Generators for GP-15-1

A variety of WWWeb sources tell me that the GP-15-1 had a D-32 main generator. This puzzles me. The D-32 seems to have been a 1960s design. (According to the tables at http://www.thedieselshop.us -- not 100% reliable, but what I have available -- the first non-turbocharged Geep with this generator was the GP-28 of 1963.) GP-7had a D-12, GP-9 a D-12B, GP-18 a D-22. (All from the same tables.)
BUT------- the idea of the GP-15-1 was that it was an alternative to rebuilding first-generation power: indeed, it was originally announced as available ONLY with a Geep of F-unit trade-in! (I don't know if this policy was maintained-- I find it a bit hard to imagine that EMD would have turned away a potential customer who wanted to order GP-15-1 at full price without a trade-in allowance!) And part of the scheme was that the new locomotive would re-use components from the trade-in!

So. How does this work? Are D-12, D-22 and D-32 similar enough that the EMD people, in reconditioning one of the earlier generators from a traded in F-7/GP-7/F-9/GP-9/GP-18 would in effect upgrade it to D-32 standard?

Sorry, dyxlesia rules! The website with the tables of specifications for many locomotive models is the dieselshOP, not the dieselshPO: I transposed the last two letters before dot us.

Hi Allen, I went and fixed the link for ya!

Charlie

Allen Hazen wrote:A variety of WWWeb sources tell me that the GP-15-1 had a D-32 main generator. This puzzles me. The D-32 seems to have been a 1960s design. (According to the tables at http://www.thedieselshop.us -- not 100% reliable, but what I have available -- the first non-turbocharged Geep with this generator was the GP-28 of 1963.) GP-7had a D-12, GP-9 a D-12B, GP-18 a D-22. (All from the same tables.)
BUT------- the idea of the GP-15-1 was that it was an alternative to rebuilding first-generation power: indeed, it was originally announced as available ONLY with a Geep of F-unit trade-in! (I don't know if this policy was maintained-- I find it a bit hard to imagine that EMD would have turned away a potential customer who wanted to order GP-15-1 at full price without a trade-in allowance!) And part of the scheme was that the new locomotive would re-use components from the trade-in!

So. How does this work? Are D-12, D-22 and D-32 similar enough that the EMD people, in reconditioning one of the earlier generators from a traded in F-7/GP-7/F-9/GP-9/GP-18 would in effect upgrade it to D-32 standard?

Allen, I think the plan was to use whatever traction generator was in the trade-in, in the GP15. In the end, so few GP15s were built with Trade-ins(MP was the only one), that they specified D32s for commonality( at least until the last order of 30 when they ordered AR6 alternators). If you look at EMD order numbers you can tell which batches "officially" had trade-ins, at least on paper. Some of the trade-in orders specified all new parts.

BTW a few very late GP18s and the last two Canadian GP9s used D32 main generators.

Jay Bee--
Thank you!
Remarks:
(1) The last (Canadian) GP-9 units were built well after the end of U.S. GP-9 production, so it is not surprising that they got components of a later model than those used in "standard" GP-9. Nor is the use of D-32 on late GP-18 surprising: there are other instances of component changes not being simultaneous with locomotive model changes-- I think some late "7 series" locomotives (F/GP/SD-7 and/or SW-9) were built with 567C engines.
(2) I am surprised that only MP GP-15 were built with trade-ins. Conrail started with a lot of F-7 on its roster, which left at about the same general time as the acquisition of GP-15 in the 1600-1699 series, so I had assumed that these GP-15 had utilized components from the F units. Moral, I guess: Never Assume!

Allen, the GP15-1 does have a D32 Main Generator with a D14. Allen we at CSX inherited several GP15-1 units from Conrail. The GP15-1 units we got do not have Dynamic Braking. These units have a modern day Battery Field Circuit for excitation. They utilize a Battery Field SCR with a Static Load Regulator that you will find on the EMD Dash 2 units. These units have only 3 modules applied to the Electrical Module Rack and they are the "VR" Voltage Regulator, "EC1" Excitation Control and "TR1" Transition Modules. These units are 1500 HP and they will make Transition in the area of 20 mph. Also Allen, these units have a 12 cylinder 645E Engine with a Maximum Continuous Current of 2350 Amps.

WVU--
Thank you for the technical details!
I am puzzled by the economics. The GP-15-1 was billed as an alternative to "capital rebuild programs" -- EMD going into competition with Paducah Shops, as it were -- so I assumed that they would be as cheap, and so use as many recycled components, as possible! I guess ConRail, at the time they ordered GP-15-1, was getting government money to help rebuild their system, and decided that in the long run it was better to have the newer generator model: initial purchase price would surely have been less if they had re-used the generators from the F-7.

Is it possible to take a early design main generator, send it to EMD, and they rewind it to the specs of a more modern design? How similar are the different models?

Engineer Spike--
That's a question I'd like to know the answer to! The economics of the program would certainly start looking more sensible if the D-32 used on GP15-1 were modified from an earlier configuration rather than being entirely built new.
-
For comparison: the General Electric GTA-24 (traction alternator used on late Dash-7, including most if not all B36-7) was structurally similar to the GTA-13 (used on U-series from about 1969 and on earlier Dash-7), and a GTA-13 could be modified into a GTA-24. The economics of GE's "Super-7" rebuilds depended on this. (Or such, at least, is the impression I have from reading.)

Ooops! I had a "senior moment" with my memory there: for "GTA-13" in my previous post, read "GTA-11." Sorry.

I ask the same question about traction motors too. I would guess that the GP15s had D77 motors. One selling point would be the lower minimum continuous speed.

Earlier someone posted about this model having only a few -2 cards. What was used for wheel slip? IDAC, WS10, or some older system?

Re: traction motors
The specification pages at http://www.thedieselshop.us aren't always accurate, but for what it's worth they say the GP15-1 had D-77 traction motors. I put rather more faith in

http://www.gatx.com/wps/wcm/connect/GAT ... es/GP15-1/

GATX: they say a GP15-1 has four D77/D78 traction motors.

I know this post is old, but my post about FT->GP9 trades might shed some light. So could the new SD40-2-> SD30eco rebuilds. I wonder if it was more of a paper deal. The trade ins might donate some parts, but it is really mostly new parts.

Even if new parts were used, the GP15 still would have advantages over rebuilds.Newer traction mothers=better short time ratings. Better wheel slip control is another plus.

A rebuilt geep might be mainly rebuilt outdated junk, depending on how thorough the program was.

Engineer Spike--
Indeed, "rebuilds" are a range: some have more original material, others less. The extreme cases can be essentially "legal fictions." (Non-railroad example: in the late 19th Century, the U.S. Navy acquired a number of warships with the same names as Civil War ships. The new ships were completely new (in at least one case there is a photo of the partially dismantled hulk of the old ship, taken after the new one was delivered), with as far as I know no components of the original incorporated, but they were officially billed as having been re-built from the Civil War ships. Reason? Congress had allocated money for "repairs," and the Navy wanted to spend it on newer, more capable ships!)
I had assumed that the GP-15-1 had incorporated a lot of original components. The publicity when the model was introduced indicated that it was meant as a fairly low-budget unit, meant to compete with things like the Paducah (ICG and Precision National) rebuilds of GP-7 and GP-15, and it had seemed obvious that one way to keep the price down would be to re-use the original generator and traction motors. So I was surprised to find out that they had newer-model generators and t.m.s.
---
There was a lot of locomotive rebuilding in the 1970s in the U.S. Apparently this was in part because of provisions of the tax laws that favoured re-building as against total replacement. I think there is something similar in Canada that is relevant to Canadian Pacific's recent acquisition of 710ECO units. Their GP-22 units are built on new frames and have all-new carbodies, but -- the tax law apparently being worded fairly precisely -- one news story about them emphasized that they DID incorporate enough old components to qualify as rebuilds.

Even if they used new or reconditioned parts, I still think the GP15 wins over in-house programs, like ICG's. The railroad could maybe get the tax advantage of a rebuild. There would be some of the modern advances.

One point which has not been mentioned is fuel usage. I'd like to see how much more efficient the 12-645, or 8-645T is vs. 16-567. Remember that the 1970s = Arab oil embargo.