精东影视

Feature, 25 February 1994

POINTS of departure

More than the new Channel tunnel itself, the two passenger terminals at Folkestone and Calais introduce a radical new transport concept. Martin Spring samples the stranges new experience of a drive-through railway station

ASTONISHING engineering feat though it unquestionably is, there is not much more to the Channel tunnel that the name tells us. It is a triple-bore 50 km tunnel below the English Channel through which trains will shuttle between Britain and the Continent.

But how passengers will actually use the tunnel when it comes on stream this summer is quite another matter. The process involves a radical new concept for rail travel in a motorway age - a drive-through railway station.

Two drive-through terminals have been built, one at either end of the tunnel at a combined cost of about 拢540m, barely one-sixteenth of the cost of the whole tunnel project.

To start with basics, there are two means of access through the tunnel, depending on whether passengers are travelling on foot or in motor vehicles.

Foot passengers will depart from Nicholas Grimshaw鈥檚 curving, futuristic extension to London鈥檚 Waterloo Station and arrive in Paris or Brussels three hours later. Other, and possibly even more futuristic, stations are planned at Ashford in Kent and St Pancras in London. Foot passengers will travel in high-speed, yet fairly conventional, trains.

However, passengers travelling in cars, coaches or lorries or on motorcycles will have a much stranger experience. They will drive directly on to their trains at two huge terminals next to the two tunnel portals outside Folkestone in Kent, and Calais in France. The process is more akin to driving on to a car ferry than boarding a train.

The other potentially alienating aspect of the two terminals at Folkestone and Calais is their vast scale, which is on a par with that of an international airport. As passengers remain in their vehicles throughout the whole procedure, there would have been no advantage in concentrating facilities together in a single building complex, as is the case with conventional railway stations catering for passengers on foot and carrying luggage.

There are loose scatterings of control buildings and canopies over toll booths. But the only really public building is an amenity centre, which is not an integral part of the transport process, but serves weary travellers with toilets, restaurants and duty-free shops.

The whole mode of operation of the two road-rail terminals and the train shuttle is innovative. The entire process of buying tickets, passing through passport and customs control and boarding the trains is done without passengers leaving their vehicles. They remain in their cars or coaches throughout the 60-minute journey then drive off the train straight on to the national motorway system on the other side of the Channel. 

The rail carriages for transporting the vehicles are unprecedented. They are twice as high and much wider than conventional railway rolling stock, and come in double-decker versions for cars. They bear little resemblance to existing car transporters, as they are sealed and air- conditioned so that passengers can remain inside their vehicles during the train journey. Lorries, on the other hand, are transported through the tunnel in special open-sided wagons while their drivers sit in accompanying passenger carriages.

The shuttle trains and boarding platforms are immensely long. Intended for vehicles rather than pedestrians, they stretch 800m. - nearly three times the length of InterCity trains.

In each terminal, eight platforms are grouped in parallel, with extra space on either side for an additional eight platforms. There is, of course, no overhead roof or connecting concourse, and vehicles travel to and from the boarding platforms by means of four road bridges which cross over them.

The terminals鈥� layout and design differs on either side of the Channel. On the English side, the main commission - covering site layout, earthworks, infrastructure, landscape, all building design and cost advice - went to the London office of the multi-disciplinary practice, BDP, which incidentally had performed a similar service for the abortive RTZ tunnel project on the same site in the 1970s. Civil engineer Mott MacDonald was responsible for civil engineering works. On the French side, the commission went to the country鈥檚 main station and airport designer, Aeroports de Paris, with Arte Charpentier as architect for the amenity building.

Of the two project design teams, BDP faced the greater challenge. This was because the English site had to be squeezed below the North Downs, designated as an area of outstanding natural beauty, and constrained at one end by Folkestone and at the other by two villages, Peene and Newington. Accordingly, the site is narrow and only 1.4 km2 in area, barely one-third the size of its French counterpart, which is on flat featureless land next to a business park. 

The layout at Folkestone, as BDP鈥檚 architectural partner in charge Tony McGuirk explains, is such that the train platforms take up roughly half of the elongated site next to the tunnel portal. Because of the narrowness of the site, vehicular access bridges cross the platforms at a diagonal angle, giving a parallelogram geometry.

The end of the site away from the portal widens out slightly and is devoted to vehicular facilities such as toll booths and the amenity centre, as well as control buildings. 

Incoming trains sweep out of the portal to the other end of the site, where they loop round and back to come to rest at the platforms. Because of the site restrictions, the rail loop has been submerged below the toll booths and amenity centre. 

Vehicles enter the site at the opposite end from the tunnel portal. After passing through ticket booths, passenger vehicles and heavy goods vehicles drive along separate routes with their own passport and customs controls. The HGVs follow the curving line of the rail loop at the end of the site, while cars and coaches cut across on a diagonal road. The semi-circular bowl left between the lorry loop road and car diagonal road forms an accessible site for the passenger amenity building. 

Various devices have been used to make the complex friendlier to both visitors and onlookers. It has been masked from neighbouring communities by banks of earth and indigenous tree belts which merge into the Downs woodlands, and by keeping all structures low. The architects have sought to bring order to the disparate engineering structures by setting them within a regular grid layout. 

精东影视s are all built out of a recognisable kit of parts, which brings together toll booths, control buildings and the amenity centre as an identifiable, cohesive family.

Even so, habitable architectural enclosures are in the minority, as the overwhelming nature of this vehicular terminal is a vast engineering complex. BDP鈥檚 layout may be elegant and sinuous when peering down from a helicopter and the layout grid may impose a theoretical order, but these are near-impossible to discern on the ground. The complex appears a vast mechanical jungle of galvanised pylons, poles, fences, boxes, signs and overhead cables, plus dominant vertical wind screens in plastic webbing - all in forbidding shades of dark grey and black.

The problem is not helped by the design and build approach of Eurotunnel鈥檚 turnkey contractor, Transmanche Link, which insisted on using off-the-peg components and pushed architectural control down the pecking order of priorities. Canopies carefully designed and co-ordinated by BDP have ended up as menial structures supplied off the peg by Conder, with translucent polycarbonate sheeting that will inevitably yellow over time. And each engineering structure in turn has sprouted its own cluttered subculture of minor brackets, light fittings, signs, security cameras, ducts. and cables.

BDP was asked by TML to design 鈥渁 modern, coherent, co-ordinated facility to which both travellers and staff would respond positively鈥�. The buildings are encouragingly bright and crisp, inside and out. And there are odd corners where the engineering works rise to a robust functional dignity, as in the heavily ribbed overbridges in smooth, near white concrete.

But to the punter on the tarmac about to disappear into one of the longest holes in the world, and to local residents, the terminal comes across not as a station for passengers, but as a vast marshalling yard for cars, buses, lorries and trains.

The Channel tunnel may offer drivers the fastest link between England and France, but don鈥檛 expect too much celebration of exhilaration in this radical new mode of long-distance travel.

ALTHOUGH THE buildings at the Channel tunnel terminal at Folkestone are in danger of being overwhelmed by civil and mechanical engineering structures, architectural design plays a vital role for visitors and users. The buildings are few and far between, but have the task of imparting a sense of order and reassurance to visitors in a largely alien environment. These special problems have been addressed by the architects at BDP under partner Tony McGuirk.

鈥淭he terminal is an unprecedented motorway/rail interchange that is totally different from a conventional railway station,鈥� says McGuirk. 鈥淐irculation is vehicular rather than on foot, and this has the effect of distancing buildings from each other. That means we cannot achieve a critical mass of buildings to give an urban sense of enclosure. Instead, we are dealing with large canopies and free-standing pavilionate buildings, like those in motorway service stations.

鈥淲e have therefore had to animate the buildings and give them a human scale by various, mostly unconventional, means,鈥� continues McGuirk. 鈥淔irst of all, we have tried to create a recognisable estate of buildings, not an architectural zoo, by using a uniform kit of parts. Second, we have given all the buildings a lightness and brightness by cladding them in gleaming white powder-coated aluminium panels. White has a calming effect and sets the buildings off well against the green landscape of the hills and trees. 

鈥淭hird, we have drawn windows of toll booths and control buildings downwards, so that they are at eye level for people sitting in cars. Fourth, we have given them soft see-through edges by placing windows at the corners.鈥�

The two most dominant buildings are the main rail control building and the passenger amenity building. The rail control building is polygonal and faceted in shape, giving it a nautical sculptural quality like a coastguard building.

The passenger amenity building is larger and more ambitious, because it is the only building in the complex open to the public. It is given pride of place in a landscaped bowl between two access roads. McGuirk describes it as a 鈥渓ayer-cake building鈥� with passenger facilities on the ground floor, sandwiched between offices and carparking for Eurotunnel above and below. The carparking on the lower ground floor serves as a future expansion zone. 

In plan, the amenity building is shaped like a square doughnut around a large public concourse bounded by shops and restaurants. Light floods the concourse through a white fabric roof which curves up to an asymmetrical peak, which McGuirk likens to Mount Fujiyama. The peak is held in tension by a tubular rod and cable structure inspired by the Festival of Britain鈥檚 Skylon of 1951, and appears to float over the concourse.

Like the other buildings in the complex, the amenity building has been glazed on all four corners of its perimeter external walls. In addition, the concourse has been glazed on all four of its corners. The effect is that visitors inside the amenity building can catch liberating glimpses out to the sky and Downs.

From the outside, the amenity building, over its open undercroft and beneath its jaunty white Mount Fuji roof, appears to float. 鈥淲e didn鈥檛 want it to be tethered to the ground,鈥� explains McGuirk. 鈥淲e wanted a more elevating experience. Passengers might be anxious about the subterranean experience ahead of them, so we have tried to create a building that lifts off the ground.鈥�

Public entrances to the amenity building are located at the centre of two sides. They are preceded by free-standing 鈥済atehouses鈥� with sloping roofs, which McGuirk describes as Assyrian in style. The gatehouses contain double-height public toilets - the most vital amenity for long distance travellers - and serve passengers away from the shops and restaurants within the concourse. Even the toilets, which are covered by rooflights, contribute to the pervading architectural motif of space and light.