• U25B gear ratio?

  • Discussion relating to the NYC and subsidiaries, up to 1968. Visit the NYCS Historical Society for more information.
Discussion relating to the NYC and subsidiaries, up to 1968. Visit the NYCS Historical Society for more information.

Moderator: Otto Vondrak

  by Allen Hazen
The "Trains" Locomotive Annual for 2013 has arrived at my local magazine shops.

On page 85, with a small photo of preserved NYC 2500, Kevin P. Keefe reminisces about seeing mail & express train 13 on the Michigan Central in March 1966, with "four U25Bs, shiny in their black-and-white cigar-band NYC paint, rumbling urgently westward with a long line of baggage cars, mail cars, and the requisite rider coach on the end -- doing all of 79mph."

79 mph? By the time the U25B was in production, GE felt that locomotives with 752 motors and the standard 74:18 gear ratio were good for 70 mph (earlier 65 mph seems to have been the standard top speed for units with this ratio), but 79?

Does anyone here know what gear ratio the NYC's U25B had? (If you ALSO know the ratios for NYC and P&LE U28B, NYC U30B and PC U33B, I'd love to know them, too!)

(Also posted to General Electric forum.)
  by Noel Weaver
A lot of times a train being watched from wayside is not traveling as fast as it might appear. Almost all early GE's were geared for and limited to 70 MPH at least on the Penn Central and New York Central. A few Alco Centruy models were OK to 75 MPH while many EMD models especially prior to GP-40 were 65 MPH except for some GP-7's and GP-9's and of course FP's that were OK for passenger service and E units. In short most locomotives that were freight locomotives were limited to 70 MPH which was the top freight speed on the New York Central and also Penn Central in former New York Central territory.
The information I posted here was mostly from an old Penn Central Noretheastern Region Timetable.
Noel Weaver
  by Pat Fahey
Hi Noel
The gear ratio for the following , NYC U-boats and PC U-boats you were looking for , all geared for 70 mph gear ratio 74:18 , Pat.
  by Allen Hazen
Noel, Pat--
Many thanks! I've had a bee in my bonnet about various sorts of GE traction motor trivia for a while now-- evidence in several strings on the GE forum. George Elwood's "Fallen Flags" site has a Conrail locomotive diagram book, but the only high-horsepower U-boats surviving when it was compiled were the four U36B originally built for Auto Train (which did have a higher-speed gearing).
I will check the GE forum now: if you haven't already done so, I will report your answers there.
Thanks again!
  by Allen Hazen
(Oh. If you are seriously into traction motor trivia... The longest string, entitled "PA-1 Traction Motors," is on the Alco forum rather than the GE forum.)
  by RSD15
Diesel Locomotives of the New York Central System by Edson, Vail,and Smith list max speed at,
U25b 70mph
U28b 75mph(2)
U28b 70mph(P&LE)
U30b 75mph
1968 PC timetable list the same except the 2 U28bs are listed at 70mph.
Same timetable list
RS32-2020,2029,2031,2038,2042, 85mph
C430 2050-59 85mph
GP30 2194-97 85mph
GP35 2394-98 85mph
GP40 3000-3104 77mph
The next TT I have is a 1970 list all of the above at 70mph max speed.
  by Allen Hazen
I've never seen the Edson & Vail book, but I gather (it has been mentioned in discussions on Railroad.net forums more than once) it is fairly reliable: information directly copied from New York Central documents. So...

The fact that some, but not all, of the RS-32 were listed as 85mph units suggests to me that the New York Central originally bought them with the same gearing as their C-430, for very high-speed service (after all, in 1961 a 2,000 hp freight unit would have sounded like high-speed and high-power!), but that by 1968 a program of regearing them for more ordinary road-switcher applications had been started: this would also account for the change between the 1968 and 1970 timetables.

The Pittsburgh and Lake Erie, I think, was one of the slower mainlines of the NewYork Central system: a lot of coal and iron ore, and probably not as much fast, long-distance, freight as on, say, the Lake Shore ore the original (Albany-Buffalo) New York Central. So it makes sense that the U28B bought for the P&LE would be have the standard 74:18 gear ratio but that those intended for mainline service on the rest of the system would have been geared for higher speeds.

Why all the New York Central's second-generation EMD units were geared for such high speeds I don't know, but I gather (from something said a LONG time ago on either the NYC forum or the GE forum) that the GP-40 struggled at lower speeds: there was a story of great glee at the GE locomotive factory when it was reported that a bunch of GP-40 had stalled with a westbound freight train on the West Albany Hill, and had had to be rescued by some U25B.

Thanks for posting this information. I will put a reference in the string on the GE forum directing people here.
  by Allen Hazen
For what it's worth... GE, in the 1960s and 1970s, built locomotives with 81:22 and 79:24 gear ratios. 81:22 would give the 75 mph of some of the U-boats Edson & Vail report, and 79:24 would do for the 85mph of New York Central's late Alcos (which, of course, had GE traction motors). (References in posts in the "Traction motor gear ratio miscellanea" string on the GE forum.)
  by Tommy Meehan
Looking at a Detroit-Michigan Division employee timetable, No.19 issued 04-26-66, reveals a few things.

First of all, the schedule shows No. 13 was a hot train. It entered the Michigan Division at Wayne Jct. (MP 255.24 at 1:11 PM) and covered the 173.81 miles to Niles (MP 429.05) in two hours and fifty-nine minutes. No. 13 made one stop in between, at Jackson. That's an average of not quite 59 mph. Only passenger train No. 369, The Motor City Special, beat that time.

On page 18 of the ETT it shows the maximum authorized speed for passenger and mail trains on the Michigan Division main line was 80 mph. However the 2500 series U25Bs are shown as restricted to 70 mph.

What I found interesting was, individual units within a class are sometimes allowed higher speeds. As example, most of the 2020 series RS-32s are shown as restricted to 70 mph but individual units are permitted 85 mph: 2020, 2029, 2031, 2038 and 2042.

Below I pasted the section from the Detroit-Michigan Div. ETT showing authorized maximum speeds for the various classes of diesel power. As you'll see there were exception within classes. A former NYC employee told me that some of the Geeps that are shown authorized 85 mph were probably geared that way to serve as relief or protect passenger power.

Btw, just to add, these are system (not Detroit-Michigan Div.) maximum speeds for the locomotives shown. There's a chart like this in every Central ETT. They also do not, of course, supersede local speed limits.
  by Allen Hazen
Tommy Meehan--
Thank you for those details, and the extract from the ETT!
A dozen years later,
http://www.rr-fallenflags.org/cr/cr-rnbr.html" onclick="window.open(this.href);return false;
(at George Elwood's stupendous "Fallen Flags" rail image site) there is the locomotive speed limit (etc) page from a 1978 Conrail ETT. By that time all the 4-axle U-Boats, of whatever origin (other than the four U36B, which are not shown) are listed as having a top speed (with train-- light engines restricted to 60) of 70mph, as are the RS-32 and C-430. Whether this means that the formerly higher-speed units had all been re-geared, or just that Conrail's operating department was trying to simplify, I don't know.
  by Noel Weaver
The New York Central for some years seemed to have a policy of buying a specific diesel for a specific job at a specific location. You had some RS-3's that were good for 85 MPH while others were good for maybe 70 MPH or so, I do not have my timetables handy right now. They did the same thing with Alco/GE yard engines, a few of them had the control stand right in front of the engineer's seat which made switching moves with cars coupled on the rear very difficult to do. The New Haven used a lot more sense when buying diesels, not geared quite so high but generally suitable for either passenger or freight service as the need be. Our (New Haven's that is) RS-3's did a respectable job on a Shore Line passenger job and they also did a respectable job on M-6 to Worcester or on a Maybrook Job as well. I can't imagine an RS-3 geared for 85 MPH doing a good job on a tonnage freight train, not even on the New York Central which in spite of their slogan "Water Level Route" was not all water level. There were significant grades all over the place.
Noel Weaver
  by Tommy Meehan
Noel Weaver wrote:...You had some RS-3's that were good for 85 MPH while others were good for maybe 70 MPH or so, I do not have my timetables handy right now...
The RS-3s do show up on the Michigan Div. table. Don't forget, by 1966 they had been renumbered into the 5100-5300 series (freight) and 5500 series (thirty-one dual-service units).

5100-5352 were geared for 70 mph. The dual service RS3s were also geared for 70 mph with six exceptions: 5501, 5503, 5508, 5509, 5512 and 5514. In 1966 I'm pretty certain almost all of the units in the 5500-5514 series were assigned to Harlem Division commuter service. Possibly a few more 5500s worked the Harlem as well as I think originally there had been about eighteen in all. However by 1966 they were using RDC cars on the off-peak trains to GCT so maybe there were only fifteen RS3s assigned.
  by Bigt
In the early 1970's, I knew quite a few of the men who operated out of Massena,
New York on the Penn Central. These, of course, were all old NYC men. By this
time, the RS32s had been relegated to yard and local service. The men told me
that the RS32's were purchased by the NYC in 1962 for " the Main Line" in Flexi-Van
service, thus, their higher speed capability. I do not know if by this time they had been
re-geared, but, it would seem likely. By this time, top speed was 30mph on this
line. As I recall, the crews liked these units as they were good haulers.
  by Tommy Meehan
I was curious if Kevin Keefe had a source for his caption about the U25Bs on NYC No. 13 that started this thread, I thought maybe a retired railroader had told him the U-Boats were making the MAS.

Turns out that was not the case. I have contacted Kevin before and he is a very friendly guy. Here's what he told me-
Actually, I had no source for the 79 mph comment, other than my own assumption that the train was doing track speed. I didn't realize the U25B's were geared for 70 max. My mistake. So, my guess is that on that day, the mail train was only doing 70.
He said to tell Allen Hazen "good catch!"
  by Allen Hazen
Tommy Meehan--
If you are talking to Kevin Keefe in the near future, you can tell him I wasn't trying to "catch" him: I was just (as an enthusiastic amateur of the history of locomotive technology) curious. I appreciated his piece in the "Locomotive Annual": I've long been fond of the U25B, and would have been thrilled to see four of them on a mail train running at better than a mile a minute!
B.t.w.: Will Davis has provided interesting historical details in a post to the corresponding string ("NYC U25B Gear Ratios") on the General Electric forum: recommended to those interested in locomotive technical history.