Tracked vehicle attrition

[Panther Al]

I rather doubt ATV's and Technical's will take on the role of tanks, or even any kind of fighting vehicle. Just too fragile. When even light small arms can eat up one of those with ease, and lets face it, with 4, 5 years of attrition the ratio of automatic weapons to troops is going to be well into the stratosphere, which means there will be far too much lead being sprayed about to let them do anything.

Now, you want to slap some armour on a truck, ala uparmoured humvee or something, maybe then. But a lot of the load capacity will be used by armour, which means less firepower and with the extra weight, more time spent up on blocks due to breakdowns.

[Legbreaker]

Anyone know if the turbine of an M1 could be ripped out and replaced with a conventional diesel?
I know that you wouldn't get anywhere near the same speed, etc, but if it saves fuel and keeps some amount of mobility.....

[Tegyrius]

Originally Posted by Legbreaker

Anyone know if the turbine of an M1 could be ripped out and replaced with a conventional diesel?

Any engineering problem is solvable with a hammer of sufficient size. The Ukrainians did it with the T-80UD, which is a diesel variant of the turbine-powered T-80.

Would a transmission replacement also be necessary?

- C.

[Legbreaker]

The next question is just how big would said engine need to be to give say 80%+ of the performance of the turbine? Would it be possible to shoehorn such a beast into the available space?
Would it even be worth it if the turbine still worked?

[dragoon500ly]

Originally Posted by Tegyrius

Any engineering problem is solvable with a hammer of sufficient size. The Ukrainians did it with the T-80UD, which is a diesel variant of the turbine-powered T-80.

Would a transmission replacement also be necessary?

- C.

Certainly a bigger hammer tends to fix most things on a tank!

But replacing the power pack on any modern tank is going to be a major engineering challenge. The engine and transmission normally comes in one unit. Most battalion maintenance sections do have the expertise and tooling to break packs apart so that the engine could be used on one vehicle and the trannie on another. The key problem will be adapting a engine to not only fit the trannie, but fit into the remaining space in the engine compartment.

On of the key problems with the M-1 design process was getting a small enough engine that developed the horsepower needed to move a dang heavy vehicle at high speed. Virtually every diesel engine in production or under development was tested and simply created more problems with weight, volume, fuel consumption and maintenance access. The turbine engine, in spite of its high fuel requirements was chosen because it met or exceeded the requirements.

Its a measure of note, that in spite of of its long life time, in spite of repeated requests to develop a diesel engine replacement, the M-1 is still rolling on, powered by the same turbine engine that it started out with.

When ever the discussion turns to replaceing engines, armament and fire control systems on tanks springs up, I am reminded of a quote by Major General John G. Willis who, in the 1980s, was the British Army's Director of Vehicle Procurement. He was often frustrated by the inability of his political bosses to understand how very difficult it is to design and build a tank. After one memorable session in which a politican had leveled the charge "After all, the tank is a simple tin box." General Willis replied, "Yes, you're absolutely right that a tank is indeed a simple tin box. Unfortunately it is a simple tin box that most move across country. To move across country, it requires an engine of the highest possible power density you can get and is therefore putting out a lot of heat. What do you do if you wrap the engine in a box and therefore make your cooling problem even worse than it was before? You start putting thermal stresses on this engine that no engine should be subjected to."

"What is more, you then put a gearbox behind it. You ask that gearbox that it not only give you a range of gears in forward and reverse but also act as a steering mechanism. Furthermore, you demand of that gearbox that the power you do not require for the outside track when you are turning is delivered to the inside track so you do not waste any power. You produce a gearbox the like of which has no civilian application whatsoever."

"You wish this vehiclle to move across country at a reasonable speed and therefore have to supply it with a suspension and tracks which must be capable of withstanding the shocks of cross-country travel but not so heavy as to totally nullify the whole thing. This box must also carry fuel which is highly volatile. And so on and so forth. And you end up by putting in it human beings, without whose presence the vehicle would be a total nonevent, but who, of all the elements within that weapons system, are probably the most vulnerable."

"So yes, the tank is a very simple tin box."

"The trade-offs are infinitely more difficult to achieve than in an aircraft. People say to me that perhaps weight doesn't mean very much in a tank. It is crucial....crucial!"

That's the problem in a nutshell.

[StainlessSteelCynic]

Something else strikes me as important to Mohoender's original post. Perhaps part of the reason the French tracked vehicles got such a low track time was because they were designed for European fields and roads.

Panther Al mentioned that the M1 isn't a great rough terrain tank particularly compared to a Merkava. I wonder how much track time a Merkava gets considering it is operating in the region it is designed for (unlike the French vehicles, designed for Europe but working in the more demanding conditions of Lebanon)

[95th Rifleman]

Originally Posted by StainlessSteelCynic

Something else strikes me as important to Mohoender's original post. Perhaps part of the reason the French tracked vehicles got such a low track time was because they were designed for European fields and roads.

Panther Al mentioned that the M1 isn't a great rough terrain tank particularly compared to a Merkava. I wonder how much track time a Merkava gets considering it is operating in the region it is designed for (unlike the French vehicles, designed for Europe but working in the more demanding conditions of Lebanon)

Not so sure about that, the UAE uses the Leclerc and they don't seem to have too much in the way of enviromental issues.

[Mohoender]

Originally Posted by 95th Rifleman

Not so sure about that, the UAE uses the Leclerc and they don't seem to have too much in the way of enviromental issues.

Actually the Leclerc sold to the UAE are quite different from the French ones. Still, conditions in Lebanon are in no way conditions in UAE.

Stainlesscynic has a point and I should have recall that the German had tracks problem in USSR and not only in winter.

That must make things even more complicated as the need for mechanical replacements are more common on tracked vehicles than on wheeled ones. As someone said, with time most tanks will be turned into pillboxes.

[dragoon500ly]

When the M1 first came out, we had mostly rubber chevron tracks (1980s), life span in Europe was roughly 2,500 kilometers before replacement.

By the time of Desert Storm, the M1 had switched to mostly metal with rubber replacement pads. Estimated track life for the metal portion was 4,000 kilometers with the replacement pads having to be replaced roughly every 1,800 kilometers.

After the Merkava was introduced, an Israeli colonel on exchange duties claimed that the track was good for 5,000 kilometers. I would take that figure with a large bag of salt as the Israelis are famous for being "tight" with reliable info!

Now the figures I quoted are for European service! In rough, rocky terrain, track life is roughly halved.

[Mohoender]

Originally Posted by dragoon500ly

Now the figures I quoted are for European service! In rough, rocky terrain, track life is roughly halved.

Really interresting figures. Then, IMO it will effectively render tracked vehicles in T2K useless outside of the local level where a commander can gather sufficient technical supports. I'm thinking that because the lack of available spare parts will make necessary to maintain some type of repair shop.

Could be interesting to look at the haganah in 1948 or at what has happened in Africa over the years. With time, I would expect to find a larger number of hybrid vehicles in the ranks of most armies.

[StainlessSteelCynic]

Originally Posted by 95th Rifleman

Not so sure about that, the UAE uses the Leclerc and they don't seem to have too much in the way of enviromental issues.

Interesting, I'd wager that the UAE doesn't have as much hard ground surface as Lebanon though

Originally Posted by dragoon500ly

When the M1 first came out, we had mostly rubber chevron tracks (1980s), life span in Europe was roughly 2,500 kilometers before replacement.

By the time of Desert Storm, the M1 had switched to mostly metal with rubber replacement pads. Estimated track life for the metal portion was 4,000 kilometers with the replacement pads having to be replaced roughly every 1,800 kilometers.

After the Merkava was introduced, an Israeli colonel on exchange duties claimed that the track was good for 5,000 kilometers. I would take that figure with a large bag of salt as the Israelis are famous for being "tight" with reliable info!

Now the figures I quoted are for European service! In rough, rocky terrain, track life is roughly halved.

That was kind of my train of thought, the harder rocky terrain of Lebanon would probably chew through the tracks much quicker than if they were running on soil or sand.
As a point of interest, the Merkava originally made use of the tracks from the Centurion and I believe that later track types evolved along with the tank itself.
Not too surprising as the prototype for the Merkava was little more than a Centurion with the turret placed to the hull front and the whole vehicle turned around so that the engine was now the front!


Merkava prototype, Yad la-Shiryon Museum, Latrun, Israel

[Panther Al]

Originally Posted by Legbreaker

Anyone know if the turbine of an M1 could be ripped out and replaced with a conventional diesel?
I know that you wouldn't get anywhere near the same speed, etc, but if it saves fuel and keeps some amount of mobility.....

The answer is:


Actually quite easy relatively speaking. MTU has a repower package that shoehorns a 1500hp diesel into the bay with a minimal reworking done to the engine bay. Keeps most of the fuel load, and massive increase in fuel savings. They also have a 1650 from what I understand that is a little more complex, and cuts the fuel load by 30%, but... still.

The downsides is that the M1's agility is seriously compromised. The weight of both diesels are much higher than the turbine (Remember, a third of the engine compartment is actually empty space for the intake.) and it doesn't give the tank the massive power on demand that a turbine does, so accel is way down.

People don't understand, but the M1 isn't a great rough terrain tank: A Merkava going cross country will actually leave a M1 in its dust due to its suspension having a higher bounce than the M1's - almost triple the range of travel.

[Legbreaker]

Ah, good. I can see that as the war drags on and fuel becomes a major concern (as early as Christmas 1997) the turbines are likely to be removed and replaced with 1500's. Initially perhaps as just a temporary measure while the turbines undergo major service, but as more and more turbines become unrepairable, and fuel consumption grows into a critical issue....

Perhaps a Division would maintain a supply of a dozen turbines in their stores for "just in case fuel supply improves" or they are sent on an offensive. As most modern vehicles have relatively easily changeable power packs, changing over a dozen tanks may well take less than a day for one engineering crew to accomplish.

Obviously this isn't something that would be done ordinarily, but since when was anything about T2K ordinary?

Gives a GM (and players to some extent) more options for keeping the tanks on the field for longer.

[Panther Al]

Don't get me wrong: this isn't a field swap, from what I understand its a 40 level (depot) operation.

And also: In the next 5 to 10 years all M1's are going to have to have it done in the real world. Why?

Things to note:
All engines, especially high stress types like Turbines can only run so long before needing a rebuild.

Every time you rebuild one, the hours till it needs another is less than before.

We haven't made a new Turbine for the M1 in almost a decade - even the new tanks going to Australia and Iraq are going out with (admittedly very good) rebuilt engines.

Something to consider: Back when my old 1SG was a buck Sgt, he said that to swap a M1 engine was a call a Spec4 could make at anytime without a second thought. In 05, in order to swap out a engine required the approval of the Motor Pool CWO. Says something about the engine supply situation doesn't it?

[Legbreaker]

Yes, I can see it's not something that would be done lightly and would only occur with at least several days notice and planning (those tanks aren't going to be very useful while it's happening).
Once swapped, I imagine the engine would remain the same for months (or longer) before the need to swap back came along.
I see it a little like fitting your car with Nitrous - you're not going to need it on a daily basis, but it's damn good to know it's there as an option. Of course flicking a switch to kick in the gas is a little easier than swapping out a whole engine...