The rail heater car is a machine that uses LPG, propane gas to fire heaters that heat up the rail in order to relieve it from stresses. It is a three piece machine with the front portion used to heat the bold of the rail. The middle of the machine holds a propane fuel tank and supplies, and the rear section is used to heat the web of the rail on both sides. Rail temperature must be 90 degrees Farenheit when it is laid.  Before it can be permanently set to the ties, it must be heated to the proper temperature.  The rail heater travels slowly along the rail, using the heater units above and along the side of the rail head.  A special rail temperature guage is used to measure rail temperture, to determine now much of the rail length will need to be heated.

The rail heater unit is used to stress and de-stress section sof tracks which have been used for long periods of time. When the track has been fastened and is exposed to both hot and cold temperatures, the rail stresses over time.