• Why was the BL-2? (A thought)

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

  by mtuandrew
Also regarding the GP7's frame strength, it doesn't seem to have been a major issue - the Wiki article at least gives the impression that it was correctable in later models and perhaps by retrofit.

I also suspect that Mr. Hazen is right, the BL2 and GP7 frame strength issues didn't matter when they were in EMD's suggested service. Drilling 20 cars in a yard, working a 12 car branchline mixed, or running a 4 car suburban scoot wouldn't overly stress these trusses or weldments. These issues did matter when they were the fourth unit out of six on a 120 car coal drag coming up the valley from Louisville, back in the era when it was common to see six 1300-1500 hp units on a freight. Now that 1950s-vintage diesels have essentially disappeared from road service, it is back to being a minor issue at best.

As for the GP22ECOs, EMD must magnaflux the frames, repair problem areas, and reinforce weak spots in the reman process. I certainly wouldn't accept less if I were a railroad CMO.
  by Engineer Spike
The CPR's GP22s have new frames. My point was that they had GP7s in service right up until this program started, which was within the last year or so. I had never heard of frame problems on the GP7 before.

BNSF had GP7s in service until recently too. The problem might have been addressed in the rebuild porgrams.
  by Allen Hazen
Well, I've found (while unsuccessfully searching for something else) a bit of testimony about the frame weakness of the GP-7. In April - June of 1979, "Trains" published a four-part article (1) on the anatomy, care and feeding of diesel locomotives, by Vernon L. Smith, who had retired shortly before as Chief of Motive Power of the Belt Railway of Chicago. In the first instalment occurs the paragraph:

"A good underarm may determine the total life of a locomotive. The otherwise excellent EMD GP7, for example, unfortunately has a relatively light frame, and on my former railroad, the Belt Railway Company of Chicago, it will not survive in service as long as the older cow-and-calf TR4, which has side sills 4 inches thick."

Note that the BRC's business involves heavy switching and transfer work: precisely the sort of low speed, maximum tractive effort, duty I think is rob ably hardest on locomotive frames. And that the use of the future tense ("will not survive") in 1979 suggests that even this would take over two decades to kill a GP-7.


(1) Subsequently re-issued by the publisher of "Trains," Kalmbach Publishing, as a pamphlet. Written, of course, back in the days of DC traction motors and the 646 and FDL engines, but still, I think, a good introduction for rail fans to the technicalities of locomotives.
  by JayBee
Allen, you missed on your guess as to which railroad discovered the weakness in the BL2 "frame", it was the Western Maryland RR. They bought their pair for freight service, and within a few years had to use them in Yard Service. The Western Maryland gathered a lot of Coal from mines around Elkins, WV and had to lift it up a 3.0% grade out of the Cheat River Valley. The line also featured some 14 degree curves, so to the very end six-axle power was banned, and newer high-horsepower Geeps were very rare. It was common to see 5 to 7 locomotives on the head-end and 4 to 5 locomotives cut-in as pushers. Very quickly the BL2s were banned from the pushers, and not long after they were not allowed to trail in the leading consist either. I have read an account saying that if you looked carefully you could see the deflection in the BL2 body under the heavy loads.

Part of the reason for the lighter framing on the BL2 and the GP7 was intended use of the locomotives. Most railroads were buying locomotives for specific jobs, F-units for mainline freight, Geeps for branchline freights and mainline locals. Take the Frisco for example, all the F-units were built with dynamic brakes and 24RL air brakes, all their GP7s were built without dynamic brakes and with 6BL air brakes. It wasn't until the 1960s that a modification was developed that would allow a 6BL air brake to lead a 24RL air brake, let alone the newer 26L air brake. Very few GP7s were built with the 24RL brakes, a much higher percentage of GP9s had the 24RL air brakes, a few late GP9s were built with 26L bakes.
  by Allen Hazen
O.k., fair enough! I mentioned the Monon because Hundman mentioned it in the "Mainline Modeler" article mentioned a few posts back, but Western Maryland's operations and topography are at least as well-calculated to reveal frame weakness. I'd be tempted to think that this had something to do with why WM only had two BL-2, but at the time they were sampling locomotives of a variety of types with tiny orders, and by the time they would have been ready to go back for more the BL-2 had been replaced in the builder's catalogue…
Switching, in 1949, tended to be done with units of at most 250hp/axle (EMD's NW-2, Alco's S-2, Baldwin's DS44-10, and FM's H10-44 were all 1,000 hp units: except for Alco all these builders uprated their "big" switchers to 1200 hp, but not until the year after the BL-2 was discontinued). I imagine the WM management must have been overjoyed -- just bubbling over with enthusiasm for EMD products!! -- to find that, having spent the money for a 1500hp unit with a 16-cylinder engine, the only thing they could safely use it for was switching! ;-)
  by EDM5970
I've done a fair bit of research on the WM, and have always thought that they did a great job of motive power utilization. My understanding of the BL-2 issue was not so much underframe as it was draft gear. Of course, the draft gear attaches to the underframe, so we're essentially talking about the same thing here. On the WM, the BL-2s were only allowed to operate as a pair, or as lead units. If used as pushers, they were to be at the rear of the consist. In both cases, this was to keep stresses off the draft gear and underframes. Most of the photos I've seen of 81 or 82 with slugs in Hagerstown have shown the slug up against the long cuts of cars being switched, I'm sure for the same reason.

With respect to utilization, WM took pains to make sure that all the road power, with the exception of the Baldwins, would operate in MU. This included the BL-2s, Geeps, SDs, Fs and Alco RS-2s and RS-3s. Even thought the BL-2s were not equipped with dynamic brakes, they had DB controls added so that they could lead a consist of DB equipped power.

Not to digress too far here, but the GP-7 was originally conceived as more of a switcher (and wired a bit differently) than as a road unit, which explains the wide use of the 6 brake schedule. The GP-9 was more of a road unit, wired more like an F, (and many had 24 air) which most likely came about when EMD realized how the GP-7s were actually being used. (My speculation, of course, but I think it makes sense-)
  by Engineer Spike
Might EMD have had more than one frame? Some of the GP7s were designed more as switchers. Look at the ones with switcher trucks. They may have had lighter frames, with which to stay under weight restrictions. Many of these came with cheap components, and few options, like no DB, and #6 brake. This fits in with the remarks made a few posts ago.

I know that some of B&M's GP7s (2nd. order) were built cheap. They had no MU, nor DB, and had #6. With a steam gen., they were for commuter service. Something I read said that this order was a lighter version of the GP7. I wonder if the other orders (1st & 3rd) had beefier frames. The 2nd order units did eventually get MU, and 24RL. Who knows if these units were somehow restricted to mostly local service, while the others could be used on heavy road trains.
  by jr
An interesting discussion; wish I had seen it sooner. I have a copy of Chesapeake and Ohio BL2 Diesels by John C. Paton, published by the C&O Historical Society.
It is 64 pgs, soft cover, and covers the 14 PM/C&O units in some detail, and also has a short chapter on the WM units, which came into the "Chessie" family much later.
Althought it seems intended more for the modeler, with great deal of information on paint schemes and exterior details, it does give a fair amount of technical detail as well. Some of this information supports previous posts, and some of it contradicts.

Weights - the 80 class is listed as 210,025 dry, and 224,800 total. The 1840 class is 214,960 dry, and 229,900 total.
Frames - Both C&O and WM had problems with frames. The WM chose to "patch and weld the cracks" (his words). The C&O stored unit 84 after only 11 years, and stripped it for parts, due to a cracked frame. The remaining 13 units (apparently) continued in service.
Branch lines - The C&O units were used extensively, but not exclusively, on light-rail Michigan branch lines.
Service life - The C&O units were retired and turned back to EMD after only 13 to 14 years; a remarkably short time for EMD units. He indicates that the WM units were placed in yard service after about 15 years.

I have no other supporting information, so I can't testify to the accuracy of the book. Just tossing this stuff "onto the pile" .

  by Allen Hazen
Thanks for adding to the discussion! There are too many books for any one person to have them all, and neither university nor public libraries specialize in railroad books: as a result it is very difficult to compile information from different sources. So your post is much appreciated!
Retired and traded in after 13 to 14 years is certainly a short life for an EMD unit. (I'm a GE fan, so please: nobody embarrass me by telling me once again how long the U50C lasted!) C&O was a prosperous railroad in the 1960s, so they probably replaced old units that more impecunious railroads would have nursed along for a few more years, but it certainly does sound as if they didn't think much of the BL-2!
  by CarterB
How long did the C&EI use their one and only BL1?
  by jr
How long did the C&EI use their one and only BL1?
According to Diesel Locomotive Rosters, a compilation of Railroad Magazine articles, the BL1 and both of their BL2s were "rebuilt , then traded to GM-EMD for 239-241 (2/63)". So it appears to be approximately 15 year careers for all three.
239-241 constituted C&EI's first order of GP30s.
The data apparently originated from the C&EI.

  by Engineer Spike
There is a book about Richard Dilworth, which was published by GM. I found a copy which was uploaded to a website. He talked about the GP7, and how they (GM/EMD) wanted to get the remaining branch line steam replaced. It talked about how the BL2 never invaded that service, as intended. Some of this could be GM propaganda, to cover for the fact that Alco had the product which the railroads were really looking for, with the RS2.
  by Allen Hazen
I read the Dilworth book many years ago. (Gave my already second-hand copy to a friend.) It's very hero-worship-y, and is definitely EMD propaganda: there are a couple of places where I think it has out-and-out falsehoods to make EMD products look better than the competition. One that is mentioned by Kirkland in one of his books: EMD's biography of Dilworth ridicules the Baldwin Centipede, but it actually had lower axle loadings (the load was spread over a LOT of axles!) and was easier on track than EMD's F-units.

The GP-7 (Dilwoth at least oversaw its design) was a great success, and EMD through the 1970s was big enough and successful enough that it could survive the failure of the BL-2… but the embarrassing fact remains that EMD only achieved "branch line" success on its second try!
  by Engineer Spike
The whole cab and booster concept, which EMD pioneered, with the FT was stupid. They had limited capabilities, and could only be used in road service. My employer didn’t fall for this. They bought some switchers, but mainly roadswitchers. Some even had steam generators for passenger service. This policy was instituted even before the GP7 was developed.
  by Engineer Spike
Last night I was at my model railroad club. A fellow member had found a book about EMC/EMD called "On Time", which was in our library. Knowing my interest in EMD, he set it aside for me to take home to read. There was some interesting information which might explain EMD's thinking.

One of the early chapters talked about you Mr. Hamilton designed the early gas electric cars with truss sides. This saved weight, since the under frame and center sill wouldn't need to be as heavy. This was required because the internal combustion engine designs were at a point where they just didn't make that much power. To be able to use a reasonable sized engine, yet keep the power to weight ratio reasonable, weight savings were required.

The BL in the BL2 model was for Branch Line. Many of these lines likely had light rail, and also light bridges. The light weights may have been by design, so that the customer could have a more powerful unit than a switcher, yet fall within weight limits. The truss frame may have been exactly the answer.

I think that by the time the GP7 arrived, several factors had played out. In the post war era the higher power of diesels made the car sizes increase. Also in the same era many roads were upgrading everything from equipment, to infrastructure. This was partly because everything was worn out during the war, when replacement was unavailable. Still, this doesn't answer why EMD wouldn't emulate Alco, which was selling the RS2 like hotcakes.