The M1 Abrams: The Army Tank That Could Not Be Stopped

[Cavguy]

See thread here for a great discussion on the utility of Armor in COIN.

[Compost]

First four paras lifted from longer item at http://blogs.defensenews.com/ausa/.....gd-has-a-plan/

General Dynamics is kicking off a new strategy to sell the Army the infantry vehicles and tanks it (eventually) needs to ferry troops to the next fight, wherever that may be.

More specifically, the company is looking to tweak its existing Abrams tanks, Strykers, and Buffalo route-clearing MRAPs to offer better protection while guzzling less fuel, thereby giving Army formations greater range at less cost, according to a briefing delivered by a group of GD execs.

Mike Cannon, GD’s senior vp for Ground Combat Systems said that the company is “getting away from being platform specific” when it comes to this new strategy, instead focusing on the ground assets of the infantry brigade as a whole.

First up is the company’s plan to install a diesel engine on the Abrams tank, which would result in a 14 percent cost reduction per mile when compared to the turbine engine currently in the tank, while extending its range by 105 miles.

The news release from GD omits mention of two further benefits.

The current gas turbine runs at a high temperature and generates a large volume of hot exhaust gas. The exhaust can be hazardous to accompanying dismounted infantry and even when diverted it serves as a beacon for heat sensors and heat seekers. Also the engine deck is officially assessed as too hot for riders. So one, the lesser volume of exhaust from a diesel engine will substantially reduce the hazard and beacon affects, and also the engine deck temperature. Relative to the gas turbine that diesel is likely to be heavier, require more power to start, vibrate more and have a deeper engine note but generate less high pitched noise.

The current APU with its fuel tank is installed in the Abrams turret basket. When that APU’s light armoured enclosure has in the past been defeated by small arms, heavier weapons or other cause the resultant leakage of fuel has often lead to a fire on the engine cover and subsequent damage to the gas turbine, and in the worst cases loss of the MBT itself. However two, the reduced volume of a diesel engine together with fuel tanks for greater range will still leave sufficient space for installation of an internal APU that has the same level of protection as the main diesel.

The suits and uniforms involved in the original selection of a gas turbine have all hopefully gone to some other place where they will be unable to influence decisions on any engine upgrade.

[Compost]

From: carniflex 31-Oct 15:47 to: autogun

The company is offering MTU's 883 engine and an Allison transmission – essentially the same powerplant proposed for General Dynamics' Ground Combat Vehicle (GCV) submission – and Cannon said this could reduce the Abrams' cost per mile by 14% compared with its current turbine-powered engine.

Australia is the only country in the world to buy M1, were there was a choice of Leo2 and Abrams. I was at the School of Armour when Australia was thinking of getting M1. The gossip was we would not get the turbine but "europower packs".

Instead we bought the turbine with the promise that the new gas turbine would fix the issues (ie 8 liters/km vs 4 for euro). We also aquired M88 with MTB engines (WTF).

We use diesel not kerosene here for ground vehicles. We are destroying engines at a rapid rate (GE is suppose to fix this).

Also because of the extra fuel tanks needed, the APU cannot be fitted under armour (Iin the R rear sponson). It's attached to the turret rear. Our tanks still have no air-con, cooking the crew and electronics up North. My son's mate just finished his term up there and can't wait to leave.

What is amazing with M1, is the resistance to have other M1 support variants (unlike M60). Every time there is a new non-tank variant, they make a dozen and kill it. Wolverine, grizzly, ARV. With 1700 in store why not?

I saw this Jane's article at the same time as the tracked Stryker. It really annoyed me that the Army stuck with turbine, and have a tank that infantry cannot get near the rear of.

Rant over. (I'm sounding like MustangAus!)

http://forums.delphiforums.com/autogun/messages/ Thread: Tracked Stryker Post: 57 of 148

The above post highlights a third reason for re-engining Abrams MBTs - and especially mobility support variants - with a diesel. An ARV can be required to do a lot of work in a small area. The hot and high volume exhaust from a gas turbine main engine could make that area almost uninhabitable for dismounted mechanics and crews. Similar work conditions can apply to an AEV and dismounted engineering personnel. The lack of companion ARVs and AEVs (except for USMC’s Breacher) may largely result from powering the Abrams chassis with a gas turbine.

One suggested reason for procuring the M88-A2 has been to keep BMY in business as a second source of heavy armour. If that need still applies then GD might produce the diesels and re-engine Abrams MBTs and Wolverine AVLBs, and BAE/BMY could rework stored Abrams to produce ARVs and AEVs. And usefully the ARV could - even if fitted with a heavy-lift A-frame - have a jib-crane for precise manipulation of loads such as a turret or replacement engine.

[Compost]

Have been asked about an inconsistency in my views: “ why upgrade rear-engined Abrams with a diesel instead of expanding GCV project to include a front-engined gun-armed vehicle or MBT ? “

That's a good question and it will probably be asked again so here is an early answer. A ‘best’ path for US heavy armour development could seem to be a new front-engine chassis - incorporating some Abrams components and sub-systems - as a common basis for AEV, ARV, AVLB, BW and MBT variants. But an alternative ‘ one step at a time ’process reduces the risk of creating a Gordian knot such as doomed the FCS.

The monstrously heavy concept that seems to have been adopted for the GCV will result in lengthy delay before the project is revised to be something more objective and manageable. That will require at least two major changes. One, the proposed scale of issue will have to be reduced and directed to companys (rather than battalions) of assault infantry and combat engineers. Two, the large turret and armament will have to be supplanted by something smaller and less heavy that is still able to deliver intense prophylactic fire. Hence the definitive vehicle will be smaller and probably less weighty. Eventually the chassis of that smaller ‘GCV’ (in other words Battle Wagon) could become the basis for future mobility support variants and also a MBT successor. That process would approximate ‘ one step at a time ‘ and might be described as sequential or familial development.

But for an interim period - possibly into the 2030s – believe US force structure would be better served by upgrading what exists today. And that means the Abrams, almost certainly in its current rear-engined form.

[Compost]

An Abrams hull with new running gear by Diehl and a diesel engine and ancillaries by GD and MTU is being shown at AUSA 2013.

See http://www.aviationweek.com/Article...._p0-629179.xml

But to get such an upgrade running as an Army project in the current climate could be as difficult as a push-start on an uphill grade.

[RTK]

If the exhaust isn't in the rear how will dismounted troops warm themselves?

[tankersteve]

The current gas turbine runs at a high temperature and generates a large volume of hot exhaust gas. The exhaust can be hazardous to accompanying dismounted infantry and even when diverted it serves as a beacon for heat sensors and heat seekers. Also the engine deck is officially assessed as too hot for riders. So one, the lesser volume of exhaust from a diesel engine will substantially reduce the hazard and beacon affects, and also the engine deck temperature. Relative to the gas turbine that diesel is likely to be heavier, require more power to start, vibrate more and have a deeper engine note but generate less high pitched noise.

The current APU with its fuel tank is installed in the Abrams turret basket. When that APU’s light armoured enclosure has in the past been defeated by small arms, heavier weapons or other cause the resultant leakage of fuel has often lead to a fire on the engine cover and subsequent damage to the gas turbine, and in the worst cases loss of the MBT itself. However two, the reduced volume of a diesel engine together with fuel tanks for greater range will still leave sufficient space for installation of an internal APU that has the same level of protection as the main diesel.

Sorry for the incredible necro-post, but I never saw this thread. There are a few inaccuracies in this post that need addressing.

First, as hot as the exhaust is, it really isn't THAT hot. I never saw a Goretex melted by infantry guys inches away, drying out gear. The idea that you can't work around it is just silly. However, the exhaust deflector, commonly constructed by the unit welder, alleviates almost all of this issue for working in/around tanks. Further, there is a deep-water fording kit (costs money and usually just USMC tanks) that also achieves this.

There are relatively few heat-seeking ATGW. Most are laser-guided or SACLOS systems. It does hinder hiding from aircraft and thermal viewers, but the quick-starting and accelleration were considered acceptable trade-offs back when the tech was new.

Finally, infantry don't ride on the back deck. They ride on the turret. I have slept on the back deck and it does get hot, but not so much that they couldn't do it. But the old FM 7-8 has them on top of the turret.

Now, Cavguy mentioned COIN and I'll just add, they are very useful in that environment. Precision long-range MG and main gun fires, available at the section level, with the ability to withstand lots of punishment. Can they be defeated? Sure, but they work better than most platforms. Are they expensive? Yup. But nothing (NOTHING) can give a warmer feeling to a grunt than realizing that he has 70 tons working for him.

Our biggest failing is not integrating tank battalions into the infantry divisions to at least conduct joint training and familiarization, like the WWII divisions. Most light guys really don't know what armor can do for them in a MOUT or urban COIN environment.

Tankersteve

[Compost]

First, as hot as the exhaust is, it really isn't THAT hot. I never saw a Goretex melted by infantry guys inches away, drying out gear. The idea that you can't work around it is just silly. However, the exhaust deflector, commonly constructed by the unit welder, alleviates almost all of this issue for working in/around tanks. Further, there is a deep-water fording kit (costs money and usually just USMC tanks) that also achieves this.

There are relatively few heat-seeking ATGW. Most are laser-guided or SACLOS systems. It does hinder hiding from aircraft and thermal viewers, but the quick-starting and accelleration were considered acceptable trade-offs back when the tech was new.

Finally, infantry don't ride on the back deck. They ride on the turret. I have slept on the back deck and it does get hot, but not so much that they couldn't do it. But the old FM 7-8 has them on top of the turret.

Appreciate the argument re alternatives. However, infantry should be able to shelter behind a tank and use its intercom/phone without being tanned or toasted. Also infantry or combat stores that may have to ride on a tank are likely to better protected on the engine deck behind the turret rather than on top of it exposed to overhanging vegetation and incoming fire.

The capabilities of heat seekers have been continuously improved. And even when diverted and diffused the large volume exhaust from a 1,500hp gas turbine provides a more detectable and trackable target than the exhaust of a 1,500hp diesel. So why not a diesel Abrams and the related benefit of a well protected and presumably quieter APU ?

In terms of fuel and probably also maintenance, gas turbines are relatively expensive to operate. They also need routine refurbishment and when practicable upgrades to reduce maintenance and operating costs. Hence the AGT-1500 Tiger program which reportedly passed $1.5billion in 2010. It was also intended that the AGT-1500 be replaced by a more economic and compact LV100-5 gas turbine. But bracketed with Crusader, that engine project evaporated with cursory explanation and little comment.

For reasons presumably well understood and agreed within GE at least, company funds have recently been spent on building a ‘prototype’ diesel Abrams chassis. So has something changed ? Or is that prototype just a speculative venture offered in the hope that some party somewhere just might become interested in a diesel Abrams MBT ?

Possibly and/or a diesel Abrams ARV and/or AEV ?

[Compost]

http://www.cpbj.com/article/20141006...-Army-contract

Rebuilding another 53 M88A1 ARVs into M88A2 ARVs for $153.6M means BAE/BMY will continue in the heavy armoured vehicle business. But the same result could have been achieved by having BAE convert surplus Abrams MBTs into ARVs with the 120mm turret replaced by a jib crane and winch arrangements.

The A-frame lifting device of the M88 ARV is better suited to static usage such as in construction and mining rather than manoeuvre and military operations. It is already common for military mechanics to use a self propelled jib crane for accurate and rapid changeout of an engine or turret instead of the slow and less accurate manoeuvring of an A-frame equipped M88. Provision of an Abrams ARV with jib-crane would enable US Army and USMC planners and managers to concentrate on variants of that chassis and to competitively procure engine (GT and/or diesel), driveline and running gear spares from GD, BAE and subcontractors while using warehoused and cannibalized M88 engines etc to maintain gradually reducing numbers of A1 and A2 vehicles.

Moving forward it would be useful to learn if and how the experience and candid comment of US Army and USMC mechanics was factored into the procurement process.

[Compost]

Some comment on the inadequate /obsolescent nature of the M88A2 has been available since at least 1996. http://www.alu.army.mil/alog/issues/...6/mjlognot.htm

Have no copy of anything publicly reported since that item. However, recollect M88A2 being criticised also by an Australian maintainer - and reported probably in Army Newspaper - in the period 2005 -2010.

In the recent past it seems that diesel-powered Abrams chassis shown by General Dynamics at AUSA 2013 should have been configured as an ARV.