A FIREMAN died yesterday after an attempt to rescue two workmen from a huge silo of chemical dust went wrong.

The accident happened as a team of firefighters fought to free the workers from the 40ft-high silo at Perth harbour yesterday morning.

Fireman Roderick Nicholson, 43, became trapped himself amid five tonnes of sodium carbonate ash - described as similar to quicksand - and died at Perth Royal Infirmary.

The firemaster of Tayside, Mr Derek Marr, said last night his officer had made ``the ultimate sacrifice''. His death is understood to be the force's first fatality on active duty in the last three decades.

More than 30 firefighters from Dundee, Perth, and Coupar Angus arrived at the Shore Road site occupied by Daltrade, after reports that the two workers had become engulfed in the ash.

It was not clear last night why they had entered the silo. The ash, which is used in the glass and textile industries, is not toxic but has irritant qualities.

The only access to the silo is from a small inspection hatch in the top. Firefighters climbed down an internal ladder and used ropes to reach the men, while cutting equipment was used in an effort to drain the container from its base.

Both workmen, Mr Alistair Lockhart, 54, from Aberuthven, and Mr Paul Martin, 22, from Perth, were eventually lifted free within two hours of the rescue beginning. They were taken to hospital after receiving medical treatment at the scene. Their injuries were last night understood to be serious but not life-threatening.

Firemaster Marr said Mr Nicholson had been instrumental in the rescue of the two men but the officer, who was wearing breathing apparatus, was sucked into the ash and became submerged before his colleagues could pull him free.

He said the team had been forced to work under the most difficult and trying conditions. He described the inside of the silo as extremely claustrophobic, clouded by dust, and with temperatures at levels which most people would be unable to bear.

``We understand at the end of the day he had to be dug out and pulled out by his colleagues. That is the most harrowing of tasks for officers to be forced to face the rescue of a colleague.

``I can only commend the courage of the officer concerned who had gone into the silo to try to help members of the public.

``That officer has lost his life though his brave actions. There is no praise high enough for an officer who is prepared to make the ultimate sacrifice.''

He said fire crews were ``stunned and shocked'' and added: ``They've lost a good friend and colleague.......an officer who was prepared to lay down his life for others.''

Mr Nicholson, from Scone, who is survived by his wife, Yvonne, and a young child, had been with the force for more than 20 years.

Officials from the Health and Safety Executive were last night at the harbour site. A fatal accident inquiry is almost certain to be held.

Management at Daltrade, a chemical supply company, refused to comment on the accident.