Running Diesels in Tandem

[johnd]

Question for "Real Railroad" people. The ones that sing "I've been Working on the Railroad" in the shower.

When railroads ran diesels in tandem, was there a rule of thumb if they ran one of the A units in reverse?  Looked up pictures on the Internet and they show the trailing A unit facing in either direction.

[ebtnut]

Back in the beginning of diesel-dom, the railroads usually kept their units in sets, like A-A, A-B-A, etc. with the trailing unit facing rearward.  That way, the set didn't have to be turned for a return trip.  Later, as moved more towards matching the horsepower needed to the train weight, they got away from keeping the matched sets, mixing and matching as needed.  The units didn't care--they run equally well in either direction.

[johnd]

Thank you ebnut. I thought I might have to rewire one of my A units to run in reverse!

[JerryB]

You don't have to rewire anything to get powered units to run the same direction regardless of the way they face. Properly wired D.C. powered models will always run in the same direction, whether turned with the cab toward the front or back.

You can prove this by setting the direction switch so the unit runs forward. Stop the unit and turn it around without changing the direction switch. Turn the power up, and the unit will continue in the same direction.

This means you can mix which direction the units face, just like the real thing.

Happy RRing,

Jerry

[johnd]

Thanks Jerry. Stupid me did one of those ASSume things.