'This is one of those projects that is trying to do an awful lot for an area that needs moving along' ... the National Waterfront Museum. Photograph: James Brittain  Wales claims to have been "the world's first industrial nation". If the number of museums relating to Wales' industrial heritage is any measure, it has now become the world's most advanced post-industrial state. You'd expect a substantial amount of industry to be on display in institutions such as Cardiff's Museum of Welsh Life, but there are also national museums dedicated to coal mining, woollen and slate industries, plus numerous decommissioned industrial sites that have been converted into heritage parks and the like. Perhaps in some future museum of 21st-century Welsh life, there'll be an exhibition about the current craze for museum building.  Now we have the new £30m National Waterfront Museum, which opens in Swansea tomorrow, and aims to tell "Wales's story of industry and innovation". It sounds like the last thing the country needs, but this new institution is a welcome arrival. That's partly because it combines two existing facilities - Cardiff's Welsh Industrial and Maritime Museum, and Swansea's Maritime and Industrial Museum, thus reducing the total number of museums - but primarily because it is a piece of quality architecture in Wales's second city.  Swansea could certainly do with an image makeover. The Lonely Planet guide described it as "an ashtray of a place", the movie Twin Town called it "a pretty shitty city", and even native son Dylan Thomas damned it as "a graveyard of ambition". In the post-industrial world, the city's most notable export has been Catherine Zeta Jones. Added to which, the flag-waving structures of recent years - Richard Rogers's Welsh National Assembly, the Wales Millennium Centre, and the Millennium Stadium - have all gone to Cardiff. Scarred by heavy industry and second world war bombing, much of Swansea is a jumble of old industrial buildings, decaying modern office blocks and cheap new commercial buildings resembling giant Travelodges. Despite its location on a beautiful bay, it's often difficult to guess the city is anywhere near the sea. Even in the former dockyards to the south, where the National Waterfront Museum is located, a 1970s housing development completely blocks the view to Swansea Bay. The "waterfront" of the title refers to a basin 100m inland.  "I hate the phrase 'catalyst for regeneration', but this is one of those projects that is trying to do an awful lot for an area that needs moving along," says Martin Knight of architects Wilkinson Eyre, best known for their acclaimed "winking" Millennium Bridge in Gateshead. That Stirling prize-winning project has become the symbol of a rejuvenated Tyneside, and Wilkinson Eyre's presence here, in another post-industrial port city, suggests Swansea is ready for its own "Gateshead effect". There is even another striking Wilkinson Eyre footbridge - the Swansea Sail Bridge - just around the corner from the new museum. "You probably haven't got enough to make a quarter or a district like they did there, but there's a framework you can build on," says Knight. "The main thing is to make a new heart for this area that will tie into the existing building stock."  The former Swansea Maritime and Industrial Museum occupied a two-storey brick warehouse alongside the basin. This area was once a rail yard, but in recent times it has been a huge car park serving the leisure centre next door - a hulking 1970s box now closed for refurbishment. Echoing the goods carriages that once pulled through here, the new section of the museum adds a curving series of four interlocked steel and glass cubes, peeling away from the warehouse building. Joining the old and new components together is a glazed internal street that forms an axis running from the basin, through the museum and its grounds, and back into the city centre. The architects have tried to forge a direct connection between the city and the sea with this new axis. If someone were to demolish the 1970s houses across the basin, the job would be complete. "We've done the best we possibly can," says Knight.  Approaching the museum along this new route, the translucent boxes hardly feel like a spectacular climax - some have even compared them uncharitably to a business park - but it was more important to build a flexible, practical building than a local icon, say the architects, especially for a museum concerned with industry.  The facade looking away from the city, however, is more of a show-stealer. It is clad in heavy Welsh slate - vertical slices of it arranged in irregular horizontal bands that imitate the glass on the other side. It has become almost a cliche to use slate as shorthand for Welshness - the new Welsh National Assembly and the Wales Millennium Centre also bring out the Welsh slate, the former as a heavy plinth, the latter in a sort of dry-stone wall pastiche - but this is arguably the most successful. The effect is contemporary but warm. Set off by aluminium channels between them, the slate panels' colour and surface textures change with variations in the light and weather.  "We wanted to use the widest variety of Welsh quarries we could," Knight explains, "and make this really representative, but in the end we could only find two that could deal with the logistics of the programme and the budget. Part of the problem was that smaller suppliers are geared more towards doing headstones."  On the inside, the architecture takes a back seat to the exhibitions, which were created by specialists Land Design. As you'd expect, there are a few big pieces of machinery, but the museum's emphasis is more on the social history of industrial Wales. There is no single point of entry, but it is hoped visitors will be led up a giant new staircase to the first floor of the old warehouse. Here, the displays begin with a wall-sized live panorama of the city, followed by an interactive exhibit based on the 1851 census (the first to show that industrial workers outnumbered agricultural workers, and the basis of the "first industrial nation" claim).  The route then opens out into the main volume of the old warehouse, which has been stripped back as far as possible to reveal the original roof structure, before winding across a mezzanine bridge into the new building, and down to the open hall housing the big machines (tilt hammers, steam engines and the like). Here, Wilkinson Eyre's expertise with bridges pays off; the heavy steel elements supporting the external glass complement the exhibits. Lastly, there is a separate and rather forlorn little room projecting the industrial narrative into the future with some virtual exhibits on Wales's new growth industries, such as nanotechnology and renewable energy.  If there's one lesson the millennial rush of new museums has hammered home, particularly those that have failed after a couple of years, it's that the numbers have to add up, both in terms of visitors and revenue. Whatever it brings to the city and its people, the National Waterfront Museum (which will be free to all visitors) must also generate cash to stay alive. Perhaps it's not even accurate to describe such a building as a museum. Most of the old warehouse building's ground floor is given over to commercial space: a museum shop and café inside, plus units for external bars and restaurants that will come into life after the school coach trips have gone home. It is also hoped that the grand upstairs gallery of the warehouse will double as a venue for the hosting of corporate events. The display cases are designed to slide back to the perimeter of the room on rollers, creating space for a 200-person banquet. So as much as cataloguing the past, this is a museum that might point Swansea towards the future. If the end result is a revitalised cultural destination for the city, the slurs about ashtrays and graveyards could become history too.
With its sleek new museum, built by 'winking-eye bridge' architects Wilkinson Eyre, Swansea may yet become the next Gateshead, says Steve Rose.