Construction of the world's largest baggage system at the UKs Heathrow Airport, funded by the British Airports Authority (BAA), is underway.
The £900m baggage system requires a 1.8km-long tunnel costing £260m that will link all the terminals, enabling Heathrow to handle 110 million bags a year by 2012.
The tunnel will connect Terminals 3 and 5, eventually linking into the existing baggage tunnel network at a building to be constructed airside.
Work is already underway to replace Terminal 3's baggage system and refurbish the systems in Terminal 1 and 4 with the latest technology.
A new system will also be installed at Terminal 5C, set to open in 2011.
A team of experts is using £3.3m tunnel-boring machine for the excavation process.
BAA is investing £4bn across Heathrow over the next five years to completely redesign, rebuilt and refurbish the airport.