The centrepiece of London's Olympic transport plans is the special Olympic Javelin service running from Central London to the Olympic Park in just seven minutes.

Built by Hitachi, the company that pioneered the famously successful and efficient bullet trains in Japan, the 140mph Class 395 High Speed One service will carry up to 25,000 passengers per hour each way between King's Cross St Pancras station and Stratford International.

Named after famous Olympians such as Tanni Grey-Thompson and Sebastian Coe, there are a total of 29 six-carriage electric trains in the Javelin service, which is operated by Southeastern Rail and will run for the duration of the Summer Games.

Spectators with a ticket for an Olympic event will receive a free one-day Games Travelcard which will include the Javelin service as well as the Tube, buses, London Overground, National Rail Services and Docklands Light Railway. After the Games, the Javelin trains will be reintegrated into Southeastern Rail's high speed fleet.

Eight trains an hour will run along a largely underground rail link formerly used by the Channel Tunnel service. After stopping at Stratford International, which is located just a few hundred metres walk from the Olympic Park, the Javelin will continue to Ebbsfleet International on the south-eastern edge of London for motorway park-and-ride access.

There will also be Javelin connections to Ashford in Kent and with Eurostar services from France and Belgium, with incoming travellers not obliged to enter central London en route to the Olympic Park.

The journey between Stratford International and Ashford will take just 30 minutes at an average speed of 114mph not bad when considering the usual 80 minutes it takes for a conventional commuter train.

A Javelin test run from St Pancras to Stratford International took place in July 2009 three years to the day ahead of the Games.

Lord Coe, the London 2012 chief and former Olympic god medalist, took the role of train conductor for the inaugural ride.

Speaking to an illustrious cargo that included Mayor Boris Johnson, then-Olympic minister Tessa Jowell, a cluster of athletes from Team GB and a whole host of media representatives, Lord Coe came onto the intercom and joked: "Hello, this is Seb Coe. The good news is that I am not your driver this morning. The bad news is that I have Daley Thompson (the double Olympic decathlon champion) here who is. The train will depart as scheduled at 9.42am."

And despite heavy rain lashing down, the maiden voyage was completed marginally ahead of schedule, clocking an impressive time of six minutes and 45 seconds.

While the blue and yellow trains were flagged up by The Guardian for their "stark" interiors and described as "no-frills railway travel", the same newspaper praised the "coolly stylish" Javelin trains as "sleek and silent railway ambassadors".

Mrs Jowell underlined the important role the Javelin would play in making sure that 97 per cent of visitors to the Olympics dubbed "the public transport games" would arrive by train, bus or tube.

The BBC described the Javelin trains as "fast, impressive and essential", claiming that the high speed locomotives "will be the real workhorse for London 2012" but stressing that other transport options would be "vital" for the smooth running of the Games.

Indeed, such are the concerns that the Javelin service will become so inundated during the Games that rail bosses have made contingency plans to turn thousands of passengers away at peak times.

Despite the promise of a seven-minute journey from A to B, the likelihood of a one-hour wait in a purpose-built queuing area alongside the Eurostar terminal at St Pancras may force many spectators to seek other means of reaching the Olympic Park.

For more information on transport during the London Olympics please read our Olympic Travel section.