• Conrail 2789-2798

  • Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.
Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.

Moderators: AMTK84, MEC407

  by Allen Hazen
A 1989 Conrail diagram book, available on the WWWeb at George Elwood's marvelous "Fallen Flags" railphoto site, lists Conrail 2789-2798 (the last U23B-- and last domestic U-series diesels-- built) as having the GT581 main generator. Other sources (e.g. the U23B roster in "Extra 2200 South" issue 75) list these units as having the GTA-11 traction alternator.
My SUSPICION is that the Conrail document is in error. (A few pages earlier it lists 2777-2788, the U23B built for the Lehigh Valley, as being ex-Penn Central, and, as Descartes said, "it is prudent never to trust completely those who have deceived us once." (Grin!))
I think some of these units are still in existence, having been sold to shortlines. Does anyone here know for certain what sort of transmission they had/have?

  by mp15ac
I'm not sure, but I recall that originally U23B's came with DC generators, but later may have had the AC alternator available as an option.


  by Allen Hazen
Yes, the first U23B (the D&H units of 1968) had GT-581 DC generators. The second order, however (the C&O units of 1969) had AC/DC transmission. This option-- at least initially it seems to have been an extra-cost option-- became more popular as time went on. According to the "Extra 2200 South" roster previously alluded to, just under half of U23B had alternators, with AC units forming the majority of production in the later years of the model's life.
Conrail 2789-2798 are a funny case. They were the only U23B ordered directly by Conrail, and earlier "Conrail-ancestor" U23B -- both the Penn Central units and the dozen Lehigh Valley units (which were apparently paid for by the USRA, the government agency that oversaw the transformation of the northeastern bankrupts into Conrail) had DC main generators, so it would not be surprising if Conrail had gone with the GT-581 for the sake of standardization. On the other hand, the GTA-11 seems to have been superior from an operational and/or maintenance standpoint, so (since they had lots of government money to help them get started) it ALSO wouldn't have been surprising if they had gone AC/DC.
I don't have Greg McDonnell's "The U-Boats" handy, but I'm pretty sure the roster in that volume agrees with the "Extra 2200 South" roster in saying that the Conrail order was for AC/DC U23B. On the other hand, the McDonnell roster seems to have errors: there was a long discussion on this forum a couple of years (?) back, the upshot of which was that a bunch of U28B that McDonnell lists as AC/DC were almost certainly DC/DC.

  by EDM5970
One of the few GE schematics I have for GE locomotives in my Alco collection is for the LV U-23Bs. I don't know if this will add anything, but LV 501-512, later Conrail 2777-2788, were indeed built with the 5GT581F1 main generator. Other salient features were dynamic braking, 5GE752E8 motors (74/18 gearing), three field excitation (5GY50B1 exciter), and the advanced engine speed schedule.

My understanding is that USRA paid for these units, and that they were intended to be used on the Valley's fast TOFC/COFC trains, which I believe were the Apollos and Mercuries. The advanced engine speed schedule was supposed to be an advantage there.

I'm curious as to whether Conrail ordered their own, later units with the advanced engine speed schedule, and also if the Valley units ever got converted back to a normal throttle schedule. Standardization?

At the risk of tangling up threads here (which I'll take, with a big grin!!!), it seems to me that running higher revs for more of the time will shorten engine live (power assemblies and bearings) as well as generator life (brushes and bearings), to say nothing of increased wear on the eddy current clutch/RA drive and the compressor.

I've had the same thoughts expressed above in regard to the U-34CHs and the Amtrak and commuter agencies F-40s. Its a waste of fuel and engine life to use a 3000 or 3600 HP V-16 engine to generate 500 to 800 kW of HEP. Moving the train seems to be an afterthought (another big grin). But perhaps this (mis)use of big diesels contributed in a small part to GEs being thought of as throwaways.

(OK, call in the thread police-)

I will make this comment, about the LV U-Boats. They had a switch, on the control stand, that moved the idle speed, up to the third notch, for switching in the yard. The theory was, with the engine already reved up, it would be able to kick cars. The switch, when operated, did rev up the engine, but EMD would not have to worry, about the competition coming up with a suitable switcher. I noticed no benefits, to the operation of the switching feature, when it came to performing switching work. Regards :-D

  by Allen Hazen
All the sources I had seen were agreed that the LV U23B were DC/DC, but thanks! Given the general reliability-level of railfan scholarship, it's good to get further confirmation. (I think the Conrail diagram book on George Elwood's site says "GT581F1," but either the original wasn't too well printed or the image was degraded in scanning: the "F1" part is hard to read. So thanks again!)

Golden-Arm AND EDM5970--
There was some discussion of switching modifications to Conrail's B23-7 on this forum a LONG time ago (probably before one of the occasions on which the archive was lost, alas). I can't remember exactly what was said, but I ***think*** Conrail had its B23-7 set up with some modification to their throttle and excitation systems to make them better switchers: possibly a switch such as Golden-Arm mentions on the LV U23B. So, if I had to GUESS at this point, I would guess that CR 2789-2798 had a similar modification. (But if GUESSING was good enough, I wouldn't be posting questions, and wouldn't have the pleasure of learning from the more knowledgeable people on the forum!)

  by Allen Hazen
Well, I finally got around to doing what I should have done at the outset: looking at the OTHER Conrail locomotive documents on George Elwood's site!
One says, in a list of the equipment on different models, that all U23B had DC main generators: since this is an abbreviated summary list, I don't put MUCH faith in it.

I didn't see anything that looked like a mention of special, switching-friendly, excitation schedules. About 69 of the 98 U23B -- randomly through the series -- had "Harmon Selecta-Power," whatever that is. (??Fuel-saving equipment that, when the full power of a consist isn't needed, allows some units to be put into idle and others full power rather than having all at some, less efficient, intermediate notch??)

2789-2798 were the ONLY U23B with anti-climbers, with cabs set up for "clean-cab" radios, and with clearance for operation in third-rail territory. They had the same "power knockout" (??engine shutdown in event of emergency brake application??) system as the earlier Penn Central units; the ex-LV 2777-2788 had a different (?more sophisticated and more expensive?) system. ... 2750-2776 (the second Penn Central order, low-nose but acquired while PC had an ex-Southern Railway man as president) were, along with 9 GP38, the only units listed as having "bidirectional" cab controls.
None of which answers the original questions. Something which disappoints me, but-- given experience in other areas of scholarship-- doesn't surprise me.

  by LCJ
That's an accurate description of Select-A-Power. For a while in the early '80s, there were competitions between engineers for using these devices the most for fuel saving purposes. The jury is still out on whether the actual fuel savings was greater than the damage done to over-worked traction motors, though.

As for the power knock-out, there were two types on CR locomotives. One type, which had been used by PRR, would not activate the pneumatic control switch (PCS) except when there was a penalty brake application, or if the automatic brake handle was placed in "emergency." A train initiated emergency application would not activate it. Almost all CR units were equipped this way as a matter of policy.

I should say at this point that the PCS, when activated, would bring engine speed of all units in consist to idle, with notch 1 power (it did not shut down the engines).

A second type of PCS was as used by NYC. This set-up, in addition to activation by penalties (dead man or automatic train control activations) and handles-in-emergency-position, would be activated by any emergency brake application (such as a break-in-two or burst AB hose). CR used this type of PCS on all units that were regularly used for mountain helper service. That way, if a train went into emergency while being pushed up the mountain, the helper's power would immediately be cut, thus avoiding compression derailments ("pop-outs").

A few former Central units retained this type of equipment until retirement in the early '90s. An example I can think of is some of the GP30s that spent a good bit of time in storage anyway. Perhaps the former LV U23Bs are in this category as well.

As for these "bi-directional" units, while that was the official description of them, they were actually set up to be primarily operated long hood leading. Running them on the road in the other direction was very awkward and uncomfortable, since the operator had to turn the seat around and have the controls sort of behind him/her. They were not really any more "bi-directional" than any other unit in the fleet.

The various bits of information about locomotives in the booklets CR issued to personnel were intended to be relevant to operating them. Thus, the type of main generator was not part of that thought process. There really was no difference for an engineer operating a DC/DC unit compared to an AC/DC unit.

That being said, Allen, my guess is that these final U23B bombers were probably alternator equipped, since that was pretty much the standard by the time they emerged from Erie -- on the cusp of the -7 series.

My opinion remains that all of the U23Bs were minimally effective as locomotives -- especially as compared to the GP38 and GP38-2.

I'm not sure, if the "switching selector" feature would be mentioned, on the docs on those locos. EMD has a similar feature, in several variations, on it's switchers, Geeps and even SD series of locos. A manual selector/transition operator, on older equippment, and a rotary version of that, as well, but mounted on the control stand. Typically it would be labelled as "switching, switching series, road/auto" The last variant was just a switch, also control stand mounted, labelled "switch/road", and it operated up and down, like the other switches on the EMD control stand. The LV switch was identical to the other switches, on the U-Boat control stand. It was left of the controller handles, just right of the independent brake. Up was the mode for switching, down was for "normal". Every LV U-boat I ran, had this feature, I don't recall seeing it, on any other locos, though. Those "Select-A-Junker" boxes, were added by Conrail, to all road locos, for reasons mentioned by LCJ above. They would drop the locos back to first notch,(not isolating them) starting at the rear of the consist, with each loco being dropped being the next one in line, towards the head-end. Dynamic brakes were un-affected, by this feature, and the box only allowed control of six locos total. (the lead unit was first on the box, but un-controllable, as far as isolating via the Select-A-Power feature.) A very innovative feature, that unfortunately, never caught on, with any other roads. Regards :-D

Last edited by GOLDEN-ARM on Sat Jul 15, 2006 12:12 am, edited 1 time in total.
  by H.F.Malone
CR U23B 2798 became P&W 2203 in 1990, and was acquired by Railroad Museum of New England from a loco dealer in 2003. It is a regular unit operating on RMNE's Naugatuck Railroad in Connecticut (www.rmne.org).

NAUG 2203 is equipped with a GTA11 alternator, not a DC generator. Also, no anti-climber like the B23s have, and I have yet to see any "switching switch". It is indeed possible that it was removed by P&W or CR. It switches cars fast enough, not quite up to the speed of an RS-3 though.

P&W did swap out the GSC drop-equalizer trucks for GE FB trucks; easy to change brake shoes, but a bit rough-riding. RMNE would like to eventually replace the FB trucks with GSC trucks.

The last U-boat is in regular service from May to Nov, and is the usual NAUG winter locomotive, as it has been equipped with a standby engine heating system. Interested persons are invited to stop by and see the loco, and cab rides can be arranged, also.

  by Allen Hazen
Thanks for the details! The Conrail 1988 locomotive data book on Elwood's site lists units with "type 1" and "type 2" power knockout. Besides the ex-LV U23B, the minority with type 2 include a bunch of GP30 (those would, I take it, be the ex-NYC units you refer to), two SD45-2 and a few SD40-2: I think I remember that the SD45-2 were assigned Altoona hill pushers. Why the LV U23B got it is a mystery: a cynical guess would be that GE's people asked LV's what they wanted, and the LV people said "USRA's paying for these; give us the more expensive kind!" (But if I suggested that on the internet some ex-LV motive power person would correct me and I'd be better informed but VERY embarrassed. (Grin!))
... I like your comment about fuel savings vs. traction motor damage! Seems to me that analogous unforseen side-effects show up in LOTS of places. Isn't technology wonderful?
... I assume the cab set-up on the (nominally) bi-directional U23B 2750-2776 was similar to that used on the Southern's diesels.

H.F. Malone---
THANK YOU! THANK YOU! THANK YOU! Question answered!
About the anticlimber: I wondered about that after I posted last night, since (going by a photo) Conrail's first order of B23-7 (2800-2816) didn't have anticlimbers. I checked on George Elwood's site again: the Conrail 1988 locomotive data book SAYS that ALL B23-7 and U23B 2789-2798 had anticlimbers... proving, I guess, that you shouldn't rely on official documents.
(((And, I am VERY happy to say, I have family in Torrington CT. So maybe next time I am in the U.S. I will be able to visit the last U-Boat!)))

  by LCJ
Allen -- type 2 vs. type 1 PCS was not a matter of expense, I believe. To change a "1" to a "2" merely requires a short piece of copper tube and a couple of fittings to connect the A1 Charging Cut-off Pilot Valve to the PCS. Someone should correct me if I'm wrong about that particular item.

The choice by individual road on this option was based on operating philospohy or physical characterisitics of the railroad. PRR (and CR) wanted engineers to be able to maintain power in the event of a break-in-two, so they could keep the slack stretched and avoid harsh run-ins. Mountain helpers, as described above (those SD45-2 and SD40-2 units in captive helper service in Altoona), had a different purpose/program, of course.

NYC's operating folks felt differently, I guess. I really don't know about LV's approach, or why these units were never converted as the rest of the fleet was.

  by Allen Hazen
I'm better-informed, and not too badly embarrassed. (Grin!) Thanks!
...I had assumed that, since the type 2 was more capable (it shut down in response to things-- like break in the air line or emergency brake application from the caboose-- that type 1 ignored) it was bound to be more expensive. ... Maybe the Lehigh Valley's motive power chief in 1973 or 1974, when the units were ordered, was an ex-New York Central man: your guess is almost certainly better than mine!
...Actually, the list of units with type 2 was pretty miscellaneous, including even one or two GP40-2, which don't strike me as obvious choices for pusher service. Perhaps it just comes down to what parts were on hand when which locomotives came to the shops for overhaul, and the difference wasn't thought important enough (exhept for hill pushers) to be worth a real effort at standardization. But that's just another Allen guess, and we know how much they're worth!

  by LCJ
My thoughts are that it's primarily the heritage of these miscellaneous units with type 2 PCS equipment that leads to them being so equipped. Remember that CR absorbed the fleets of 6 bankrupt roads, each with their own peculiar equipment schedule.

In the mid-'80s there was a bit of an uproar in Philadelphia, as I recall, over the fact that there were still units around that were as yet not painted blue. No doubt there were still some that hadn't been completely "Conrailized" in the air brake department as well.

The ones that never received the full treatment were most likely storage cows that were only taken out in a pinch (like the GP30s, GP35s, oh and yes, U23Bs). The loss of all those solid GP38s (Taken back by EMD on the lease - Ouch!! Conrail bluffed and EMD called them on it.) came at a time when no one expected it -- throwing off plans for obsolescence and more immediate retirement of many of these aging hulks. The ones that continued to run got a few more years out on the road as a result. Needless to say (then why say it?) failure rates were enormous.