World's tallest wooden skyscraper planned for Vienna; city's fire service concerned

Image: Rüdiger Lainer + Partner.

Unlikely as it sounds, wooden skyscrapers are a thing these days. As we noted last year, concerns about the environmental impact of steel and concrete are driving some architects and designers back to wood as a more eco-friendly alternative. There's already a nine storey tower built from specially laminated timber in London, and a 12 storey wooden building under construction in Bergen, Norway. 

A planned tower for Vienna, however, is due to leapfrog both in terms of scale and height. The HoHo project in Vienna's Seestadt Aspern area will feature two wooden towers, the tallest of which will stretch to 25 storeys and 84m. The towers will be 76 per cent wood; Kerbler, the firm behind the designs, claim the material will produce 2,800 tonnes of CO2 when compared to a similar sized tower built from concrete.

However, according to the Guardianthe plans didn't go down so well with the Viennese fire department. Christian Wegner, spokesperson for the department, said:

A few of us were upset because it was crazy to present an idea like this that has not been discussed with everyone yet.

They have to carry out special tests on the correct combination of concrete and wood. We also want to develop a more fail-safe sprinkler system. I expect they will pass the tests but if they develop the building as they say they will, it will be a serious project.

The fire service is now working with the architects to ensure the building meets safety standards. If all goes to plan, construction will begin later this year, and should be completed in 2016.

Despite the fire service's hesitancy, the tower's height shows that planners and designers alike have a growing faith in the safety of timber structures. In the UK, it was against planning regulations to build a timber structure above three storeys until the early 2000s, when safety tests showed that taller timber structures could meet the same safety regulations as concrete or steel ones. Recent tests in Canada, meanwhile, have shown that timber treated in the right way can resist heat and flames for up to three hours.

Daniel Safarik, editor of the Council on Tall Buildings and Urban Habitat, says resistence to wood-based construction stems from a lack of understanding around the materials on offer: 

[The Vienna project] will encounter some of the same issues as other structures in obtaining approvals, mainly that the local fire codes are often predisposed against wood as a material, due to the combustibility of traditional stick framing.

Cross-laminated timber panels, however, are quite thick and develop a “char layer” that allows them to support the building for several hours during a fire – just as concrete or masonry would. Most of the buildings we have seen proposed are not “pure” wood structures anyway. Many use some combination of steel, wood and concrete. In general, the arguments in favour of wood construction are strong. 

In summary: building giant towers out of wood is actually much safer than it sounds. 

 
 
 
 

Network Rail let me have a play on Manchester’s new rail bridge. Here’s what I learned

The new bridge in all its glory. Image: Network Rail.

By the time the railways arrived in Manchester, the city was already built up, forcing trains to finish their journey on the edge of the urban area. To this day, it still has two main stations: Victoria, which sits on the northern edge of the city centre, and serves destinations across the north; and Piccadilly, which serves a smaller chunk of the north, but also provides trains to Birmingham, London and points south.

There are many ways in which this situation is less than ideal. For a start it means that travellers get off a train, only to find they’re still surprisingly far from the city centre. For another, terminating services take up more space (because you need more platforms) and time (because crews need to change ends) than through ones.

Then there’s Manchester Airport, the busiest in the north, used by travellers right across the region. But that’s to the south of the city, on a line into Piccadilly, which makes it annoyingly hard to get to by train.

The proposed PiccVic tunnel. Image: Wikimedia Commons.

So what with one thing and another, linking up Manchester’s two stations in some way has been an ambition for decades. In the mid-1970s, there was a plan for a “Picc-Vic” tunnel, which would have served five underground stations in the city centre – but that, inevitably, got cancelled due to lack of funds. The city council instead started to focus its efforts on the new Metrolink tram network; but while that’s been great for locals and commuters, it’s not done much for longer-distance travellers

A few weeks from today, though, trains will travel directly between Piccadilly and Victoria for the first time. To do so, they’ll use existing lines to the south and west of the city centre, as well as 300m of new track, known as the Ordsall Chord.

And, for reasons that aren’t exactly clear, the nice people at Network Rail let me have a go on their new bridge. Here I am, in my fetching new personal protective equipment:

Jacket, trousers, boots, gloves, eye protection, hard hat: all present and correct. Ability to take a remotely flattering selfie: conspicuous by its absence. Image: author provided.

(The trousers were my size, which was unexpected, because I hadn’t actually told Network Rail what size I was. This lead me to worry they kept a database of such things, but the press office assured me that this had literally never happened before, and was extremely unlikely to happen again. So anyway.)

The Ordsall Chord has been talked about for a very long time: parliament actually agreed to build the thing, then known as the Castlefield Curve, all the way back in 1979, just after the cancellation of the Picc-Vic tunnel. In some ways it’s an obvious missing link – remember we’re talking about just 300m of new track, costing under £100m, which isn’t that much as these things go. But Britain being what it is, it proved rather easier to persuade ministers to build London’s £15bn Crossrail instead.

A schematic of the new curve. Image: Wikimedia Commons.

In 2011, though, then chancellor George Osborne unexpectedly announced £85m of funding. The project somehow survived austerity and the new bridge in the borderlands between Manchester and Salford, officially opened last week (although the first trains won’t run until next month).

A scale model of the new link, nearby in what was Manchester Liverpool Road station; it’s now a part of the Museum of Science & Industry. Image: author provided.

I say it’s a bridge: as it happens, it’s actually two bridges. The bit your eye is drawn to is a structure known as a “network arch”, which means those wires crosses at least two others. That part will carry trains over the River Irwell, which divides Manchester from Salford.

Beyond that, though, there’s a second bridge: a flat one, across a section of the inner ring road. Linking them is a slight dip in the metal sides of the bridge (though not, obviously, in the track).

A map of the area. New curve highlighted in yellow. Image: Google.

This, along with the asymmetrical shape of the arch which facilities it, is a purely aesthetic feature. So is the colour: the metal was allowed to rust in the Manchester climate, apparently for no other reason than to make it look cool. “We don’t want it to read as different structures as you look along the river,” Peter Jenkins, the head of transport at architects BDP and lead architect on the project, explained at the official opening ceremony. The design, he added, was “not uncharted, but rarely charted.”

To be fair, it is a great looking bridge: something that looks like a landmark, rather than just a piece of infrastructure. One of the guys who’d worked on the project told me, as a group of us stood on the bridge, that he hoped it would be illuminated at night, just to show it off and make it a feature of the city’s skyline.

(Incidentally, as excited as I was to go play on the bridge, it wasn’t entirely clear what I was meant to do once I got there. I tramped up and down a bit, took some pictures of the city’s skyline, and occasionally checked nervously that there was no way a train could get near me. But what was I actually meant to do? And what was a decent interval before it was acceptable to, y’know, get off the bridge again? Ah well, better take another photo I suppose.)

A view from a bridge. Image: author provided.

Looking good is all very well, of course, but what will the Ordsall Chord actually do? 


For a start, it’ll allow travellers from Yorkshire, the north east and other parts of the north to travel directly to the airport for the first time: that should hopefully work out well the airport, the road network and the wider economy.

It’ll also speed up journey times. Longer distance services will no longer have to reverse, or trundle all the way around Manchester on far-flung bits of track. Instead, they’ll be able to go straight around the city centre.

(Seriously, I’ve been up here 20 minutes now. Is it okay to get down again yet? Surely they must all have noticed that I have no idea what I’m doing right now. Surely.)

Mike Heywood, the director who managed the project for Network Rail, pointed me to another, less obvious benefit. At the moment, the various trains terminating at Piccadilly often have to cross each other’s paths to reach their platforms. This, if you don’t want trains to crash into each other, limits the number of trains you can actually run.

By diverting a share of trains via two new through-platforms and the chord, Heywood told me, you can reduce that, and add 25 per cent to Piccadilly’s capacity at a stroke.

The side view. Image: author provided.

Oh, and by making the new bridge look good, those who built it also hope it’ll help kick-start regeneration along a rather neglected stretch of the River Irwell, too.  Not bad for 300m of new track.

This is only one part of what the industry has termed the Great North Rail project. Others include an extra platform at Manchester Airport, electrification on assorted routes in the north west, and – best of all, given the state of the existing rolling stock – vast numbers of new trains, due to appear next year.


 The region’s transport network is still not getting anything like the care or attention that we take for granted in the south east, of course, but all the same, it’s nice to be able to write about a new railway line in the north for once. AND they let me go play on a bridge.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

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