A friend asked me how long the railroads have been using propane tanks to heat the switches at interlockings? I did not even want to guess, I do know I have seen photos during the Penn Central era, with the tanks at the interlockings, but I am not sure if they been around longer or not.
Without knowing the correct answer…once propane fired switch heaters were invented…which I would guess to be the late 40’s once the cariers started to try to save by eliminating manpower.
Circa 1950 at one Class 1 I’ve worked for.
RWM
Yeah, I think propane really took off after WWII although developed much earlier. While they were not as labor intensive as the kerosene pots or having men shoveling and sweeping constantly, it was also both a cheaper and more effective fuel. They could be turned on by remote control from stations, towers, and dispatchers’ offices quicker than calling a man or crew, organizing, and sending them out; they could also be thermostatically controlled, too, of course. Their pipe design clipped to the any given length of rail or switch allowed for a more even heat, too.
BNSF has them at about every location around here with a switch. [South Central Kansas]