TWO soliders from Wirral were killed when their armoured vehicle rolled in to a canal in Afghanistan after colliding with an Afghan National Police car, an inquest has heard.

Private Douglas Halliday, 20, from Rock Ferry, and Private Alex Isaac, 20, from Eastham died in the incident alongside Colour Sergeant Martyn Horton and Lance Corporal David Ramsden.

The soldiers, all of The 1st Battalion The Mercian Regiment (Cheshire), were members of a police advisory team and travelling as part of a two-vehicle convoy near Gereshk in Helmand province on June 23, 2010.

Their vehicle, a 20-tonne Ridgeback protected patrol vehicle (PPV), driven by Lce Cpl Ramsden, collided with a 2-tonne Afghan National Police car by the Nahr-e Bughra canal.

Salisbury Coroner's Court heard the "glancing" impact between the vehicles pushed the Ridgeback onto two wheels before it rolled into the water - landing upside down about 13 metres away.

Dr John Searle, a consultant in accident reconstruction, said: "In my opinion, the front left corner of the Ridgeback has gone at right angles with the front right corner of the Ranger.

"It was a glancing impact, an impact where the vehicle carries on and is not stopped by the impact.

"The Ranger is rotating anti-clockwise, the Ridgeback is rotating clockwise and it climbs up onto two wheels over the bonnet of the Ranger.

"These movements are happening at the same time. After that contact, the Ridgeback goes into the canal to land upside down."

Dr Searle said the tyres of the Ridgeback had a very high friction, which resulted in a "grabbing" effect on the Afghan National Police Ranger.

He said the visibility in the vehicle at the time of the collision would have been similar to a car driving in normal night-time conditions.

"The Afghan National Police Ranger is a dark object being seen against a dark background," he added.

The inquest heard that it is impossible to estimate the speed the Ridgeback was travelling before the collision, but it is thought to be above 30mph.

"From the physical evidence, I wouldn't say that you could rule out a high speed," Dr Searle said. "It could well be that it was travelling at a high speed."

The inquest - which resumed today after being adjourned in November last year - heard how the incident happened as the vehicle was travelling to police checkpoint five (CP5).

The Afghan National Police had asked the advisory team to return to CP5 on the evening of June 23 following an attack of three explosions and gunfire.

After passing over a bridge near CP5, the lead Ridgeback collided with the Afghan National Police vehicle at around 9.40pm.

A loud bang was heard followed by someone shouting "we're going in" as the Ridgeback rolled down a steep bank and into the canal.

Pte Michael Peers, who managed to escape from the submerged Ridgeback, said the occupants were wearing seatbelts and opened the back hatch near the water, as was recommended.

"I heard a loud bang which was like an explosion, I do not know where it came from or where it impacted if it did impact," he said.

"I felt the vehicle jolt and I thought it might be an IED. I felt the vehicle swerve then flip over on to its right hand side.

"The whole event lasted a couple of seconds or less. The vehicle then fell over on to its left side and submerged in the water, I didn't have time to take a breath."

Private Douglas Halliday, 20, from Wallasey, joined the 1st Battalion The Mercian Regiment (Cheshire) in 2008 and served in Northern Ireland, Kenya and on operations in Afghanistan.

His family said: "Dougie was always the life and soul of the party and will be missed by all. We are all extremely privileged to have shared his short life."

Private Isaac, 20, was from Eastham and and also joined the Army in 2008, serving in Kenya and on operations in Afghanistan.

After his death, his mother Annette said: "My beautiful darling son who was a fighter, and so brave, you will always be in my heart, my soul and my thoughts. God bless."