Page 56 - Australian Defence Magazine September 2018

LAND
TANKS
with a turret featuring a large calibre can- non and machine guns which fire at a tar- get within eye sight (direct fire). Tanks are fitted with protective armour to survive all but the most significant threats faced on the battlefield. Further, a tanks propul- sion system and tracked drive train enable it to move across country at high speed and fight alongside infantry soldiers on broken ground. Army’s current fleet of 59 M1A1 Situational Awareness Main Battle Tanks, M1 hereafter, was acquired in 2006 to re- place the aged Leopard AS1 tank which had been in service since 1977.
The M1, like all AFV, is a blend of design trade-offs which create a unique combina- tion of characteristics. These characteris- tics are firepower, mobility and protection –colloquiallyknownasthe‘IronTrian- gle’ of AFV design. The M1 complements the other AFVs in the ADF’s inventory; including the Australian Service Light Armoured Vehicle (ASLAV) and the M113AS4 Armoured Personnel Carrier (APC), each of which have a different bal- ance of trade-offs. To understand why the tank is unique among armoured vehicles a brief examination of these characteristics is necessary.
First, the tank generates the greatest amount of direct firepower of any land vehicle. Firepower is the measure of the amount of ‘fire’ or shots a capability can generate, the effect of these shots on a tar- get and how long these effects can be sus- tained. The M1’s firepower centres upon a 120mm cannon which fires a variety
of munitions to destroy tanks, other ar- moured vehicles, low flying aircraft, for- tifications and buildings. The tank is also equipped with a heavy machine gun and two medium machine guns which fire rap- idly at less well protected targets such as trucks, utility vehicles and soldiers.
Importantly, these weapons are mated to an advanced fire control system which al- lows accurate, stable long range direct fire for several kilometres whilst the vehicle is moving. This system incorporates a 2nd Generation Forward Looking Infra-Red thermal imager which allows the tank to see by day and night; enabling it to detect, discriminate and engage a target with accu- rate direct fire often beyond the range of ad- versary systems. This fire can be applied at longrangewithprecisionandatcloserange
to provide an overwhelming weight of fire support. The tank stores a large amount of ammunition for all these weapons, allow- ing it to fight for prolonged periods without rearming.
In comparison a Combat Reconnais- sance Vehicle (CRV) like the ASLAV, which will be replaced under Land 400 Phase Two, is equipped with a small cali- bre rapid firing auto-cannon and machine guns. These provide the ability to fight for information and self defence, however, have less utility in destroying fixed instal- lations and heavier AFV. CRV are primar- ily tasked to find an enemy force’s vulner- abilities and exploit them, not engage in sustained close combat. Recent experience in Afghanistan highlights the ASLAV’s limitations in the direct fire support role.
‘While the 25mm [auto-cannon] is an excellent weapon for traditional cavalry operations, it had significant limitations in its range and penetration, which was ampli- fied when the enemy were able to use thick walls for cover... the 25mm was unable to penetrate a number of structures used by the enemy. From my experience,
I am confident that the infantry would have been provided far better protection and direct fire support... should we have been equipped with MBT [tank] in Afghanistan.’
Email provided by Cavalry Troop Leader regarding an engagement which occurred on 24 August 2010 around the village of Derapet.
Similarly APCs, which are optimised to transport infantry and cargo around the battlespace, often make compromises in terms of firepower and protection to do so. APCs are frequently equipped with self-protection weapons systems only, lacking the range and destructive effects of cannon. Likewise, to optimise their
TABLE 1. ILLUSTRATES THE TANKS GROUND PRESSURE WHEN COMPARED TO OTHER VEHICLES.
Table 1. Comparative Ground Pressures
Vehicle
Ground Pressure in kPa (approx)
Human male (1.8 meter tall, medium build)
55 kPa (8 psi)
M1A1 SA MBT
103 kPa (15 psi)
ASLAV CRV
111 kPa (16.1 psi)
M113AS4 APC
113 kPa (16.4 psi)
1993 Toyota 4Runner / Hilux Surf
170 kPa (25 psi)
Average Passenger car
205 kPa (30 psi)
Mountain bike
245 kPa (40 psi)
Racing bicycle
620 kPa (90 psi)
Table from Hunnicutt, R.P., 2015 (reprint), Abrams: A History of the American Main Battle Tank, Vol.
56 | September 2018 | www.australiandefence.com.au
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