NS Military Realism Mk. 7: NO

[Yukonastan]

Thirdly, they produce a lot of heat. The exhaust is very hot, less so with diesel.

Importance of turbines exhaust's been overstated. Wasn't this talked about in these threads recently?

It needs to be dealt with, and is an engineering problem.

[Gallia-]

Power density, better low-end acceleration, better multifuel capability.

If you've come to the conclusion that turbines hold no advantage over diesel engines in this application, then you should maybe re-evaluate your source materials.

They hold advantages, they hold disadvantages.

First off, gas turbines drink like fish. M1 Abrams holds 1900 litres of fuel, which results in a maximum range of 426 kilometres.
Secondly, they need to be precisely built. Clearances less than one thousandth of an inch. Not very damage resilient in other words.
Thirdly, they produce a lot of heat. The exhaust is very hot, less so with diesel.
Forthly, turbines are fairly maintenance-intensive.

However, all the advantages listed apply.

First off, range varies. At optimum road speed for fuel consumption and preservation, yes you will achieve somewhere near 430 km. In a realistic scenario, you might achieve a quarter of that at best.
Second, all engines need to be precisely built. Not just to work, but for interchangeability of parts. This is hardly a hit on turbines, and the reliability of M1 is certainly better than that of Leclerc or AMX-30.
Third, so what? The tracks and dust thrown up by them are a greater IR signature.
Fourth, so is any tank.

A real disadvantage is fuel consumption during idling, which is significantly higher than a diesel. On the other hand, you have greater mobility and acceleration, so it comes down to if you feel that is a worthy tradeoff.

[Tule]

We're even operating on Mars.

trust me im special forces.

theres aliens under the surface of mars btw.

Well they are holding on to some space oil we want. But its ok I support our troops.

I wish their was a break down of where the money went. Because I feel like deployment across the world doesn't adequately explain the 300,000 gap.

Researching, developing and procuring the most advanced military equipment on earth is far more expensive than buying the almost as good, 5 year old equipment.

[San-Silvacian]

I really hope the M1 is more reliable than an AMX-30.

Also the AMX Leclerc is, from what I understand, plagued with issues.

However that is also because of a very bad lack of spare parts.

Well they are holding on to some space oil we want. But its ok I support our troops.

I wish their was a break down of where the money went. Because I feel like deployment across the world doesn't adequately explain the 300,000 gap.

Researching, developing and procuring the most advanced military equipment on earth is far more expensive than buying the almost as good, 5 year old equipment.

Though I am against privatized armies, I am 100% for certain, non-military jobs to be given to private sector companies.

[Gallia-]

I imagine it's just that France has historically been shit at making tank automotive components for the past 50 years. They're not suddenly going to get better.

[New Vihenia]

Common core engine anyone :3 ?

So basically my tank use gas turbine which core is interchangeable with my helicopters.

[San-Silvacian]

I imagine it's just that France has historically been shit at making tank automotive components for the past 50 years. They're not suddenly going to get better.

Even French tanks from the pre-war were kinda shitty with parts ;-;

However when it came to fight they were all prepared to go.

[Gallia-]

Common core engine anyone :3 ?

So basically my tank use gas turbine which core is interchangeable with my helicopters.

Might look at why AGT-1500 lost the competitions for the powerplant for UH-60 and AH-64.

[Dewhurst-Narculis]

Common core engine anyone :3 ?

So basically my tank use gas turbine which core is interchangeable with my helicopters.

Might look at why AGT-1500 lost the competitions for the powerplant for UH-60 and AH-64.

Too heavy I'm guessing and can't produce the required specs for a rotor?

[Freihafen]

Eh. Turbines are actually easier to maintain than diesels, while reliability is comparable. One could just as well argue that turbines are generally less smoky than diesels.

AFAIK the LV50 and LV100 are both developed from helicopter cores, while AGT-1500 has been developed into a helicopter core, so technically yes.

[Gallia-]

Might look at why AGT-1500 lost the competitions for the powerplant for UH-60 and AH-64.

Too heavy I'm guessing and can't produce the required specs for a rotor?

Sadly it's never really between "this works" and "this doesn't".

[Dewhurst-Narculis]

Too heavy I'm guessing and can't produce the required specs for a rotor?

Sadly it's never really between "this works" and "this doesn't".

Yeah, shame other wise we could have more standardized systems

I imagine the torque would be more than ample

[San-Silvacian]

yeah wow imagine that everything being standardized doesn't work out in the end.

Sometimes you need to make stuff specifically for something.

[New Vihenia]

Might look at why AGT-1500 lost the competitions for the powerplant for UH-60 and AH-64.

Looked into it.. For some reason, i can't find any technical reason for this. Is the engine unusually heavy or some other else.

[Gallia-]

Might look at why AGT-1500 lost the competitions for the powerplant for UH-60 and AH-64.

Looked into it.. For some reason, i can't find any technical reason for this. Is the engine unusually heavy or some other else.

It was probably related to management if not for a technical issue.

yeah wow imagine that everything being standardized doesn't work out in the end.

Sometimes you need to make stuff specifically for something.

Hey there, LAV III!

[The Akasha Colony]

From reading about the T-80, I've come to the conclusion that gas-turbine engines kind of suck, so why does the Abrams use it?

At the time, the US was investigating a whole host of propulsion types for their tank projects. There were even some interesting diesel proposals, like the General Motors AX-1100, a ten-cylinder engine with two banks of four cylinders and one bank of two, with the idea being that when the tank was stationary it could just run the single bank of two cylinders as an APU while the rest of the cylinders were inactive to conserve fuel.

Ultimately, the US also believed that fuel efficiency for the turbines would improve. At the time, projections indicated it was possible for turbines to achieve greater fuel savings to become reasonably competitive with diesel engines, and using a turbine saved a good deal of weight and space versus a diesel. Abrams carries 1,900 liters of fuel versus the 1,200 liters carried by the Leopard 2, but the Abrams is a more compact tank. Unfortunately, AGT-1500 never quite met the efficiency targets that had been expected, and by then the Army was already committed.

Turbines in general were extremely popular in the 1960s and into the 1970s. It was even hoped that they would be the ideal power source for high-speed rail, with developments like the UAC TurboTrain, and the US Navy had begun build gas turbine warships with the Spruance-class. This of course was a time when fuel itself was fairly inexpensive, so sacrificing fuel efficiency for improved power density was considered useful for applications requiring lots of power (e.g. trains, tanks). They were also more flexible in terms of fuel sources, although modern diesels are also quite flexible. The entire US Army vehicle fleet runs on JP-8 jet fuel.

For the Abrams program, Chrysler developed their XM1 prototype with the AGT-1500 while General Motors favored a diesel (AVCR-1360). General Motors' proposal was slightly cheaper, but the Army wanted a diesel, so it asked both companies to submit versions of their testbeds with the other engine as well (Chrysler had to develop a diesel tank, and GM had to develop a turbine tank). Chrysler took the opportunity to reduce the price of their bid, which had already factored in the price of the turbine. In contrast, GM's bid price increased due to the cost of the turbine, so Chrysler won the contract and their XM1 prototype was developed into the current M1 Abrams.

As to why the US Army doesn't switch from the gas turbine, it doesn't really have a very strong incentive to do so. In the short term, the costs of licensing and procuring a new diesel would be significant, as would refurbishing the tanks to accept them. There would also be a need to retrain every Abrams crewman on the new engines. Tanks make up only a relatively small portion of the Army's vehicle fleet, especially compared to the real gas guzzlers like helicopters, or the tens of thousands of Humvees it operates. Replacing the engine is a "nice to have," but compared to other programs that increase lethality or protection, it's a pretty low priority for the budget. On top of that, troops reacted very favorably to the turbine engine compared to the diesel-powered M60.

From reading about the T-80, I've come to the conclusion that gas-turbine engines kind of suck, so why does the Abrams use it?

Designed around the same time, on the other side of the Iron Curtain. Back when jet fuel was cool. But I believe they're considering tossing the AGT1500s for proper diesels, at least I heard a few rumours to that end.

It has been rumored but there are no plans to do so. M1A3 is a pretty conservative upgrade.

Okay, I wanted to know if it had any advantages over normal engines. If it doesn't, they should definitely replace the engine.

It is lighter and more compact. As mentioned, they are mechanically simpler because they only have a handful of rotating parts, whereas reciprocating engines have many moving parts that don't necessarily move in such simple patterns (e.g. pistons, valves).

Thank you; the source was basically a Russian Army evaluation of the T-80, which recommended never using gas-turbine engines again because of the costs. So it would seem to me like a bit of a trade-off, but that the normal engines reduce necessary expenditures considerably.

The Russian army largely scapegoated turbines after their experiences in Chechnya, blaming them for poor performance. Turbines do have higher fuel consumption at idle though, since they by necessity are still operating at a significant fraction of their maximum output.

It needs to be dealt with, and is an engineering problem.

A minor one at best. Diesel exhaust is also still in the hundreds of degrees.

[United Marxist Nations]

You mentioned the M1A3, and I haven't really heard of what the upgrade really entails. There are rumors, and a supposed photo of a prototype on the back of a train car, but I don't actually know what it entails, and you said it was "conservative".

[Roski]

So, SR-72, what do you think its most practical purposes will be.

Its an unmanned aircraft set to fly at Mach 6, and set to be released by 2030 (Therefore making it PMT)

[The Akasha Colony]

You mentioned the M1A3, and I haven't really heard of what the upgrade really entails. There are rumors, and a supposed photo of a prototype on the back of a train car, but I don't actually know what it entails, and you said it was "conservative".

There are rumors flying around about L/55 guns, diesel engines, and GLATGMs, but really M1A3 is most likely just an electronics modernization, conversion to fiber optics from standard metal wiring (where possible), a lighter 120 mm gun (but still L/44), better integration of smart shells, lighter armor, and perhaps a lower-profile RWS. These at least are the features the Army has already been testing. Nothing radical like some of the rumors, and certainly not like some of the rumors surrounding T-99.

The train photograph is almost certainly not M1A3, I've seen a few pictures claiming that it is but it's usually just old photos of the CATTB or other testbeds.

So, SR-72, what do you think its most practical purposes will be.

Its an unmanned aircraft set to fly at Mach 6, and set to be released by 2030 (Therefore making it PMT)

Its practical purposes will be being tossed around on internet forums as an example of PMT.

It isn't "set" to be released at all. Lockheed Martin made what amounts to a few napkin designs to drum up attention but the Air Force has no allotted funding and is research hypersonic technologies via other means.

[Roski]

You mentioned the M1A3, and I haven't really heard of what the upgrade really entails. There are rumors, and a supposed photo of a prototype on the back of a train car, but I don't actually know what it entails, and you said it was "conservative".

There are rumors flying around about L/55 guns, diesel engines, and GLATGMs, but really M1A3 is most likely just an electronics modernization, conversion to fiber optics from standard metal wiring (where possible), a lighter 120 mm gun (but still L/44), better integration of smart shells, lighter armor, and perhaps a lower-profile RWS. These at least are the features the Army has already been testing. Nothing radical like some of the rumors, and certainly not like some of the rumors surrounding T-99.

The train photograph is almost certainly not M1A3, I've seen a few pictures claiming that it is but it's usually just old photos of the CATTB or other testbeds.

So, SR-72, what do you think its most practical purposes will be.

Its an unmanned aircraft set to fly at Mach 6, and set to be released by 2030 (Therefore making it PMT)

Its practical purposes will be being tossed around on internet forums as an example of PMT.

It isn't "set" to be released at all. Lockheed Martin made what amounts to a few napkin designs to drum up attention but the Air Force has no allotted funding and is research hypersonic technologies via other means.

A hypersonic plane does not have to be an expensive, distant possibility. In fact, an SR-72 could be operational by 2030. For the past several years, Lockheed Martin Skunk Works® has been working withAerojet Rocketdyne to develop a method to integrate an off-the-shelf turbine with a supersonic combustion ramjet air breathing jet engine to power the aircraft from standstill to Mach 6. The result is the SR-72 that Aviation Week has dubbed “son of Blackbird,” and integrated engine and airframe that is optimized at the system level for high performance and affordability.

Sorry, didn't mean specifically set

[The Akasha Colony]

A hypersonic plane does not have to be an expensive, distant possibility. In fact, an SR-72 could be operational by 2030. For the past several years, Lockheed Martin Skunk Works® has been working withAerojet Rocketdyne to develop a method to integrate an off-the-shelf turbine with a supersonic combustion ramjet air breathing jet engine to power the aircraft from standstill to Mach 6. The result is the SR-72 that Aviation Week has dubbed “son of Blackbird,” and integrated engine and airframe that is optimized at the system level for high performance and affordability.

Sorry, didn't mean specifically set

And? They don't have the engine, nor do they have the air frame. It's a paragraph of buzzwords and phrases ("optimized at the system level," "working with [x] to develop") that don't mean anything and are just meant to try to win development contracts. And the USAF isn't interested.

For comparison, the USAF announced the ATF program in 1981. The YF-22 and YF-23 prototypes competed ten years later in 1991, with YF-22 winning. The first production F-22 was not flying until 1997. So that's sixteen years from program initiation until the first production aircraft was unveiled. And the F-22 is a lot less ambitious from a technological standpoint than this SR-72 "proposal." Likewise, the F-35 started in the early to mid 1990s, and twenty years later is not yet in active service.

There is no reason to believe that Lockheed Martin would somehow be able to rush a plane this complex into service in only 16 years.

[Rich and Corporations]

The main advantage of turbine engine is greater torque over a broader RPM range in comparison to diesels (and even greater when looking at hyperbar like Leclerc). This translates to better acceleration and greater tactical mobility. There was a pretty chart that compared diesel and turbine torque ranges on Tanknet but I can't find it now.

Multifuel engines existed long before AGT-1500 did.

http://www.honeywell.com/sites/servlet/ ... 2E8F6A88FB
This is the source of the chart.

You mentioned the M1A3, and I haven't really heard of what the upgrade really entails.

They will use a titanium gun barrel to save weight, maybe implement electro-thermal ignition, use a fuel efficient turbine or diesel, among other upgrades. They will also likely upgrade the alternator.
http://www.army.mil/article/89746/
http://www.generaldynamics.com/news/pre ... 1811=17962

[San-Silvacian]

lal that tank on the fucking trainbed was CATTB.


M1A3 is most likely just going to tie all the neat bits of SEPv2 and some new digital stuff.

[Gallia-]

lal that tank on the fucking trainbed was CATTB.

This isn't CATTB. It's far less impressive.

[Mitheldalond]

How effective would the M103's gun be against modern tanks if you were to develop single-piece APFSDS ammunition for it?