Protype Spacing on FT EMD "B" Units

[willrupe]

Is there any easy to get realistic spacing between EMD FT A & B units. My stock factory models have this glaring discrepancy assaulting my eyeballs everytime I look at them. I am willing to make drawbars for them if neccessary. Also while I am on this subject I was wondering if an ultra short shank coupler is available to mount at the nose end of an A unit. I feel that the coupler trip pin should just barely clear the pilot of the locomotive. Mine appear to be about 1/8th of an inch too long. I have put the shortest shank couplers I have on my GE 70 tonner and have not experienced any problems on my club layout after making this change. All comments appreciated. Yours, William Rupert

[rogertra]

IIRC, it should be three feet.  You may have to change couplers to achieve a scale three feet between the units.

[Atlantic Central]

William,

Most of the original prototype FT's where drawbar coupled in A-B sets. If you notice, one end of the B unit is shorter in relation to the trucks than the other. This is the end that was toward the A unit. When the railroads decided they wanted couplers, this required special couplers and draft gear to be constructed for that end of the B units and the back of the A units.

Also you will notice that unlike later F3 - F9's, most FT's do not have stirups or grab irons at the these short ends where they where drawbar connected. All later F's have them at both ends.

The drawbar connection used a single diaphragm between the units and resulted in a spacing of about 20" measured at the car body corners. The back to back coupling of the "coupler" end of two B units (as in an A-B-B-A set) resulted in the typical F unit spacing of slighly less than 3 feet. So in an A-B-B-A set the spacing was about 3' between the two B units but only about 20" between the A-B sets.

When the drawbars where replaced by couplers, that spacing did increase to 32"-36" and in many cases the diaphragms where simply eliminated.

Replacing or remounting the couplers will get you close to these spacings depending on the brand of your units. Drawbars are the only way to get the original close look of the FT A-B. Kadee makes several short shank couplers which should work.

As a side note, GM built a few special short B uints without the rear coupler overhang for drawbar coupled A-B-A sets. No manufacturer has produced models of these to my knowledge (except maybe in brass).

All later F units are 2'-6" longer and have a different truck spacing/possitioning than the FT to allow for better draft gear/coupler mounting because GM learned quickly the railroads where not going to want drawbar coupled units.

Hope this helps.

Sheldon