Hello:
I came across the "thread" on ANZ EE locomotive
control system whilst surfing railroad sites, and thought that I might add a
few comments.
In respect of control systems and MU
compatibility, as far as I know, EE more-or-less standardized on air
operated throttles with continuously variable engine speed control from
circa 1954, starting with BR/SR 10203. Before adopting this
electropneumatic (EP) control scheme, EE had used 8 and 10 notch
electromagnetic (EM) control systems with a limited number of fixed engine
speeds and automatic load control (torque regulation) on the top notch or
top few notches only.
Nevertheless, EM control systems were used
on some later locomotives, presumably because of individual railroad
preferences or for compatibility with earlier locomotives.
Information on hand indicates that at least
the following EE locomotives, excluding UK domestic models, had EM control
schemes: NZR De (8 notch); NZR Df & Dg (10 notch); SAR 900 (10
notch).
I'm guessing that the QR 1200 most likely had 10 notch EM
control. And the NZR Di surely did for compatibility with the Dg and
Df, although maybe with more engine speeds and with automatic load control
on more notches than was the case for the earlier models. Does anyone
have full details on the Di control system?
And simply because they predated EE's adoption of EP
control, one can assume that both the TGR X and the Egyptian 16 cylinder
1A-D-A1 model had EM control of some kind.
Of the Australian EE models, I understand
that all of those supplied to QR, MRWA and WAGR had EP control, as did the
SAR 800s. No doubt, though, Australian-domiciled readers will be able
to comment definitively on this aspect.
Also basis information on
hand, the following EE locomotives definitely had EP control, excluding UK
domestic and Australian domestic models: Brazil/Argentina 8 cylinder
A1A-A1As; Zimbabwe DE2 & DE3; and Jamaica 6 cylinder BB. (the
last-mentioned is a close cousin to the SAR 800.)
It seems likely that the Kenya 8 and 12
cylinder models, and the Portugal 1400 and 1800 classes also had EP control,
although I've not seen specific confirmation.
On reference suggests that the Malaysia
Class 20 had notched, i.e. EM control. The few photographs I have seen
show the usual EE MU jumper socket, but not the ESCP (engine speed control
pipe) that would indicate EP control. Even scarcer photographs of the
derivative Sudan 12 cylinder model also do not reveal an ESCP, so maybe
these were EM as well. Both these models had vacuum brakes for the
locomotive as well as the train, a feature shared with one or two other EE
export models, although air-on-locomotive/vacuum-on-train was more usual for
vacuum-braked railroads. But the Sudan locomotive also had
dynamic brakes, so, very unusually I think, must have had provision for
independent control, or at least independent release of the locomotive
vacuum brake.
Unknown to me are the control schemes for
the Ghana and Nigeria 6 cylinder models (both very much like the NZR De
except with Mk II engines), the Ghana 12 cylinder model, and the Malaysia
Class 22/Zaire 8 cylinder model. If the Malaya 22 was MU compatible
with the Class 20 (and I don't know this to be the case), then likely it had
EM control.
I don't know why EE stayed with EP control
and 110 volt auxiliaries, and did not, for example, adopt the US standard 8
notch, 74 volt EM system. Whatever the technical arguments in favor of
each, the latter was surely the de facto world standard by the 1960s, and it
might have served EE better to adopt it, or at least makes its locomotives
compatible with it. Perhaps, based upon UK operations with lower load
factors than say in the US, there was a perceived need for finer control
than 8 notches would allow. E.g., although the majority of first
generation BR diesel-electric locomotives (from all manufacturers) had EP
control, a minority had EM control with 10, rather than 8
notches.
By the way, although 110 volts was standard
for EE control systems and auxiliaries, some early locomotives were
different, such as LMS/BR 10000/1, at 135 volts, and the NZR De, I think at
90
volts.
Steve Palmano
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