How Military Tanks Work

Prolific in armies all over the world, tanks have developed significantly since their conception at the start of the 20th Century, now offering awesome levels of firepower, protection and agility.

Tanks work by providing an armoured, mobile platform upon which various weapons can be mounted, as well as a secure transport vehicle for soldiers in the theatre of war. Central to any tank’s design are three key areas: armour, mobility and firepower, which are intrinsically linked at a fundamental level, with changes in each area directly affecting the others. For example, if a tank features super-thick armour plating, while excellent at protecting its mechanical components and crew, it reduces its acceleration, top speed and armament loadout.

Today, the absolute pinnacle of tank design worldwide is demonstrated in the main battle tank (MBT) category of tanks, a series of high-powered, heavily armoured vehicles whose role consists primarily of direct/indirect fire support on the battlefield. Featuring large primary cannons that are capable of firing a range of high-explosive and kinetic energy penetrator (ammunition that has no explosive charge but relies purely on kinetic energy to penetrate armour) rounds, as well as autocannons, GPS/laser-guided missiles and smart submunitions, MBTs specialize in large-scale destruction of enemy vehicles and structures. Currently, arguably the pinnacle of the MBT category is the United States’s M1A2, a juggernaut that is presently in use in the Iraq and Afghanistan wars.

Weighing in at 67.6 short tons, measuring in at 7.93 metres in length by 3.66 metres in width, fitted with a 1,500hp Honeywell AGT1500C turbine engine and packing a 120mm L44 M256 smoothbore cannon, the M1A2 typifies current tank design. It’s fast – think a top speed of 45mph with a power-to-weight ratio of 24.5hp/metric ton – heavily armoured, and insanely well armed. Composite plates made from layered ceramic tiles and forged metal matrixes are utilised by the M1A2 to mitigate the effects of shaped charges, while steel-encased depleted uranium mesh plating is used due to its high density to reinforce key impact zones, such as the hull front and turret. The L44 M256 smoothbore cannon, meanwhile, provides awesome range and round versatility – max range at over 8,000 metres.

Key, however, to the M1A2’s success and prolificacy is its advanced electronic control and detection sensors, electronic countermeasures and modern communication systems. Light intensification and thermal imaging systems help the M1A2 detect enemies while at night, in smoke or in poor visibility conditions, while a fire-control computer collates information from the vehicle’s laser rangefinder, ammunition payload and lead angle to ensure an accurate shot. In addition to these three core factors, the fire-control computer also tracks and utilizes data from the MiA2’s crosswind sensor, pendulum static cant sensor, boresight alignment sensor, ammunition temperature sensor, air temperature sensor, barometric pressure sensor and target speed.

However, despite the current inclination for heavily armoured, well-weaponed, one-role tanks – such as the Abrams M1A2 and British-made Challenger 2 – cutting-edge tank design is seriously evolving, with increased versatility and greater mobility favoured due to the rapidly-moving nature of the modern-day war zone. Compromising a degree of protection and firepower to facilitate agility, tanks such as BAE’s CV90120-T and General Dynamics UK’s modular ASCOD SV are allowing nations to invest in multi-role vehicles, with a single-base chassis and hull, which is capable of being fitted with a variety of turrets, cranes, extendable bridges, med bays and earth movers dependent on the mission parameters and context. This way, no matter whether the tank is deployed in the heart of a city or the open plains and hills of a rural environment, it can quickly be adapted to better suit conditions, maximizing its operational efficiency- not to mention its performance.

Driving a tank

How tanks are controlled has evolved massively over the last 100 years?

Originally, driving a tank required its own dedicated team. The WWI Mark I tank, for example, required four people just to make it accelerate, decelerate or turn. The primary driver was responsible for the clutch, hand throttle and primary gearbox, which when operated correctly delivered two speeds of forward acceleration and one in reverse. Sitting next to him at the fore of the tank was the commander, who dictated orders and operated the brakes. To the rear, two gearsmen then worked two secondary gearboxes that were responsible for the tank’s individual track movements. These constituent controls had to be operated in unison – a feat that was made even harder due to the deafening noise and intense smoke inside the cabin – with every single change in movement requiring a controlled collaboration.

Driven by the complexity and crudeness of early systems and rapid advances in military technology, WWII tank controls received an overhaul, significantly reducing the amount of people required to make them move. Controls of this era (1940-1960) are typified by the T-34/M4 Sherman medium tanks. Here only one primary driver was needed, with acceleration, individual track controls and breaks all installed in the front cockpit. This system worked though a combination of twin steering sticks, five-forward one-back gearbox and manual clutch pedal.

Today, main battle tank controls have been simplified even further, with complex auto transmissions partnered with fly-by-wire joysticks. Here – as aptly shown by the Abrams M1A2 – the driver merely has to put the tank in drive mode and then can control speed and direction with a central joystick. Also, thanks to advanced multi-fuel turbine engines, noise, heat and the chances of stalling are significantly reduced.

Smart weapons

Apart from traditional high-explosive rounds, modern tanks are fitted with smart missile and shell weaponry!

From the M712 Copperhead laser-guided direct-fire round to the M982 Excalibur GPS guided missile, tanks now have various weapons systems available to them to destroy enemy targets. One of the most notable, however, is the SMArt 155, a recently released 155mm artillery round that delivers two autonomous, sensor-fused, fire-and-forget submunitions. Each submunition contains a high-penetration EFP warhead (a shaped charge designed to penetrate armour at a stand-off distance), that once separated from its carrier shell, descend downwards towards multiple targets, identifying their location through infrared sensor and millimetre wave radar.

Tank design

Three factors must be addressed when designing a battle tank: firepower, protection and mobility

Protection – Armour is a critical factor. Blocking and deflecting incoming kinetic energy penetrators (non-explosive rounds) and high-explosive anti-tank shells is of foremost importance – factors that have led to the development of composite armours, which incorporate layers of ceramics, plastics and resin matrixes between steel plates.

Mobility – Mobility is increasingly important in battle tanks, driven by the rapidly moving nature of the modern battlefield. Tanks must be able to traverse a variety of obstacles and terrains, as well as remain active for lengthy periods, capable of great operational ranges. Mobility is compromised by the weight of the tank’s armour and the size and number of its weapon’s loadout.

Firepower – Modern tanks now have large, smooth-bore cannons for traditional direct fire destruction, as well as GPS/ laser-guided smart missiles for long-range, tactical strikes. However, the level of firepower is linked to a tank’s armour and mobility levels, with an increase in cannon size leading to an increase in hull/chassis size to maintain stability and firing accuracy.

Top 3 battle tanks

Challenger 2 – Arguably the most armoured I and best-protected tank in the world, featuring state-of-the-art second-gen composite Chobham armour, the details of i which are classified.

T-90 – Packed with the largest cannon (125mm) currently on a battle tank, the T-90 can fire high-explosive and armour-piercing rounds capable of piercing up to 37 inches of steel.

Abrams M1A2 – A vast suite of electronic defensive systems and countermeasures, with a 120mm main gun, laser-guided missiles and 50-cal heavy machine gun.