About a million dollars' worth of equipment is being used to produce the 78 foot and 1,340 foot lengths of welded rail that are a major part of CP Rail's long-term program of upgrading railway plant, equipment, and operations.

In three bright green railway cars, a 30 man crew of CP Rail technicians has been turning out welded rail since the beginning of the year, first in Winnipeg (initially under the guidance of a team from the Railway Automated Machinery Company) and since mid-September at Smiths Falls, Ontario.

The welding process is actually a forging of the two rail ends with complete intermingling of material from each side, so that when joining is complete the two pieces are atomically bonded. Thus the weld is as strong as the parent metal.

Rail is cleaned and polished - Date unknown Nicholas Morant.

As the rails enter the first railway car they are cleaned and polished to remove any foreign matter that may have been left on at the mill. This cleaning assures absolute contact on welding. The two rail ends are clamped and aligned and copper electrodes are placed in contact with each rail as close as possible to the end to be welded, keeping heat penetration into the body of the rail to a minimum. Contact of the two rail ends creates a short circuit that induces resistance heating and the complete pre-heating cycle brings the rail ends to a plastic, molten state at which point forging takes place. Great pressure squeezes any foreign matter and gases and surplus molten metal from the weld joint. This is known as the "final flash" and the excess metal can be seen oozing out of the joint like toothpaste emerging from a crack in the middle of the tube.

A magnetic particle inspection - Date unknown Nicholas Morant.

After the weld has cooled from a plastic 2,200 degrees to 1,600 degrees, the metal has sufficient strength to be unclamped and moved. While still warm the burr is removed by a shearing machine and then ground smooth before undergoing a magnetic particle inspection test. This device creates a magnetic flux or flow between two coils, with the lines of force flowing parallel to the rail. Surface imperfections show up outlined by the iron particles much as a log sticking out of a river is outlined by ripples in the water. So precise must be the alignment for the welding process that rail camber can be no more than 30/1000 of an inch per foot or the rail will be rejected and must be re-welded.

It's a complex process at the outset, but one which pays big dividends in terms of fewer joints, less rail wear, longer tie life, and reduced wear and tear on trucks, wheels, and axles. The lifetime of continuous welded rail is almost double that of standard-length rail, 100-pound rail laid on the Delaware & Hudson Railroad in 1933 was still reported in use three years ago.

As C.E. Colpitts, chief engineer puts it, "We might not notice a great difference over the next two or three years, but we're looking to the next 15 or 20 years. Continuous welded rail is a long-term investment."