Wal-Mart and future Army vehicles.

So, Wal-Mart has a prototype of a new Peterbuilt/Great Dane big rig. Whether they order it into production remains to be seen.

[youtube https://www.youtube.com/watch?v=NER9X4_gtYk]

I don’t really care about the aerodynamics part, but the drive train is interesting. Spill and I were talking about future Army vehicles (hope to get the podcast edited and published today) and one thing I neglected to bloviate on was the powerplants.

This Wal-Mart prototype uses a small gas turbine to charge a battery bank, and electric motors to actually move the vehicle. 

Today, the US uses the M1 Abrams tank, which famously uses a gas turbine. It, however, is directly geared to the transmission, much as a gas turbine is used to spin the props of a turbo-prop.  That gives the Abrams great power, and more importantly, great acceleration compared to diesel powered vehicles of similar weight and horsepower. The problem is, it isn’t terribly fuel efficient, with the a Abrams being famous for sucking down hundreds of gallons of JP-8 daily.

A hybrid gas turbine/electric plant avoids some of the pitfalls of that turbine inefficiency. First, the horsepower/torque requirement is shifted from the turbine to the electric motors. That means you can likely use a significantly smaller turbine. The turbine isn’t there to move the vehicle, it’s there to run the generator. And you can optimize a turbine and transfer case to run the turbine at its most efficient speed constantly.

Alternatively, when you have a decent charge on the battery banks, you can simply shut down the turbine, and yet still have power available to instantly move the vehicle. As it stands now, Abrams spend a LOT of time idling their turbines. Guess what? An Abrams burns fuel almost as fast at idle as it does when it’s moving.  It wouldn’t take much to configure the turbine to automatically start as soon as the vehicle started moving. And since every time you move, you start charging, that means your battery bank can be comparatively small.

I can easily see a future family of integrated gas turbine/electric motor powerplants for almost every type of Army vehicle. Further, this type of powerplant is very helpful when we’re also looking at the ever increasing electrical loads place on vehicles by sensors and networking.  And if future vehicles rely on lasers for active protection against, say, anti-tank missiles, they’ll need even more electrical power.

This is also very similar to the integrated drive system the Navy’s DDG-1000 Zumwalt class uses.

3 thoughts on “Wal-Mart and future Army vehicles.”

  1. Most railroad locomotives are diesel-electric, too–it’s a proven concept–I just wonder how it would work in the space given for the current tank power pack. I also wonder what such a drivetrain will do to the maintenance system for tanks–I spent four years as a logistics officer in 1st Armored Division, which included the Gulf War–keeping up with fuel and V-packs was very difficult.

  2. This Wal-Mart prototype uses a small gas turbine to charge a battery bank, and electric motors to actually move the vehicle.

    So it’s like a gigantic Prius then, right? 🙂

    Sorry. Couldn’t resist. Sounds like a useful concept, though.

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