Mr George Matthews, 70, is the perfect docent for a police bunker turned museum in Pearl's Hill.

He has the history of the place at his fingertips, having worked in it and lived nearby in the police quarters for most of his life.

The bomb-proof bunker sits alongside the Upper Barracks, which is one of the attractions on the Police Heritage Trail, and was the nerve centre for police operations.

Called the Combined Operations Room, it also housed part of the police's radio division, where Mr Matthews was based in the 1970s as a constable.

Operators of the 999 hotline would relay information to Mr Matthews and his colleagues, who would then head out in patrol cars to assess the situation and report what they saw as the first responders on the scene.

Mr Matthews said he has responded to all sorts of incidents - from suicide attempts and armed robberies to housebreaking in progress.

"We were the eyes and the ears of the police force," said Mr Matthews, adding that there was never a dull moment.

One memorable incident involved a gang fight in Mandai Road.

The gangsters had scattered before the police arrived but did not have time to remove a dead body, and Mr Matthews had to report this to headquarters.

Another incident occurred when he responded to a case of attempted suicide in Chin Swee Road.

He took the initiative to yank a woman off a ledge as she might have jumped in the time taken for him to report the matter to headquarters and wait for instructions.

The retired inspector, who left the force in 1995, has been regaling visitors to the bunker with anecdotes such as these, adding flavour to their tours.

"Visitors are shocked that such a place existed," said Mr Matthews. "This place, for 60 years, has been providing safety and security for Singapore."