M1 Abrams MBT
Currently in service in four countries, including some 8000 in use by the US Army and US Marine Corps (USMC), the
M1 Abrams is widely considered an excellent main battle tank (MBT) in all the key areas:
protection, mobility and firepower. It would appear that from a platform perspective the
M1 Abrams is at least as capable as the Leopard 2 and Challenger 2.
Protection: Recent combat experience in Iraq would suggest that the
M1 Abrams is very well protected and able to survive kinetic energy projectile attack during close combat across a variety of battlespaces. The
M1 Abrams was the spearhead of the US advance into the Iraqi interior an operational environment as complex as any and it survived under medium- to high-intensity conventional warfighting conditions and some asymmetric attacks about as well as can be expected. No other armoured fighting vehicle (AFV) used by the US afforded the same level of battlefield protection.
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| M1 Abrams MBT |
The well-sloped glacis plate and frontal turret armour seem sufficient to prevent penetration from RPG fire and 23mm cannon fire from any angle. And, of course, it should do that and more at a combat weight of 65 tonnes (M1A1 version). The rear-mounted engine grille is reportedly vulnerable to armour-piercing rounds fired from cannon of 25mm calibre and above, but then again, how often does a tank (used in a combined arms battlegroup and supported by mechanised infantry as the Australian Army would) come under attack from behind? As in all late-generation MBT, the turret roof of the
M1 Abrams remains vulnerable to overmatch from top attack anti-tank guided weapons, of which there exist numerous types in widespread use.
The
M1 Abrams’ armoured side skirts are a stand-out feature of this vehicle and appear to be at least 60mm thick. Unlike the rubber-armoured skirts fitted to Army’s current Leopard AS1, these skirts are all armour and would clearly be effective in stopping AP heavy machine (HMG; 12.7-14.5mm) rounds and RPG fire from close range. Firepower: While it is common knowledge that the 120mm tank gun equipping late generation Western tanks is superior in every ballistic sense to 105mm ordnance in the tank-on-tank role, a chief concern for Army will be to ensure it has access to a variety of 120mm ammunition natures better suited to providing direct fire support to infantry than high explosive anti-tank and armour-piercing fin-stabilised discarding sabot (APFDS) rounds. These include high explosive squash head and canister rounds; the latter proved so devastating against enemy infantry in Vietnam.
One firepower advantage the M1 Abrams has over the Leopard 2 and Challenger 2 is the secondary armament array at the crew’s disposal. Together with the standard M240 7.62mm machine guns mounted alongside the main gun and at the loader’s hatch, a 12.7mm M2 Heavy Machine Gun (HMG) weapon station is installed in front of the commander’s station. With a 360-degree, electrically-powered traverse and 1000 rounds of 12.7mm ammunition stowed on board, the crew is able to engage a wider selection of targets of opportunity without resorting to use of the main armament particularly crew-served weapon teams, exposed infantry, softskinned and light armoured vehicles. American crews fighting in Iraq found the versatility of the M1 Abrams’ secondary armaments highly effective, particularly when ranges were too short to use the main gun or when its use was restricted due to collateral damage considerations.
Total main gun ammunition loads stowed onboard the M1 Abrams and the Leopard AS1 are 40 x 120mm rounds and 59 x 105mm rounds respectively.
Mobility: There have been no adverse reports concerning the mobility of the M1 Abrams, at least none that this author knows about. Like all modern tracked AFV it is safe to say that the M1 Abrams enjoys superb cross-country mobility across a variety of terrain types.
Of more interest to the Australian Army is how well the M1 Abrams will perform in the varied but typically confined terrain of Australia’s immediate region of interest. Clearly, there are those who believe that a tank of this weight cannot traverse the jungle and tropical terrain encountered across our region (in spite of Australia’s success at operating the 50 tonne Centurion in Vietnam). But it should be borne in mind that the M1 Abrams is a highly manoeuvrable platform with a good power-to-weight ratio (better than that of the Challenger
2 but not as high as the Leopard 2A5) and will be operated by a unit (1st Brigade’s 1st Armoured Regiment) noted for its expertise in operating in close country.
While the M1 Abrams is wider than Army’s legacy Leopard AS1 (by about 25cm overall), it will make mince
meat of ‘track bashing’. Same goes for the Leopard 2 and Challenger 2. Interestingly, the 406 M1A1 Abrams of the USMC are fitted with a deep-water fording kit for amphibious operations and additional tie-down points for ship-to-shore movement in landing craft.
Deployability: With the new tank (regardless of type) likely to be in service within 12–24 months at the very latest, the way in which the ADF’s existing infrastructure and support equipment will accommodate and cope with the introduction of a larger and heavier tank will become an issue. Army will most certainly need new low-loader tank transporters. Each tank squadron will need new recovery vehicles able to lift and
winch the new tank. Rail-rolling stock will need to be assessed as to its ability to carry heavier tanks, where vehicle width will also be a factor. Same goes for rail and ground infrastructure such as tunnels, bridges, crossing points and road surfaces around base and training areas.
Despite being the heaviest tank under consideration (the Challenger 2 is longer and the Leopard 2 is wider), the
M1 Abrams is, in fact, no less deployable than the
Leopard 2 or Challenger 2, as has been widely assumed in the mainstream media. Whether a tank weighs 55 or 65 tonnes is of little relevance; it’s the support equipment and infrastructure a deployable force has in place that makes the difference. Compatibility with the RAN’s existing amphibious transport vessels is certain to be one area where remedial work will
need to be undertaken.
Again, this will be irrespective of which tank is selected. For example, the rear ramp of an LPA is rated to only 50 tonnes. Basically, this enables the ramp to support a 50-tonne load unsupported (i.e. relying on its support chains and own structural strength). Given that the last of the LPA (probably Manoora) is not due to pay off until 2017, this will need to be rectified. From an engineering perspective, it is understood that beefing up the structural strength of the ramp is achievable; the RAN recently made similar changes to ensure the LPA stern ramp could support the 42-tonne Leopard AS1.
The US offer of the M1 Abrams to Australia is understood to involve a fully optioned package that includes
open and ongoing access to US Army and USMC M1 Abrams upgrades and rolling technology insertion programs out to 2020 and beyond. This will enable the Australian Army to tap into the product improvement initiatives for the US M1 Abrams fleet throughout life-of-type picking and choosing those most applicable to our strategic circumstances and capability requirements, including those implemented as a result of the most recent combat experiences.
