03 May 2016

Yorkshire Bridges: 11. University of York footbridges

I'll finish this short series of posts on the bridges of the University of York with a sampling of some of the other footbridges to be found at the University's Heslington Campus.

But first, I found a couple more photographs of the weathering steel footbridge, which make for an interesting comparison with my own photographs. Both of these are courtesy of the University's image library. They show the bridge as it was originally designed and built, not as hidden behind trees as it now is, and with a much more open and attractive parapet. It was clearly a genuine work of art, and deserving of wider recognition. Although it's still an attractive bridge, it's clearly not what it used to be.

Here are a few more of my own photographs of bridges at the University:


30 April 2016

Yorkshire Bridges: 10. Arched footbridge at University of York

Here's a third footbridge at the University of York. This one connects two college buildings across a small highway, and was built some time before 2010, although I can't find any information on the exact date, the contractor, or the designer.

This is a fairly straightforward steel arch bridge, although there are a few features of note.

The first is its asymmetry, with the arch ribs founded at one end close to deck level, and at the other end below deck level. I'm only guessing, but I wonder if this is due to an obstacle to foundations at one end, such as buried services. This may also explain the slightly odd struts supporting the deck at one end.

Joints in the deck edge stringers have been simply detailed, and most of the rest of the bridge is also straightforward and attractive, including the balustrades.

The choice of paving is unfortunate, with some of the paving slabs coming loose. I would think these will be a perennial source of problems.

26 April 2016

Yorkshire Bridges: 9. Cable-stayed footbridge at University of York

Here's another interesting little bridge at the University of York's Heslington Campus.

I've been unable to find out anything about when this bridge was built, or who was responsible, so if any readers can provide further information, please share it in the comments.

The bridge spans an artificial lake between two colleges, and fits the surroundings well, with a height that isn't any taller than nearby trees.

There are a number of things that I like in this bridge. The first is the very slight angle to the towers, which helps give it an open feeling, perhaps even a little jaunty. Vertical towers would look stiff and formal by comparison.

The towers themselves are nicely tapered, and attractively simple in their chevron cross-section, which ensures all sides of the steelwork are accessible for maintenance and repainting (or cleaning, should somebody be bothered).

I also like the way the towers are perched on tiny pin-pricks of steelwork, the entire bridge perched on as little as is necessary to hold it up.

I admire the modesty of the bridge deck, with simple timber decking and straightforward balustrades. The bumblebee ends to the balustrade rails, presumably intended to warn drunken students against tumbling against them headfirst, are the only jarring note.

24 April 2016

Yorkshire Bridges: 8. Weathering steel footbridge at University of York

I visited the University of York a while back. The main campus is built around an artificial lake which is crossed by a number of footbridges.

The weathering steel footbridge is not just any footbridge in weathering steel: it is claimed to be the first weathering steel bridge ever built in the UK, dating from 1967. With nearly half a century of weathering having taken place since construction, I thought this would be an interesting bridge to visit to see how the weathering steel patina can develop in the long-term.

As it turns out, the patina is probably the bridge's least interesting attribute. It's an attractive dark brown, which looks like it has stabilised well. There's no sign of ongoing corrosion anywhere, indicating that the bridge was well detailed, and no evidence of graffiti or other vandalism. The bridge drains freely into the lake via a series of scuppers along each edge.

The bridge's main interest is in its shape. It is wonderfully slender in elevation, broadly taking a three-pinned "arch" form which is vaguely reminiscent of Robert Maillart's Tavanasa Footbridge.

The deck consists of two steel box girders, each triangular in elevation. They are deepest at their points of support, which consist of slender steel box struts carrying the loads back to the abutments at a very shallow angle.

All this looks quite delightful in elevation, but is just plain odd when viewed at closer hand. The struts are much narrower than the deck girders, so it's apparent that there must be significant internal diaphragms within the boxes to transfer loads between the main structural elements. I'm struggling to see the rationale, either architectural or structural, for doing this, as the forces just don't seem to "flow" down to the ground.

Nonetheless, this is an attractive bridge, which has survived well, and clearly demonstrates both the longevity of weathering steel, and its ability to sit attractively within semi-rural surroundings.

There are some other interesting footbridges at the same site, I'll post details when I get a chance.

17 April 2016

"Calatrava: Complete Works 1979 - today"

Weighing in at 596 full colour pages for £35, Philip Jodidio's latest Calatrava tribute is exceptionally good value for money (Taschen, 2015). It updates an earlier edition, and at first glance seems to offer everything anyone could possible want to know about the world's favourite Spanish architect/engineer.

In fact, there's a clear breach of trading standards law on the proper description of goods here: despite the voluminous contents, this is nothing like a "complete works", with a large number of projects relegated to a list in an Appendix rather than featured properly. Of the four Calatrava bridges that I've written up on this blog, two are included (James Joyce Bridge and Ponte della Costituzione) but two are not (Katehaki Bridge and Trinity Footbridge). So, set the title to one side before considering a purchase.

It's no surprise that this is a super-fat brochure rather than a work of architectural criticism. Jodidio's stock in trade is invariably affirmative, congratulatory fare, and there's little here to enlighten the curious reader about the success, or otherwise, of Calatrava's completed works. Instead, this book is about bludgeoning the recipient with space-age spectacle: page after page after page of visually stunning, technologically futuristic geometries wrought in economically and environmentally unsustainable mega-tons of concrete and steel.

It's principally a visual book, with lightweight text making way for countless large-scale photos of Calatrava's characteristically grandiose oeuvre. There are some images at Amazon which will give you a good flavour of the style. Many of the photos are united by the absence or near absence of humanity, architecture frozen in that perfect moment when the cranes have left the scene but the public have yet to arrive, majestic sculptures unblemished and unsullied by the messy business of real people, traffic, or the stains to be accumulated in later life by inadequate maintenance.

In this respect they contrast significantly with Calatrava's sketches and watercolours, plenty of which are included. These frequently reference the human scale, and the relationship of the designer's abstract geometries to a poetic understanding of birds, the body, the eye and other humanist and natural inspirations. It's often interesting to try and trace a relationship between the architect's delicate and beautifully coloured artwork to the bleach-white structures that result.

Despite its flaws, I'm very glad I acquired this book. Calatrava is a monumental egoist, but also a singularly creative talent, and rare amongst architects for his willingness to exploit and explore structures rather than simply to hide them behind facades. His designs for various transportation hubs and stations are frequently spectacular in a positive way, sitting somewhere between the greatest Victoria station sheds and lofty cathedral spaces.

His designs are often uncompromising in their willingness never to say "no" - many would baulk at the challenges involved in realising his more epic designs, and there is surely a place in the world for the gargantuan, the astounding and the lavish. At the same time, Calatrava is a master of small details, of shaping not just the overall form but every element to work well together.

I particularly admire his occasional debt to history, as in the sweeping roof forms of the Bodega Ysios winery, which are a direct tribute to Antoni Gaudi's school building in Barcelona.

05 January 2016

Après le déluge

It's been a busy year at Pontist Towers, so much so that my time available for blogging has been greatly reduced. That's unlikely to change in 2016, so you can expect posts here to remain fairly infrequent.

2015 ended with a great deal of bad news on the bridges front, with four bridges which I've visited and featured here either badly damaged or completely destroyed by flooding.

The bridges of the Cockermouth Keswich and Penrith Railway survived over 150 years before succumbing to the effects of Storm Desmond in early December. These bridges had been converted to a walking and cycling path after the railway was closed. Two of them were washed completely off their supports, the spans at White Moss (pictured above) and Brundholme (pictured below). When I visited them in 2013, they were rusty but reasonably robust relics, preserved and actively used, but it seems unlikely they will be restored any time soon. These photos are courtesy of Floodpics2015.

A number of other notable bridges were damaged or destroyed by the same storm. The Grade II Listed Pooley Bridge in Cumbria, dating from around 1764, was one of the most notable casualties, completely swept away by the sheer volume of floodwater (pictured, below, courtesy of Robert McEwen).

At the end of December, Storm Frank brought further devastation. It affected two bridges on the River Dee in Aberdeenshire which I visited in 2012.

The Grade B Listed Cambus O' May Bridge is a lovely suspension bridge built in 1905, and largely reconstructed in 1988. It has been badly damaged by floodwaters and may be beyond repair. Looking at footage of the flood, it's amazing it survived at all. To get an idea quite how much flood water passed down the Dee, compare the flood footage with the more normal level of the water in my blog post.

Another suspension footbridge on the same stretch of the River Dee has been less lucky. The Abergeldie Castle Footbridge, built in 1885 and also Listed Grade B, has been destroyed, except for its northernmost tower. This was already a derelict bridge, recognised on the Buildings at Risk register. It had been disused for a long time, and clearly will never be replaced. Footage in a Daily Mail report shows the wreckage, although quite understandably gives more prominence to the threat to Abergeldie Castle itself.

The same storm has led to severe damage to the New Invercauld Bridge (1859, Grade B Listed), cutting off Braemar from the rest of Royal Deeside; the collapse of Copley Bridge (1831, Grade II Listed, pictured above courtesy of Richard Kay); partial collapse of Wharfe Bridge in Tadcaster (18th century, Grade II Listed, first picture below courtesy of Rob Whiteley); and severe damage to Elland Bridge (18th century, Grade II Listed, second picture below courtesy of Richard Kay), and no doubt many others,

It has been reported that December 2015 has seen the greatest rainfall of any month in the UK since proper records began. With that in mind, it is difficult to blame these many bridge collapses on inadequate flood defences, or lack of maintenance. It seems initially more likely that they have experienced hydraulic loads and scouring action well beyond anything they had previously survived.

However, it seems clear that the recent rainfall and flooding are unlikely to be a one-off event, but that similar events could be experienced again far sooner than would normally have been expected. Historically, severe flooding has always been one of the greatest causes of the loss of bridges, and it's unreasonable to expect to be immune in the present day. It may be that no reasonable amount of flood defence or flood mitigation measures could have prevented these disasters.

I hope that at least some of the bridges affected by recent events may be restored rather than simply replaced, and that it spurs a wider effort to enhance the resilience of bridges throughout the UK. The examples here show they are important for heritage reasons and also as key transport links. Let's hope that the reins of economic austerity are loosened sufficiently to make a difference before the next time such severe flooding occurs.

10 December 2015

"Preferred bidder" chosen for Nine Elms / Pimlico bridge design competition

Here's another thing you already know but I've neglected to mention here until now.

A "preferred bidder" has been announced for the £40m Nine Elms / Pimlico bridge design competition. The preferred design team comprises Bystrup Architecture Design and Engineering, Robin Snell and Partners, Sven Ole Hansen ApS, Aarsleff, ÅF Lighting Aecom, COWI Engineering and DP9.

 This is an interesting contest. 74 entrants were winnowed down to 4, and now to the final 1, at least assuming Wandsworth Council accepts the jury panel's recommendation (which seems to be a formality). However, it's not a contest to choose a bridge design: it's a contest to choose a bridge design team, and it's possible that once they are appointed, and enter into further discussions with key stakeholders, an entirely different design could emerge.

I covered the four shortlisted designs, including Bystrup's, previously, so I won't go over the design's merits in detail again. Suffice to say that it's key feature is cycle ramps suspended above the River Thames, protecting river bank amenities (especially a public gardens on the north bank) at the expense of taking over large areas of the river channel.

Assuming Wandsworth Council accept their jury's decision, the next step is to formally appoint the design team and begin further design development. It may therefore be some time before we hear much more of the project.

The scheme seems to remain unpopular, especially with residents on the Pimlico side of the river. The Guardian noted "public fury" over the scheme but points out that much of the anger is misplaced, as the impact on the river bank park is actually minimal.