Re-engining an Erie-built

This is a question about a particular type of diesel-electric locomotive, but could have been posted to any of three forums: F-M, EMD or GE. So... General discussion!
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Suppose it is the late 1950s (mid to late: no earlier than 1954 for the EMD engine in question). You run a railroad which has a small (they all were) but significant to you fleet of F-M/GE "Erie-built" locomotives. They spend altogether too much time in the shops and not enough on the road, but are too new (and, when working just right, pull too well) for scrapping. So, you decide you would like to re-engine them, using EMD 16-567C engines in place of the original, troublesome, 10-cylinder F-M opposed cylinder engines.
(To interject a bit of fact into the speculation, the KCS actually did have its Erie-builts re-engined with 567C engines...)
Your opposite number at the Kansas City Southern has the same idea, and will send to units to La Grange to have the EMD engines installed at the factory, but you wonder if you could save money by having the work done at your own diesel shops...

(i) Theoretically, the locomotives will be less powerful with the EMD engine, but this may be largely theoretical: the Erie-built is always described as a "2000 hp" unit, but (depending on atmospheric conditions) it could deliver less: the New York Central (whose diagram-book page on the type is available at the "Fallen Flags" rail image site) rated them at 1800 hp.

(ii) Given the similarity of power rating, and the similar top speed of the F-M and EMD engines, I would assume the original GE 567 main generator could be used with the new engine, and the (locomotive, as opposed to engine) control system might not require much change...
QUESTION: is this right?

(iii) The Erie-built had very large radiators (with lots of water capacity) to allow quite low engine operating temperature. (Their F-M engine was based on one used in U.S. Navy submarines and destroyer escorts, and, as an old "Trains" article on the type put it, the parameters of their engine installation "presupposed an ocean of cooling water.")
QUESTION: With the EMD engine, would you want to modify the cooling system so the engine will run ... hotter?

(iv) It's too much to expect that EMD and F-M had identical engine-generator interfaces. (QUESTION?) So I suppose a new engine/generator coupling will need to be fabricated. Obviously (cf. earlier reference to KCS) EMD's engineering and workshop staff and equipment can handle this task, but
QUESTION: is this something the mechanical department and backshops of a typical 1950s Class 1 raIlroad could do in house?

Interesting question, but maybe more questions will be rasied than answers/opinions given.

The engine RPMs and HPs being similar, at first this looks like almost a no brainer. But when the control system question comes up, it may get a bit tricky. EMD used Woodward governors, in combination with a hydraulic faceplate load regulator, operated by engine lube oil pressure, to control engine load and excitation.

I have no specific information on the Eries, but as they were built during the 'Amplidyne era', it sould be a safe guess that they had the same engine control and excitation system that was common to the RS-2s, RS-3s, PAs and all but the very last FAs. This is a very different system, much more complex than EMDs. The GE 17MG-x governor has no mechanical reference connection the the engine speed, speed being sensed being through an electric tachometer.

My gut feeling would be to use the 567 with the Woodward, with the EMD excitation system, as it was designed to match the loading characteristics of the EMD engine. The Amplidyne system was said to have been fantastic when it was set up correctly, but could also be very maintenence intensive.

(As an aside, the Alco Centuries were offered with the option of the Woodward governor or the GE 17MG-8; both with type E excitation. GE offered the first U-boats with only the Woodward governor and their three field excitation, both said to emulate EMD.)

As far as the cooling system, radiator sections can be removed or blocked off, if there is too much cooling capacity. With good thermostats, proper control of the shutters and fans should not be a problem. It would be better to have too much capacity, and not use it (i.e. shutters closed, fans off) than to not have enough. (Were the Erie fans mechanical, or electric like the EMDs at the time?)

Most railroad shops would be able to handle the engine to generator coupling. They had boilermakers, welders, and machinists with all the proper equipment. I've seen drawings that covered replacing a 244 with a 251; a new set of 12 holes were drilled and tapped into the engine flywheel, IIRC. I'm sure a 'blank' EMD flywheel could have the holes for FM main generator put in.

I have to look at Kirkland tonight and read up on the Eries. I'm curious to see what others would have done here, this being a purely theoretical discussion.

Depending on what NYC spec cards you're looking at (4400 class or 5000 class) you might either be seeing a rating for the 16-567 used in repowering, or else a rating of 1750 HP as a result of retaining but derating the original 10-cylinder 38D8-1/8.

-Will Davis

Will Davis-- Sorry, I was citing the NYC cards from memory (always hazardous at my age!). Key thing is that at least one of the cards gives 1750 hp for an Erie with the original engine. You suggest this is downrating; I had assumed (always a dangerous thing to do at any age!) that it was just a more realistic description of what the engine could be relied on to give (in, e.g., hot weather) at its original rating. Do you know for certain that they were downrated?

EDM5970-- Thank you for informative reply. I ***think*** the Erie's fans were electric, but not 100% sure. Insulation getting put into walls in basement, all reference books temporarily inaccessible: please check back in about a week and I'll see if I can find any relevant information.

For starters, there's no reason to think that the 4400's or 5000's as-built were incapable of delivering their advertised rating. In some cases, there are differences in rating systems that might lead to such confusion (for example, the "1000 HP" ALCO-GE units with 539 engines that actually incorporated engines rated 1000 brake horsepower, and which thus did not deliver 1000 HP for traction) but the Erie units were rated as were the 244 engine ALCO-GE units, with a "horsepower for traction" rating. Thus, there is no reason to think that there was some deficiency in output.

As John Kirkland points out quite correctly in his book on Baldwin diesels, though, non-turbocharged diesels can and do lose output at higher altitudes; I think he quoted the 1000 HP F-M units as delivering something in the mid-800 HP range for traction on the Apache (I don't have that book handy where I'm writing this from, so someone check that for me.) But on most of the Water Level Route, there is no altitude problem.

So we have this NYC spec card showing a lower rating, which itself might be suspicious and perhaps one might assume a line item error on the clerical side, either in the HP rating or else in the engine type (perhaps this was really supposed to indicate EMD re-engining.) But we have that old TRAINS magazine article, wherein we were told by a diesel maintainer on the NYC that a number of F-M locomotives were derated to prevent premature engine wear from sidelining the units. These two pieces of evidence together seem to meld well. In fact, on this forum sometime in the past we reached this conclusion in some other message string.

Absent any other evidence, we're left to match the official spec card with first person evidence and reach the conclusion that the units were in fact derated. At least that's how I see it.

By the way, the radiator fans on these units were electric. I think they were DC powered, but I'm not certain. I know they were DC on many switchers and road switchers built by F-M. The C-line introduced AC driven radiator fans on F-M units, if I get my facts straight.

-Will Davis

I did take a quick look at Kirkland last night. Excitation was Amplidyne, and the two radiator fan motors and two traction motor blowers were electric, all DC. I have no idea what was retained or replaced, however.

I'd love to see someone write a comprehensive book on repowerings, although I suspect only a dozen copies, at best, would sell-

(And Will and I submitted our posts at just about the same time-)

Edit: To add to the derating thought, I was told by a good authority that the Lehigh Valley tuned their RS-2s and -3s down to 1200 or 1300 HP to make them last longer. Also, this was not too uncommon with the 20 cylinder EMD 645s, 3200 instead of 3600 HP-

Will Davis and EDM5970--
Thanks for your replies.
Some of my references turn out to be outside the tarpaulined-off areas. So...
(1) I also checked Kirkland's "Diesel Builders, vol. 1." Radiator fans on Eries were run by DC motors, powered by a variable-voltage auxiliary generator. (C-line used AC radiator fan motors on units without dynamic braking.)
(2) There were two radiator fans.
...
(3) I also have articles from "Railway Mechanical Engineer" for November 1946 (reporting on the first Eries, built for U.P.) and May 1948 (on freight Eries for the P.R.R.). (These articles are reprinted in "Train Shed Cyclopedia, No. 64.") This gives some information about the control system.
(3a) Amplidyne excitation system. (At least the version of this used on the P.R.R. units was set up to
"control low-speed tractive force. On the first throttle notch, the current limit is reduced to allow just about enough current to move the locomotive. As the throttle handle is pulled back, the current limit is raised a little on each notch, permitting smooth starting of the train.")
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More on engine control in an hour or two (after dinner).

Continuing on a full stomach...
(3b) Both "RME" articles have lists of sources for components (e.g. Paint from du Pont,"Engine, diesel" and "Shutter operating mechanism" from Fairbanks, Morse & Co). Both lists credit the "Power plant regulator" to GE. (GE also gets credit for "Electrical equipment, fans and blowers," "Speedometer," and, on the Union Pacific units, "Trucks, fabricated steel.")

(3c) The May 1948 article has three paragraphs on "Locomotive Control" (coming after a four paragraph section on "Amplidyne Excitation System"). First paragraph introductory, saying in part
"The two major divisions of the control are a power plant regulating system, and an amplidyne excitation system for the main traction generator. Electric power for operrating controls is obtained from the 64-volt control battery and a 400-cycle, 115-volt, motor-driven alternator. Hydraulic power for operation of the governor hydraulic cylinders is obtained from a motor-driven pump which supplies oil at 125 lb. per sq. in."

Since the original articles are over 60 years old (and Newton K. Greg/Publisher's reprinting dates back to 1977), I'm going to assume there are no copyright issues and transcribe the last two paragraphs in their entirety. There's no model number, but perhaps the description will let you tell whether it sounds like the GE "17MG-x" system EDM5970 referred to.

"The power-plant regulating system is a hydro-electric system making use of an electric speed-measuring, speed setting and stabilizing system which controls a hydraulic servo-mechanism with sufficient power tooperate the engine fuel racks. A small a.c. generator measures engine speed. The associated electric circuits compare this speed signal with the speed setting of the system and operate a "pilot" control valve in the hydraulic serco-mechanism which in turn operates the engine fuel racks through motion of the slave power piston. To simplify multiple-unit operation, the position of the master controller (throttle handle position) is transmitted to all engine controls by four train wires and four speed setting control relays at each engine."

"Engine speed is regulated by either fuel or load adjustment. Regulation is accomplished by adjusting the fuel flow up to the "fuel limit" for the engine speed. (The system includes a variable fuel limit which automatically adjusts the maximum permissible fuel rate for optimum engine performance and life at any given speed setting.) For all operating conditions where the separately excited traction generator tends to load the engine beyond the power available at the preset speed and "fuel limit," the governing system controls the generator excitation to match the generator demand to the engine ability. (A control rheostat operated by the hydr0-electric servo-mechanism controls the amplidyne exciter to regulate load demand.)"

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So? I don't know anything about the details of all this. I would ***think*** that GE's amplidyne excitation system could be coupled to a variety of engine governors, but I don't know how integrated the two parts of the control system are.

(4) about engine ratings. Will suggests two alternatives to my interpretation (that it reflects a failure of the Erie-built to deliver full advertised power consistently) of the New York Central's diagram: that the units were downrated (to reduce the strain on high-maintenance diesels) or that the ard is erroneous. Both possible.

I think I remember reading, though (probably in one of the "Trains" articles by Robert (?) Aldag) that the Erie-built's engine control led to loss of power under some atmospheric conditions (and that other locomotive models of the time weren't as badly affected). I think I'll be able to find the relevant article when the basement is done...

As to ratings on old Alcos, a number of factory-rebuilt RS-3 (etc) units with what Alco called the "250" engine were rated at 1400 hp. I suppose because reduced maintenance was seen as more important than high power.

Anyway, thanks again for (both of) your comments!

(Footnote: there are two slightly unobvious documents about Erie-builts at George Elwood's http://rr-fallenflags.org : in the collection of operating manuals, the one indexed as for a C-liner is actually for an Erie. And, NOT indexed with the manuals, but linked at the index page for locomotives at the P.R.R. section there is a booklet of information and operating instructions for several early diesel models that the P.R.R. produced for its own staff.)

As far as that old article reference to the loss of power in a temporary (failed) sense, I bet you're thinking of the fuel limit pilot valve on the 17MG power plant governor. I recall reading that the temporary fix was to pull the cover off the valve indicating stem and shove three pennies under the cap, then replace it. Frankly though this is a case of "monkey-itis" and that's why, for example, later on with the U25 GE put all the control equipment OUTSIDE the cab, where it couldn't be monkeyed with while on the road. Probably what was happening was that the worn out engines weren't loading and overriding this wide open allowed over-injection. Which probably wore the engines out even faster, frankly.

The only way I can see there being an atmospheric effect is if the locomotives were operated in mountainous areas where the lack of turbocharging coupled with the fuel limit prevented rated loading. Turbocharged locomotives would be affected only marginally.

I have only noticed the 1400 HP rating on ALCO rebuilt locomotives on the Milwaukee Road's six axle, four motor units and wondered if that were because they were unable to use their full original 1500 or 1600 horsepower due to their low weight on drivers (about 158000 lbs.) Is this rating applicable to other units as well on other roads?

Oh.. yes, that description is for the same 17MG GE power plant regulating system as was used on all ALCO-GE 244 engine locomotives. Which is what the Erie built F-M units also had.

I still don't know of any good reason why in normal operating condition near sea level the F-M Erie built locomotives should be appraised as being capable of less than their 2000 rated horsepower.

-Will Davis

Will Davis--
Thanks again: I always learn a lot when I get you interested in a question!
(i) 1400 hp Alco rebuilds. I think the Monon's rebuilt RS-2 were 1400 hp, and that the New Haven had some "250" powered units (FA and maybe RS types) at that rating, so I thought it was common. (The weird little A1A-A1A units that MLW built around used 244 engines for CN to use on PEI were also 1400, I think, but in that case considerations of light axle loading and low-density service certainly apply!)

(ii) The same "Trainshed Cyclopedia #64" with the Erie-built articles also has the Railway Mechanical Engineer article on the Alco PA when ATSF 51 was new. (I referred to it back when we were discussing what traction motors were used on early PA units...) It has less detail about the power plant control, but certainly sounds as if it is describing a system similar to that used on the Eries. So unless someone comes up with definite indications otherwise, I suppose our working assumption ought to be that the Eries had the GE 17 MG system. (Which, given the build date, is plausible. Though the F-M 2000 hp endcab "heavy duty" had the same engine and Westinghouse electrical gear, and it seems very unlikely that Westinghouse would have recommended buying a GE engine regulator!)

(iii) When the basement insulation is in place I'll look for the old articles-- Aldag was an ex-FM employee, and I trust his account of technical matters more than I do the average author in "Trains"-- and see if they give more information. (Shoving pennies into the engine regulator probably isn't as downright dangerous as tying down the safety valve on a steam engine, but I certainly can't imagine it being good for engine lifespan!) Hot air is less dense than cold, so a hot summer day would have SOMETHING of the same effect on a diesel engine as high altitudes, but this is just qualitative, and I don't know quantitatively how a hot summer day in, say, Cleveland would compare to mountain operation!

Thanks again.

On the H20-44, you're right, Alan; F-M was using a Westinghouse air throttle (of design specific to F-M units and NOT compatible with Baldwins) and of course with it a Woodward governor set up for air throttle input. The rest of the control was typical Westinghouse, too, and was essentially like that on the switching engines and the road switchers. I think the governor was the Woodward UG8.

The change in air density near sea level due to normal seasonal temperature swings never causes a manufacturer to state the necessity to derate an engine, nor results in actual loss of power on a working locomotive unless something else is wrong. The change in density due to altitude has far more effect.

-Will Davis

We just checked Dave's copy of the PRR operating instructions published 1949 and in the FF-3 section, when looking at the engine governor detail you get referred to the AP-3 section for the description. That's just one more proof that the Erie-built units used the same 17MG series power plant regulating system that ALCO-GE was using on its 1500 HP and 2000 HP road locomotives and 1500 HP road switchers.

(For those saying "What?" On the PRR initially the three unit, 6000 HP F-M freight locomotives were classed as FF-3. The 6000 HP ALCO-GE passenger locomotives were classed as AP-3.. First letter was builder, second letter was service and the numeral was number of units in a set.)

-Will Davis

Thanks, Will! You're a more dedicated researcher than I am: I hadn't gotten around to looking at the PRR booklet yet!
(George Ellwood's "Fallen Flags" site is marvelous, but in this one instance its indexing isn't as helpful as it could be: the link to the 1949 PRR booklet is not obvious. For the record: http://rr-fallenflags.org/prr/prr-dloi.pdf )

To briefly answer Allen's question about how well governors and excitation systems are integrated: The GE 17MG governor, as used on Alcos and some of the FMs, was tied into the excitation system, wether it was Amplidyne, static or Type E. There is a rheostat in the governor which will prevent the excitation system from asking for too much current, bogging down and possibly even stalling the diesel engine. When the engineer opens the throttle, the revs come up, and the rheostat helps match the excitation to the engine horsepower available. (A pretty simple explaination, as I'm a terrible typist and am a bit short on time today-)

Units with Woodward governors (539s, EMDs, GEs, some Centuries, etc.) also have that load control rheostat, again tied into the excitation system, and for the same purpose.

Going back to the 17MG, Allen mentioned relays, from the RME article. The MG17 family has to have an Engine Control Panel, which has a bank of resistors; said resistors control the servo pilot valve in the 17MG. The four relays modify the rcurrent to the governor, per the A, B, C, D throttle commands, (wires 15, 12, 7, 3). The Woodward of course has A, B, C and D valves within the governor. And for what its worth, GE claimed that a 17MG could hold RPM within ONE rev, if set up properly!