Add-On Abrams Tank Kits

U.S. Main Battle Tank M1A2 SEP Abrams Tusk II

With the heavy damage inflicted on Abrams series tanks during the close-in urban fighting in Iraq during Operation Iraqi Freedom, there developed the impetus for the US Army to authorize the funding for a new program in 2004 to better equip the tank for a type of fighting it had never been designed to take part in. The program was referred to as the Tank Urban Survivability Kit (TUSK) and was publicly announced in early 2005.

In a US Army News Service article published on 9 March 2005 is this description by US Army Program Manager Lieutenant Colonel Michael Flanagan on why the new add-on armor kit was needed and what benefits it would provide the Abrams series of tanks: ‘You have to remember, the tank was a Cold War design, aimed at threats that were always to its front. It’s still the most survivable weapon in the arsenal from the front … Today it’s a 360-degree fight, and these systems are designed to improve survivability in the urban environment.’

In 2006, the US Army ordered 505 units of the TUSK kits from GDLS. The first Abrams series tank in Iraq fitted with the kit was in 2007. By the following year, most Abrams series tanks employed in country had the TUSK kits. However, some were never fitted with the kits due to shortages. Others had only certain components of the kits applied.

Reflecting the various versions of the Abrams series tanks that were deployed to Iraq during the Iraq Insurgency, there was a TUSK I kit for the M1A1 and a TUSK II kit for the M1A2 and M1A2 SEP, which included some additional items for fitting to those tanks upgraded with the TUSK I kits.

TUSK I

One of the most noticeable external features of the TUSK I kit fitted to the M1A1 and M1A2 is the use of reactive armor tiles, also commonly referred to as Explosive Reactive Armor (ERA), along the sides of the vehicle’s hull in place of the original armored side skirts. As listed on the American manufacturer’s website, the tiles are officially designated the XM-19 Abrams Reactive Armor Tile (ARAT) and first appeared in 2006.

The first public employment of ERA occurred during the Israeli military invasion of Lebanon in 1982, when they were photographed on the exterior of American-supplied M60 main battle tanks in service with the Israeli Army (IDF). The Israeli firm that made the ERA tiles assigned them the label ‘Blazer Armor’. The original design work on the Blazer Armor was done by a West German researcher working together with the IDF.

ERA tiles consist of a steel box that contains a special plastic explosive fitted in-between two steel plates. How ERA tiles function when struck is explained in a 1988 article by then US Army Captain James M. Warford titled Reactive Armor: New Life for Soviet Tanks, which appeared in the January-February issue of Armor magazine:

… the plastic explosive inside the brick [tile] detonates. The force of this detonation is directed away from the brick’s inner steel plate, and concentrates in the opposite direction of the attacking warhead. This explosion forces the HEAT-formed jet to malform and lose its energy so that the heavily-weakened jet is not capable of penetrating the tank’s main armor.

The ARAT set applied under TUSK I consists of 64 tiles, with 32 on each side of the hull, divided into two rows of 16 each. According to the manufacturer’s website the ARAT is insensitive to bullets and other types of small battlefield fragments and will only detonate when struck by a shaped charge warhead, found on the projectiles fired from shoulder-launched rocket propelled grenade launchers, such as the RPG-7.

Tusk II

Under TUSK II, the M1A2 received a new generation of ERA tiles in 2008, labeled the XM-32. They are referred to as ARAT II tiles by the manufacturer, the original version being relabeled the ARAT I. The ARAT II set consists of 78 tiles, with 32 on each side of the tank’s hull, divided into two rows of 16 each. Unlike the ARAT I set, the ARAT II includes 14 additional tiles, 7 mounted on either side of the turret of the tank it is fitted to. Pictorial evidence seems to suggest that the turret tiles are not always fitted, for an undisclosed reason.

Unlike the large box XM-19 tiles, optimized for protection from horizontally-fired shoulder-launched rocket-propelled grenade launchers, those of the XM-32 look like roof tiles. When fitted to an M1A2 SEP they are slanted downward, as they are optimized to protect the tank from Improvised Explosive Devices (IEDs) that are configured to fire an Explosively Formed Penetrator (EFP). These shaped charge penetrators are currently employed on a number of American military weapons, including the TOW-2B antitank missile. Those used by the Iraqi insurgents were improvised and typically emplaced at ground level to fire upwards.

TUSK Crew Protection Upgrades

Due to the high demand from the tankers in Iraq, the initial production run of 130 units of the Loader’s Armored Gun Shield (LAGS), one of the numerous components making up the complete TUSK kits, was rushed to theater in 2005, before the complete kit sets were assembled. When the complete TUSK I kits reached Iraq in 2007, the Loader’s Armored Gun Shield was fitted with a thermal sight officially designated the Light Thermal Weapon Sight (LTWS).

With the introduction of the TUSK II kit there appeared a 360 degree open-topped armor shield for the M1A2 tank commanders, which included transparent armor to improve his visibility in combat when engaging the enemy. A much simpler open-topped shield arrangement had also been provided for the M1A1 series tanks under TUSK II. Externally, it appears the only TUSK feature adopted by the US Marine Corps in Iraq was the LAGS.

Due to the large-scale use of standard production antitank mines left over from the disbandment of Saddam Hussein’s Army, and IEDs by the Iraqi insurgents, an important component that formed part of TUSK I was a V-shaped armored plate 200mm thick attached to the bottom hull plate of Abrams series tanks in-country. It weighed 2,998lbs.

Reflecting the widespread use of conventional land mines and IEDs by the Iraqi insurgents, part of the TUSK I included a new Mine Resistant Driver’s Seat that minimized the effect of the blast and resulting shock wave on the driver. No longer was the driver’s seat mounted to the floor, which would transmit a shock wave to the driver’s body, but attached to the ceiling of the front hull compartment. In addition, the driver was provided with a four-point seat belt system to prevent him from being thrown around his compartment upon driving over a mine or IED.

TUSK Vision Upgrades

As part of TUSK I the drivers on the Abrams series tanks were provided with a thermal sight, which could be installed in their center periscope station if the situation dictated. It is labeled the Driver’s Vision Enhancer (DVE).

The TUSK I kits for the M1A1 series tanks included a thermal sight for the tank commander’s .50 caliber M2HB machine gun called the Remote Thermal Sight (RTS). The M1A2 did not require the RTS as it was already designed with one.

Miscellaneous TUSK Upgrades

To facilitate communication between the Abrams series tanks in Iraq and the dismounted infantry they often worked in conjunction with, the TUSK I kit included a Tank-Infantry Phone (TIP) placed at the right rear of the vertical engine compartment. It has an extension cable to allow an infantryman attempting to use the TIP to seek nearby cover if being fired upon.

To minimize the collateral damage caused by firing the 120mm main gun of the M1A1 and M1A2 series tanks deployed to Iraq when engaged in urban combat, the TUSK I featured a remote-controlled .50 caliber M2HB machine gun and a 200-round ammunition box attached to the mantlet of the tank. It is called the Counter Sniper/Anti-Material Mount (CS/AMM).

The .50 caliber M2HB machine that is the heart of the CS/AMM is fixed in position and is aimed by the gunner using his main gun controls. It can be fired separately from the main gun. From a 19 February 2008 article by Pfc. April Campbell, written for the Army News Service, comes this quote by 2nd Lieutenant Frank Simmons regarding the introduction of the CS/AMM in Iraq: ‘We’re still lethal at long ranges without destroying everything. The sniper rifle mitigates the collateral damage.’

TUSK Features Deleted

As part of the original TUSK I there had been a slat armor kit developed to protect the rear of the vehicle engine deck from strikes by rocket-propelled grenade launchers. At least one US Army armored unit equipped with the M1A2 SEP had them fitted for a time. For undisclosed reasons, maybe based on their limited use in the field, the slat armor kit was deemed impractical, and it was deleted from being part of the TUSK program.

Another feature proposed for the original TUSK program included a remote-control mount for the tank commander’s .50 caliber M2HB machine gun on the M1A2. This feature did not make it into the final TUSK program and did not appear in service until the introduction of the M1A2 SEP V2, fitted with the CROWS. Another feature proposed for the TUSK program was a rear hull camera system. It, like the CROWS, did not make it into the TUSK program, but later appeared on the M1A2 SEP V2.