North East Rails
Budd Rail Diesel Engine FAQ
Further info on Doodlebugs vs. Budd RDCs:
Doodlebugs had a separate, above-the-deck engine compartment right behind the operator's compartment. Both compartments were full-width. There often was a still separate baggage compartment or R.P.O. compartment behind the engine compartment, and the passenger's compartment was last. Doodlebugs usually had a vestibule at the rear end and provisions for attaching additional, unpowered cars. Doodlebugs could be operated from the front only.
Doodlebugs were "gas-electric", "distillate-electric" or, in their final years, "diesel-electric", meaning the prime-mover was directly connected to a generator, and traction motors on the front truck, and only the front truck, operated the train. Two axles, both on the front truck are powered. St. Louis Car Company, among many others made the carbodies for doodlebugs. EMC, among many others, made the prime-movers.
Budd RDCs don't have an engine compartment at all. There are two (one for each truck) GM/Detroit Diesel 6-110 series diesel engines under-the-deck in weather-protected housings. These engines are connected mechanically to the inside pairs of wheels though a "torque converter" quite similar to that which was incorporated into the large WW-2 tanks. Two axles, one on the front truck, the other on the rear truck are powered. It is possible to operate an RDC with a failed engine. This limits the speed to about 45 mph over a 1-percent grade. With both engines operatinal, maximum legal speed (79 mph) can be maintained on a 1-percent grade.
RDCs have vestibules at both ends. A separate operator's compartment (one at each end) on the right-hand side pointing in the "forward" direction, was provided. Additional, powered cars were often attached to the lead RDC. Since the RDC had two control stations, the rear-most RDC would provide the control station for the return trip. The control station in use would control all cars simultaneously.
RDCs were constructed in four configurations, dubbed RDC-1, RDC-2, RDC-3 and RDC-4. The RDC-1 was all-passenger. The RDC-2 was passenger plus baggage. The RDC-3 was passenger plus baggage plus R.P.O. RDC-4 was baggage plus R.P.O. with no passenger space. There was also an RDC-9, which was an RDC-1, had one 610 engine. The controls were only for engine house moves. They were normally the middle unit but in some cases were on the tail end.
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