I can’t speak for anything else, but mechanically injected EMD engines have a throttle handle: the layshaft.
Of course it’s on the engine instead of being in the cab.
Found some additional info
https://www.oocities.org/wbd641/BLWcontrols.html
https://nycshs.files.wordpress.com/2014/12/gravelgerties.pdf
not sure if this applies https://patents.google.com/patent/US2546023
See section D-8-11 (ff) for how this is done on Baldwin 600A engines:
https://www.supremecourt.gov/opinions/URLs_Cited/OT2011/10-879/10-879.PDF
The CKD Praha ‘Baldwin’ engine page at oocities doesn’t open for me whatever I do; presumably it contains a similar manual.
The governor is a Woodward type, and it acts on a layshaft with similar function to the rack on an EMD, so the two can be said to be the ‘reverse of throttled’ (more fuel fed as the shaft is moved) although the actual injector mechanisms are different.
It will probably be amusing to you all, but I read the Gravel Gerties article with great interest a few years ago… but did not scroll all the way to the bottom when reading and never saw the arrangement diagram for the MU throttle. The pneumatic actuator shown would act on the Woodward governor, and if I recall correctly later specifications for the 608A read almost identically to the earlier ones with only the substitution of ‘electrical’ for ‘hydraulic’ control input – someone like Matt Imbrogno will likely have firsthand experience with the ‘AAR MU compatible’ version of one of these.
The patent cited was for a cockamamie scheme using either compressor bleed or turbo/supercharger static boost pressure to regulate, among other things, the carbon-pile load regulator mentioned in the Gerties article directly (note the reference to gas-turbine control, a ‘hot topic’ for Westinghouse in the late '40s leading up to the Blue Goose B-B-B-B locomotive) if I’m reading it correctly. The system used in the production Baldwin diesel-electrics does not involve this (although theoretically it ‘could’); to my k
https://www.oocities.org/wbd641/BLWcontrols.html
This link is an archive of a geocities link mentioned earlier in this forum.
it outlines the Baldwin D1 Controlair, the CE-100 control and the XM-781 controller.
The pneumatic diagram in the Gravel Gerties article, does not detail the pneumatic to electrical interface described by Imbrogno. The Westinghouse patent drawing link helps the imagination to see the possible electrical interface.
in any event it can be easily summised that the air throttle was not compatible with the adopted standard for MU. The notch system was a carryover from the trolley days, worked for its intended purpose, was familiar to operators, and did the job.
A small consideration for the air throttle system might have been improved fuel efficiency, certainly not ease of maintenance…
I will have to wait to reply until I get to a computer; either crApple or $@&#% Kalmbach keeps resetting pages and ‘saving me from myself’ by trying to access the cached oocities content – which is there; I tricked iOS Safari into displaying it exactly once, from the second time the link was posted, but never again.
That was enough to confirm that all three things, the ‘Carbonstat’, the carbon-pile device in the Gerties article, and Imbrogno’s soft starting all refer to the same thing: load control, where the Westinghouse system does with pressure on the equivalent of a telephone carbon-button transmitter what an EMD load regulator does with rotation.
That is not a function of drive to the Woodward governors, nor of how they need to be actuated, nor their homeostatic action in holding commanded rpm.
More later.
https://patents.google.com/patent/US2311285A/en?oq=Us2311285a
This may more accurately show the throttle/load regulation scheme, and 1941 would better date it.
While not a direct reference to steam, diesel or electric locomotive controls, of interest is a 99 point (notch), PCC car controller operated by a foot pedal. The foot pedal equated to a near linear accelerator/throttle for the electric motors in a street car. To my knowledge it was never adapted to a MU configuration.
Since I cannot get the oocities link to render correctly on any browser I have (or to paste correctly into the forum software) here is what it says (as I recall, this was written by Will Davis):
It is fairly well known in railfan circles that many Baldwin and Baldwin-Lima-Hamilton diesel locomotives were built with air operated throttles, and as such could only operate with similarly equipped units. The actual story is more complicated than that; there were two different air throttles available over the years, and there actually was one electric throttle as well. Let’s take a look at these and examine some of the differences.
Here is an illustration from Baldwin manual DS-107, which is the Operator’s Manual for 660-1000-1500 HP Switchers, Revised 12-1-48. (Yes, road switcher type locomotives which were not fitted with multiple unit controls were referred to in some early manuals as “switchers.”)
https://www.oocities.org/wbd641/blwD1old.jpg">https://www.oocities.org/wbd641/blwD1old.jpg
This control stand contains the simplest and earliest air throttle, which was known as the D-1 Controlair. The throttle handle is No. 24 on the drawing; the slot for insertion of the reverser is just below it. Pulling the throttle back towards the engineer results in the air throttle mechanism increasing air pressure in the “throttle pipe,” which acts upon the governor on the engine to increase engine speed. In some units, there is also an air operated Carbonstat Load Regulator which serves to control generator loading which is also connected to the throttle pipe. In all units which use this D-1 throttle, also connected to the throttle pip
There are a couple other relevant videos he posted: one is
PCC4609_4cam_Accelerator
which shows the coordination as the limit relay is modulated with the foot pedal.
Note his comment that the dynamic braking resistances are the ones in this controller! That gives you the proportional braking action…
I had a piece of stereo equipment with a volume control rigged much this way: the ‘premise’ was that a wired potentiometer introduced undesireable inductance into the musical signal, so a printed circuit with about 99 individual contacts each with a calibrated resistor was provided, with a wiper on the volume control knob. I thought this was nifty, but I never saw it used again.
Perhaps a “better” method was the “Opto-Isolator Module” I commented on in years past, in the Collins Radio mixdown board provided with our original stereo-FM broadcast transmitter at WPRB. This provided essentially stepless volume control in each pot, without any distortion. These were beautiful spun and brushed-finish modules, with proud enameled etched markings, that plugged into an octal socket. When one of these went out, we actually arranged to have a replacement overnight couriered to Newark Airport (the fastest service available then!) before the chief engineer and I figured it could be no harm to open the thing up and see the complex wonder inside.
What was inside was a flashlight bulb – a threaded bulb with soldered connections, to add to the kludge – shining on a photo-Darlington. Turn the pot up, the light got brighter, the Darlington response shifted … audio volume control without capacitive or inductive changes!
(I went to the local hard
I have to wonder whether this is a way to get around the EMD load-regulator system (which uses rotary control of generator field excitation) by using linear pressure on a Carbonstat to accomplish a similar purpose. He seems to be unaware of the way EMD uses the Woodward governor; he seems to think that primary field excitation is the way locomotives avoid being ‘bogged down’ (as with gas engines in the '20s) not realizing that homeostatic control over engine speed once selected as governor speed input is the way EMD’s successful locomotive control helps assure this.
It would be interesting to see how engineer Stamm would rig this for effective multiple-unit control, let alone compatibility with 8-notch AAR MU – I think it might be difficult to do it effectively with contemporary technology. Thinking about the PCC accelerator, though, leads me to wonder if steps in the progressive resistance could toggle different combinations of solenoids just as they do different contactor combinations in electric-car acceleration, to give proportional engine speed and hence HP range as governed, with the Carbonstat then performing appropriate duty comparable to an EMD load regulator…
I have to wonder whether this is a way to get around the EMD load-regulator system (which uses rotary control of generator field excitation) by using linear pressure on a Carbonstat to accomplish a similar purpose. He seems to be unaware of the way EMD uses the Woodward governor; he seems to think that primary field excitation is the way locomotives avoid being ‘bogged down’ (as with gas engines in the '20s) not realizing that homeostatic control over engine speed once selected as governor speed input is the way EMD’s successful locomotive control helps assure this.
It would be interesting to see how engineer Stamm would rig this for effective multiple-unit control, let alone compatibility with 8-notch AAR MU – I think it might be difficult to do it effectively with contemporary technology. Thinking about the PCC accelerator, though, leads me to wonder if progressive position of the ‘wiper arm’ around the circle of progressive resistances in the accelerator could toggle different combinations of solenoids just as they do different contactor combinations in electric-car acceleration, to give proportional engine speed and hence HP range as governed (that could be sent through AAR-compatible MU wires and pins) with the Carbonstat then performing appropriate duty comparable to an EMD load regulator…
The technology of the air throttle is a reminder of the pneumatic player piano/orchestrions or calculators built from decatron tubes…
Not that I have anything but serious respect for Welte-Mignon, or the technology of fluidic amplification used by the Air Force in the '50s, or the Honeywell proportional control in the A-12. There’s a lot to be said for full proportional control; we have it in most drive-by-wire automobiles, and as noted this ‘could’ be made multiple-unit compliant with a comparatively small amount of technology (strain gages trainlined with some kind of high-rate multiplexing). All you really have to do is equilibrate the strain-gage readings among the engines in the consist, with simple feedback control of the throttle positions when necessary to develop more power at rpm and of the load regulators…
Now, decatrons I’ll grant you are as pointless as EBCDIC … base 10 is sooooo much less useful than base 16.
I think one of the chief attractions of the air throttle (aside from getting around EMD patent coverage) is that most of the components would be familiar to existing shops. One of Westing’s books, I believe, mentions the culture shock involved in putting injector-rebuild facilities for Baldwin engines in one of the PRR shops – the idea of very clean, essentially controlled-atmosphere facilities being alien to their general practice. We might conclude that their working on EMD 567 unit injectors – where a fingerprint on some of the components precludes assembly – would be more difficult still…
Which makes me think…if locomotives had to be built to MIL specs?
They would cost $172 million and change apiece, be design-frozen with flat-pack electronics and ‘EMP-resistant’ Ignitrons, and not be reliable for several more years…
Speaking of ignitrons, weren’t they used in Budd’s shotwelding machine , along with precision timing charge networks, for controlling spot weld time while constructing the Burlington Zephyrs? And back to throttle settings…guess enough has been said…
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You raise a highly interesting point. The original Shotwelding (as used up to construction of the Silver Slipper and the “Michelines”) used a mechanical timer. Meanwhile Westinghouse introduced the Ignitron-tube timer sometime in 1934… but I don’t know precisely when.
Both were described in this article (from 1937):
The way this was written appears to indicate that the Budd Company was preferring to use the mechanical timer system for much of its heavier work later than the time the Zephyrs were built, but I don’t know.
Closely associated with the practical development of Shotwelding was a system that could quickly assess weld quality. The original version of this to be patented was 2093932, which was filed in 1932 but not granted until 1937, not being improved in process; this shows only the mechanical timer. Heitman’s improved version, 2138790 (filed 1935 and granted 1938) clearly references a “Thyratron timer” as an essential component.
Have to do more reading!
(The posts on October 21 and 22, 2008 really answered the original poster’s question regarding ‘why the eight-notch throttle’, so I think you’re right about letting what’s left of the horse find surcease… [;)])
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I see Kalmbach is trying to quadruple my posts again. At least I caught it myself this time.