Six curious bits of Heathrow you never get to see

Tens of metres beneath the feet of hundreds of passengers milling their way around Heathrow’s Terminal 2, awaiting flights to far-off destinations including Canada, the US and Singapore, there is a vast, cavernous basement through which no one ever passes.

In the centre of the eerie, dimly-lit space, a metal staircase descends from the ceiling but stops short of the ground in anticipation of serving a train platform of which there are no plans to build.

The basement three floors below ground underneath the Queen’s Terminal is one of a number of secret sights at the UK’s busiest airport that Telegraph Travel was given exclusive access to during a behind the scenes tour of Heathrow’s curious corners.

The existence of the “ghost station” beneath Terminal 5, awaiting a connection from Southern Rail, is well-documented but the space here, beneath the Star Alliance gates, is lesser-known.

The product of remarkable foresight from the airport’s architects in the mid-Noughties, the space, which Heathrow is keen to rent out to film crews imagining the lair of an evil mastermind, is intended to house an inter-terminal train service that will link passengers with other areas of the airport once Heathrow fully adopts its “toast rack” formation after construction of the third runway.

For now it lies empty but for the rare sound of footsteps. Here are five more things you might not know existed at the place so many holidays kick off from...

1. A network of tunnels

To enable the flotilla of operation vehicles, caterers, refuelling equipment and emergency services to manoeuvre around the five square miles that is Heathrow, the airport has its own road network replete with pedestrian crossings, traffic lights and tunnels.

There are a number of tunnels that move cars, vans and lorries around the site, linking terminals, gates and remote hangars, but perhaps the most peculiar is the airside road tunnel or ART tunnel.

The twin bored tunnel (so separate tunnels for the two sides of the road) runs at 0.88 miles long and connects the airside roads around Terminals 1, 2 and 3 to Terminal 5 - only accessible to vehicles with security clearance.

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It winds its way left and right and up and down to avoid both the Heathrow Express and Picadilly Line, passing at one point only three metres from the former.

The speed limit in the ART is 30mph but to ensure the smooth flow of traffic an alarm sounds if a vehicle slows to a snail’s pace or stop for too long.

2. The view from the control tower

With views stretching from London to the east and Windsor Castle to the west, the control tower, rising 87 metres into the air, in the centre of the airport, is one of the key nerve centres of Heathrow.

Handling on average 1,300 take-offs and arrivals a day from more than 80 airlines, the control tower, managed by air traffic control provider Nats, is a constant hub of activity.

Such is the level of concentration the tower is a mobile phone-free space, except for operational phones. Staff can put their mobiles in lockers at the foot of the stairs leading up to the tower.

Heathrow was the first airport in the world to use “time based separation” to manage the space between its arriving and departing aircraft as opposed to distance. This innovation, developed in conjunction with Nats, was to reduce delays caused by strong headwinds in the area but still keep planes at a safe distance from each other.

In terms of slot capacity - spaces for aircraft - Heathrow is all-but full, but there remains space for passenger handling. It is for this reason the airport encourages and incentivises airlines to increase their load factors (how full a plane is) and is more than happy to accommodate as many as A380s - the world’s largest passenger aircraft - as possible. The London airport is home to the largest number of airlines operating the A380 in the world.

3. Fire-fighting fire power

Airports in the UK are categorised from 1 to 10 by the European fire authorities according to the type and size of aircraft they handle. As a category 10 airport - with two runways - Heathrow requires to have on-hand at all times a wealth of fire-fighting equipment.

The airport has two fire stations, one east, one west, from which any of 107 firefighters must be able to reach, by law, an incident anywhere on the grounds in just three minutes. The nationwide average is eight minutes.

This is because aviation fuel burns with a higher calorific value and so must be dealt with as soon as possible. The Heathrow fire service is also duty-bound to attend any incident within 1,000 metres of the ends of the runways, which can mean going off grounds. As such, the service is one of few airports around the world to have a traditional general fire engine (or domestic tender) in addition to their airport specialist vehicles. When a team leaves the airport to deal with a fire out of bounds, they are subjected to a thorough personal and vehicle search before being allowed to return.

Fighting fires in an airport is hard, fast and aggressive business, which is why Heathrow has nine Rosenbauer specialist engines, each costing around ￡500,000, able to “surround and drown” aircraft fire situations.

The service uses the rusty, burnt-out Green Goddess, a specially-designed replica Boeing 747-DC10 cross you might see when arriving at or leaving the airport, as a training ground for regular exercises.

4. T5's phantom station

As mentioned above, Terminal 5 has its own “ghost station”, built with the same foresight in 2002, and now earmarked to provide Southern Rail access into Heathrow.  

Completed in 2008, with platforms but no rails or signals, the ghost station would house new platforms one and two ready for connection by 2030.

The damp, dark space as you see it today would be completely renovated, with all but the structural elements removed and revamped.

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5. Its own honey production

Heathrow is the only airport in the UK in charge of its own biodiversity sites - and even produces its own honey.

The airport has been recognised by the Wildlife Trusts for its work on a number of spaces around the perimeter fence, amounting to around 63 hectares of land, some home to a wide range of habitats for animals including grass snakes, bats and pipistrelle. Heathrow is also one of the most diverse areas in London for spiders and beetles.

The airport even has 24 hives with more than 1.3 million bees, with the first ever batch of Heathrow honey produced in 2016.

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