, to withstand the impact due to sudden heavy shocks. Thehoisting tackle should be of chain or wire rope for very heavy weights,and the best quality of pure manila rope for lighter weights. Only ironor steel tackle blocks should be used in lifting. A spring shock-arrestermay be attached to the lower tackle block, consisting of a cylindrical casecontaining a heavy coiled spring carrying the hook bolt to which the loadis attached. Steam wrecking machines should have sills of plate girders,I-beams or channels, sufficiently deep to give vertical stiffness, and wellbraced laterally. The frame for the machinery should be of heavy iron orof steel, with the bearings for the movable parts formed in them. Thepower should consist of at least one pair of reversible engin
Size: 2417px × 1034px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
