A young family who were flung from their car when a father lost control of the caravan he was towing were not wearing seatbelts, an inquest heard.

Patrick Nolan, 29, suffered catastrophic head injuries in the crash and died, while his 21-year-old wife Barbara and two year-old son David were critically hurt.

The accident happened when the caravan on the coast bound carriageway on the A2 near Canterbury began to weave, quickly causing it to flip and his Mitsubishi pick-up to roll over.

Serious collision investigators from Kent Police determined the 7.6 metre Hobby caravan was also being towed at almost 70mph - nearly 10mph above the legal limit - and was probably too heavy for the towing vehicle which could have added to the loss of control.

The family had been staying at a caravan site near Faversham and just set off for Dover on the afternoon of September 15 last year to travel around Europe when the accident happened near the BP service station.

Mrs Nolan suffered multiple fractures and her baby boy left with serious head injuries because his child seat had not been secured and he wasn’t strapped in.

At an inquest on Tuesday into Mr Nolan’s death, a couple told the hearing how they were overtaken by his Mitsubishi L200 and saw the tragedy unfold.

Retired Peter and Eileen Clarke were driving from Faversham to Canterbury and told assistant coroner James Dillon they took particular interest because they are keen caravanners.

Mrs Clarke said: "It pulled out and started to overtake us. I have never seen a car and caravan being driven so fast. It started to snake and I said to Peter ‘he’s not going to make it’ because he was still going at break neck speed."

Mr Clarke told the coroner that he had 30 years experience of towing caravans and it was unusual to see a twin axle being towed so fast.

He estimated his own speed to be between 55mph and 60mph when the pick-up and caravan overtook him in the outside lane.

"I said to Eileen, ‘he’s tanking it, why so fast'? In my experience he was pushing it."

Mr Clarke said he saw the caravan start to weave from side to side before hitting the central reservation and the vehicles roll over.

Other drivers rushed to the aid of the casualties lying in the road but Mr Nolan had not survived.

A post mortem revealed he had died from a fractured skull.

The investigation involved examining both the pick-up and caravan and while no defects were found in the Mitsubishi, there was a problem with the caravan.

A specialist engineer discovered that its ‘over braking system’ - designed to stop the caravan travelling faster than the towing vehicle - was not adjusted properly and ineffective which may have contributed to the crash.

Senior crash investigator PC Simon Masterson, who led the inquiry, said the speed of the pick-up and caravan at almost 70mph had also been determined by evidence from a CCTV camera in a bus which recorded its progress in the outside lane.

He believed the cause of the collision was a combination of factors, including the speed of the coupling and the weighting of the caravan. But he also noted the ineffective over-braking system could have been a contributory factor.

He added: "Had Mr Nolan been wearing a seat belt, it is unlikely he would have been thrown from vehicle and it could have been survivable."

Recording that Mr Nolan had died as a result of a road traffic collision, assistant coroner Mr Dillon said the vehicle and caravan had been travelling at excessive speed for the safe towing of the caravan.

He remarked that the ineffective over-braking system of the caravan could have been a contributory factor to the loss of control.

He added: "It is very relevant that no one was wearing safety belts at the time and sadly the consequence of that was that all three were ejected as the Mitsubishi was rolling."