Diesel Engines Will Run Underwater

As long as you can suck air in, and blow exhaust out, you can run a diesel engine completely submerged in most cases. The New Jersey National Guard apparently tried to take advantage of this capability, without quite enough common sense on driving through flood water:

If you follow the video through to the end, you’ll see where Chris Christie gets it from. Not too smart, I have to say. But I’ll give them credit for trying.

Hat Tip to WizardPC, who notes that there’s no “S” in HMMWV. Though, I would note those don’t look like hum-vees to me. Still, it’s good that the equipment will still allow our troops to do something that could be necessary at some point, but probably not wise in most conditions.

14 thoughts on “Diesel Engines Will Run Underwater”

  1. Lends new meaning to the phrase, “When in doubt, gas it!”
    Seriously, where’s the snorkels they’re supposed to have?

  2. I believe those are FMTVs, Family of Medium Tactical Vehicles, the 2.5 ton model, operating in “How close to the top of my chest waders can I go?” mode.

  3. Don’t think so Drang, FMTVs are much taller. Those look like the military “station wagon” model, sort of a hard top lowback. The Marines have HMMWVs with lifted air intakes and exhaust pipes that can do stuff like this. The Army? Not so much. They kinda needed to stop when the water got up into the cabin.

  4. Its kinda surprising how far they got, but you’d think a little scouting would have told them that they weren’t going to make it.

  5. You’d think at some point after Major Pain said “the trucks have snorkels, let’s drive through the water!”, that Pvt Latrine-Duty would have replied “sir, do the men have snorkels?”.

  6. Those are the 2 1/2 ton LMTV’s (Light Medium Tactical Vehicles) manufactured by Stuart Stevenson. Active duty started receiving them in the mid-90’s. They replaced the M35 series trucks. I’ve taken them through shoulder-high mud, but that beats all.

  7. Having been through a lot of deep water crossings in 4×4’s …

    The water looks a little deeper from the front that it actually is, as there is a bow wave washing up over the windshield. But as the truck passes underneath the bridge look at the air intake — it’s still a few inches above water. So they’re not being as nuts as you might think. AT least at that point.

    Of course … it’s apparent that on the other side of the bridge they did push it too far and sucked water into the air intake … so game over.

    And if that water made it through to the cylinders it’s probably game over for the engine. Water doesn’t compress well and cold water on hot steel and valves can cause some serious warpage and issues.

  8. Might have made it through without them kicking up the bow wave. That’s right in my neck of the woods, saw pics of the troops being pulled off the roofs of the trucks

  9. When the first civilian Hummer was sold here in Anchorage the local news interviewed the buyer. He ran a fairly off the beaten track but still trail accessible lodge.

    When asked “Why buy a Hummer?” he replied “It’s gotta be tough, it was designed from the ground up to be driven by 18 year olds who didn’t pay for it.”

    Thus our flooded little armada there.

  10. Gas engines will run underwater, too, as far as I know, ‘long as you have waterproof ignition gear. (And the same caveats about air in and out.)

    (Just like a diesel with electronic injection needs a waterproofed injection wiring setup, too… and both need a waterproofed ECU, if they’re remotely modern.)

Comments are closed.