Some musings on future power trains

rgatijnet1 wrote:
You really over-complicated that. First off there are computers now so synchronizing multiple electric motors is a piece of cake. A train has lower friction on steel rails BUT it still takes a huge amount of torque to get it moving in the first place. Much much more than getting a MH moving, even with rubber tires. Locomotives do not have a bank of batteries to supply power when needed. An electric motor can provide the necessary torque necessary to get it moving and then it will use much less power once the vehicle is moving, just like any diesel or gas engine does with any vehicle. There is no need for a complicated transmission that a diesel or gas engine needs because they have to operate in the engines power band. An electric motor has the necessary torque as soon as the power is applied. Just like the starting torque needed for your AC compressor, or for the starter motor on a diesel engine. With today's battery technology, and with future development, I feel an electric powered RV is there to develope and a diesel back up to charge the batteries is necessary ONLY to increase the range.

But you don't need to synchronize multiple motors on an RV. You are solving an issue that doesn't exist.

It's not so much the huge amount of torque needed. Scaled to size/weight, it will actually be less. The bigger point is once a train gets moving, it just runs along at a steady speed. Acceleration is really a non-issue as they don't care if it takes 5 minutes to get up to cruising speed. As a result, they can size the diesels for cruise speed. For climbing grades, they can actually add helper engines. The big engines in most cars/trucks are mostly related to the desire for quick acceleration with hill climbing largely a secondary issue.

There is a need for a complicated transmission even more so because of the narrow power band. They just figured out that an "electric" transmission is so much simpler that as train engine power increased, they dropped the mechanical transmissions.

Diesel-Electric train engines do not use batteries. They really aren't hybrids (where there are two sources of propulsion joined). The generator/electric motors are only serving as a transmission to get power from the diesel to the wheels.

There may be some advantage in a Plug-In-Hybrid for an RV is the battery bank is big enough to service the house loads for an extended period but your average RV'er:
- Avoids stop and go traffic and this is where hybrids really shine as they smooth out the power demand to the ICE. Running at steady speeds on the freeway, there is negligible advantage to a hybrid.
- Also, the plug in aspect is questionable in an RV. A 40mile battery range works great on a commuter car as most days, that may cover 100% of the travel with charging at home over night. Even a relatively short RV run will typically exceed 100miles, so an RV battery bank would have to be huge. Then recharging at your average 30amp outlet while running air/con and other high demand items will overload the electrical systems at most older parks if these RVs show up in any significant numbers.

If the pure battery powered semis turn out good, that may eventually trickle down to RVs but it will take a while and there will be a lot of issues to sort out.