(ARMOR) Modern Tank Question...

I've been wondering...

The Abrams designers came under a lot of heat for using a gas turbine for propulsion but most modern-designed, latest-generation tanks (Abrams, Challenger, LeClerc, Leopard II and the Russian and Chinese offerings) bear a resemblance to each other. They share the angular armor, the lower, more angular forward hull and the raised rear hull around the engine compartment and in most cases, side skirts. What are these other tanks using for engines? It would appear some similarities are carrying through and I wondered about propulsion as well... There was a website I came across some time ago whose author posed facts and figues on why diesels should have been used but the folks 'inside the Beltway' conspired to use the gas turbine. It would seem that the turbine has vindicated itself and JP-4/5 is more plentiful than any fuel in the US Armed Forces...

Frank Kranick

Reply to
Francis X. Kranick, Jr.
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The gas turbine engine in the Abrams is a true multifuel design, and can run on most anything, including diesel, though it has more pep with hotter fuel mixes. The other NATO countries favored the low fuel consumption and low risk of fire associated with traditional diesel engines in the 1200 horsepower range, while the US favored the high speed and acceleration offered by the 1500 hp turbine. Compared to a diesel, the turbine is also much quieter, so tank columns don't announce their coming quite so early. In service, very few Abrams have ever been penetrated, so the fire risk of jet fuel has rarely been an issue, and the fire supression systems are pretty effective, allowing the crew time to get out if a fire cannot be extinguished. The downside of turbines is that they are very sensitive to particulate contamination. Dust is very unkind to them if it gets past the filters, and their reliability suffers accordingly. After the first Gulf War, the British press was full of articles snubbing the Abrams' supposed lack of reliability, though much of this was political spin. Their own Challenger 1 Mk 3 was a compromise design that jammed a highly advanced fire control system into a turret that just wasn't designed for it. British tankers had suffered much embarrassment at NATO firing competitions over the years, so they saw the Gulf War as something of a vindication (the UK finally bit the bullet and introduced a redesigned turret in the Challenger 2).

Ultimately, both the US and British tanks have done what they were designed to do when they confronted Russian bloc tanks in the two Gulf wars. In more limited service in the Balkans, the German Leopard 2 has also performed admirably, so there doesn't seem to be much point in belaboring the decision over powerplants.

Gerald Owens

Francis X. Kranick, Jr. wrote:

Reply to
Gerald Owens

Gerald is pretty much right on the money.

The Soviets had a lot of fights over engines, with three different approaches.

Kharkov (T-64) wanted a high-speed two-stroke diesel and came up with the 5TDF of 700 HP. It was smaller and lighter, but reluctant to start below 50 degrees F and the tank had really poor running gear.

Nizhny Tagil (T-72) stuck with the V-12 series of diesel engines which eventually got up to 840 HP in the V-84 series engines. Nothing flashy, but reliable and able to get the tank up to about 60 kph.

Leningrad/Omsk (T-80) went with a turbine, which in its early versions was a dog -- a full tank of fuel plus three 200 liter drop tanks barely got it 385 km on highways, and as they found out to their horrow in Chechnya, thirsty engines with no APU tend to drain the tanks in less than eight hours at idle. New ones are better but Russian MoD has made a decision to stick with the V-2-based V-12 type diesels for all future tanks. T-90 uses the V-92 series models which can be run up to 1200 HP.

Kharkov now produces the "T-80UD" (T-84) with newer 6TD series engines of 1000 to 1500 HP, but again they love hot weather and are finicky about starting in cold weather.

Cookie Sewell

Reply to

seems oxymoronic for the russians to have hot weather motors. or did they intend to only export to the mid east? doesn't the abrams get real crap mileage. i thought it was 2 gallons to the mile?

Reply to

"Francis X. Kranick, Jr." wrote

It's more plentiful because the DOD has a policy of "One Fuel Forward" to simplify logistics. All vehicles in theater - land and air - use the same fuel. The particular fuel has varied in time and place based on local availability, environmental conditions, and price.

It's not "We lucked out in making cars that use 87 octane gas because that's what's at most gas stations", rather "Gas stations carry a fuel that can be used in any car."


Reply to
Kurt Laughlin


Gentlemen, thanks for the info on my previous question. One more that occurred to me was this:

In WWII, the basic tank gun was the 75mm. By the time of the Pershing's arrival, the 90mm gun appeared and also equipped the M47 and M48. The upgraded M48 fitted out with a 105mm main gun as did the M60 series. The M1 started with the 105mm and now sports a 120mm gun.

What *is* the magic of 15mm increments?

Frank Kranick

Reply to
Francis X. Kranick, Jr.

There really isn't any magic, it jsut appears that way. Germans went 37mm (early Panzer III) to 50mm (Late Panzer III) to 75 mm (Panzer IV, Panther) to 88 mm (Tiger) to 128mm (JagdTiger). Russians went 76mm (T-34/76) to

85(T-34/85) mm to 122mm (IS-2/3) down to 100mm (T-55) to 125mm (T-72 and up).

However, the second Sherman gun was a 76mm, only 1mm up, but a longer barrel., so US tank guns actually went 37mm to 75mm to 76mm to 90mm. It's kind of hard to link the next two guns (105mm and 120mm) directly to the series since they were actually non-US guns (the 105mm was based on the British L7 gun and the 120mm is a German Rheinmetall cannon).


Reply to
Dave Williams

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