Ronald Coleby was a young man when he stood on the deck of HMS Warrior in the South Pacific and waited for Britain's first hydrogen bomb to explode.

The engineering mechanic and hundreds of other seamen stood about 30 miles from the target, Christmas Island, with their backs turned as an aircraft flew overhead.

It was carrying a weapon designed to be the most powerful yet detonated to give Britain the status of a nuclear power as the Cold War reached its height.

More than half a century later Mr Coleby, 73, is one of more than 1,100 claimants from the Atomic Veterans' Group seeking compensation from the Ministry of Defence.

He has suffered from throat cancer and received a diagnosis of leukaemia 30 years ago but the Government has never accepted a link between atomic testing and ill health.

Mr Coleby was just 22 when he was posted to Christmas Island in 1957, where he remained while three bombs were tested. With other aircraft carrier crew he listened to the countdown from the speakers on the ship's upper deck. The sailors were ordered to put their hands over their anti-flash goggles to protect their eyes and wore a specially designed suit for protection from the heat of the explosion.

Afterwards they were ordered to face the mushroom cloud which had formed about the island, when they were knocked off their feet by the force of the blast.

Mr Coleby, of Dyke Road, Brighton, said: "We had our uniform and goggles on with a film badge to measure the radiation levels.

"But they just collected the badges from us afterwards and we never got to see the results, which must have been pretty alarming. The blast was quite a sight. It was like the eighth wonder of the world. It exploded in the air and was like a mushroom cloud with fire in the middle."

Mr Coleby had been in the Royal Navy for four years when the bombs were detonated.

He had married wife Joyce in November 1956 and been sent to the South Pacific three months later, where he remained for ten months.

HMS Warrior carried scientists to and from the island with equipment to monitor the effects of the bombs. Mr Coleby is one of a dwindling band of survivors from the blast. Most of the seamen present at Britain's 1950s nuclear tests have died.

Others have seen their children and grandchildren born with deformities and cancers.

Mr Coleby's daughter Susan died aged two having been born with spina bifida. His son Stephen, 49, has health problems and daughter Linda, 46, has been unable to have children.

Mr Coleby said: "We think it's all connected.

There are lots of stories of veterans whose children have been affected. I didn't think about the health aspect until I read in a newspaper people involved in the experiments should get checked.

"I went to my GP and straight away he looked at my throat and said he could see a growth. They removed the lump and tests revealed it was cancerous.

"That was about 25 or 30 years ago. I had my blood tested and it wasn't right. I was diagnosed with chronic lymphoid leukaemia and have had it ever since. At the time I didn't give the dangers much thought. Someone has since asked me if I feel like a guinea pig. I didn't at the time because I was young and naive but on reflection I realise we were used."

The Atomic Veterans' Group represents about 1,000 ex-military personnel - 450 of whom are still alive - from Britain, New Zealand and Fiji who served the British government during the 1950s.

It filed writs to the High Court two years ago on behalf of these people. Now 180 more have claimed against the Government.

The group will be represented in court by Rosenblatt Solicitors. The first hearing is expected to take place in January next year.

Although a date has not been set, it is believed the case could continue until 2011 or 2012.

Mr Coleby was on HMS Warrior with Dennis Ward, of Saffrons Court in Eastbourne. Mr Ward was 23 when he watched a bomb explode in the South Pacific.

Other people from Sussex who are claiming damages against the Government include Frederick Paine, of Cookson Gardens, Hastings, Ernest Hughes of Aldwick Road, Bognor, and Lawrence Richards of Bentswood Road, Haywards Heath. In addition Muriel MacCrossen, of North Road, Three Bridges, is claiming on behalf of her late relative Edwin MacCrossen. The Government denies a link between the experiments and illnesses among former troops.

Mr Coleby, who became a painter and decorator after leaving the Navy in 1960, retired at the age of 60 with failing health.

He said: "Every other government has taken responsibility and paid out. I'm one of the fortunate ones. Some of those people who had to go on Christmas Island afterwards to get samples were signing their own death warrants.

"I was in the firing line but I never had to clean up the mess. People who were ordered to do that died very young."

A Ministry of Defence spokeswoman said: "When compensation claims are received they are considered on the basis of whether the Ministry of Defence has a legal liability to pay.

"Where there is a proven legal liability compensation is paid."

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