Prius-Amazing similarity to rairoad locomotive

Sorry to bust the bubble, but the Prius is even more different from
a diesel-electric loco than you think. The train is a completely
series hybrid, but the Prius uses 72% of its engine output to
DIRECTLY drive the wheels. And wastes as little of the regen as
possible. Unfortunately for a locomotive to capture most of the
energy stopping an entire train would require one or more cars
full of batteries, in all likelihood.
.
I would hope the railroad industry is nonetheless working toward
designs that aren't quite as wasteful. Trains are *very* efficient
to begin with; if hybrid-car technology could help improve their
fuel consumption, that might help give rail infrastructure more of
the attention it has deserved for the last, oh, 100 years.
.
_H*

 

As a switch engine, hybrid locos have been around for several years.

Green Goat

[Broken External Image]:http://www.railpower.com/images/Picture8_000.jpg

Now that's a battery pack.

 

Actually, pure electric locomotives sharing a common power source (power plant) are more efficient than a diesel-electric, to nit-pick. It's the "plug-in versus hybrid" debate.

But yeah, it's no secret diesel-electrics have been in service for half a century, and for good reason. Of course, those locomotives do not need to be lightweight, nor do they need to be cheap, and both of these were challenges facing the hybrid-car engineers.

 

Husband, Dan, says power companies have been using hybrid trucks as service vehicles for years. Don't know who makes them but I bet it ain't an American company.

 

The DC series diesel-electric locomotive is closer to 60 years old. You have the advantage of enormous torque from a dead stop, and it's easy to run the locomotive in reverse with the same torque and speed, with no loss in efficiency.

I'm sure we have all seen 2-4 diesel locomotives pulling a long heavy train of cars behind. Not all the locomotives have to face the same direction, the master control in the head locomotive can easily control the "slave" locomotives behind at synchronized speed.

The Green Goat is used for yard switching work.

 

I had no idea that locomotives operated in this way! So this thread has been really informative and I thank everyone for it!

Jan

 

Our Washington State Ferry boats work about the same way -- huge steerable electric motors, powered by diesel-charged batteries.

 

I think the Pruis drive system is closer to the one developed by the Owen Magnetic Car company. Like the Pruis, the Owen Magnetic has a transmisson consisting of a generator and electric motor attached to the drive shaft. Acting like a clutch, the generator would power the drive motor, as the speed of the drive motor increases to match that of the gas engine, the generator becomes magnetically locked with the gas engine. There is no mechanical connection at any time between the rear axle and the gas engine, all the torque of the gas engine is transmitted to the wheels by magnetism. During braking, the drive motor could act as an electric brake. Owen built cars between 1915 -1921. I will try to upload a pdf from Dyke's Automobile Encyclopedia explaining in more detail the working of the Owen's Entz transmission.

BTW: Ralph Owen did hold a few railroad patents for his drive system

 

I've explained the Prius' dual-propulsion system at least a half-dozen times to my 82-year-old father-in-law - a retired engineer with a life-long fascination with locomotives - but he keeps defaulting to the old diesel-electric model with which he's familiar. He simply cannot conceptualize the Prius being propelled by both the engine and the motor.

 

The main issue with pure electric is the need to string and maintain the overhead wire system. Also, pantographs are sometimes very fickle in inclement weather and third rails are not easily protected from accidental contact.

The main reason that diesel-electrics have been around that long is because GM manage to sell a bill-of-goods to the railroads using the idea that they could reduce the number of engine crews and that they could reduce the roadbed maintenance since the D/E was a lot easier on the rails than the large steam highly efficient engines that were just emerging. What they neglected to tell the railroads was that the engines they provided wouldn't pull anywhere near as much load and the railroads would have to buy/maintain a lot more motive power. In addition, as cars got heavier and longer it took the railroads some time to realize that they really couldn't save on roadbed maintenance or you would end up with your cars pushing the rails apart.

So today, you have a vast network running diesel-electrics that are using oil at a rate that cannot be sustained. At the same time the technology for developing clean coal burning locomotives with high traction power has been all but lost. This in a country that is rich in untapped coal reserves.

 

Agreed! Thanks!