ATSF 50/50A technicality

[Allen Hazen]

According to Kirkland's "The Diesel Builders, volume 2: Alco" the traction motor used on Alco Dl-10X units (this is the pre-PA, "Needlenose," passenger design) with the high-speed, 58/25, gear ratio was the GE 730. (The GE 726 motor was used on 80 mph "dual service" units of these models: over three quarters of the total production run, given that the New Haven's sixty units had this option.) On the other hand, the ATSF roster published in "Extra 2200 South" (the relevant part was in issue #130 of 2007) says that 50 and 50A, though having 58/25 gearing, had GE 726 motors.

Are there any ATSF locomotive historians out there who can cast light on this?

(I can ***imagine*** an explanation-- the two units were originally equipped with 730 motors, but this was an unusual type: I have never seen any reference to it being used on any locomotives other than the purely passenger Dl-10X. The 726 was probably more available: it was used on the majority of Dl-10X, on Alco HH-1000 switchers, and apparently on some early, 1946-built, locomotives with Alco 244 engines. So, when the motors on 50 and 50A came due for replacement, ATSF used the more available 726 motor instead of the original design. But this is speculation, and I'd be interested in any more
credible information anyone has.)

(This and related topics have been discussed, a while ago, on the Alco forum, but without conclusive answers to a number of questions.)

[SSW9389]

Allen: There is an account in John McCall's Early Diesel Daze about the 50's only trip out west with the Super Chief in 1941. It seems the train stalled on Raton Pass with a steam helper. The steam helper was used on trips over the Pass with EMC diesels and made it. The trip made with the #50 set stalled at the same speed. This suggests that the lighter duty GE motors were installed. ". . . Long before the top of the hill, 50's traction motors were smoking badly...the Super Chief ground to a halt and the maintainer crawled underneath the locomotive. There wasn't "too much solder laying around" so the journey was resumed...with the steam helper doing a larger share of the work than was customary with Electro-Motive Diesels up Raton Mountain. The 50 continued on to Los Angeles and back again with the Super, never again to venture into the mountains of the transcontinental route." . . .see page 113.

IMHO the 50 set was built with the lighter motors and then rebuilt with the 726 motors at a later date. The 726 motor seems to be the big difference between the DL109/DL110 and the earlier DL103, DL105, DL107, and DL108 units.

Ed in Kentucky

[Allen Hazen]

SSW9389--
Thanks, Ed! I've never seen that book, and the story certainly is suggestive.
As for whether the 730/726 motor difference was a major part of the distinction between Dl-109 and 105/107...
According to Kirkland ("The Diesel Builders, v. 2: Alco"), only the 730 was used in units geared for top speeds over 80 mph (most non-New Haven units, in what in most cases must have been gross overoptimism about the speeds attainable on existing track!), and the 726 and 730 motors used different gear ratios for the 80 mph top speed. Elsewhere (article in one of the smaller-circulation model railroad magazines) I have seen a list of the gear ratios used on Alco Dl-10X units. Putting these two sources together suggests that even some very late units (Southern's second order, built after the first New Haven Sl-109) had the 730 motor, and that the GM&O's first units (built very early in the series) had 726. So, it's complicated!
--
We're having insulation installed on our basement, making access to my reference books difficult for the next couple of weeks, but I'll try to get back to you about this...
(Apologies for slow reply: I was out of town and out off computer contact for a bit.)

[SSW9389]

Earlier this week there was a discussion on the Santa Fe Listserve about #50L and #50A. The discussion was about whether it was a DL-107/DL-108 set or a DL-109/DL-110 set was started up by me. And some primary source documents were offered up. The Santa Fe Class 50 drawing shows that #50L was built with four GE-730 traction motors, 58:25 gearing and 41 inch wheels. Then another fellow wrote in that there had been a change to that drawing showing it was rebuilt with four GE-726F1 traction motors, with 40 inch wheels. John McCall's book Early Diesel Daze on p.254 shows the characteristics of #50 as 4 GE-726F1 traction motors, with 58:25 gearing and 40 inch wheels. I don't have a date for the rebuild.

I'm going to cross post this to the Alco list. Allen Hazen and I already discussed this bit a couple of days ago, but hopefully he will add to this discussion.

Ed in Kentucky

[swissrailfan]

Alco's original twin engine PA locomotive was experimental. The PA locomotive was returned to Alco many times for modifications rebuilding and adjustments. The final spec no. to ATSF no 50 is DL109/110. Alco assigned the spec no's after the fact.The only other possible spec no. DL103 was assigned to the first PA that had both radiators at the rear. That locomotive was the RI 624. The ATSF 50 and 50A were rebuilt and modified, EXTRA 2200 South has photos of original built and rebuilt photos. I will try to post the photos later they are black & white.

[chrisf]

Alco's original twin engine PA locomotive was experimental. The PA locomotive was returned to Alco many times for modifications rebuilding and adjustments. The final spec no. to ATSF no 50 is DL109/110. Alco assigned the spec no's after the fact.The only other possible spec no. DL103 was assigned to the first PA that had both radiators at the rear. That locomotive was the RI 624. The ATSF 50 and 50A were rebuilt and modified, EXTRA 2200 South has photos of original built and rebuilt photos. I will try to post the photos later they are black & white.

Alco PA/PB locomotives never had dual engines; ATSF 50/50A and RI 624 are not PAs. Mechanically and cosmetically they're very different.

[Backshophoss]

Alco DL-109 was a 2 prime mover engine for the New Haven RR used on the shoreline between NHV and Boston South Station,as
passenger power,equal to EMD's E-5/E-6 series, The PA/PB were based off of the passenger FPA-4/FPB-4 series.
The PA's were not great on Raton Pass or Glorieta Pass,started/stayed on the San Diegan services on the west coast or ran
on secondary trains routed over the Belen Cutoff routing(Today's Transconn for BNSF) due to the easier grades there
There were a batch of PA's repowered by EMD that gained roof humps in the process,with mixed results at best.
Believe 50(L) and 50 A were the forebearers of EMD's E-series units,Built as oversized Boxcab style locos on B-B trucks

[chrisf]

50A was the B-unit equivalent of Alco #50, of the DL-109 lineage.
http://abpr.railfan.net/abprphoto.cgi?/ ... anColl.jpg

Santa Fe had a couple different EMD boxcab style passenger units, seen at the top of this page: https://donsdepot.donrossgroup.net/dr2517.htm

[swissrailfan]

You seem to be confusing the EMD 1, 1B and later classed 10 boxcab and the EMD demonstrator 512 boxcab then renumbered 1C That AT&SF often leased while the 1 or 1B were in for modifications. Locomotive with the 50 class Alco PA /DL109/110. At no time was any EMD loco motive on the AT&SF were 50 class. Only the Alco PA / DL109/110 and PA1 DL304/305. were classed as 50,51,52,59. EMD were classed 1,1A,2,10,11,11A and 80. EMD's first real production passenger box cab locomotives were TA,EA, E1 thru E9.

[Allen Hazen]

Swissrailfan-- Thank you for the classificatory note!
One terminological point: I know it's very tempting to think of Alco's twin-engined passenger locomotives as "PA-0," but this isn't standard: probably to avoid confusion it is best to avoid the digraph "PA" in reference to them.
I think Also only introduced the "PA" and "FA" designations some time after these 244-engined units went into production: Alco issued a bulletin trying to assign these model designations retroactively to units already in service, but only to the post-War 244-engined types: they didn't try to classify the Dl-103-105-107-109 units as PA.
--
Since you bring up the EMD TA model... They were built while EMD was still using traction motors from GE and Westinghouse. Does anybody recall what model? My guess is that, IF the TA had GE electrical equipment, they would have used 716 traction motors, but it would be nicer to have a documented answer instead of a guess!

[SSW921]

Swissrailfan--
Since you bring up the EMD TA model... They were built while EMD was still using traction motors from GE and Westinghouse. Does anybody recall what model? My guess is that, IF the TA had GE electrical equipment, they would have used 716 traction motors, but it would be nicer to have a documented answer instead of a guess!

Rock Island's EMC TA units were built with GE electrical equipment. Additional TA information will be posted to the EMD and Granger boards. I have to research 16-201A engines first.

Ed in Kentucky