No vehicle used by the British Army at the time that six soldiers were killed when their armoured Warrior vehicle was blown up would have been able to take the blast, an inquest has heard.
Major Douglas Nelson, an expert on the Warrior vehicle, said several improvements have been made to them since the deaths of the six men in March last year, but warned: "They (insurgents) can always build a bigger bomb."
Sergeant Nigel Coupe, 33, Corporal Jake Hartley, 20, and Privates Anthony Frampton, 20, Daniel Wade, 20, Christopher Kershaw, 19, and Daniel Wilford, 21, all died when an improvised explosive device (IED) detonated under their Warrior in Helmand Province on March 6 2012.
The vehicle was patrolling with another Warrior when it was blown up by the bomb about 25 miles north of the capital of Helmand, Lashkar Gah.
The force of the explosion turned it on to its side and "flicked off" its turret, an inquest at Oxford Coroner's Court has heard.
The blast caused a fire which also ignited ammunition on board. The incident was the biggest single loss of life for British forces in Afghanistan since an RAF Nimrod crash killed 14 people in September 2006.
Maj Nelson told the court today that a number of improvements have been made to Warriors following the incident, including thicker armour; the fuel tank; improvements to ways of getting out in an emergency; and better firefighting and detection systems.
He said that although fellow armoured vehicle the Mastiff was specifically designed with IED protection in mind, "they can always build a bigger bomb".
"This was a very large device and what I would say is no vehicle that we had was designed to take that," he told the inquest.
"It was a large device, the effects were worse than what we anticipated."
He said the IED hit the right-hand side of the Warrior, and the blast "flicked off" its turret, with a fire breaking out almost instantly.
But he said, from previous events, it was believed that the likelihood was that everyone inside was either dead or unconscious.