• ALCO 251

  • Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.
Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.

Moderator: Alcoman

  by NorthWest
I think it is pretty well known that the NASA launch pad crawler that brings spaceships to the launch pad is powered by 251s.
Some ships use the 251 (usually small ships such as tugboats). Other industrial plants have 251s as backup generators, which need parts. I believe Will Davis remarked that they are common at nuclear plants. They used to be common in 'peaker' electrical generating plants, but I don't know how common this is anymore. Imagine a bank of 10-12 18-251s at full throttle in a room. Music.
  by MEC407
The sewage treatment plant in Montreal (I think?) has several 18-251s as emergency backup generators.

You'll also find EMD 20-645s in many of those same places, including nuke plants.
  by Allen Hazen
But, re the original question…
In standby service a good diesel engine can last a LONG time: my guess is that there would still be a reasonable number of Baldwin engines in various stationary applications. But what about NEW ones? The rights to the 251 engine belong to a company (Colt?) that has lots of other strings to its bow. My guess is that the 251 engine is still "in production" on a "by request" basis, and that the actual rate of 251 production is pretty low, and that a larger proportion of the factory's work consists of newer designs.

(i) that's a GUESS, and
(ii) just how many engines of which designs the company made last year probably isn't one of the pieces of information they put on their website.
  by MEC407
http://www.fairbanksmorse.com/engines/fm-alco-251f/" onclick="window.open(this.href);return false;
  by Allen Hazen
Thanks for posting the link to the manufacturer's flyer on the 251 engine.
(1) The photo on the first page shows an engine that has obviously been mounted for stationary rather than locomotive use, ut elsewhere there are photos of what look like locomotive-style 251 engines.
(2) Not much about rail in this brochure, but elsewhere on the manufacturer's website there are references to the 251 engine's historic use in locomotives (with a photo of a Perurail Alco pulling a train through dramatic Andean landscape).
(3) If you delete the "fm-alco-251f" part of the URL you get a page with a thumbnail version of the photo… along with similar photos of 11 other engine types they can provide. So my guess, as I suggested in my last post, is that they can keep the factory lights on without building very many new 251 engines.
(4) I poked around the website last night, and didn't find anything that give a hint about how many engines they build in a typical year: that, I suppose, is "commercially sensitive".
O.k., here's a null hypothesis that I'd like to see refuted: they have the rights to the 251 engine, and will build one for anyone who comes in with a check book, but almost all their work is on the various French and German designed engines that they also have rights to. PLEASE, if anyone knows better, let us know!
  by MEC407
They'll also build their namesake engine if someone asks for it. :-D

http://www.fairbanksmorse.com/engines/o ... -model-38/" onclick="window.open(this.href);return false;

If I'm converting the kW to HP numbers correctly, it looks like the 12-cylinder is now rated at over 4000 HP, compared to 2400 HP in the heyday of FM locomotives. How cool would it be to see/hear one of THOSE in a locomotive today?! :-D
  by Kuyahoora Valley
The US Navy uses ALCOs for diesel generators...Here are pics of one on USS BATAAN (LHD 5) which was built in 1998. I used to ask the Chief Engineer to let me know when they were running them...had an exhaust pipe below the flight deck that would billow nice clouds of ALCO smoke. The last LHD built, USS Makin Island (LHD 8), has 6 Fairbanks Morse diesels for her Aux generators. They need to be used of backup main propulsion so have a higher output than the LHDs with steam turbines for main propulsion. Makin Island has gas turbines for high speed propulsion.
BAT Alco Nameplate.jpg
BAT Alco side view stbd.jpg
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  by Allen Hazen
Kuyahoora Valley--
Thanks! We now have at least one data point: assuming the Navy bought new equipment, F-M built NEW 251 engines as late as 1998. … The name-plate in your photo says it is a 251-C engine, with a b.h.p. of 2800: I think the 251-C was the version Alco was using on locomotives in the early 1960s, and this rating for a 16-cylinder engine suggests it is comparable in output to the engine of C-425 (though apparently at 900 rpm rather than the 1000 Alco used on locomotive engines). F-M offers later versions of the engine (their web site talks about the 251-F), but apparently the Navy (for dependability reasons?) specified the tried-and-true rather than the higher-tech engine.
  by Kuyahoora Valley
Hi Allen:
I think we can safely assume that the Navy standardized in order to minimize impact to training, spare parts, tech pubs, etc. Every time a new piece of equipment is introduced there is a huge cost associated with the logistics support...unless there is a compelling reason they tend to stick with the tried and true.
  by MEC407
Allen Hazen wrote:The name-plate in your photo says it is a 251-C engine, with a b.h.p. of 2800: I think the 251-C was the version Alco was using on locomotives in the early 1960s...
The MLW M420W, introduced in 1973, also used the "C" version of the 251.
  by Pneudyne
I wonder though whether the core mechanical improvements that were developed for the successively higher-rated versions of the 251 engine were reflected back into the lower-rated versions that remained in production. Thus at any given stage of development, the differences between suffix variants might be largely related to turbocharger sizes, fuel injection pump capacities, etc. And so a later 251C might have some differences as compared with an earlier version built when “C” was the highest available rating. So whereas originally the “C” suffix signified what was probably a comprehensive set of changes as compared with the preceding “B” version, by the early 1970s it simply signified a lower power rating than the top “F” version.

For example, East African Railways in 1971 acquired MLW export models with both 12-251F (its 92 class) and 12-251C (88 class) engines. It was new to the Alco engine, and I imagine that it would have wanted as much commonality as possible, including interchangeability of the major components.

900 rev/min is a 60 Hz alternator synchronous speed (8 poles). So that may explain the USN choice. The next suitable speeds up and down are 1200 rev/min (6-pole) and 720 rev/min (10-pole) respectively. Where rotational speeds are not so constrained and maximum power output is required, typical medium-speed engine practice is to push towards piston speeds in the region of 10 m/s (or 2000 ft.min).

  by NorthWest
To add another builder to the mix, the USS Bataan was built by Ingalls Shipbuilding in Passalouga, MS, near where the 4-S was constructed.
Now, if only we could get the 251 to meet TIER IV...
  by Typewriters
There are a number of ALCO 251 engines that have been used as EDG's (Emergency Diesel Generators) at commercial nuclear power plants in the United States. I can tell you that I have reference to seven units (located on a total of five different power plant sites) that use ALCO diesels.

Of course, Fairbanks-Morse provides the service and parts for these engines these days.

-Will Davis
  by NorthWest
Will Davis has returned! Welcome back!