SP Repeater Car

[ndbprr]

About twenty years ago I used to travel to the San Francisco area quite regularly and on several occasions saw an SP 40' box car at the Oakland station that had Repeater Car written on it. It gave every apperance of being some kind of company car rather than for general freight as there was no stenciling on it that would be on a typical box car. I sent a picture to Trains and they returned it with the comment, We have no idea what it is". any SP people out there that could clear this up? Thanks

[Anonymous]

I'm no SP person, but I do know what it is. A repeater car was used to pump more air into the train line brake system for long trains. It would be put in the middle of a long train (I'm pretty sure, it might have been end). Since the SP had plenty of grades, they would need multiple brake applications and releases, often times exceeding the capacity of the locomotives' pumps and reservoirs. Hence, the repeater car, that aided in regenerating the air pressure. No idea how they worked, though.

[ndbprr]

So in all probablity there was an air compressor inside the car? I'll have to pull the slide when I can because there are no external fuel tanks of any kind. Wonder if it could possibly have been just a big resevoir so the pressure wouldn't bleed down? I thought it might have had something to do with signals but there were no wires or antennas either.