A BLAZE at a submarine factory was caused by a sand-blaster explosion that ignited rubber tiles on a £1.3billion vessel.
The huge fire spread through highly flammable tiles glued to the hull of nuclear sub HMS Agincourt.
The tiles are designed to dampen the sub’s sounds and absorb enemy sonar but they are made of a highly combustible foam-like polymer.
A source said: “It was a bit like burning tyres, but worse.”
The 12-hour blaze at BAE Systems’ plant in Barrow, Cumbria sparked fears of Russian sabotage.
But multiple sources have since said it was an industrial accident.
The Sun understands a compressor powering a sand-blaster exploded just after midnight on Wednesday.
Two night shift workers and five BAE firefighters were taken to hospital and the submarine was badly damaged.
Residents were told to close windows and doors to avoid toxic fumes.
Defence Minister Maria Eagle said there was no nuclear risk.
