A tunnel 35 metres underground is not normally a reason to visit an airport, but yesterday the British Airports Authority, stung by criticisms of its running of Heathrow, unveiled its latest development to demonstrate it could at least handle a new transit system for passengers' bags.
The tunnel, which will run for a mile and a half under the airport between terminals three and five, is being excavated under the runways by a giant £3.3m earth-boring machine. Burrowing at 15 metres a day, it has already skirted the Piccadilly underground lines and passed under Heathrow's giant aviation fuel tanks and plane taxiways.
The aim, when the tunnel is in operation by the end of 2011, is to transport 110m bags a year. In the same period all the airport's baggage handling operations are being upgraded at a cost of £900m. The tunnel will cost £260m.
BAA staff yesterday insisted the plans had nothing to do with the fiasco surrounding last year's opening of the fifth terminal, or criticisms of the way the authority treats its customers. They insisted the tunnel represents the first steps towards the largest baggage system at any airport in the world.
An authority spokeswoman said: "Our problem last year was a people problem, not a baggage problem. It was about staff training, not about the transfer of luggage." That may come as a relief to frustrated passengers who were reunited with their bags after days or weeks during which they were ferried around Europe, some never to be seen again.
Unfortunately, the new system will not guarantee that all passengers will instantly be connected with all their luggage. Chris Millard from BAA said: "There are so many different reasons why bags can go missing: wrongly loaded at other airports, wrongly labelled or without labels, flight delays and bags splitting open. Baggage is a very complex world."
The new tunnel should shave 20 minutes off the time it takes bags to pass between terminals, which can currently take more than an hour. Being underground, they will in future do so in the dry, without having to be handled on the tarmac or transferred onto trucks.
Nearly six metres wide, the new tunnel is a major feat of engineering. The work continues 24 hours a day, placing 1,800 prefabricated concave concrete panels to shape the walls after the ground has been bored open. Yesterday the borer had reached 243 metres since its start in February. Conveyor belts feed the London clay back out of the tunnel: 148,000 tons of it is to be shifted by the time the job is complete later in the summer. The earth is going to cover local landfill sites.
"It is astonishing, looking at material which has not been disturbed for millions of years since London was a swamp," said Millard.
