In the 80s Budd produced the SPV as a new generation RDC. I have the following questions:
Thanks
I remember riding them from New Haven to Springfield in the early '80s.
As happens, one of my projects was addressed at solving an SPV problem. The concept was a “bigger, more powerful” RDC… but the engines would get out of sync on acceleration, and first one truck and then the other would slip, which led to nasty excursions of the governors.
The trick was to figure out the instantaneous torque in the driveshaft (after the torque converter) and derive the rate of change information from a stream of torque information. This could then be used to control a modulating valve in the torque converter and give a ‘coarser’ control signal to the engine governors, so that the acceleration rate could be kept high, and to perform antilock modulation of the affected wheel brakes.
The fun part was that the electronics were entirely self-contained in the shaft, with optoisolated transmission of the signals via a ring of LEDs, and continuous induction charging of batteries inside the shaft via permanent magnets in the ring that held the LED detectors. Everything potted in epoxy and basically immune to hundreds of G of shock… I enjoyed this.
I think the downfall of the SPV, at the time, was that it was a big, heavy, very expen$ive vehicle in a world that didn’t need its capabilities at the time. Locomotive-hauled trains were more convenient, and could have variable consists, add a car or two for peaks, and didn’t put lots of investment out of work when an engine or control system broke. Amtrak got sick of the powerplants and converted their cars to trailers later in the '80s – these IIRC kept the distinctive rooftop ‘humps’; I think CDOT ran them up to within the past few years. Some recent argument about scrapping the 'Constitution liners" has occurred within the last few weeks on the Budd-RDC-SPV and BUDD-RDC Yahoo groups.
I know at least one has been preserved, at the Connecticut Eastern museum: