>> Again, not looking at the checkbook, could it be even better to get the innards
>> of a Vectron, and replace the traction motors?

> Between the trolley wire and the motor leads, all the electrical equipment has to do is
> take the available trolley voltage and convert it to something the motors can use,
> which would be anything between 0 hz and 25 hz and vary between 100 and 380 volts for
> the original traction motors (if your are going to use only one motor of each pair, it
> would degrade the locomotive's hp by 50%).

Using only one motor of the pair would not be recommended, because of different mechanical load on the drive.

Are you sure that the motors could be operated under DC? (I simply don't know).

Considering that the motors would have to be rewired anyway (also update the insulation), it might be worthwhile to find out whether a comparably rated 3-phase AC motor with the same mechanical connectors would be much more expensive (I have a hunch that there might be light rail motors off the shelf could be used. (12 x 200 kW or so, would give 2400 kW, definitely sufficient).


>> I am aware of one historic vehicle (an EMU) where the complete traction equipment
>> from a (at the time) current EMU was used.

> ORM's Red Bird was motorized with electrical equipment from a North Shore car, no
> drilling necessary to mount the electrical gear to the car's underbody.

That looks like a much simpler job to me, and DC in general is much easier to deal with. I also assume that the age difference of the two vehicle was not thaaat big.

The example I am referring here is an EMU from the mid-1940s, which was equipped with a slider transformer (similar to those lab transformers which allow to get any secondary voltage). This got replaced with a fixed secondary voltage transformer and a single-phase AC thyristor control (kind of comparable to what is used in the AEM-7).


>>In another case, they were apparently in talks with Bombardier for a 4-system TRAXX
>> equipment to put into another historic train. However, they eventually decided to do >> a "soft" renovation, and stayed with the original concepts.

> After speaking with someone familiar with MMTB practices, it won't surprise me at all
> to learn that the cause of the recent trolley fires in Memphis was the result of the
> rebuilder straying from the "original concepts" (like removing the LB protection from > the controllers).

That sounds more like "not so state of the art" in Memphis. I wonder who made the control system of those vehicles.

In the case I am referring to here (an EMU from the early 1960s (yeah, the famous RAe TEE of the SBB), the original concept was "pseudo DC motors" (motors which could be run under straight DC but also rectified (and smoothed) AC)); the 1500 VDC and 3000 VDC control was using series/parallel operation together with "simple" resistors; the 15 kV/16.7 Hz and 25 kV/50 Hz AC got through a transformer and a rectifier and then to the (I think) 1500 VDC drive train.


> There is no reason to go to all the expense and trouble of modifying the quill drives
> for a different type of motor. Besides, changing the number of powered axles would
> adversely affect tracking characteristics. I was once told by a knowledgeable person
> that the PRR experimented with adding traction motors to the pilot trucks but found
> it ruined the GG1's excellent tracking qualities at track speeds.

I am not surprised about that. Really decent tracking without pilot trucks became available only in about 1950.