I was watching the old Trains magazine video. The host mentioned that FM engines are widely sought after for marine and stationary applications.
My questions is, if the FM OP motor was so good, why did FM fail in the locomotive field?
What issues did the RRs have with this design?
Here’s a neat cutaway of the F-M engine:
A problem I can see is that you can’t get to the “top end” without disassembling the engine. No ring changes, no piston changes, no wrist pin changes.
Another problem is sort of self-fulfilling: If you have orphan engines, there’s fewer people who know how to take care of them. It’s a tough fight for the new guy to get market share; and, at first, they have to do the old Avis trick of “trying harder”. A lot. Keep in mind that EMC, when they were first sending out their newfangled diesel locomotives, placed an employee on every freight locomotive to ensure an absolute minimum of angst for the purchaser. Or so I recall hearing. This cost them big bucks. Perhaps F-M didn’t supply adequate support for its product. I am uninformed on that matter. But I have read that SP&S dropped Baldwin when Baldwin didn’t get them replacement parts in a timely manner. And Baldwin is long, long gone from locomotive production.
Ed
i think it had a lot to do with the environment and operating conditions. if you think about it, marine and stationary applications have pretty much constant temperature and other conditions. also, the engine runs at a fairly constant speed, usually where it is happiest and most efficient.
the railroad world is somewhat more harsh and the power output needs are constantly changing. guess fm’s just didn’t do so well under those conditions. the emd engines might not have fared so well in the applications that suited the fm’s but that is a guess.
Charlie
me again, the new kid on the block thing and being the oddball in the game no doubt played a big part in fm 's lack of success. as the other post before mine stated, these are big factors in success of a machine. it wasn’t just problems with the prime mover if that is what my previous post implied. if engine failure was the death knell of a locomotive, the alco would have been gone long before it was. their early 244 was a piece of junk according to what i have read. as a matter of fact, the NYC put up a “firewall” and tried to keep them all east of buffalo. there was a reason why roads like the IC stayed all EMD for so long if they had no need to dieselize as quickly as a some of the rolling junk yards.
Charlie
The F-M ‘OP’ power plant is a very successful design, just not for railroads. It has been used in marine applications for years, and old FM switchers were sought after in the 70’s & 80’s just to get the ‘OP’ power plant out of them. A lot of tow boats are ‘OP’ powered.
The problems are two fold:
Serviceability - Getting at the lower end for service meant pulling the entire power plant out of the locomotive. An EMD could have a power assembly pulled with the block still bolted down.
Application - The ‘OP’ power plant excels at constant speed operation. Marine and stationary power plant applications are an example. Up/down throttle changes lead to piston scuffing and lubrication failures. After becoming leaky, the engine can start to ‘eat’ it’s own lube oil and sometimes cannot be shut down until it runs out of lube oil and the bearing seize up. An old ex-PPR Road Foreman of Engines told be about a FM helper dropping down grade and the crew could not shut it down…
FM still sells parts/service for the ‘OP’ and also for the ex-Alco 251 series engines. BTW, the power plants in the NASA launch ‘crawlers’ are V12 ‘251’ series diesels.
Jim
The engines had issues with overheating and didn’t care for the shocks a rail application recieves. I remember reading several years back that the upper crankshaft tended to fail because the cooling systems couldn’t keep up with the load. A ship has a million gallons of 40- 60 degree water to use as a heat sink. Not so much a locomotive.
I’m sure having twice the moving parts as a conventional engine probably didn’t endear it to master mechanics
I saw FM engines being shipped for marine applications well into the 1980’s
Dave,You are correct…Crankshaft failures doomed the FMs…Even PRR kept those engines near a shop.
The book “Union Pacific Salt Lake Route” has some information on why UP’s Erie Builts and H20-44s earned such poor reputations. Several reasons are cited, including:
I would think lube oil getting past the top piston rings would be a problem.
Very interesting comments.
Many of the FM locomotives suffered from being the oddball in a sea of EMDs. GM by far had the best training for the maintenance people so on the roads that had many EMDs everything was maintained using the EMD procedures. Of course maintining a machine using the wrong methods will result in less than optimal operation.
Where the FM locomotives were in the majority, like on the Virginian, or the P&WV or a large minority like on the Milwaukee, they worked well. Also when railroads concentrated the FMs, like SP in the San Francisco area and PRR/PC in Chicago, the maintenance people became familiar with the OPs and they became good locomitives. In fact, when SP replaced the Trainmasters with SDP45s and GP40Ps the mainenance crews treated them like FMs and the EMDs suffered many breakdowns. Retraining the crews to maintain the EMDs eliminated that problem.
There’s also an unlimited supply of air for cooling. You just have to have a proper radiator system to use it. Actually, the F-M’s in marine service have “radiators” also–they’re called heat exchangers. They just dump the heat from the engine coolant into the seawater, the same as a radiator does to air.
As far as air density goes, they had a supercharger. It’s main job is compressing the intake air. And, with proper design, it’ll compress it as much as is needed. As for humidity, I think that’s more of a cooling/radiator issue rather than an intake issue.
I seriously doubt that. For air cooling, the engine would be covered with fins and there’d be a big old fan blower to move air across it.
I agree–see my earlier comment about having a proper radiator system. I’ll note that the piston crowns are not cooled by the cooling system directly. They are kept “cool” by being inside an engine running at the design temperature.
Such things are frequently the result of
Many US Navy ships had this type engine. In 1962 I was on, a WWII built Destroyer Escort that had a pair of these, each on its own screw. No reverse, the engine was easily stopped and reversed. Air starter. Direct drive. Easily started. Minimum speed, about six knots on one screw. I saw the crew change a cylinder a few times while at sea. Top or bottom. Smelly exhaust as I recall. Ran until 1975.
Rich
That left me confused in the text of the book I was quoting too. I thought it sounded odd.
Ask and ye shall receive. In a word, higher maintenence costs were the issue.
From Joseph Strapac in Rio Grande Diesels, Volume 1 page 33:
“The prime mover, however, was a Fairbanks Morse exclusive. Designed before World War II as a submarine power plant, it was adapted to railroad service in inline six, eight, ten and twelve cylinder versions - but with two crank shafts, one at th etop and one in the “normal” position. The pistons thus occupied each cylinder, compressing the intake charge betwen them. This design resulted in an unusually compact engine, which took up little floor space within the locomotive hood, but which required some unique maintence prodedures. The EMD diesel is designed so that an entire cylinder liner, head and all, can be removed in an hour or two without disturbing the rest of the engine. F-M’s engine, however, had everything locked up between the upper and lower crankshaft - requiring a heavy overhead derrick to remove th eupper crankshaft before cylinder liners could be removed. As a result, railraods which owned F-M’s invariabley concentrated them at a few mentenence oints with specialized tools. Of course, the “mechanic’s flat rate” for repairs on an F-M engine was ginificantly hgher than on an EMD.”
.I believe the “air cooling” they are referring to is the incoming charge air from the scavenging air blower. The incoming air cooled the upper piston quite well, but the lower piston suffered from overheating,according to some accounts. From the cut-away, there is very, very little area devoted to water jackets around the cylinders. It seems there is more around the exhaust manifolds.
I have a copy of a service manual. Here are some graphics.
In chassis lower piston removal / installation. Rod / piston assembly comes out the side. Note cable lifting tools attached to outside of block.
In chassis upper piston removal. Rod comes out the top, piston goes down and out of the side after lower has been removed. Note rope attached to eye bolt to raise / lower piston.
Speaking of flat rate, the manual recommends if over half the upper pistons need removal, the upper crank should be pulled.
I don’t see the point of transferring heat from the cylinders into the incoming charge. That’s only putting it back where it came from. Heat needs to be removed from the engine. It would make sense, I think, to do this if the engine were cold, but once it’s warmed up, it looks like a bad idea.
I did some more internet exploration on F-M. I really do believe that their biggest problem was management. I find it interesting that EMD, the youngest of the mid-century locomotive producers, was also the survivor. I attribute this most of all to failures in management in the old-line companies.
Ed
Jim,
Wow. Great drawings. So, it appears one could do top end work on the F-M engines without pulling the crankshafts. I did not know that.
Ed
PS: “top end work” means work on the pistons, piston rings, cylinder head (none on the F-M) valves (none of them, either)–the top “half” of the engine. In the case of the F-M, it would actually be the middle.
Rings, rods and pistons can be serviced without the cranks pulled. Like riogrande said in his post, the liners required complete upper crank removal.
Maybe another factor is the work environment itself. Marine and stationary typically have their mechanic nearby. They can monitor the engine and tuck it in at night. Not so for rail roads with a whole fleet to deal with.
Thanks for all the interesting comments and information. I learned a lot.