Along with the usual pentagon obsession with high-tech and the desire of defence contractors to empty its excessively deep pockets.
I’m all in favour of pushing forward the technological boundaries, but I don’t believe the gas turbine gives much of an advantage to outweigh the logistical difficulties it causes. If you look at the M1 compared to say the Leopard 2 it’s not vastly different in performance.
Not really. DU is pretty inert, in fact I believe the M1 uses it in its armour. I don’t think there would be any consequences beyond what you’d normally expect from kinetically breaching a running nuclear reactor… :eek:
If someone set off an ER tactical nuke nearby, on the other hand :eek: :eek: :eek:
xtisme - I would think that if you are concerned about lgoistics, you’d be better off spending your money on a bazillion fuel bowsers and diesel-engined tanks than on nuclear tanks. I would think the unit cost differential versus a normal tank would be something akin to that between an F22 and a Sopwith Camel, whereas the capability difference would be minor.
And valves leak, small breaks happen in the piping, efficiency isn’t 100%. All these little things add up over the course of a day to require adding water to your system. On a Nimitz class aircraft-carrier, the amount of make-up water needed on a daily basis is astonishing (granted, some of that goes towards operating the steam catapults.)
Maybe it would be best if retrofitting a nuclear/steam powerplant to an M-1 woild be doable if you simplytake the soldiers/marines out and make it a computer controlled automaton. Room for the reactor, steam turbine, condensor, and extra ammo. No personell to get sick and die from radiation poisoning.
I hear Cyberdyne Systems are making progress in this area.
In 1980, when the Abrams M1 debuted, the Lycoming Textron gas turbine engine was a major innovation for a MBT: it was more reliable and much quieter than comparable tank engines. And hey, it was a Chrysler product. Would you have trusted them to put one of their own engines in it?
Unfortunately, the A1 and A2 designs (including the M1 to M1A2 upgrade program) did not address the engine. The power-to-weight ratio has dropped (although it still falls between the British and German MBT for horsepower per ton), and Lycoming doesn’t even make the engine anymore.
And, the M829A1 APFSDS-T ammunition has a depleted uranium core. It is not depleted of uranium.
recently saw a program on tv called the “top 10 tanks” (or something like that).
Had an Israeli design in there that was friggin MASSIVE. (Could actually carry troops in the back along w/the crew).
The narrator had a good point with regards to why it wasn’t internationally successful: Bigger tank is harder to transport internationally.
Not a worry if you’re only needing it for local use, but damned important factor if you plan on expeditionary forces.
In other words, you can make a tank big enough to use a nuclear reactor, and you could probably run it quite effectively (assuming all the other triffling little details mentioned in other posts were resolved ) but it wouldn’t be any good beyond self defense or attacking your next-door neighbours.
Don’t laugh - the January 2006 issue of Popular Science has the cover headline “TOMORROW’S ROBOT ARMY Inside the Pentagon’s Plans for a Soldier-Free Battlefield”.
It makes a nice complement to the banner across the top: HOMEMADE BLACK HOLES
That would be the Israeli Merkava. It actually weighs about the same as other MBT (~62 tonnes), but it’s about a metre taller than European tanks, and about half a metre taller than the Abrams. Height is the primary concern with regard to a tank’s profile, since most threats for a tank are terrestrial (other tanks and anti-tank weapons; helicopter gunships and ground attack aircraft are going ruin your day regardless of your profile).
Forgive me if it’s already been mentioned, but the most likely limiting factor is cost. Building a viable nuke powerplant small enough and safe enough to operate in thse conditions would be exceedingly expensive.
Tanks need to be built in sizable numbers, and quickly enough to replenish numbers in a wartime situation. Those tradeoffs would really offset the relatively minor issue of range factor.
In the first Gulf War, one of the tactics was to fuel the Abrams tanks with chopper fuel, this enabled them to act as mobile supply depots for helicopters. The tankers didn’t like it, since chopper fuel is apparently more flammable than standard tank fuel, and if they’d been unfortunate enough to get a round in just the wrong spot, they could have gone up like the Sherman tanks of old.
Afraid you have exactly the same problems as a boiler-steam engine combo. Thermionic generators are still heat engines, albeit with no moving parts. They’re not even very good heat engines - less efficient than a boiler-steam engine-generator combo. (This may change in the future however as new thermoelectric materials are developed.) Their main advantage is that there’s nothing to go wrong with them; no wear, no lubrication required, they’ll run for decades.
Additionally, the radioisotope system generates heat by radioactive decay rather than fission. It has a much lower power density than a fission pile. To generate enough heat to turn into enough power to run a tank, you’d need a huge chunk of plutonium or polonium or whatever you’re using. You’d probably be able to fit the tank inside it rather than the other way around!
The waste heat disposal issue: this is a big problem. Think about the past 2 Iraqi wars and the effects of thermal weapons sights. This thing is always going to be radiating heat.
Armor/Shielding: might not be such a problem; you want nice dense material between you and the bad guys; rad shielding would probably fit the bill nicely.
Refueling? Well, this might be an advantage actually. Modern tanks need to line up for hydrocarbon fuels to keep going. The nuke tank just needs water. Which is a lot easier to find naturally occuring than diesel fuel.
[Homer]Lisa, in this house we obey the laws of thermodynamics![/Homer]
There’s no magic to water, nor in the waters oft-quoted x1600 expansion ratio at 1 bar. In fact, the expansion ratio is not particularly relevant. You could make an engine that works by expanding steel bars - their expansion ratio is pathetic but the expansion force is enormous!
Some working fluids give a few percent efficiency improvement over water, but lose out in convenience. A Stirling engine beats out a steam plant for efficiency by a long shot, and works best with hydrogen or helium gas as a working fluid. But you still have to conduct heat to the gas at one end of the thing and dump it into the outside world at the other.
Here’s an interesting little factoid - boats that used gasoline as their working fluid to get around bureaucracy applied to steam launches…
To illustrate that point - this is a 290-watt RTG for the Cassini spacecraft. That’s less than 1/2 horsepower. You need 3000 of those to power an Abrams M1 tank.
) but it wouldn’t be any good beyond self defense or attacking your next-door neighbours.