Souschef's switch engine project

[Souschef]

I imagine you have other diesels with similar battery requirements, and that you don't run them all at the same time? If so, would some sort of wheeled battery cart work out, to share these batteries across a couple machines?

Or are you too much of a purist for that?
-ERD50

Dear ERD 50, This is the only working? diesel engine that we have. Your suggestion is valid if we had more than one, but sadly, that is not the case.
We are a very small railroad society, and do not have the many engines that places like the Pacific Railway museum does. If this one had not been donated to us, we would not have any.

 

[ERD50]

Dear ERD 50, This is the only working? diesel engine that we have. Your suggestion is valid if we had more than one, but sadly, that is not the case.
We are a very small railroad society, and do not have the many engines that places like the Pacific Railway museum does. If this one had not been donated to us, we would not have any.

Only other thing I can think of, and probably just not worth messing with, would be a group of five 6 V batteries, which might be more common and cheaper. But that's 30 V in a 32 V system, so electrical changes would probably be required (maybe just a tweak of the regulator to avoid overcharging the batteries), but I don't know your physical constraints, plus I imagine you want it to be historically accurate as well. That rules out a parallel/series combination of about 16,000 AA cells!

-ERD50

 

[Souschef]

Today I took the starter and solenoid to a repair shop to get overhauled.
This is what they looked like when we got the locomotive.
The plan is to reinstall and try turning the engine over without the injectors so there is no compression.

 

[Bamaman]

Is the locomotive run by a generator hooked up to the diesel engine? If so, how are the electric motors, wiring, etc.?

 

[Souschef]

Is the locomotive run by a generator hooked up to the diesel engine? If so, how are the electric motors, wiring, etc.?

Yes,
The diesel engine drives a generator. The generator feeds the traction motor mounted between the wheels.
I have a complete electrical diagram so I can see how everything is connected.

 

[OldShooter]

... I also bought a roll of Military grade aircraft wire to aid in rewiring the engine. ...

Make sure you understand what you have. There is no such thing as "military grade." The military has various specifications for various purposes. I have some mil-spec wire here that I used for wiring race car electrics; IIRC is it PVC with a clear nylon overjacket. No real resistance to heat IOW. Teflon is nice stuff, very heat resistant, but you have to be careful not to bend it around sharp corners because it has a tendency to cold flow under pressure. For more heat resistance, there are mil-specs that have a fibrous (probably nomex, kevlar, or another aramid) jacket. Finally, ordinary THHN stranded house wire from Home Depot might be an inexpensive choice. Short version: Try your "military grade" wire with a match & if possible look up the MIL-xxx specification to see what you have.

More than you wanted to know, probably.

 

[Souschef]

Dear Old Shooter,
Thank you very much for the information. I am going to use the same aircraft grade wire that I used on a 1947 Stinson aircraft. I had to totally rewire the plane, as it was a mess.

 

[Souschef]

Just picked up the starter. It was completely overhauled. I have posted after and before pictures

 

[Walt34]

Wow, at least going by appearances whoever did the rebuild did a great job!

 

[ERD50]

Wow, at least going by appearances whoever did the rebuild did a great job!

+1 And one day turnaround!? Wow!

Maybe the re-builder is a rail fan?

-ERD50

 

[MikeD]

re: the last picture, is that skinny little wire replacing that big fat wire?

Mike D.

 

[Souschef]

re: the last picture, is that skinny little wire replacing that big fat wire?

Mike D.

No Mike,
The skinny wire is a ground connector to the starter solenoid. The big honking wires are still on the engine. If you look at the bottom right of the before picture you can see the old skinny wire connected to the stud on the starter.

 

[Souschef]

Just received a new air brake pressure meter. The scale is a little different, but that does not matter

 

[Souschef]

The main problem with this engine is the cracks on both sides of the bell housing. Apparently the cast iron bell housing was used as the rear support for the engine, which is not a good idea.
Today we put a floor jack under the rear of the engine, and sure enough, the cracks got a little smaller
We then loosened the 12 nuts holding the bell housing to the generator. You can see 2 of the studs in the picture. We then jacked the bell housing up more, and the c racks closed even more.
We are going to fabricate a brace for the rear of the engine to take the stress off the bell housing.

 

[aja8888]

The main problem with this engine is the cracks on both sides of the bell housing. Apparently the cast iron bell housing was used as the rear support for the engine, which is not a good idea.
Today we put a floor jack under the rear of the engine, and sure enough, the cracks got a little smaller
We then loosened the 12 nuts holding the bell housing to the generator. You can see 2 of the studs in the picture. We then jacked the bell housing up more, and the c racks closed even more.
We are going to fabricate a brace for the rear of the engine to take the stress off the bell housing.

Sounds like a plan.

 

[CoolRich59]

Apparently the cast iron bell housing was used as the rear support for the engine, which is not a good idea..

Probably a dumb question, but the reason being the weight of the housing?

 

[Souschef]

Probably a dumb question, but the reason being the weight of the housing?

It was not a good design. The only supports for the engine/ generator combination were a front engine support and the generator mounting.
As you can see from the photo. the rear of the engine is mounted to the bell housing which is bolted to the generator.

 

[38Chevy454]

A mid mount is a good idea. Unless you can find a replacement bellhousing, welding that one up is very difficult being cast iron.

 

[Souschef]

A mid mount is a good idea. Unless you can find a replacement bellhousing, welding that one up is very difficult being cast iron.

You are correct. I found a place called Lock n Stitch that has special bolts to fix cracks. Otherwise you have to furnace braze the unit.

 

[painterbill]

It is possible to arc weld cast iron, I had a tractor that I broke/cracked the bell housing on using a 3pt backhoe without a subframe. A friend who owned a welding shop brought his truck out to the farm and welded the bell housing, never had a bit of problem with it. He was a very good welder with about 50 years experience around big equipment. He welded it in place so that I only seperated the engine from the transmission a few inches to allow him a little room. You could always try the bolts first then if they fail try welding.

 

[38Chevy454]

You are correct. I found a place called Lock n Stitch that has special bolts to fix cracks. Otherwise you have to furnace braze the unit.

Those cracks are likely fatigue cracks, and have substantial corrosion. Corrosion will prevent a good braze.

Welding is tough because of the high carbon content of cast iron. I am a metallurgical engineer by degree. I won’t get too technical, but the basic problem welding is forming carbides along the fusion line which leads to cracks. Carbides are brittle and low ductility, which is bad when you have shrinkage stresses during solidification of the weld metal. The usual tricks are ductile filler metal and lots of preheat and slow cooling/post heat to try to minimize the fusion line cracks.

 

[Souschef]

Those cracks are likely fatigue cracks, and have substantial corrosion. Corrosion will prevent a good braze.

Welding is tough because of the high carbon content of cast iron. I am a metallurgical engineer by degree. I won’t get too technical, but the basic problem welding is forming carbides along the fusion line which leads to cracks. Carbides are brittle and low ductility, which is bad when you have shrinkage stresses during solidification of the weld metal. The usual tricks are ductile filler metal and lots of preheat and slow cooling/post heat to try to minimize the fusion line cracks.

I appreciate your comments. I got a Power Point presentation from Lock n Stitch saying the same thing. I believe that either their special method, or furnace brazing of the entire bell housing is the only way to repair the unit.
The alternative is to luck out and find a replacement bell housing somewhere.

 

[painterbill]

Given that the switch engine is 70+ years old (44 yo engine replacement) and most of the extreme stresses have already been placed on the bell housing and only fatigue cracks are appearing is encouraging. Its new life will be at minimal stress comparably in not moving heavy loads shift after shift. While I was not recommending brazing, which would probably work to bridge the minimal stresses it will see in its new role and finding a replacement housing would be the most preferable, welding or drilling and bolting would more than suffice . Worse case scenario would be that it cracks completely, with the amount of beef and number on mounting bolts in the housing it would more than likely still be operational especially if you could fabricate a mid mount to help relieve stresses.

Link to Lincoln Welding site referencing cast iron welding:

Guidelines for Welding Cast Iron

 

[Lakewood90712]

You might check with an industrial motor rewind shop for ideas on the cracked generator housing.

 

[Souschef]

You might check with an industrial motor rewind shop for ideas on the cracked generator housing.

Thank you for your suggestion, I do appreciate it. However, the bell housing is a separate part from the generator.