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US Army Unveils Hybrid-Electric Propulsion System

Posted by ScuttleMonkey on Sat Aug 18, 2007 12:49 PM
from the we-look-for-things-things-that-make-us-go dept.
Gary writes to mention that the U.S. Army recently unveiled a new hybrid-electric propulsion system for use in a new line of manned ground vehicles (MGVs). The new line will have eight different variants, all using the same chassis. The unique feature of the new MGVs is that the traditional engine has been decoupled from the drive train and is used only to recharge the battery and power other systems within the vehicle.
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  • Choo! Choo! (Score:2, Informative)

    by Anonymous Coward
    "The most unique feature of the new MGVs is that the traditional engine has been decoupled from the drive train and is used only to recharge the battery and power other systems within the vehicle."

    Gee. Kind of like a Diesel Train.
    • Or kinda like the Porsche version of the Tiger II ( King Tiger )
      or the Maus.
    • Hm, I was going to look up a suitable quote from "Diesel Traction - Manual For Enginemen" (British Railways, 1962), but you basically beat me to it.

      They invented a diesel-electric propulsion system. How exactly is this news?
  • Silence is golden (Score:5, Insightful)

    by schwit1 (797399) on Saturday August 18 2007, @12:57PM (#20277889)
    Being able to roll into your position quietly is a huge advantage. This was learned when Strykers replaced Bradleys when doing insurgent sweeps. The bad guys weren't aware nearly as soon.
    • Yep, stealth (Score:5, Informative)

      by b0s0z0ku (752509) on Saturday August 18 2007, @01:09PM (#20278035)
      and also the ability to have an individual electric motor for each of the two tank treads. Right now, tanks use a complicated transmission to vary track speed for turning. Electric motors will actually reduce complexity, increase reliability, and possibly improve turning ability.

      -b.

      • Re: (Score:3, Insightful)

        Or as more frequently seems to have been the case, civillians got an even bigger surprise than usual.

        Civilians certainly haven't been surprised to have armed insurgents forcing them to shelter them (or in some cases, happily sheltering them). If it's coming as a surprise that sometimes those insurgents will be attacked wherever they happen to have set up shop (and now, with a greater element of surprise), one advantage of that is... exactly what's now happening more frequently: the civilians are providin
  • The IC engine can be optimized for its recharging duty. No need to provide gearboxes or variable speed drives to mechanically couple the engine to the wheels.


    Electric drives, particularly when freed from the constraints of having to work alongside IC engines, can have drivetrains optimized for their characteristics.

    • Electric drives, particularly when freed from the constraints of having to work alongside IC engines, can have drivetrains optimized for their characteristics.

      And this will be lighter and simpler than a pure-IC drivetrain. No need for a complex transmission, clutches, etc, to vary the speed of the tank treads in relation to one another for turning. Just power each side individually with an electric motor (or two, if you prefer, for redundancy).

      -b.

      • However, for more extreme requirements of both high torque AND high speed you might run into limitations of electric machine design, which might force you into adding a smaller gearbox anyway.
        • However, for more extreme requirements of both high torque AND high speed you might run into limitations of electric machine design, which might force you into adding a smaller gearbox anyway.

          How do diesel trains do it, since they handle both extreme low-end torque and reasonably high top ends?

          • Re: (Score:3, Informative)

            I agree with you in that there is no need for complex gearboxes.

            But your reply sounds like you consider a planetary gearbox to be simplier than a countershaft gearbox... ;-)
            And by the way: every gearbox is modulating speed and torque of the shafts with respect to each other. You multiply the one with a certain factor and divide the other by the same factor. That's the way it works.
            • Re: (Score:3, Informative)

              But your reply sounds like you consider a planetary gearbox to be simplier than a countershaft gearbox... ;-)

              They ARE simpler -- not necessarily to build, but to control. Everything is done with wet clutches or brake bands, so there's no real chance of breaking off engagement dogs or gear teeth.

              Notice that almost all automatic transmissions before about 1995 used planetary gearsets, not a countershaft system. Good automated countershaft boxes like BMW's SMG and the VW DSG are comparatively recent deve

              • Re: (Score:3, Informative)

                You are gravely mistaken. Countershaft transmission have been around for a long time, actually longer than planetary gearboxes. They are the typical gear box as invented before Christ. You confuse the recent development of double-clutch transmissions with countershaft technology. I design these things, I know. :-) Anyway, also in countershaft boxes the gear-pairs can be in constant engagement, what you use is a sort of spline or wet disc couplings to connect them to the torque-carrying shaft. No need to mo
  • by spectrokid (660550) on Saturday August 18 2007, @01:05PM (#20277983) Homepage
    hybrid or not, this thing is going to pull around a gazillion tons of steel. Tanks are heavy, strong, maneuvrable. They are NOT green. I guess the idea has more to do with being able to drive in "stealth mode" for a couple of hundred meters.
    • by couchslug (175151) on Saturday August 18 2007, @01:20PM (#20278155)
      It does have to do with reducing fuel consumption, which is a huge logistics burden.

      The systems previously developed (this research predates FCS by many years) will go far more than a few hundred meters on batteries alone.
      Now that decent batteries are available, a hybrid AFV looks much better. They can easily drive heavy electrical loads to provide both weapon system and facility power, they can charge each other via slave cables, they provide full torque at zero RPM allowing very slow creep, and if properly sealed can be used for marine assault and fording rivers (even fully submerged with no snorkel) without fear of drowning out (and destroying) a diesel engine.

      This tech will give a huge boost other systems that would benefit from hybridization. Efficient small turbines like Capstone are already charging hybrid buses. These systems can burn clean fuels at optimum rpm, charge batteries, and make for very eco-friendly farm and construction equipment in the future.
      • Re: (Score:3, Informative)

        It does have to do with reducing fuel consumption, which is a huge logistics burden.

        This is especially true since the current big US tank (M1 Abrams) is turbine powered, which causes really awful fuel consumption at idle and low speeds. If the turbine could run at its optimum speed, it would improve consumption significantly.

        Also, being able to turn off the turbine and creep forward would reduce the infrared signature of the vehicle, adding yet another "stealth" aspect.

        -b.

        • by couchslug (175151) on Saturday August 18 2007, @02:08PM (#20278681)
          This refers to the UD effort that predates FCS by many years:

          http://www.angelfire.com/art/enchanter/hybrid.html [angelfire.com]

          Ralph Zumbro, Author of "Tank Sergeant", writes about the Hybrid drive M113 that United Defence have built:-

                          "Phil, The one I was in, and it may be the only one, is state of the art. They steer it with a Bradley gunner's control and it will run for an hour at 30mph on two batteries which are in boxes sized approximately 18"x36"x48". Then a standard issue genset cuts in. The motors are rated at 250 hp each and are oil cooled. It is weird to see a 3 inch diameter drive shaft coming out of a motor the size of a 5 gallon can.
                          The rubber tracks are soundless, and they've got 2500 miles on them with very little wear showing. That adds up to a VERY quiet vehicle for recon work. Put electric motors, rubber tracks and a two man turret with a 30mm gatling weapon on a standard 113 hull and you've got a recon Tankita.
                          I mentioned to the people at United Defense that not needing air for the engine made the vehicle capable of running around UNDER water and was told that that had been thought of. That means that you could add enough armor to stop larger weapons, as long as you don't compromise the mobility."

          More links:
          http://www.defensetech.org/archives/002338.html [defensetech.org]

          Hybrid M113
          http://www.youtube.com/watch?v=RbWbkOkTydk [youtube.com]

          Hybrid HMMWV
          http://www.evworld.com/archives/conferences/evs14/ humvee.html [evworld.com]

    • Re: (Score:3, Insightful)

      Yes, that and the possiblitiy of acutally saving some fuel along the way. For the US Army, shipping fuel to all the remote locations where they are waging a war is a logistic nightmare at a huge cost.
    • Re: (Score:3, Insightful)

      Green is relative. Tearing up the landscape with tracked vehicles and tossing supersonic projectiles around is not very green. But if the vehicles use less fuel and the projectiles are made of non-toxic substances (lead bullets are a big environmental hazard) warfare is a little greener than it was before.

      However, I would guess the military's main concern is not the environment, it's logistics. The supply infrastructure needed to keep all those vehicles gassed up is mind-boggling. The less fu
      • One of the US Army's favorite alternatives to lead is Depleted Uranium [wikipedia.org]. It's 70% denser than lead, and was initially developed for attacking heavily armored Soviet tanks. It has lots of potential problems, none of which apply when the Bush Administration uses it.


        I don't know if there are other commonly used materials for tank shells - steel or something?

      • Tearing up the landscape with tracked vehicles and tossing supersonic projectiles around is not very green.

        True, but it's a little bit greener than say carpet bombing the whole area and when you're in a combat zone, you gotta get the other guy before he gets you.

        Of course, a running, moving enemy tank is better for the environment than one that's on fire (not better for your troops tho).
    • Ever hear of a diesel-electric locomotive? They have existed for years.
      • So this is more a case of miniaturization than entirely new tech.

        Next thing you know we'll be seeing diesel-electrics, such as for big trucks such as semis.

        Electric motors scale well, and such vehicles already have a huge, heavy, and expensive gearbox, the elimination of which can help offset costs and weight penalties.
        • by Firethorn (177587) on Saturday August 18 2007, @02:15PM (#20278757) Homepage Journal
          Bleh... I need to go back to english class

          Next thing you know we'll be seeing diesel-electrics in big trucks such as semis.

          Then it'll trickle down to pickups and SUVs.

          Small cars actually make the least amount of sense to try to make into a hybrid - you have a lot of static costs, making them proportionally more expensive(IE $3k for a $13k car vs $5k for a $30k SUV). Plus - you have the least to gain. Going from 30mpg to 40mpg saves you less fuel per mile than going from 15mpg to 25mpg. Over the course of 10k miles, you'd save 83 gallons of fuel for the car, vs 267 gallons for the SUV replacement.

          Then again, we're also finding out that they can produce a four-door 40mpg car without making it a hybrid. The biggest difference I've seen in them is going from a 4 speed auto or 5 speed manual to systems with six gears. Extra gears equals extra expense, and probably extra weight, though the efficiency gains clearly beat it.
          • "The biggest difference I've seen in them is going from a 4 speed auto or 5 speed manual to systems with six gears. Extra gears equals extra expense, and probably extra weight, though the efficiency gains clearly beat it."

            The extra weight of another gear in a modern consumer manual transmission isn't much, maybe 20lbs including the larger gearcase. IMO expense is what drives manufacturers to keep down the number of gears available. Where efficiency matters (18-wheelers) more to the customers many more speed
      • Re: (Score:3, Informative)

        Logistics is a huge, huge part of war.
        I'll go as far as saying that it was the reason WWII ended.

  • by Anonymous Coward on Saturday August 18 2007, @01:13PM (#20278077)
    The lastest design for naval destroyers from both the USN and RN have also gone all-electric, and have decoupled all fuel-burning engines from the drive train. If it can work for destroyer, I guess it should work for relatively small ground vehicles.
    • The lastest design for naval destroyers from both the USN and RN have also gone all-electric, and have decoupled all fuel-burning engines from the drive train.

      This is nothing new in naval design, though -- subs have been doing this for about a century. Some ocean liners did it as well (SS Normandie comes to mind). Reading more about the DD(X) program, though, I'm surprised that the next generation of destroyers and missile frigates aren't being planned as nuclear-powered ships.

      -b.

      • From what I heard nuke ships are a pain in the ass.

        nuke plants are expensive, you need a LOT of training (the navy nuke program is essentially a bachelors degree w/o the English and basket weaving courses crammed into a two year school), the navy is perpetually strapped for the personnel and offer insane reenlistment bonuses for those that stay in (I've heard of $100k, but it might have been a rumor).

        Also the plants are never really off, so being a nuke in the navy is an awful job in port. Reactor Officer
        • I'm amazed that all four old fire-support providing BBs have been entirely replaced by ... a cool drawing on a piece of paper =)

          The Iowa-class battleships were outdated, not in great repair, and unsafe for their crews (see also: the USS Iowa turret explosion). They were decommissioned in the 60s, and hastily reactivated in the 80s, as part of Reagan's naval saber-rattling. This did NOT make them terribly effective or useful weapons.

          AFAIK, their role was replaced by guided missile frigates.

          -b.

          • Enough battleships were destroyed by obsolete cloth-covered biplanes in WWII to prove that their only effective combat role is that of a sitting duck.
  • by roman_mir (125474) on Saturday August 18 2007, @01:22PM (#20278187) Homepage
    This is great stuff, finally we can kill people and go all out to be very environmental about it.
  • The most unique feature of the new MGVs is that the traditional engine has been decoupled from the drive train and is used only to recharge the battery and power other systems within the vehicle.

    M1 Abrams tanks have a turbine engine that is hooked directly into a generator which powers a 1500 hp (1119 kW) electric motor.

    However, you can hardly call it fuel-efficient :)
    • by thynk (653762) <slashdot&thynk,us> on Saturday August 18 2007, @02:00PM (#20278597) Homepage Journal
      M1 Abrams tanks have a turbine engine that is hooked directly into a generator which powers a 1500 hp (1119 kW) electric motor

      Let me set this straight.

      Unless the Army has completely refitted it's tanks, the above is only partly true. It does have a turbine engine and does produce 1500hp, but it's not an electric motor. Has a plain old drive train that goes into the rear sprockets. There are no massive batteries to store the charge (IIRC it has 8 12v batteries).

      What makes these things so darn quiet (for a tank, you hear the treads clanking before the engine when it's moving) is that the exhaust is directed up at about a 45 degree angle so the majority of the sound doesn't echo off anything. Of course, that gives it a massive thermal signature, but at the time of it's design, soviet block tanks were not using thermal sites.

      This is speaking from experience, I spent 4 years as an M1A1 tank crew member (19k) and prepped the engine(power pack)for removal more than once. There is no greater rush than firing the 120mm main gun at a target 2100m away and/or moving 68 tons of combat steel over any terrain.

      Hope this helps, I don't see any "green tanks" in the future and they get horrible gas mileage - a full tank of 504.4 gallons gives you about 200 miles over flat terrain @ 35mph.
      • Re: (Score:3, Interesting)

        "Unless the Army has completely refitted it's tanks,"

        It hasn't, and they remain as described in your post, though there is some discussion of modern diesel powerpacks for the Abrams that will use less fuel.
         
  • and the hummer .... the military is now in the vehicle design business.

    on an old reflection, I have plans from the mid 1970's from mother earth news that show how to convert an Opal GT into a hybrid electric. It used a DC jet engine starting motor powered by a 5 HP Briggs and Stratten lawn mower engine. Ojh hell that was 30 years ago....

    • The Volkswagon was not initially a military vehicle. It was designed by Ferdinand Porsche (at Hitlers request) as a car even factory workers could afford. This was slightly before WWII. During the war, they produced military variants, but the original design was for what it once again became afterwards: a super-inexpensive civilian car.

      As far as your larger point, the military has always been in the vehicle design business. Jeep, Hummer, etc.
    • the military is now in the vehicle design business.

      The US military has experimented with innovative vehicles and solicited vehicle designs for, oh, about the last century. There were plenty of military vehicles (tanks, Gama Goat trucks, etc) that didn't have civilian counterparts before 2007 :)

      -b.

  • As someone who has been fretting about the environment for quite some time, and a firm believer that only business had the power to get us out of this mess since the 80's, it's a hopeful time for me.

    As gas stays above $3.00 a gallon, people, and businesses and organizations and governments who don't give a rats ass about the environment are going to start looking around at ways to save or make money.

    Now, I'm not a complete libertarian on this issue. I think regulation from the feds can really help move

    • That does seem to be the key to environmental issues.

      Make doing the "right thing" cheaper than the alternatives.
    • As gas stays above $3.00 a gallon, people, and businesses and organizations and governments who don't give a rats ass about the environment are going to start looking around at ways to save or make money.

      Glad you're not a complete libertarian on this, I'm completely with you. Round where I live (in the UK) petrol (gas) is 7.20 dollars /US gallon in my local station. People are still filling up their cars and 4x4 SUVs are still fashionable, it's a disease we've caught from over the pond (I mean, in the mount
  • Does anyone else enjoy the irony of ground-breaking use of "green" engines in vehicles that are likely to be deployed in missions to secure more fossil fuels to burn?

      • Oh, I forgot - Jews are "God's chosen people" (according to them)...

        I'd say that the Promised Land is just a metaphor and doesn't necessarily have to be the historic "holy land" where the Jews came from. Just give Texas and New Mexico instead -- plenty of sparsely populated area, desert, mountains, forest, cities, everything you could possibly want. And the influx of 8 million Israelis would raise the intellectual level quite a bit ... :)

        Israel? The Arabs can have the place if they'd like and good ri

  • I know for a fact that at least one of DARPA Unmanned Ground Vehicles already has a hybrid power system [howstuffworks.com]. That beast can sneak up on you. Glad to see that tech also going into the manned vehicles.
  • Other Advantages (Score:4, Informative)

    by PPH (736903) on Saturday August 18 2007, @02:00PM (#20278603)
    Two other advantages come to mind:

    The use of all-electric drive can provide some interesting opportunities for advanced systems such as traction control. By placing multiple, smaller drive motors at each wheel, power can be directed optimally for terrain conditions. No complex mechanical equipment is needed as the algorithms can be implemented completely in software.

    The other advantage can be the ability to optimize the IC engine for changes in the fuel available without screwing around with the entire drivetrain. Heck, they can make the IC portion modular and, if the economics of fuel sources change, just pop in the appropriate engine.

    • Re: (Score:3, Interesting)

      Defence electronics designers have licked the EMP problem a long time ago already. There are devices called tranzorbs that absorb transcient pulses. Tranzorbs are also common in consumer electronics to provide protection against EMP from lightning strikes. Also consider your common garden variety spike arrestor power bar.