were held in London, in 1948 - are long gone.

At London 2012, the starter's gun will be electronic and entirely integrated with a quantum timing system which will allow races to be timed to the nearest one thousandth of a second - 40 times quicker than the blink of an eye.

The fired gun sends an electrical current to the starting blocks - specially modified with pressure pads to detect false starts - which starts a quartz oscillator in the timing console.

'Top technology'

The sound of the shot is amplified through speakers on each set of blocks so all competitors hear it at the same time.

At the finish, a laser is projected across the line at a photoelectric cell or electric eye which, when crossed by an athlete, sends aa radio transponder attached to the front tyre of each bicycle emitting an identification code to antennae placed at the start and finish lines.

In swimming, touch pads are used to record when a swimmer dives into the pool and when they touch the edge of the pool at the race's end.

A former athlete, Mr Bell has started some big races - not least Usain Bolt's world record 100m in Berlin 2010, and his disqualification in the 100m final at last year's world championships in South Korea - but to officiate an Olympics on home turf will be, he said, the pinnacle of an incredible career.

He said composure was key to starting a race, but would not be drawn into a discussion on the "one strike and you're out"