Challenger 3: What will the Army's next main battle tank be like?

The retirement of the Challenger 2, the British Army's main battle tank, was confirmed in March's Defence Command Paper.

The document featured information on what the coming years look like for a number of the UK military's land vehicles.

It said 148 Challenger 2s will be upgraded to 'Challenger 3s' as part of a £1.3bn investment in the UK's armoured capability, with the remaining 79 vehicles from the fleet being retired.

The Challenger 3 will "become one of the most protected and most lethal in Europe", with a contract worth £800m going on creating the new tank.

The upgrades, which include a new turret, will give the vehicle "added mobility, survivability and lethality".

What do we know about Challenger 3 so far?

• The British Army will get a 148-strong fleet of Challenger 3 tanks.

• The tanks are expected to reach initial operating capability by 2027.

• The MOD then aims for the tanks to be fully operational by 2030.

What new technology will it feature?

• The new tanks will be fully digitised.

• The Challenger 3 will have a top speed of 60mph.

• They will have high-velocity ammunition capable of travelling at faster speeds and have an increased range.

• Ammunition will be programmed from a new turret with a 120mm smoothbore gun.

• The upgraded tanks will feature a new automatic target detection and tracking system.

• They will have thermal long-range cameras and an upgraded engine with a new cooling system and suspension.

The Defence Secretary says the "far more integrated vehicle" will allow personnel "to deliver immense warfighting capabilities in battlespaces filled with a range of enemy threats".

"It won't just be a vehicle on its own, it will be a vehicle that will be able to queue targets, talk to other parts of the battlefield in a way that, in my day, would have all gone back to a brigade through a battalion headquarters," Ben Wallace, a former British Army officer, added.

He said the Challenger 3 will offer a "fuller picture" of the battlefield to those operating it.

Watch: The expert's view on what the Army's future main battle tank could offer the service.

Prior to the latest announcement, we asked an expert to describe what capabilities the Challenger 3 will need to give the British Army.

Nick Reynolds, Land Warfare Analyst at the Royal United Services Institute (RUSI), said the new tank will "allow the UK to retain a heavy armoured capability", adding that the combination of protection, mobility and firepower still carry weight in ground war.

"A Challenger 3 will likely look different from a Challenger 2 in several ways," he added.

"While the hull will remain the same, it will feature an entirely new turret and, notably, a 120-millimetre smoothbore main gun – as opposed to the current rifle design.

"This will enable it to use the latest ammunition, as is used by the United States and other NATO partners," said Mr Reynolds, highlighting greater interoperability across the alliance.

"It will also have an updated electronics suite and, hopefully, we would see an integrated active protection system to protect the vehicle from incoming projectiles," he said.

Electronic changes to the tank, including a fire control computer and "digital backbone" will test the UK's force integration, the analyst explained.

One prototype for an upgraded Challenger 2 unveiled in 2018 was the 'Black Night', which focused on enhancing sensor systems, panoramic sight with thermal and optical channels, night vision, and an active protection system to detect enemy fire.

The Challenger 3 will join the Ajax armoured fighting vehicle and the Boxer, which will replace the capability offered by the Warrior, to form what the military describes as a "modern armoured nucleus".

New Challenger features may improve communication and data-sharing with other vehicles and ISTAR (intelligence, surveillance, target acquisition, and reconnaissance) assets, such as drones, during future deployments, said Mr Reynolds.

Main battle tanks have been shown to be "vulnerable" to these same ISTAR technologies, he added, highlighting the importance of the Challenger's evolution.

The expert believes tank crew personnel will benefit from the Challenger 3 upgrades, without losing the familiarity offered by the Challenger 2 over the last two decades.

"While the layout is very traditional in terms of crew roles, the improved fire control system, for example, will ensure that the tank is more lethal," he said.

"The improved protection will provide the tank crews with greater survivability in the event that they go into combat against other heavy armoured vehicles or against forces with a significant anti-armour capability."

Mr Reynolds described the Challenger upgrades as "long overdue" in light of developments in anti-tank technology, adding that 2003 was the last time the vehicle was updated.

He also stated the Challenger 2 "doesn't have a modern active protection system" and that: "Its armour is now not as capable of defeating the latest array of threats."

Watch: A German Leopard 2 on exercise in Sennelager, Germany. The tank is considered to have been an alternative option to upgrading the Challenger 2.

Although crew safety has benefited from a vehicle retaining a "great deal of survivability" in modern warfare, he said anti-tank guided missiles are evolving and making armour increasingly "at risk".

Despite anticipated improvements, the expert admitted the number of tanks being upgraded is "low" and restricts the UK's deterrence capability which has been offered to NATO in the past.

A 148-strong Challenger 3 fleet demonstrates the "fiscally constrained environment" facing the military post-coronavirus, Mr Reynolds explained, alongside a shifting focus from conventional deterrence to cyber and intelligence.

Had the UK opted to replace rather than upgrade their main battle tank, Germany's Leopard 2 vehicle was the primary alternative, according to Mr Reynolds.

Unlike Germany, Britain has not manufactured battle tanks for several years and will have to "play catch-up" during the Challenger 3 programme, said the analyst.

As for when the vehicle is likely to enter service, he explained that the design is still in its "early stages" and is unlikely to be seen within the next three to five years.