Engineering Wonders of the World
Volume I

RAILWAY SNOW-PLOUGHS. 243 KOTARY WITHOUT HOUSING, SHOWING BOILER AND MACHINERY. placed in front of the leading wheels, consist of two parts—the wing, to clear the top of the rail ; and the cutter, to make a path for the flanges of the track - wheels. The flangers, mounted behind the front bogies, are scoop-shaped, and clear the angles which the circular cutter-wheel cannot reach. These accessories are raised and lowered by com- pressed air or steam. The body of the plough is covered by a spacious cab, containing a compart- ment in front of the boiler for the pilot, and another at the rear for the engineer. The plough is moved by one or more powerful locomotives, according to tho physical conditions. When leaving for the scene of action the pilot sees that the flangers are raised, and has the wheel started. Fifty feet from the drift he drops the flangers, and signals to the rotary engineer to increase the speed of the cutter to about 150 revolutions per minute ; and just before the bank is struck he orders the locomotive driver to quicken up. If he finds that the rotary cannot stand the full power of the pusher, he signals to that effect. Should the feed prove too great, he ap- plies the air brakes ; and if this does not suffice, has the pusher slowed. The cutter is slowed when the drift has been almost penetrated, and is brought to normal speed as soon as out of the bank. In an exceptionally deep drift it may be necessary to shovel off the top snow down to the level of the hood, and to back the rotary out to clear the scoops. The first rotary ever built was used on the Union Pacific Railway in 1887 to raise block- ades which had baffled the staff for weeks. In February of that year the plough ran more than 3,000 miles, and forced its way through snow fifteen feet deep in places. Its success and economical working led to a number of similar machines being commissioned. Next winter they attacked the snow at many points. One of the most noteworthy feats they accomplished was the clearing of the Northern Pacific track in the Cascade Moun- tains. The road had been blocked com- pletely for nine days previously to the arrival of the rotary ; and the difficulties to be over- come were further increased by the temporary IN THE TRACK OF THE ROTARY.