GE237 Traction Motor Information

[DERM]

I'm just wondering if anyone can help me with electrical specifications for GE237 traction motors? I'm particularly interested in a characteristic curve but any information would be appreciated
Thanks

[Allen Hazen]

I'm not familiar with the 237: could you give us a hint by saying what locomotives or m.u. cars it was used on? (At a guess, something from the 1930s: early GE t.m. for electric locomotives had two-digit model numbers, and in the late 1930s a new series with model numbers in the 700s was introduced: if you search this forum's archive you can find discussions of some of them.)
(The 287, on the other hand, was used on Alco's HH-600 and EMD's SC switchers: there are New York Central diagrams of these units in the New York Central section of George Ellwood's indispensable "Fallen Flags" rail image site, which might at lest give you a continuous rating…)

[DERM]

Thanks for the feedback Allen. GE237's were used in Australia (Victorian Railways) multiple unit electric sets from the early 1920's. The VR also used them in the locally assembled EMC doodlebugs. Once the original MU sets were scrapped the VR even cascaded the bogies(trucks) and 237 motors into locally built EMD 600hp locos. Some of these locos are still in service today.

[Allen Hazen]

DERM--
I thought you might be writing from Oz! (I used to live in Melbourne: have since moved to Edmonton, Alberta, Canada… which has an ex-MMTB W-class tram that is used on a heritage/touristic tram line on summer weekends.)
--
The re-use of trucks and motors from old e.m.u. cars ("Red Rattlers"?) on diesel switchers (well, they look like switchers to a North American, being an end-cab model, but I suppose were used for light freight trains as well as in yards) in the 1960s is an amazing story. But then, a D.C. motor can last a VERY long time: I think one of the elevator motors in my mother's New York apartment building may have served about 95 years before being replaced by an A.C. motor.
--
The bad news is that I probably don't have any useful information about the characteristics of these motors: I have one book that MIGHT have something, and I'll look, but don't get your hopes up.

[DERM]

Yes Red Rattlers Allen! Ran right up to the mid 1980's Fingers crossed your book has something

[Allen Hazen]

Sorry, nothing useful. The New York Subway system (and its predecessors, the IRT and BMT companies) apparently never used GE 237 motors. (There were New York subway cars with GE 248 motors -- some as early as 1919 -- and also with GE 282 motors from the late 1920s. With some very early ones using GE motors with two-digit model numbers, and more recent ones with model numbers in the four-digit range. Diesel locomotive historians are perhaps most familiar with GE traction motors in the 700 range, apparently introduced in the 1930s: there was a GE 714 that was used on some subway cars.)

This, alas, tells us essentially nothing: traction motor model numbers don't seem to encode any technical data, nor does the numeral sequence of model numbers tell you the date of introduction.

Looking at Kirkland's "Dawn of the Diesel Age," I get a little bit of a sense of the safety margins GE thought appropriate. The early 300 horsepower diesel switchers (with I-R diesel engines) came with four traction motors of a nominal 100 horsepower rating. (I skimmed the chapters that seemed likely to have anything relevant: Kirkland often gives generator and traction motor model numbers, but annoyingly I didn't see whether 237 motors were used on EMC railcars for North American customers. I would think it is likely that the technology package sold to Victorian Railways would have been the same as used in contemporary domestic production, but it would be nice to have confirmation…)

Sorry again. I hope you find useful information elsewhere. (And if you do, I hope you will consider posting a report here!)

[DERM]

Thanks again Allen. I did some more digging and found the following data for GE237(self cooled):

1 Hour Rating = 140hp
1 Hour Rating Amps= 166
Continuous Rating = 90 hp
Continous Amps = 120

Max voltage = 900
Max amps = 300

Armed with this information and the loco with GE 237's tractive effort curve I was able to derive the characteristic curve for the motor

[Pneudyne]

I suspect that the GE237 motor may have been designed for 1500-volt DC electric railway applications, which might explain its apparent scarcity in the USA. Typically such motors were insulated for 1500 volts (probably with larger air gaps than on lower voltage motors), although they operated only at up to half line voltage, 750 volts, as they were used in series pairs. Thus a four-motor equipment in an electric locomotive or EMU car would have had 4S and 2S2P groupings.

As re-used by Victorian Railways on its Y class diesel-electric switching and transfer locomotives (Clyde-GM G6B model), the GE237 motors were rebuilt with improved insulation (Class H) and modified for separate ventilation, which in combination apparently allowed for higher ratings.

Cheers,

[Allen Hazen]

… Which would explain why I didn't find a reference to the 237 in a book on New York subway cars: the subway's electrification (third rail) is 600 v., so a (cheaper?) model of motor, not insulated for 1500 v, would have been appropriate.

(Details on the book on request. It's frustratingly light on technical details; the diagrams reproduced are of different vintages and have different information on them.)

[Pneudyne]

For the first series of the Victorian Railways Y class, with the EMD 6-567 engine and GE237 motors, the continuous tractive effort (CTE) was quoted as 12 000 lbf at the minimum continuous speed (MCS) of 15 mile/h. This equates to 480 hp, or 120 hp per motor. So the rebuilding of those GE237 motors resulted in a significant continuous rating increase. The MCS though seems rather high for this kind of locomotive. In comparison the Western Australian version of the Clyde-GM G6B (WAGR J class), with EMD D29 motors, was quoted as 26 480 lbf at 7 mile/h. So in the VR Y class case, it looks as if the rebuilt GE237 motors still had lowish capacity in relation to the job to be done, although evidently adequate for the job, considering that the fleet totalled 75 built over the 1963-68 period.

Cheers,

[Allen Hazen]

(Tangential comment: nothing particularly relevant to the 237 motors, but about the diesel locomotives they were used on.)

Vic Rail … bought a lot of small locomotives in the dieselization era: power suited to a sort of traffic that has largely disappeared. The Y-class, and even the T-class, are of a power rating that to an American would suggest switching duty, but I think they were acquired with short freight trains in mind. (VR had many 4-wheel freight cars, and was able to do some of its switching with "rail tractors": engine suitable for a farm tractor, on a 4-wheel rail under frame.) In terms of the range of diesel locomotive powers they thought they needed, VR was perhaps more comparable to British Rail than to a typical American Class 1 railroad. So the Y and T classes maybe compare to some of British Rail's Type-1 and Type-2 classes acquired at roughly the same time.

Or, if not exactly British Rail, given the far lesser population density, perhaps to CIE, with its fleet of 8-567 engined power.

(I moved to Melbourne somewhat later, in the 1980s. By that time Australian railroad freight business was changing radically: a lot less of the "retail" light duty the Y and T classes were bought for, more concentration on "wholesale" business: hence the C and G classes in the 3000 hp range.)

[Pneudyne]

Quite a few of the Australian state railroads acquired locomotives of around 1000 hp for secondary and branch line duties in the 1950s and 1960s, and the VR T class fell into this group. New South Wales (NSWGR), South Australia (SAR) and Queensland (QR) all opted for light-axle load six-axle locomotives, to enable their use on lightly-laid branch lines, whereas VR chose four axles. Collectively, this group of locomotives was often referred to as the branch line type, to distinguish it from the more powerful main line group. The branch line locomotives were equipped for road service, with road-type brakes (A7EL or B7EL) and MU, but not dynamic brakes.

The most common branch line type was the Alco DL531, operated by NSWGR and SAR, pertinent here because some of that fleet were fitted with GE electrical equipment, either full or partial sets. Otherwise, GE’s only other participation was in the first group of QR branch line locomotives, which were GE 70 tonner derivatives, and less powerful than the bulk of the branch line fleet.

Below that level, in the realm of switching and transfer locomotives, there was more diversity, including the use of locally built Walkers B-B diesel-hydraulic locomotives. (Which despite their “disadvantaged” start in life as derivatives of an NBL design, apparently performed satisfactorily.) The VR Y was equipped to MU with its larger brethren, but on the other hand had a simple braking system with a #4 automatic brake valve and a Type W self-lapping independent brake valve, the independent not being trainlined. On the other hand, perhaps by circumstance, it had swing bolster trucks, which with their MU car origins, may well have ridden and tracked better at higher speeds than the flexicoil trucks under the T class. On the other hand, the SAR’s home-built 500 class, generally similar to the Y albeit a little lighter and less powerful, had rigid bolster trucks, was not fitted for MU, but had A7EL brakes to cover any main line use.


Cheers,