Cruise control: built like a ship, Yokohama's new port terminal is an audacious fusion of architecture and engineering that creates a topographic landscape for public activities.

In Japan, the economy has been mired in recession for at least a decade. Banks are sagging under the weight of bad debts, the social contract of guaranteed lifetime employment is beginning to fray. and yet construction is booming. Jean Nouvel, Richard Rogers, and Kevin Roche have built prestigious towers in the expansive new Shiodome office park, located on former rail yards in central Tokyo, and the huge Mon mixed-use development is nearing completion across town in Roppongi. Bridges and expressways are still heading off to remote areas, though few can afford the tolls and they are customarily deserted. Prefectural governors continue to build imposing museums, sports stadiums, and other public works in remote locations, without pausing to consider how they will be used and maintained. The juggernaut seems unstoppable.

The Yokohama International Port Terminal is the latest of these grandiose gestures, and, like the Tokyo International Forum (AR November 1996), it was probably inspired more by a craving for prestige than a recognition of need. Yokohama, a poor fishing village when Commodore Perry landed there in 1853, has become the second largest city in Japan, rivalling Tokyo as a port, and it would like to be seen as something more than an industrial appendage of the capital. It seems an unlikely destination for cruise ships, though, and the present total is only 50 to 60 a year, staying for an average of two days each. However, the authorities decided to replace the small 1960s terminal with one that can accommodate up to four ships at a time, and Foreign Office Architects won the 1995 competition with their brilliant concept of a self-supporting steel structure, built like a ship, that would integrate the flow of passengers with public gathering places into a seamless whole.

As visitors to the same architects' British Pavilion at the Venice Architectural Biennale discovered (AR October 2002), the design is extraordinarily complex, but the product of these stacks of working drawings (many revised on site during construction) is one of beguiling simplicity and power. Spaces and surfaces are woven together and flow continuously from one end of the 400m long building to the other. Ramps link the different levels and blur the divisions between enclosed space, the cantilevered decks, and the undulating roof promenade. The terminal sits atop the Osanbashi pier, and is built from prefabricated sections of fire-resistant steel plates that are folded like origami and backed by stiffened girders to form an integral structure-skin and provide clear spans of up to 30m. Floorboards of ipe, a dense Brazilian hardwood, flow through walls of glass that are stabilized with glass fins. The consistent use of steel, wood, and glass ties the whole structure together.

Visitors can drive into the first floor parking area or walk into the arrivals and departures hall from the top of the entry ramp. Ships dock on either side of the pier and board or disembark their passengers through walkways into the customs and immigration area that is separated from the public area by movable barriers. On either side of this secure zone, enclosed ramps arch over to Osanbashi Hall, a cavernous multi-purpose room that can also be accessed from a broad ramp leading down from the roof.

It was the inspiration of the architects-- Farshid Moussavi, Alejandro Zaera-Polo, and their team--to go beyond the original brief for a terminal, and develop the promenade as a major public amenity: a place where locals could stroll out into the harbour and look back at their city. Anticipating that cruise ship traffic would be insufficient to make full use of the complex, they designed it as an infrastructure that could be used for markets, expositions, and group activities of every size. Show cars can be driven into the arrivals hall, and down the ramp to Osanbashi Hall, and this broad walkway is flanked by bleachers for outdoor performances. Moussavi envisages the building serving as a huge foyer for floating attractions that might be moored here at the pier as cruise traffic allows.

Foreign Office had to fight to preserve the integrity of their design while keeping it within the allocated budget. Five years elapsed between the competition and the start of construction, and when the job was put out to tender, there was a steel shortage in Tokyo that drove up the price. The architects reduced the thickness of the plates and found alternative sources in Japan and Korea. Sections were prefabricated in shipyards and brought to the site by barge--an appropriate use of local technology that strengthens the structure's links to its site. As an economy, skylights were eliminated, but, happily, so was the client's misguided impulse to cover up the steel with plaster. Furniture that would have made the promenade more user-friendly was also cut, leaving only a few uncomfortable steel-pipe benches, some token canopies that fold up from the deck, and entirely too much chainlink fencing-primly shutting off the steeper contours where (horrors!), someone might stumble and fall. Lawn was added at both en ds of the boardwalk to secure a grant for introducing greenery, but signs warn visitors against stepping on it.

The uplighting within the three halls can be boosted with downlights as needed; however, there is less natural lighting than the architects had intended. Though customs officers work here for only a few hours a week at most, they insisted on enclosed offices, walled in translucent glass, obscuring the side windows. Former retail tenants, however tacky, were allotted similar areas along the edge of the arrivals hall, and the cafe, which could have been entirely transparent, was enclosed. As a result, the halls have to be artificially lit even on bright days, and the sweeping panorama of the harbour is blocked.

But these are minor criticisms of a remarkable achievement. It's a miracle that so audacious a building was completed in just over two years (by three contractors working closely together), and that solutions were found to the engineering challenges and client change orders while going only two per cent over the original budget of 23 billion yen (129 million pounds). In contrast to the Sydney Opera House, which dominates its waterfront and has become an internationally recognized icon, or the Constructivist exuberance of Michael Rotondi's Dragon Promenade in Nagasaki harbour (AR December 1998), the Port Terminal is intentionally low-profile, deferring to the floating hotels; from a distance it resembles an earthwork more than a building. The roof promenade divides at the entry and extends forward in two steep banks to embrace the approach road and draw people up to explore its folded and rounded terrain. From this sensuously modelled landscape, evoking without mimicking the roll of the ocean, the new trophy buildings that line the waterfront look like a row of Alessi tchotchkes. And the interiors have the sweep and authority that Le Corbusier recognized in the George Washington Bridge; architecture and engineering indissolubly fused.

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Foreign Office Architects, London

Project team (detailed design and construction)

Farshid Moussavi, Alejandro Zaera-Polo, Shoukan Endo. Kensuke Kishikawa, Yasuhisa Kikuchi. Izumi Kobayashi, Kenichi Matsuzawa, Tomofumi Nagayama, xavier Ortiz. Lluis Viu Robes. Keisuke Tamura

Structural engineer

Structural Design Group

Services engineer

P. T. Morimura & Associates

Associate architect

GKK

Photographs

Satoru Mishima