a machine for the mechanized flow assembly of railroad track units. Such machines assemble units of track equal in length to the standard length of rails (in the USSR, 12.5 and 25 m).
A track-assembly machine consists of a tie feeder, a drilling machine (when wooden ties are used), a chain conveyor, an assembly stand, and carts for receiving completed units. The tie feeder delivers ties to the conveyor, from which they go to the drilling machine, which drills holes for the spikes and treats the holes with a wood preservative. The ties then pass onto the chain conveyor, on which the backing material is laid out, the rails are laid, and spikes are set into the holes. The spikes are pressed into place on each tie in an assembly machine, and the completed units are stacked on carts in packets of three to four units each. In semiautomatic track-assembly machines, the backing material is laid out and the spikes are inserted manually. There are also fully automatic machines. The output of automatic machines is 0.2 km/hr; that of semiautomatic machines, 0.5 km of rail-and-tie sections per eight-hour shift. Track-assembly machines are being developed (1971) for assembling units on reinforced-concrete ties.