Skip to main content

I have a post war 3451 log dump car.   As I understand it, activation of the sliding shoes activates the 'dump' action but it also activates the coil uncoupler. The obvious question is WHY?  Is this just an idiotic design or was there a rational reason why?  And can I modify/disable the coil uncoupler, even permanently without losing the functionality of the 'dump'? I could look for a wire to snip but if these functions are in series that will not work.  The critical wiring to see and determine this is hidden in the under-carriage...   There is a closed topic on this in this forum but the question is not answered.


Original Post

Replies sorted oldest to newest

You are making a very good observation.

Actually, only one coupler opens when the car is unloaded. "Uncouple" fires both couplers.

This is a carry-over of the prewar versions that operated the same way and were identical electrically.  The big difference is that the prewar couplers "re-closed" when the unload button was released... as they were operated(closed) by gravity. The train stayed together.

Which leads up to the early postwar development and eventual 1948 beginning of the roll-out of the magnetic coupler system still used today. The new system had to be completely compatible / reverse-compatible electrically with those prewar operating cars and all knuckle-couplered cars that had been built since 1945.

Last edited by ADCX Rob

Disconnecting the coupler will not be easy. The power to the coupler is through a brass spring that also applies the spring force to the sliding shoe. The magnet wire from the coupler coil is wrapped around a hole in a hard fiber board that the spring also snaps into.   The magnet wire from the coupler could be cut, but the might not leave enough wire to ever restore it. 

A reasonable modification to correct this issue would be to change the electromagnetic coupler trucks to magnetic tab coupler trucks.   The type TC trucks could be changed to the 482 trucks. Or just the bottom plate could be changed to the 482-3.  A lot of these 482-3 bottom plates are around as this was a common modification. 

This modification would essentially converted the 3451 log car to a 3461 log car. 

Add Reply

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
Link copied to your clipboard.