A 55-year-old man is in hospital today with serious burns after a massive blast at an explosives factory.Factory owners are today trying to determine what caused the blast at Wardle Storey's manufacturing plant in Brantham after materials thought to be used in making missile heads for the Ministry of Defence exploded and caused a massive fire.

A 55-year-old man is in hospital today with serious burns after a massive blast at an explosives factory.

Factory owners are today trying to determine what caused the blast at Wardle Storey's manufacturing plant in Brantham after materials thought to be used in making missile heads for the Ministry of Defence exploded and caused a massive fire.

The emergency saw more than 40 firefighters from Suffolk and Essex, ambulance crews, the air ambulance and police officers sent to the factory.

Police scenes of crime officers were expected to be attending the site today along with fire investigators to ascertain the cause of the blast.

The explosion, which happened at around 3.40pm yesterday caused chaos on the railways as trains on the London to Ipswich line had to be replaced by buses as it ran directly through a 200m cordon enforced around the site.

Assistant Divisional Officer Ian Bowell, who was in charge of the team of firefighters, said the main problem they faced was dealing with volatile chemicals.

Mr Bowell said: “By the time we got there, there had already been a serious explosion and our efforts were concentrated on preventing any further explosions.

“We were dealing with some hazardous chemicals - there was a danger of further explosions if they mixed together.

“The firefighters did not have to wear chemical protection suits, but they did need breathing apparatus to allow them to get near enough to bring the fire under control.”

He had to close the railway line because it passes within 50 to 60 metres of the building that was damaged.

Mr Bowell said: “I am sorry for any inconvenience the line closure caused to the passengers, but the line had to be closed because of safety fears.

“We imposed a 200-metre exclusion zone around the building because of the danger of further explosions and fears that could send out projectiles.”

He said: “We send the injured man all our best wishes and we hope he makes a full and rapid recovery.”

John Nicholls from the Essex Ambulance Service said: “The air ambulance flew a 55-year-old male to Broomfield burns unit in Chelmsford with extensive burns to his hands, chest, face and abdomen.

“They are serious burns and possibly critical.”

Two fire engines from Manningtree and Holbrook were initially sent to the factory but once the scale of the blaze was confirmed another four pumps from Ipswich, one from Felixstowe and one from Woodbridge were dispatched.

A vehicle from Felixstowe, operation support units from Ipswich and Haverhill and the hydraulic platform from Colchester were also sent.

Firefighters used three ground monitors, an aerial monitor used from the hydraulic platform, four jets and six breathing apparatuses to tackle the fire. By 7pm they had surrounded the fire and were tackling hotspots.

The explosion is believed to have happened during the process of making Xylonite - a highly flammable plastic.

One member of staff said: “There was an explosion in a xylonite mixer.

“Xylonite is a highly flammable plastic we make for the Ministry of Defence. It's really explosive and is used in mortar heads and stuff like that.

“They have made it in there for years and the building is obviously well protected.”

Another member of staff who was working in the building at the time said the fire alarm alerted him to the problem.

He said: “About 100 people were evacuated from the building but we weren't told much.

“We were working in the production line and didn't see or hear anything despite being only about 200 yards away.

“The fire bells went off and there was a message to get out.”

In 1958 a man was killed in a fire at the site, which was then known as BX Plastics Ltd.

Mervyn Austin, former chairman of East Bergholt Parish Council, used to work at the factory.

He said: “The original factory came down from London and one of the original products was xylonite. I think it is quite a dangerous product to make.

“As I understand it nowadays it isn't made all the time and I think it is made for specific, reasonable sized orders. The equipment is mostly standing idol. It is not a continuous process.”