Pipelaying machinery in North America is dominated by tracked vehicles manufactured by Caterpillar. Allied is the only winch manufacturer able to supply rear-mounted towing winches for Cat 572R, PL83 and PL87 pipelayers. Allied is the only winch manufacturer to engineer a towing winch for the PL61 pipelayer. Allied is the only manufacturer able to offer a choice of PTO and hydraulic winch on tractors from D7R to D10T. The PTO winch offers the distinct advantage of not overheating the tractor hydraulic system when making long pulls on steep slopes.