We are trying to trouble shoot our 1953 GE center cab 80 ton... It was used at the Nevada Test site after Navy service where it had a strange MU capable control stand installed, which has since been replaced with a more original control stand out of a GE 70 ton locomotive.

Since its arrival it refuses to go into transition. Its a great reliable locomotive, but won't go over 6 or 8 mph...

We have a wiring diagram, which shows the circuits for series and parallel, but it is not clear what would trigger the transition. There are lots of thoughts on what may have been disconnected by the test site to control top speed. The two leading theories are that the new(est) control stand is missing the circuit to trigger transition, or that there is a circuit to the generators that is missing...

Suggestions on what to look for are welcome.

Randy

Randy,
Do you have an electrical schematic for the locomotive that you can post here?
Mike Tillger

There just happens to be a(nother?) GE 80-tonner being rebuilt at McHugh Bros. in Pa. right now. Any chance they can help?

Here is the 1987 reference manual (in PDF format) for the military 80-ton:

http://militarynewbie.com/wp-content/uploads/2013/11/US-Army-Operator-and-Unit-Maintenance-Manual-Locomotive-Model-B-B-160-and-160-4GE747-A1-TM-55-2210-224-12.pdf

Note schematics 1-12 and 1-14, etc.

I have an amusing story to relate in this context. When I was a sophomore in college, I had a '62 Thunderbird with the 390FE and Cruise-O-Matic transmission. One of my roommates had a smaller Ford of similar vintage with the Ford-O-Matic, and he came to me for technical advice one night. "I can't get the transmission to shift right. I went out on Rt. I and took it up over 80mph and couldn't feel it shift into 3rd no matter what I did..."

I told him "if you ever feel that transmission shift into third, go straight to the Vatican and get yourself submitted for canonization."

A Ford-O-Matic doesn't HAVE a third gear. Likewise, according to that manual, the traction motors on an Army military 80-tonner are permanently wired in parallel. There is no series-parallel transition.

That, of course, does not explain why your achievable speed is so low. My initial speculation -- and it is only that -- is that you have very high gear ratio in your motors -- I think they are double-reduction already. If railroad speeds on base are restricted for the same reason vehicle traffic speeds are ... the lack of top speed might be intentional.

This is very helpful. We have a wiring diagram, which was given to us by the test site, and is very different (I will get it scanned). It shows series and parallel relays. Ours was a Nnavy unit, and there are differences from those purchased by the Army

Ours doesn't seem to have low gearing... it doesn't jump the way you would expect if geared that low.

We have a military manual for the locomotive from the 1950's... again a very different document. It includes a page on how to destroy or disable the unit if you fear it might fall into enemy hands... and cautions you to get far away if using heavy weapons to avoid flying debris... I doubt we will ever need the information on that page.

The question came up because we may want to use the locomotive for weekend trains. Currently our GP-30 is in the shop being painted, our NW-2 is down with a grounded traction motor (replacement on the way) leaving or FM as our primary power... FM's are known for running hot, and its been over 110 the last three days with the trend expected to continue. At 8 mph the GE is slow but not so slow we can't or don't use it.

Randy

I wonder if you could rig up something like environmental misting, with a few gallons of water, a pump, and some spray nozzles -- there's tons of room in the radiator section, right? When it's hot, assist airflow through the radiators with a little spray of water on them. Worked very efficiently for steam-turbine locomotive condensers when 'nothing else would do'...

From my memory, GE critters make transition based on voltage, typically there will be a relay coil V1 or VT connected to main generator + with an adjustable resistor. Perhaps someone disconnected the wire leading to the coil or the resistor may be burnt open or even its adjustable contact may be oxidized not allowing current to flow.
Mike Tillger

I operate two 1950's GE 80 center cabs. They were built to the same specs as the Army center cabs. Not sure about the Navy, I know the main difference was the Navy engines were not MU capable.

My locomotives will transition at about 18mph. I can feel it kick in and hear the relays going. It is controlled by two solid state computer boards. I believe it works like Mike said, sensing the voltage. I still think you could get better than 8mph without transition, regardless if something was bad or disconnected. I can go pull the cards in mine and see how fast she will go...

I know the top speed for mine is listed as 45mph, and I have gone 40 with little effort. (my line is very well maintained 115lb rail)

I would poke around as others have said and see what your wiring looks like, clean contacts, etc. If there is a resistor in the circuit it could have failed.

From what I can see, all of them were built in the '50s but many were upgraded, with an electronic transition unit (black box with cards), and MU capability, it sounds like his perhaps was one of those but later got reverted back to a more primitive state.

How many relays, control units, etc are in the cabinets?

I recently was moonlighting on a 25 ton switcher for an industrial customer, I found the unit had been reverted to 'extra basic' mode. It had a H-600 cummins out of a truck, so it used the truck compressor, and they had used a standard auto/truck style starter. They had just one working contactor left in the cabinet, just a closing contactor. One speed all the way now!

Being that his is a 80 ton with mirror image ends, it sounds like someone did something to cause this. I would expect only one end to fail at a time normally.

Dear Randy:
Valley railroad operates three GE 80 tonners (1 navy, 1 USAF, and 1 GE plant switcher) all 45MPH models.
One of our guys who is good with CAD did a series (no pun intended) of wiring diagrams which shows the positions of each contactor, etc. in each "state" (controller off, series, parallel, etc.) As I recall, there are 6 drawings.
We would be pleased to make you a set of copies (at cost).
Please advise...
J.David

Looking at the drawing, your field shunting contactors (FS1, FS2, etc.) may not be picking up. When closed, these contactors would provide a higher speed.

Gord M.

Looking at the diagram it occurs to me that a failure/premature activation of the wheel slip system might severely chop the available speed.

Make sure the prime movers are making rated RPM (the documents say 2100 RPM)

Also high up on the list, make sure that the main gens are making rated voltage.

Randy
We obtained a trouble shooting guide for GE 65 -144 Ton Electrical TS Manual.pdf but it is a 97mb file. We got it through drop box.
How could that be posted on this thread and the 44 tonner thread?
Thanks

You can:

1. Make sure the permission settings on Dropbox allow the file to be publicly read.

and

2. Post a reply with the link directly to the Dropbox file.