1. Usual processes

All welding workshops include :

• supply by rail;

• truck feeding ;

• a waiting storage area ;

• a display area where the rails, side by side, are parallel to the weld line;

• the welder line comprising the welder, a cooling length, a horizontal and a vertical straightener assisted by a laser measurer, and a mushroom finishing grinder.

There are several types of welders:

• fixed AC welding machines (power of the order of 150 kW), which are now disappearing, with the exception of mobile welding machines designed to work on tracks, used in the USA and Russia, but whose joint straightness qualities are unsatisfactory;

• ...