• Throttles in 539-powered diesels

  • Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.
Discussion of products from the American Locomotive Company. A web site with current Alco 251 information can be found here: Fairbanks-Morse/Alco 251.

Moderator: Alcoman

  by BabyM
 
I have been looking at the operating manual for the S1, S2, & RS1. It's not clear from the way it's written whether or not the throttle has the usual eight notches, or is infinitely variable, or has some other arrangement of power settings. Does anyone know? In particular, how was it set up on B&O S2s and 4s?
  by jr
 
If a 539 is equipped with M.U., it will have an eight-notch throttle. This allows the throttle setting to be passed through the jumper wires to the trailing units. Non-M.U. units have the continuously variable throttle.

JR
  by BabyM
 
That's what I needed to know. Thank you.
  by AllenPHazen
 
I'm guessing that the operator's manual you have been looking at is Alco TP 107A, the operating manual for S1,S2 and RS-1, available on line at George Elwood's marvellous "Fallen Flags" rail image site, at
https://rr-fallenflags.org/manual/s1-gen.html ?
(Also available at at least one other internet site, by the Fallen Flags version is better formatted, and makes figuring out page numbers a bit easier.)
The early sections of this manual don't give details about the throttle, but later (about page 36 or 37), under the general heading of operation of multiple units, the third paragraph of the section "Single Unit Operation" mentions the eight notch throttle.
I think the final control of the engine was by a Woodward governor, which ***I THINK*** (somebody please correct me if I'm wrong) is designed to give a finite number of throttle settings: eight in usual American practice. My ***GUESS*** is that this was Alice's standard offering: whether they built some S1/S2/RS-1 with different controls as customer options, I don't know.

(TP 107A is in the "Fallen Flags" section devoted to manuals. One manual elsewhere on the site -- under "diesel locomotives" in the Pennsylvania Railroad section of "Fallen Flags" -- is a manual the PRR prepared for its enginemen early in the dieselization process giving instructions for Alco, Baldwin, EMD, and F-M locomotives in one book. Doesn't help with the current question, because it only covers 6,000 horsepower, multiple unit, freight and passenger types, not switchers. But interesting.)
  by AllenPHazen
 
I'm guessing that the operator's manual you have been looking at is Alco TP 107A, the operating manual for S1,S2 and RS-1, available on line at George Elwood's marvellous "Fallen Flags" rail image site, at
https://rr-fallenflags.org/manual/s1-gen.html ?
(Also available at at least one other internet site, by the Fallen Flags version is better formatted, and makes figuring out page numbers a bit easier.)
The early sections of this manual don't give details about the throttle, but later (about page 36 or 37), under the general heading of operation of multiple units, the third paragraph of the section "Single Unit Operation" mentions the eight notch throttle.
I think the final control of the engine was by a Woodward governor, which ***I THINK*** (somebody please correct me if I'm wrong) is designed to give a finite number of throttle settings: eight in usual American practice. My ***GUESS*** is that this was Alice's standard offering: whether they built some S1/S2/RS-1 with different controls as customer options, I don't know.

(TP 107A is in the "Fallen Flags" section devoted to manuals. One manual elsewhere on the site -- under "diesel locomotives" in the Pennsylvania Railroad section of "Fallen Flags" -- is a manual the PRR prepared for its enginemen early in the dieselization process giving instructions for Alco, Baldwin, EMD, and F-M locomotives in one book. Doesn't help with the current question, because it only covers 6,000 horsepower, multiple unit, freight and passenger types, not switchers. But interesting.)
  by Pneudyne
 
Re:

“I think the final control of the engine was by a Woodward governor, which ***I THINK*** (somebody please correct me if I'm wrong) is designed to give a finite number of throttle settings: eight in usual American practice.”


The answer there is “it depends….”

The Woodward New SI and PG governors fitted with integral electro-hydraulic speed control had a finite number of engine speeds, 15 maximum. This was achieved using four speed control solenoids, A, B, C and D, of which the D solenoid also doubled as the shutdown solenoid (on an energize to shutdown basis). This mechanism introduced the well-known triangular plate mechanism upon which the A, B and C solenoids acted. It was introduced with the New SI model circa 1945, and carried over to the PG in the late 1940s. It was covered by US patent 2496284 of

I am aware of the following speed pattern implementations using it, but there are no doubt others:

8 speeds, equally spaced, using all four solenoids, according to the pre-1945 established American pattern, later becoming the AAR pattern, hitherto executed with four-solenoid external electro-pneumatic devices.

8 speeds, equally spaced, using all four solenoids, according to a slightly different pattern used by Lima-Hamilton.

8 speeds, equally spaced, using just the A, B and C solenoids, D for shutdown only.

9 speeds, equally spaced, using all four solenoids, being the AAR pattern with the addition of low idle.

6 speeds, equally spaced, using just the A, B and C solenoids, D for shutdown only.

10 speeds, unequally spaced, using all four solenoids.

14 speeds, equally spaced using all four solenoids.

15 speeds, using all four solenoids plus the overriding solenoid repurposed for speed control, in the Alco DH-643.

The New SI and PG were also available with integral pneumatic-hydraulic speed control. This provided continuously variable speed control, usually directly proportional to control air pressure, between defined limits, the air pressure range being adjusted according to locomotive builder requirements. Solenoid shutdown could be either energize to run (e.g. Alco) or energize to shut down (e.g. EMD). A variation on the control pattern, used by English Electric (EE) and perhaps others, was a divided regime with the first increment of air pressure (30% in the EE case) increasing engine load at minimum speed, and the second increment increasing both engine speed and load.

Where external speed control was used with Woodward governors, then the speed control unit determined the number of settings available. EMD had an external four-solenoid speed control unit that also did shutdown, the governor being fitted with rod shutdown (speed control rod moving in the reverse direction). I have never found a diagram showing the internal works of that unit, though. GE had its own four-solenoid mechanism, the 17MK3, which did the same job. There was also a version of this with just three active solenoids (the fourth omitted and its air cylinder unused) that provided speed control on the MU-fitted Alco 539-engined models, which had a three-solenoid, eight-speed throttle sequence. Here, the three solenoids were labelled T1, T2 and T3 rather than A, B and C. On these, the governors had solenoid shutdown of the energize-to-run type. The non-MU models had direct mechanical control from the throttle handle to the governor. Another variation of the GE 17MK3 unit used all four solenoids to provide seven-speed control on MU-fitted domestic GE 70-ton models. Here the solenoids were labelled T1, T2, T3 and T4. These had Woodward UG8 governors with solenoid shutdown, energize-to-run. (Some export versions of the 70-tonner had seven notch pneumatic control, though.)

Re the locomotives at interest, Alco manual TP-700 might contain the pertinent information on throttle control. It can be found at:

https://www.morscher.com/rr/manuals/Loc ... anuals.htm


Cheers,
  by AllenPHazen
 
Thank you, Pneudyne, for the clarification!
(Also for the link to the Morscher site's collection of manuals: a very useful complement to the collection at "Fallen Flags," including a number of manuals that "FF" doesn't have.)
  by BabyM
 
The manual I have is TP-600, dated 8-51. The section on multiple unit operation starts on page 56, and mentions the existence of throttle notches kind of in passing on page 58.

"
  by Pneudyne
 
Alco manual TP-700 does appear to have somewhat more detail on the matter.

The Woodward SI governor is dealt with on pages 101 to 122, with the PG on pages 123 to 129. Engine speed setting, with a picture of the mechanical linkage, is on pages 130 to 132.

But the MU throttle operator assembly does not appear until page 1901, with no mention as to how it relates to the governor:

ALCO TP-700 p.1901.jpg


It may be compared with the version used on the GE 70-Ton model, in which all four air cylinders were active:

GE 70 Ton GEI-25289C TK-5582.jpg





Cheers,
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