EE Locos

Hello All:

Firstly, many thanks to Trevor Gibbs for the information he provided in respect of the QR 1200s and the SAR 350s, 500s, 800s and 900s, and to Kevin Lawrence for passing on his excellent database of EE locos.

Re the SAR 500s, I've not come across much information on these. Does anyone know whether or not they have ever been the subject of a detailed technical description in a magazine (e.g. Railway Transportation) or a book? That the design was proposed as a standard, and might have been used by QR and WAGR, is fascinating. One wonders how much the weight and axle load could have been reduced for a narrow gauge version - I guess somewhere in the range 48-50 tonnes.

Still missing from the data are definitive information on the control systems used on the TGR X and Y classes. By its vintage, the X must have had a notched control system, but was it 8 or 10 notches? Logically the Y was the same for MU compatibility. Does anyone know?

Sometime back Ben Scaro asked about the MU compatibility of the EE models and other British locos used in Australia. Maybe the following information will help get to the eventual answers.

MetroVick literature for the WAGR X/XA class shows that it had a 110 volt, 10 notch electromagnetic control system. Thus, in theory, the XA/XB could MU with EE (or other British) locos that had a 110 V, 10 notch EM control scheme, and were otherwise compatible with respect to braking systems and the details of MU wiring. As far as I know, all of the WAGR EEs had continuously variable air operated throttles, so on the face of it, would not have been compatible with the XA/XB.

The CR NSUs had 110 volt auxiliaries, but I don't know whether they had notched or continuously variable air operated throttles. Sulzer, like EE switched from the former to the latter, and NSUs were probably built on the cusp of that change. Does anyone know? The NT's must have been the same as the NSUs for MU compatibility. If the NSUs and NTs did have air operated throttles, then in theory, they could have MU'd with similarly equipped EE locos with compatible brake systems.

Ben also asked about the MU compatibility of the WAGR R/RAs. Some references state that these could MU with the WAGR Cs. So if such combinations were not used, it seems that it must have been for operational reasons. The ex-MRWA F and G classes had the same basic control scheme, but of course there may have been brake piping and/or MU jumper wiring differences.

All of the above assumes that compatibility of the basic engine power output control scheme is a necessary, but not sufficient condition for MU compatibility. Strictly speaking, even this is not true as arrangements for interworking amongst locos with fundamentally different control schemes have been devised. The coupling of 74 volt, 8 notch EMDs to 110 volt, 10 notch EEs in New Zealand has already been mentioned by John Regan in this thread, although I've never seen an explanation as to how it was achieved. I think, though, that this was a one-way system in that the specially equipped EMDs could control the EEs, but not the other way around. Another example is the BR Southern Region scheme that allowed bidrectional control between EMU 4 notch and diesel air throttle systems. In the USA, UP MU'd standard, 8 notch diesel electrics with gas turbines that had 20 notch controllers, whilst (I think) that SP MU'd air throttle Kraus-Maffei diesel hydraulics with standard diesel electrics, and Milwaukee controlled standard diesels from the multinotch "Little Joe" electrics. And of course, in Australia, QR had leading EMDs controlling mid-train air throttle EEs via Locotrol wagons. With the exception of the BR system, I've never seen technical descriptions of any of the above in railfan-accessible publications, and even with the BR system, some aspects remain sketchy.

In the days of electro-mechanical control systems, the complexities of such interconnections probably limited their application. Today, electronics appears to make it a whole lot easier. For example, in South Africa, some of the 50 kV Class 9E electric locos on the Sishen-Saldana line have been equipped with so-called "smart cables" to control trailing EMD and GE diesel electrics in order to facilitate increased train loadings without increasing the electric loco fleet. And the Tranz Rail Arataki system, described in the October, 1999 issue of (NZ) Rails, although designed for remote control of switching operations, could also likely be used as an MU interface between different control systems.

Cheers,

Steve Palmano