C-415

[Herr Spreng]

The C-415 was said to be the result of 'market research' or perhaps more accurately,a survey of railroad mechanical personnel.

Three-field was nothing more than an attempt to ape the competition, i.e. EMD's SW-1500. A simple, open loop system a la' the EMD three-field main generator. In this case, GE used their simple shunt field main generator and impressed the complicated field structure on the GY-50 exciter (same as U25/28 DC). After all, the main generator just amplifies the signal impressed upon it.

Obviously, the combination of 8-251 and three-field was completely underwhelming vs. the competition.

[EDM5970]

Hindsight is 20-20, of course, but I've often thought that a conventional end cab switcher would have been a better bet, or something like an updated RS-1 (26L, rollers, MU, 752s) with a 6-251 putting out 1200 HP. (MLW was able to get 200 HP per cylinder from the 251.) I have seen the "survey" that was circulated, and still marvel at what Alco eventually built

Another idea "might" have been to use an NA 12-251, at maybe 1500 HP, but that would have required new manifolds, a muffler, and cams. Easier to design an 8-251, or so it seems-

Split pole excitation seemed to work well enough in the S series and the S-6/T-6, something they should have kept for the C-415 (or "C-412"). But none of us were there, that I know of, so all we can do is speculate.

[MEC407]

Why was the 8-251 more problematic than 12 and 16 cylinder versions?

[Allen Hazen]

MEC 407 asks
"Why was the 8-251 more problematic than 12 and 16 cylinder versions?"

Just to start the discussion going... The "conventional wisdom" is that it had more vibration problems, that there was something about the V-8 that made it harder to balance than straight 6 or V-12 or V-16. This is the story that has been repeated in the railfan literature: I think some of the places where it started (*) may have been articles by knowledgeable people, but it has now been repeated so many times that I am getting worried...

Apparently Alco felt there was a problem: the 8-251 had extra components added to the design to damp the problem. Why the V-8 configuration, at locomotive diesel sizes, should be problematic I don't know. Certainly EMD seems to have had good success with 8-567 and 8-645 engines in switchers and export units, and GE managed to do pretty well with the FDL-8 on units exported to many countries and to the Maine Central!

(*) The article on the C-4-15 by "Win Cuisinier" in the March 1985 "Railroad Model Craftsman" is (as one would expect from the author) informative and convincingly written: it mentions assorted problems with the locomotive's configuration (poor visibility from cab, long cable runs from the oddly positioned main generator, radiator fan drive shaft extending under the cab, unfortunate need to have radiator overflow vent on the cab roof...), but doesn't specifically criticize the engine.

[espeefoamer]

I once asked an SP engineer his opinion of the C415s,which were then operating on SP. His view was that they were pieces of junk(He used a different word. )He told me that SP had ordered 50 C415s,but when the first 10 arrived,the railroad cancelled the rest of the order.

[Alcoman]

The C-415 was said to be the result of 'market research' or perhaps more accurately,a survey of railroad mechanical personnel.

Three-field was nothing more than an attempt to ape the competition, i.e. EMD's SW-1500. A simple, open loop system a la' the EMD three-field main generator. In this case, GE used their simple shunt field main generator and impressed the complicated field structure on the GY-50 exciter (same as U25/28 DC). After all, the main generator just amplifies the signal impressed upon it.

Obviously, the combination of 8-251 and three-field was completely underwhelming vs. the competition.

Check out this link and see what Alco had proposed for this locomotive
http://jmech.tripod.com/id12.html[url][/url]

[Lehighton_Man]

Wow, thanks for sharing that Alcoman, one looks like they were looking to revert to a older HH600 design with it. I wouldnt know if it would have as much sucess, but who knows.
Cheers.
Sean

[rrboomer]

A lot of the C-415 problems were not necessarily related the the 251 as much as design goofs:

The main generator was located at the front of the forward hood, the high voltage cabinet was located at the rear of the cab. the railroads didn't like this when Baldwin did it...

The radiators were at the rear of the rear hood, the engine was in the front hood, longer pipe means increased opportunities for leaks.

There was a approximately 13' drive shaft under the cab from the 251 back to the radiator fan and air compressor near the rear of the rear hood. That's a
long rotating mass that caused lots of vibration problems, including increased opportunities for water leaks.

In the Rock Island's case they couldn't get the high "360 degree vision over the top of the hoods" version because they wanted them to fit under 12th St bridge
and into LaSalle St station. Their C-415's had "360 degree vision" around the inside of the cab.

As delivered to the RI, the cab control layout was unusable. RI had to modify just to put units in service.

They virtually would not move in throttle positions 1-4, when throttle advanced to #5 unit would then just slip if much of a load behind it. They would however, perform like champions on a three or four car suburban train.

The only thing I can think of that the C-415 had superior to the SW1500 was the ride quality of the trucks over flexicoils. Most crews would prefer the slightly
harsher ride to have a locomotive that could actually perform some yard switching.

[Phil12string]

The 8 cylinder 251 suffered from severe vibration, a problem partially addressed by the use of internal counterweights. The C-415 design was pushed by ALCO management, after an executive saw similar units in service during a business trip to Europe. Obviously, he did not know that the European machines were/are Diesel Hydraulics. The design department tried their best, but designing a off-center cab Diesel-Electric posed too many logistical equipment placement problems to be successful. One case in point was the fact that the cooling water tank/fill was located in the cab roof, as it was the only place on the locomotive high enough to prevent air introduction into the cooling system.

[tomjohn]

I only know of one and that's on the BUFFALO SOUTHERN RR ,not to say that there not any more in existence. However, I am curious is this the same one that I mentioned?

[ex Budd man]

WOW, I had no idea they were such a POS They were a big hit with model manufacturers and modelers too! I guess any one can make a blunder. God knows Red Lion put out its share. The Keystone, the GT-1 and GT-2 gas turbines, the Metroliners and my personal favorite, the SPV-2000.