Engineering Wonders of the World
Volume I

THE PANAMA CANAL. 147 Many of the steel “ spoil cars ” have been designed specially for work on the Canal, and have a capacity of from 25 to 40 tons each. After being loaded, the cars are hauled to one of the principal yards and there made up into trains, or are taken direct to one or other of the dumping grounds. Of the last there are now in use about fifteen, with a total capacity in less than ten minutes. As a single un- loader can dispose of sixteen trainloads, or 5,000 cubic yards of spoil in eight hours, ten unloaders, handled by forty white men and sixty firemen and labourers, can deal easily with a normal day’s output. Assuming that a man with a shovel would unload 15 cubic yards in eight hours, there would have been A “ TRACK THROWER ” SHIFTING RAILS SIDEWAYS AT TAVERNILLA DUMP. In eight hours this machine, handled by nine men, can move over 5,000 feet of track 9 feet laterally. With hand labour 600 men would have been needed to execute the same work. of 50,000,000 cubic yards, the largest being that of Tavernilla, about ten miles from the centre of the cutting, able to deal with 15,000,000 cubic yards. Much time and labour are now saved in unloading the spoil and spreading the dumps by the use of mechanical appliances. On a flat car behind the locomotive used for haul- ing the train of cars to the dump is placed a strong steam-winch, which winds in a cable attached to a plough in the last car. This plough travels over the intervening cars, pushes the earth and rock over the side nearer the dump, and so unloads a train of twenty cars required under the old methods, for the same job, no fewer than 4,080 labourers and, pos- sibly, 100 white overseers ’ To avoid the delay that would be caused by throwing the track to the edge of the dump after each trainload of spoil has been unloaded, mechanical spreaders are used to push the material some distance from the track, and so make room for another deposit. This work can be done usually by eight machines handled by forty-two men in about one-fifteenth of th© time that would be required were hand labour Mechanical Spreaders and Track» throwers.