Gulf War and the M1 A1 Abrams Main Battle Tank (Part 4)

The previous instalment of this series analysed how the US-led coalition forces successfully misled the Iraqi army and retook Kuwait during Operation Desert Storm in the 1991 Gulf War. The article analysed the deception plan devised by the US Army, its objectives and implementation, the reaction of the Iraqi army and the factors that contributed to its success. The analysis focused on the ‘Two Corps’ concept and the ‘Left Hook’ manoeuvre, which specifically targeted Iraq's weak western flank. The article emphasised the importance of successful military deception, showing the interaction of intelligence, logistics and military strategy. The relevant section can be accessed from the link below.

https://strasam.org/savunma/kara-silah-ve-sistemleri/korfez-savasi-ve-m1-a1-abrams-ana-muharebe-tanki-bolum-3-3608

Cover Photo: M1A1HA Abrams H Company, 3rd Armoured Cavalry Regiment, Operation Desert Storm, February 1991. infographic by Peter SARSON

In 1990, Iraq's invasion of Kuwait led to the formation of an international coalition led by the United States of America and the launch of a military operation to remove the Iraqi Army from Kuwait. This crisis was the first combat mission of the M1 Abrams main battle tank. In 1990, the first M1 Abrams units deployed to Saudi Arabia were battalions of the 24th Mechanised Infantry Division, which at that time had older M1 and IPM1 models in its inventory. In the face of the increasing likelihood of ground operations, the US Army has embarked on an effort to equip as many units as possible with the M1A1 HA (Heavy Armour) configuration, preferably the most advanced version, in order to increase combat effectiveness.

M1A1HA Abrams

Company H, 3rd Armoured Cavalry Regiment, Operation Desert Storm, February 1991

Features

Crew 4

Combat weight 62.6 tonnes

Power-to-weight ratio: 24.0 Bg/tonne

Body length 26.0 ft

Overall length: 32.3 ft

Width: 12 ft (with side skirts). 11.4 ft (with side skirts removed)

Engine: Textron Lycoming AGT 1500 gas turbine,1500 Bg

Transmission: Allison XI 100-38 hydrokinetic, 4 forward, 2 reverse

Fuel capacity: 504.5 US gallons Maximum speed (road): 41.7 mph Maximum speed (Off-road): 30 mph

Best cruising speed: 25 mph Maximum range: 275 miles at cruising speed

Fuel consumption 1.83 gallons per mile

The turbine engine of the tank is capable of operating on multiple types of fuel. These include petrol, diesel fuel and jet fuel (JP-8).

Transit depth: 4.0 ft (unprepared), 7.8 ft (prepared)

Armament M256 smoothbore 120 mm gun

Main cannon ammunition:

M829 APFSDS (Armour piercing. wing stabiliser, sabot )

M830 HEAT-MP (high-explosive. anti-tank, multi-purpose)

Muzzle velocity: 5500 ft/sec (APFSDS)

Muzzle velocity:3735 ft/sec (HEAT-MP)

Max. effective range: 3500 m (APFSDS),

Max. effective range: 3000 m (HEAT-MP)

Stored main gun shells: 40

Weapon lowering/raising: - 10 degrees/ +20 degrees

Turret machine gun: 7.62 mm M240 machine gun

Loader (loader) weapon: 7.62 mm M240 machine gun

Commander's weapon M2 Browning 50 calibre heavy machine gun

Due to the limited availability of the M1A1 HA configuration, a modernisation programme was initiated to modernise M1A1 tanks with a heavy armour package. Under this programme, a total of 835 tanks were upgraded to the heavy armour configuration, and in addition, fire control systems were upgraded, an NBC (nuclear, biological, chemical) system heat exchanger was integrated, repainted with Chemical Agent Resistant Coating (CARC) and Tan Desert camouflage paint, and a number of other technical improvements were implemented.

As a result of these modernisation efforts, only two Army battalions were still operating M1 tanks at the start of the ground campaign. As of February 1991, the US Army had deployed a total of 2,494 M1A1 tanks in Saudi Arabia, including 1,966 M1A1 tanks assigned to combat units (733 M1A1s and 1,233 M1A1 HA) and 528 tanks in non-combat strategic reserve.

Although strategic airlift was provided by the Lockheed C-5 Galaxy, the limited capacity of these aircraft (the C-5 could carry two M1A1 tanks) led to long deployment times and significant logistical difficulties during the First Gulf War. As a result, the vast majority of the 2494 tanks assigned for the operation were transported by sea.

In the months leading up to the operation, various modernisation efforts were undertaken to improve the combat effectiveness of the M1A1 fleet, including the procurement of improved T-158 tracks. The US Marine Corps (USMC) tank battalions participating in Operation Desert Storm were predominantly equipped with older M60A1 RISE/Passive tanks, comprising 277 of the 353 tanks deployed. In contrast, the Marine Corps 2nd Tank Battalion was equipped with M1A1 HA tanks inherited from the US Army. Two companies of the Marine Corps Reserve's 4th Tank Battalion were equipped with the new M1A1 configuration. As a result, the USMC deployed a total of 76 M1A1 tanks in Operation Desert Storm, of which 60 were M1A1 HA and 16 were in the M1A1 configuration.

What were the main reasons for the success of the M1A1 Abrams in the Gulf War?

As a general assessment, the M1A1 Abrams demonstrated a significant superiority in all technical areas against the T-72M, the most advanced tank in the Iraqi Army's inventory, and inflicted disproportionate losses on Iraqi armoured units.

The main reasons for the success of the M1A1 Abrams tank in the Gulf War stem from the combination of technological superiority, crew training, logistic support and the characteristics of the operational environment. This technological superiority has clearly manifested itself in critical issues such as firepower, armour protection, mobility, situational awareness and crew survival design, which are the key elements of combat effectiveness.

1) Firepower and Ammunition

The 120 mm M256 smoothbore gun manufactured by the German Rheinmetall Landsysteme GmbH. The 120 mm calibre of this gun allows the use of high-impact 120 mm calibre ammunition. The M1A1 Abrams tank uses the 120 mm M256 smoothbore gun. Although this gun is smaller in diameter than the 125 mm 2A46M smoothbore gun on the T-72M, it has higher firepower thanks to the modern ammunition it uses. This advantage manifests itself in the following ways.

The combat effectiveness of the M1A1 Abrams tank has been significantly increased by the superior range, accuracy and armour penetration capabilities of the ammunition used. These munitions provide the M1A1 with the capability to hit targets with high accuracy from greater distances, allowing the M1A1 to neutralise enemy armoured vehicles from a safe distance. In particular, the M829A1 armour-piercing ammunition used by the M1A1 had a higher armour penetration capability than the ammunition used by the T-72s. Depleted uranium (DU) penetrator ammunition has better armour penetration performance than tungsten carbide penetrator ammunition, giving the M1A1 a more effective engagement advantage over enemy tanks at longer distances.

The quality of the ammunition used by the Iraqi army for the T-72 tanks had a significant impact on their combat performance. Due to the Soviet Union's export policies, Iraq was generally supplied with lower quality ammunition. This significantly limited the Iraqi army's ability to effectively penetrate the advanced armour of the M1A1 Abrams tank. As a matter of fact, while the Iraqi T-72s used older ammunition such as 3VBM-3 or 3VBM-7, which were the technology of the 1960s, the M1A1s had much more modern ammunition such as M829A1, which made a significant difference on the battlefield.

The ammunition used by the M1A1 Abrams tank has a significantly higher armour penetration capacity compared to the ammunition of the T-72M tank. This superior penetration capability enables the M1A1 to penetrate even the thickest armoured areas of enemy tanks, providing a decisive advantage on the battlefield. Therefore, the M1A1 has a clear advantage in armour penetration against rival tanks such as the T-72M.

As an important feature that increases combat effectiveness, the M1A1 Abrams tank has the ability to use a wide range of ammunition for different target types. This versatility allows the tank to adapt to changing combat conditions and respond effectively to different threats. For example, high kinetic energy armour-piercing ammunition (APFSDS) is used against armoured targets (such as main battle tanks), while high-explosive (HE) or multi-purpose (MP) ammunition is preferred against softer targets such as fortified positions, buildings or infantry units. This variety of ammunition gives the M1A1 superior operational flexibility in the dynamic and complex nature of the modern battlefield.

It should be emphasised that the T-72M variant in the Iraqi Army's inventory is an export version with significant shortcomings compared to the standard models used by the Soviet Union in its own units. This variant featured weaker armour protection, less sophisticated fire control systems and lower performance ammunition. This was an important factor in the superiority of the M1A1 Abrams tanks over Iraqi armoured units during the conflict. Indeed, the performance evaluation report published by the US Government Accountability Office (GAO) after the operation confirmed this point. This report revealed that the weaknesses of the T-72M significantly affected the combat effectiveness of the M1A1.

Main Ammunition Types Used for the M1 Abrams Tank

The M1 Abrams main battle tank uses a range of ammunition for different purposes in order to maintain its effectiveness in various combat scenarios. The types of ammunition used by M1 Abrams are as follows.

Kinetic Energy Armour Penetrating Ammunition

APFSDS (Armour Piercing Fin Stabilized Discarding Sabot): This type of ammunition is designed to pierce armour using kinetic energy. The high velocity penetrator penetrates the armour and causes destruction. The main APFSDS munitions developed for the M1 Abrams tank are M829, M829A1 (used in the Gulf War in 1991), M829A2 (used since 1994), M829A3 (from March 2003), M829A4 (formerly M829E4) (from April 2015)

Sabot ammunition is a sophisticated type of ammunition designed to penetrate armour through the transfer of high speed and momentum, acting as kinetic energy penetrators. Its basic principle of operation is similar to that of an aerodynamic arrow or spear, using kinetic energy rather than explosive action to penetrate armour.

When we examine the structural features and functioning of sabot ammunition, we see that at the centre of the sabot ammunition is a long, thin, high-density metal rod called a penetrator. This penetrator is usually made of depleted uranium (DU) or tungsten alloys. The high density and self-sharpening properties of depleted uranium significantly increase armour penetration. The design of the penetrator incorporates a pointed nose at one end and stabilising fins at the other to maximise aerodynamic efficiency. These fins provide stability in flight, allowing it to follow a straight trajectory towards the target.

In the image above; Armour Penetrating Wing Stabiliser Sabot (APFSDS) projectile. The sabot is separated from the penetrator as it has completed its mission.

Before the ammunition is fired, the penetrator is placed in a sabot (separator). The sabot acts as a carrier that keeps the penetrator on the central axis of the gun barrel and ensures that the high-pressure gases generated during firing are delivered to the penetrator with maximum force. The sabot, usually made of light metal or composite materials, is separated by aerodynamic forces immediately after leaving the barrel. When we look at the ignition and penetration mechanism, at the moment of ignition, the high-pressure gases generated by the combustion of gunpowder push the sabot and the penetrator inside it along the barrel at a high speed. After leaving the barrel, the sabot separates rapidly due to aerodynamic resistance, while the penetrator flies freely at high speed. The narrow profile and high speed of the penetrator cause its energy to be concentrated in a very small area.

On impact with the target, the penetrator's kinetic energy is converted into a tremendous force. This force is sufficient to penetrate armour. During the penetration process, the penetrator and the armour material reach high temperatures due to excessive friction. This leads to a ‘self-sharpening’ effect of the tip of the penetrator and improves penetration performance.

In the event that an armour-piercing ammunition successfully penetrates tank armour, the penetrator core and armour fragments enter the tank interior at high velocity and temperature. The main effects of this event are as follows; High velocity fragments can cause serious injuries or fatalities by direct hits to crew members. If the fragments hit the ammunition depot, it may cause chain reactions and severe explosions, leading to the complete destruction of the tank. May cause system failures. The tank's electronic systems, hydraulic lines and other critical equipment may be damaged by fragments, causing the tank to lose its functionality. Again, high-temperature fragments and explosions can start a fire inside the tank, creating additional hazards for the crew.

The M1A1 Abrams tank is armed with a 120mm M256 smoothbore gun, capable of firing a variety of ammunition, including APFSDS (armour-piercing, finned, breakaway sabot) and HEAT (high-explosive anti-tank). In particular, the M829A1 APFSDS round with depleted uranium penetrator offers exceptional armour penetration capability, while the M830 HEAT round has shown high effectiveness against light armoured vehicles. Although the M1A1's primary choice for anti-tank missions is APFSDS ammunition, due to the extreme penetrating power of this ammunition against lightly armoured targets, HEAT ammunition was considered as a more suitable option for such targets. In this way, combat effectiveness was optimised by using appropriate ammunition against different threat levels.

The T-72 tank is armed with a 125mm 2A46 smoothbore gun and is capable of firingAPFSDS and HEAT ammunition . However, the APFSDS ammunition in the Iraqi army's inventory was generally a generation behind the most advanced ammunition used by the Soviet Union. Although precise information on Iraq's 125mm ammunition stocks is limited, it is known that the Iraqi army frequently used the older 3VBM-3 ammunition during the 1991 Gulf War. The Soviet Union's most advanced APFSDS ammunition, the 3VBM-13 ‘Vant’, was capable of penetrating approximately 560 mm of armour at 2 kilometres, while the penetration of the Iraqi 3VBM-3 ammunition was about half that. HEAT munitions available for the T-72 include the 3VBK-7 and 3VBK-10. Although the 3BK-14M (3VBK-10) was capable of penetrating approximately 500 mm of armour, it was not capable of penetrating the frontal armour of the M1A1 Abrams tank. This is considered to be a factor that significantly affected the combat effectiveness of Iraqi T-72s against M1A1s.

The image above shows the different ammunition used by the M1A1 and M1A2 Abrams main battle tanks. M829 APFSDS-T / M829A3 APFSDS-T / M830A1 MPAT / M1028 CANISTER / M1002 / M865 TPCSDS-T. Image Source AFV Club USA 120mm M1A1 and M1A2 Abrams cannon ammunition set box cover.

A small note

120 mm M1002 Target Practice Multi-Purpose Tracer (TPMP-T) training projectile; This projectile is to enable military personnel to train in an environment similar to real combat conditions. In particular, it is designed for training in the use of the tactical M830A1 High Explosive Anti-Tank Multi-Purpose Tracer (HEAT-MP-T) projectile.

The M1002 training projectile behaves in a similar wayto the real M830A1 projectile. Thanks to the fact that it has a ‘dummy air/ground switch’ and its ballistic characteristics (flight time, velocity, etc.) are matched to the M830A1, firing drills provide a realistic experience. In other words, soldiers feel as if they are using real bullets during training. The M1002 has a safety feature called ‘tail cone stabiliser’. This feature limits the range of the projectile to less than 8 kilometres. This makes the training area safer and reduces the need for over-range safety measures. In other words, by preventing the bullet from travelling too far, possible accidents are prevented.

120mm M865 TPCSDS-T Kinetic Energy (KE) training round; The M865 training round behaves in a similar manner to real combat rounds. Thanks to its ‘matching external ballistics’ (i.e. flight trajectory, velocity, etc.), it mimics the performance of real bullets. This allows soldiers to feel like they are using real bullets during training.

The M865 accurately reflects the accuracy of real bullets and the time to reach the target (flight time). This ensures effective learning of aiming and shooting techniques. The M865 is designed similarly to the 120 mm M829 Armour Piercing, Fin-Stabilised, Thrown Sabot Tracer (APFSDS-T) round, which is a real anti-tank round. The cartridge (shell casing) used is the same and has similar performance characteristics. In this way, the training round effectively replaces the live round. The M865 has a special safety feature called ‘cone stabiliser’. This part keeps the range of the projectile below 8 km, making the training area safer. Thus, possible accidents during training are prevented and fewer safety precautions are required.

Chemical Energy Ammunition

HEAT (High Explosive Anti Tank): This type of ammunition is designed to melt and penetrate armour by focusing explosive energy. M830 HEAT ammunition belongs to this class.

MPAT (Multi Purpose Anti Tank): This ammunition has both HEAT effects against armoured targets and fragmentation effects against personnel and lightly armoured vehicles. The M830A1 MPAT ammunition belongs to this class.

The image above shows some technical details of the M830 HEAT-MP-T ammunition.

HEAT (High Explosive Anti-Tank) ammunition relies on the effect of a shaped charge, also known as the ‘Munroe effect’, rather than kinetic energy as an armour penetration mechanism. An impact sensor in the front of the munition triggers a precise detonation upon contact with the target, melting a copper liner. The shaped charge generated by this explosion condenses the molten metal and high-temperature gases into a thin jet of metal that penetrates the armour at high speed. To explain in more detail.

HEAT (High Explosive Anti-Tank) ammunition uses chemical rather than kinetic energy, i.e. the effect of the shaped charge, to penetrate armour. The impact sensor at the tip of the munition triggers a series of events on contact with the target; the armour penetration mechanism of HEAT ammunition relies on a series of rapid events. First, when the ammunition comes into contact with the target, the impact sensor triggers a high explosive that envelops a copper liner. The explosion instantly melts the copper and generates high-pressure gases. The critical point is the shaped cavity (usually cone-shaped) inside the munition. This cavity concentrates the energy of the explosion and the molten copper into a narrow jet that travels at an incredible speed of several kilometres per second. This focused jet of metal cuts through the armour like a knife, penetrating and damaging the systems and crew inside the tank.

Other Ammunition Types

HEOR (High Explosive Obstacle Reduction): This ammunition is designed to overcome obstacles (e.g. walls, barricades). M908 HEOR ammunition is used for this purpose.

HE (High Explosive): This type of ammunition is designed for general purpose use and is effective against a variety of targets such as personnel, light armoured vehicles and fortifications. M1069 HE ammunition belongs to this class.

M1028 Cannister : The M1028 Cannister has been in the US Army inventory since 2005. This ammunition is a type of pellet ammunition designed to be used against personnel targets at close range. The M1 Abrams main battle tank is designed to provide an effective defence against various threats it faces on the battlefield.

One of these threats is infantry elements at close range, which can occur especially in residential operations and sudden attacks. In such situations, the M1 Abrams tank provides an effective defence mechanism using the specially developed M1028 Canister ammunition. Close-range effectiveness The M1028 Canister cartridge is fired from a 120 mm smoothbore cannon, producing a high-intensity effect at ranges as short as 200-500 metres. When fired, this ammunition ejects a large number of tungsten balls from the barrel. These balls spread over a wide area in the target area and have a highly lethal effect against infantry masses. Blocking infantry attacks and dispersing masses: The M1028 Canister ammunition is specifically designed to disrupt sudden infantry attacks, neutralise RPG (Rocket-Propelled Grenade) teams and disperse enemy infantry concentrations. With this feature, it saves time for the tank crew and increases the tank's chances of survival.

In the image below, the internal structure of the M1028 Cannister ammunition is seen in the lap of the loader personnel of the M1A2 Abrams tank.

The image above shows the internal structure and development of the M829 APFSDS family of ammunition.

The M829 series is a kinetic energy anti-tank ammunition designed for the M256 120mm L/44 smoothbore gun used by the United States on the M1 Abrams main battle tanks. This ammunition family, which operates on the Armour Penetrating Wing Stabiliser Firing Sabot (APFSDS) principle, has gone through various development stages over time and has different variants. These variants differ in terms of armour penetration capability, range and other ballistic characteristics.

This document presents a comparative analysis of the main variants of the M829 series.

The M829 is the first variant of the M829 series. It uses a penetrator made of depleted uranium (DU) alloy, which has a high density and high armour penetration capability. The main technical characteristics of the M829 are as follows: Total weight 18.6 kg, penetrator length 627 mm and penetrator diameter 27 mm. When fired with JA-2 propellant weighing 8.1 kg, the munition can reach a high muzzle velocity of 1,670 m/s. In this way, it is stated to have an effective range of up to 3,000 metres. Tests have shown that the M829 can penetrate 540 mm thick Rolled Homogeneous Armour (RHA) at a distance of 2,000 metres. The M829, which has been discontinued today, has been replaced by more advanced variants.

The M829A1, also known as the"Silver Bullet ’, is an improved version of the M829 series. This variant was recognised for its high performance against Iraqi Army tanks (Iraqi Type 59 (Chinese T-55) and Asad Babil (Iraqi T-72)), especially during the 1991 Gulf War (Operation Desert Storm). The main technical specifications of the M829A1 are as follows: The total weight is 20.9 kg and the penetrator length is 684 mm. When fired with JA-19 propellant weighing 7.9 kg, the ammunition can reach a muzzle velocity of 1,575 m/s. Thus, it has an effective range of 3,000 metres. According to estimates, the RHA (Rolled Homogenous Armour) penetration capacity of the M829A1 varies according to the distance: 620 mm at 1,000 metres, 570 mm at 2,000 metres and 460 mm at 4,000 metres.

The M829A2 represents the next development stageof the M829 series. In this variant, significant improvements have been made over the previous model, the M829A1. These include a longer depleted uranium (DU) penetrator, more precise and efficient manufacturing processes, and a carbon fibre reinforced composite sabot that provides a lighter and more durable structure. Thanks to these improvements, the muzzle velocity of the M829A2 reached 1,680 m/s, an increase of approximately 100 m/s over the M829A1. This contributed to a significant increase in the armour penetration capability of the M829A2.

The M829A3 represents another important development phaseof the M829 series and is designed to provide an effective solution against Explosive Reactive Armour (ERA) systems, which are widely used in today's modern battlefields. This variant uses a segmented penetrator to neutralise advanced ERA systems such as the Russian-made Kontakt-5. It is stated that the M829A3 has a heavier penetrator than previous variants, but has a lower muzzle velocity. This ammunition is also referred to as ‘super sabot’ by Abrams tank crews. However, it is claimed that the low speed of this projectile can be easily neutralised by the Russian Relikt ERA.

The M829A4 is the most recent and advanced variantof the M829 series. This ammunition is specifically designed to provide superior performance against Russian-made Relikt Explosive Reactive Armour (ERA) systems, one of the most challenging threats faced by modern battle tanks. The M829A4 has advanced features such as a multi-piece long rod penetrator, a three-leaf carbon fibre reinforced composite sabot, a low friction fin with tracer and a windscreen and tip assembly that improves aerodynamic performance. The ammunition's propellant system ensures consistent muzzle velocities even in harsh environmental conditions (from -32 to 63 °C) without compromising ballistic performance.

In addition, the new Advanced Combustible Cartridge Case (ECCC) has been redesigned and the cutting joint repositioned to maximise crew safety.

To summarise, the M829 series represents a continuous evolution in the field of kinetic energy anti-tank ammunition. Since its inception, each new variant of this family of munitions has focused on addressing the weaknesses of the previous version and providing a more effective solution to the new generation of armour threats emerging on modern battlefields. In this context, the M829A2 variant stands out with its higher muzzle velocity and thus increased armour penetration performance, while the M829A3 and M829A4 variants incorporate special technologies designed specifically to counter Explosive Reactive Armour (ERA) systems of Russian origin.

This concludes the 4th part of our article series. See you in the 5th part. Bibliography will be included in the last part of the series.