We have a Budd RDC that is in excellent physical condition. This cars current use is as a trailer, and has been upgraded with electric heat, modern air conditioning, and modern electrical controls for the HVAC and lighting, and does not rely on the engines for these functions. The onboard systems can be powered via HEP or a modern undercar generator.

Thoughts of late are that, if only the car could be self propelled again, this would be a great car for use on days with slow traffic or a bus group -- oddly enough, the same premise the RDC was built on.

Problem is, one motor is missing, and the other is in poor condition along with the transmission. For tourist service, operation on one motor would be adequate. Anyone who owns an RDC will attest to the scarcity and expense of parts for the motors, and the reliability and maintenance issues. For those unfamiliar with RDC propulsion, one motor at each end hydrostatically drives one axle on each truck, the other axle on the truck is "free rolling".

Our informal discussions led to the thought of re-powering the car using gen-set concepts/technologies. Hang a large Stadco generator under the car strictly for traction power, use modern electronic controls, and go with a traction motor powering the axle (something of the size found on a GE 44-tonner) instead of the hydrostatic drive. The car would need to propel itself at no more than 25-30mph on level track. This is about where our mechanical knowledge stops, and we're not sure who or where to turn for advice. Is this something that may be feasible? Is it economically viable? If it is, why hasn't anyone done it?

Ideas and suggestions welcome!

Hydrostatic drive components are readily available off the shelf.....I'd first see if everything on the receiving end of the hydraulic pump is in decent or readily rebuildable shape. If so, a standard DDA with a hydraulic pump of adequate capacity is all you need.......some brill cars and Edwards cars were hydraulically retrofitted.

If you do decide to go electric, I think many fo us with old GE critters would be very interested in the genset you choose, and how you control it.

dave

Rather than hydrostatic, there is a phenomenal semi traditional pump/motor hydraulic system offered by Parker. The motors are capable of free wheeling without burning anything up. Really a great design!

In terms of going electric..... Stadco producing 440 3 phase to power V.F.D. motors (likely through a gear box). Variable Frequency Drive motors are available in plenty adequate horsepower ratings.


Just a few thoughts, Jason

The New Haven RR's "Roger William" Hot Rod RDCs had electric motors on the other axles for Grand Central Terminal and the Park Ave. tunnel. The Amtrak Turbotrains and some of the Turboliners had something similar. You may find some ideas there.

Do you have at least one good transmission and axle gearbox? While the Stadco and VFD drive sounds like a workable solution, just how deep are your pockets? The original GM 6-110s were around 275 HP each; I have no idea of how to do the math, but my gut says that you would neeed something around a 100 HP motor to move along at your 25 or 30 MPH. Big bucks for the genset, VFD and motor-

My suggestion would be to look around at some truck junkyards, and see if you can find a late model RTO Cat, Cummins or Detroit, etc. from a wreck. Mate it up to your good transmission; no sense in re-inventing the wheel here.

Colorado Railcar used Voith turbo-transmissions in their DMU's. The units were designed specifically for railcar use and are used in other European DMU's. I wonder what Industrial Rail in Canada used in their RDC rebuilds? I know they beefed up the motor with 400HP Cummins' as opposed to the 275HP Detroits, but can't find any info about the transmissions. I'm not aware of any diesel-electric self propelled cars. I suspect a genset large enough to move a passenger car or two at normal speeds would be too big to fit underneath. Or maybe the mechanical and hydraulic solutions are cheaper and/or easier? However, I would think for a single car at 30mph or less, D-E could be done as already described, but I'd think the mechanical/hydraulic route would require less "kit-bashing" and therefore may be cheaper? I don't know, I figure its worthwhile to look at what others have done recently.

Didn't Philly's SEPTA re-enegine at least one RDC with Jimmy bus engines? I wonder how that worked out -- or maybe that's obvious since you never hear much about it.

Wait...RDC's had hydrostatic drive, as in engine drives pump, hydraulic motor turns axle? Are you sure about that? No mechanical connection, just hoses (just like electric drive is connected only with cables)? I don't believe anything like that was the case. I thought it was a mechanical drive that included a hydraulic torque converter. But I'd be glad to be set straight on this.

Steve

You are correct.

A couple of thoughts on repowering..,.

First, the designation for GM two-stroke engines is the number of cylinders, followed by the number of cubic inches per cylinder. The letter "V" following the number of cylinders (i.e. 6V-71) designates an engine that is in a "v" configuration, rather than inline. So the 6-110 used in the RDCs displaced 110 cu.in. per cylinder and developed 275 h.p. The 6-71, which was the commonly used bus engine displaced only 71 cu. in. per cylinder and was rated at 170 h.p. Thus it follows that replacing a 6-110 with a 6-71 will result in a significantly-underpowered RDC car (and nobody ever suggested that an RDC car in its original configuration was overpowered!). The most common repower is done with Cummins engines, of which there are varieties beyond counting. Turbocharging is to be preferred to reduce engine smoke. Be aware that both the GM and Cummins engines for this application are special products, so-called "pancake" or horizontal engines. They have unique oil pans and oil pumps and other differences; you cannot repower an RDC by simply laying a truck motor over on its side.

Second, the transmission used on the Budd RDC was not a hydrostatic transmission; it was a heavy-duty version of the transmission used for many years in buses, a 2-speed planetary gearset. In low range the panetary gears rotate freely and power is directed through a typical torque converter to get the vehicle moving. In high range, the planetary gears are locked and the torque converter is bypassed, giving direct drive. The shift from low to high is accomplished automatically, but there is a momentary cutout of the engine as the shift takes place. Sound complex, but it was a relatively simple, bulletproof design.

Patient searching may well produce for you both 6-110 engines and the planetary transmissions. Commercial marine and truck power suppliers and stationary generating equipment dealers are often good sources of somewhat esoteric engines, as these engines found a lot of use in fishing boats, back-up power supplies, and oil field equipment. Your friend Google should be able to help you find these suppliers in your area. You might start with a "Wanted" ad on RailSwap: http://www.railswap.com

Mike

Mike gave a real good explaination of how the RDC power train works. I had forgotten about the 'pancake' engine orientation. Think Chrysler/Dodge slant six- Perhaps a smaller, shorter stroke truck engine (small V-8?) could be made to fit?

I don't know about SEPTA doing a repowering; it would make sense because they had a decent fleet of the old Reading cars. I do know that NJ Transit (or maybe, earlier, CNJ with NJDOT money) redid a pair (or even more) with Cummins engines. I remember riding them on the Bayonne shuttle between Cranford and Bayonne.

Somewhere on the web, perhaps here on RyPN, I picked up on the name W. W. Williams, http://www.wwwilliams.com which is a company that specializes in Detroit Diesel and Allison transmission parts and repairs. Perhaps they can be of assistance.

EDM

http://www.4btswaps.com/forum/showthrea ... -Rail-Cars

... Are these photos the original configuration for the Budd Car engines..?

Rather than re-inventing, this may help with a new original prime mover. http://www.scharfco.com/gm6110.htm

Yes, those photos are about as original in configuration as they get-

Why does that guy presume there are no mufflers? Isn't there something between engine and rooftop?

Steve