Yes, the Baldwin-Westinghouse locos that I have worked on have the HL-189 control resistor assemblies.

It is as you described. #5 wire is the 600V feed, and the 140-70-70 arrangement creates a moderately stiff voltage divider with wires 6 and 7 sitting at 300 and 150V respectively to ground. However, I think the resistance of each magnet valve coil is quite a bit more than 35 ohms. With a 150V nominal operating point, the resistance should be around 300-500 ohms. Depending on the circuit combinations, there can be two or even three magnet coils in parallel so yes, it does pull the voltages around a bit but these are simple magnetic devices not precision electronics. A 150V coil will work reliably down to about 75V (50%) and up to 225V (150%) or so without burning out.

I had to do what others described in replacing these oddball resistors with a new panel using off-the-shelf 225W power resistors. It would be an interesting project now to experiment with laser-cutting these ribbons from a sheet of high resistance alloy.

JeffH was correct in pointing out that the magnet valve coils are higher than 35 ohms as I had stated. I missed a zero, they should be 350 ohms. I have measured the resistance of these coils both on the locomotives as well as a few in the storeroom and they run between 340 and 360 ohms. Looking forward I have started to fabricate (wind from scratch) these coils. Winding is not difficult, duplicating the wire connections and spool geometry a little more so.

The R and RR series coils can have up to 6 in parallel at once on the Wire6/Wire7 circuit, and up to the same number of the others on the Wire7/Ground circuit. I ignore the two coils on the reverser as they are only momentary if everything is working properly. I am currently working on an Excel spreadsheet HLF simulator using VBA to program the state of the wires and magnet valve relays for changing throttle conditions.

I have thought about giving a buddy who is an Electrical Engineer the problem of designing and building a solid state regulator(s) to replace these two voltages. I'm sure it could be fitted into the current enclosure and would be able to provide constant voltage as the load changes.

Why do you need to rewind the coils? Are they blown?



You may be "overthinking" this! Do you have a control schematic? You did not say what locomotive this is for. It sounds like it might have been dual-voltage based on R1 and RR1. I'll attach a reference schematic. It gives the sequence of contactors: no need to simulate it.



Now, you are definitely overthinking it. There is no need for precise control of the voltages. The magnet valves are very forgiving. They'll operate perfectly fine over a 3:1 voltage range! They are binary devices, on and off. As long as they voltage is sufficient to pull in the magnet valve, it will work. Nothing is gained in the performance of the locomotive by making the voltage more accurate.

There is a tendency now in the railway preservation field to replace something simple, which will be maintainable for centuries, with complicated, sensitive electronics. If the control resistors are defective, I'd recommend replacing them in-kind with off-the-shelf power resistors. I can't find my sketch right now, but I did this for our BW 50 tonner, using standard 225W tubular resistors.

However, with laser cutting becomng so much more affordable, it might be a fun project to make these old WH elements new again using "ni-chrome" or similar alloy in sheet form.

Is it possible that British Rail Class 315 emus might yield some of the parts that are being sought, as these cars used Westinghouse components?

The last of these cars were recently withdrawn from revenue service and many are now headed to the breakers.

There is a preservation group dedicated to these cars, with more information on their website: https://www.class315preservationsociety.com/class-315-history

I got into creating coils from scratch because the quote for an old Westinghouse relay coil was $950. I was able to fabricate a new coil for about $25 in material plus my free time. WH magnet valve coils are a little more complex but there is no reason one cannot be fabricated. The locomotives have considerable vibration pulling tonnage on grades and occasionally we loose a magnet valve coil. I want to ensure, if needed, there are drawings and instructions on how to create these new from scratch. Of course, if you have a reasonable source of supply . . . . .

WH drawing number 813009 for a 600 volt HLF control for 1920's class C is the only drawing that I have obtained over the years. It is close to the actual locomotives but there are a couple of changes. I think it was a pre 1920 drawing and that changes were made for the 1920-1924 builds. We have a class D that is different yet but I haven't had the time to trace the circuits. My goal is to produce an accurate circuit drawing, including wire numbers, for what we have.



Tubular resistors for control appear to have been used before 1920. That means the paddle resistor boards were a modern replacement. The Ohmite 225 watt tubular resistors have also been used for headlights, the case placed inside of each "nose" with the air compressor. A common failure, due to vibration, is that when a wire breaks within a resistor a high resistance gap is formed and it gets hot enough to finish the break as well as actually melt the ceramic material in the break area which drips on things.

If you have a copy of the WH HL instruction pamphlet which is dated 1911, it contains a photo of the control resistor and it is clearly the "paddle" style. The photo that you posted looks like a modern replacement for the failed paddle resistors.