30 August 2009

Bridges news roundup

Open week to reveal hidden secrets of Forth Road Bridge
October proposed to allow visitors into main anchorage chambers

1909 Irish concrete arch bridge to be rebuilt as replica of itself

Contractors shortlisted for Gifford / Wilkinson Eyre twin bascule bridge at Poole

Brisbane footbridge looks like an "umbrella blown inside out in a thunderstorm"

Signature bridge sought for Chattanooga factory

29 August 2009

Iron Bridge

I was in Shropshire recently, and had the chance to visit the Iron Bridge at Coalbrookdale. Built in 1779, this is the oldest surviving cast iron bridge in the world.

It wasn't the very first metal bridge - an iron bridge was designed in Lyons in 1755, but not completed, while in 1769 iron bridges were built at Kirklees Hall in Yorkshire (spanning 20m), and over a canal at Boroughbridge in Yorkshire. English Heritage still have a sign on the Coalbrookdale bridge proclaiming it "first iron bridge in the world", but what do they know?

Designed by Thomas Pritchard, and constructed by Abraham Darby III, the Iron Bridge was built at the heart of an area pioneering the development of industrial-scale iron smelting.

Today the bridge is recognised as a key monument to the Industrial Revolution - the River Severn Gorge and several other local sites form part of a World Heritage Site; the Iron Bridge is Grade 1 Listed; a Scheduled Ancient Monument; and an ASCE Historic Civil Engineering Landmark. But even when it was first built, the 30m span bridge was recognised as a marvel.

There's no meaningful way to judge the success of this bridge design other than by the mere fact of its achievement at all (without precedent), and its survival for 230 years (assisted by some largely invisible remedial work over the years). Its appearance and construction borrowed heavily on carpentry principles, and its filigree, open appearance was quickly superseded by the stronger designs of Telford, Rennie and others. While it was widely imitated (near-exact replicas were built both at Worlitz and at Raincy, near Paris), it was a jumping off point for others to improve upon, not a definitive prototype.

If pressed to pass judgement, I'd point to the unfortunate peak at the crown as one flaw (a vertically curved deck would look better), and while the south arch spans today look very fitting, these were added several years after the bridge was first built - it originally had a much heavier masonry abutment at this end. However, what I find most remarkable is how aesthetically attractive it is (partly a result of its picturesque setting), especially given that many other prototype bridges in new materials are far more awkward. It's a great shame that similar devotion to appearance isn't being given to present-day innovations, such as fibreglass footbridges, for example.

See also:

18 August 2009

How to win a bridge design competition

My last post had an interesting comment from ABC, who asked:

"The chances of winning an open competition seem very low, do you:

1) Try to win with an "extreme" or "practical" design

2) Try to be vague or detailed?

3) Develop the concept as a portfolio piece and forget about winning?

4) Forget to mention your an engineer

5) Change my name to Frank Lloyd Calatrava

I'm not sure I'm the best person to answer but here are my thoughts, with the St Patrick's Bridge competition especially in mind.

Questions to ask yourself before entering

1. What will I do if I am shortlisted? Am I happy to fly to Calgary for interview (if not local)? Am I competent / sufficiently resourced / legally qualified to enter a contract for the detailed design if I win?

2. Let's say I spend two weeks on my entry, and I have a 1 in 10 chance of winning. If I enter ten competitions, I'd expect to win one. So having invested 20 weeks of my time for free, how much work should I get out of that single win to make all that investment worthwhile? And how does that change if my odds are only 1 in 100? Is there a better way to spend my time (does the attic need clearing out)?

3. My design will be on public display. Am I happy for smart-arse bloggers to critique it online?

4. Am I in this because I want to win? Because I want it on my CV (although there's probably nothing worse on a CV than a string of competition failures!)? Or because I want to stretch myself?

5. Am I properly qualified, or if not, can I get hold of someone who is (presumably a P.E. licensed to practice in Alberta)?

None of these questions should rule out an entry, but it's certainly worth thinking about before taking the plunge.

How to compete

1. If at all possible, visit the site. Understand the landscape. Talk to the locals. Look for unexpected opportunities. Get a feel for the character of the place.

2. Understand the politics. In Calgary, there will be very strong pressure for local firms to be shortlisted. Do you have a local link? There will also be greater demand for public consultation - will your design appeal to the experts or the public? They will be looking both for something that's very different to the Calatrava design, but which will impress the public more - there will be rivalry between CMLC and the City of Calgary. CMLC will want to prove that their competitive procurement route gets a better result.

3. Understand the evaluation criteria (and whether they're real, or whether the promoter will fudge them to get what they really want, which is normal). Calgary has no clear criteria - it's not clear if a cheaper solution will score extra points; there's little reference to the promoter's aspirations, which as written amount to little more than providing "a link". Do they want something iconic? A landmark? Elegant? Low maintenance costs? They don't say any of these things. But I'm sure they want them all. How important is your experience, or brand name? They ask for that information, but don't say how they'll use it in the evaluation. So Calgary leaves you guessing: personally, I think experience will count, and because entries aren't being judged anonymously (as would be normal for an open competition), there is little likelihood the judging will be fair - if they know your reputation, they're bound to take it into account.

4. An average implementation of a unique solution may be better than an excellent implementation of a common solution. "Common" doesn't just mean beam-and-girder, it just means any solution that many entrants are going to think of - if there are twenty self-anchored suspension bridges with a single mast on the island, what's the chance that yours is the best version?

5. Is it really a bridge that they want? Or is a sculpture (most Calatravas)? A piece of the landscape? Or just a means of getting from A to B (in which case - why not a ferry? Or a cable car?) In Calgary, I'd say they want the crossing; they also want the sculpture; and they have CAN$25m that they have to spend or they will lose it. Can you give them value by using some of the money for other facilities that they couldn't otherwise afford - additional paths; a viewpoint facility on the island etc?

6. Has the brief imposed unnecessary restrictions? Does it really matter if the bridge deck drains into the river? Why can't the deck be timber? Why not two bridges (for CAN$25m, they could have several bridges at this site quite easily)?

7. Who are the judges and what will they want? Do they have any pet hates or likes? Normally the key question, but CMLC don't tell us who they'll be, so insiders may have an advantage. But I'd assume CMLC head honcho Chris Ollenberger (a qualified geotechnical engineer) will call the shots; there will be engineering advisers, possibly from Stantec, who have a vested interest (why would they want a bridge which will overshadow their own Peace Bridge project?); almost certainly some form of community representative. To keep the professionals happy, the design must be at least superficially rational from an engineering perspective. But the community will want something that's visually easily comprehensible. Are they looking for modesty, or for the kind of flash and bang that shows they're getting their money's worth?

8. Assume the judges will spend a maximum of five minutes looking at your entry in the initial run-through. Possibly not even that. The presentation board is 100% key. It must be professionally presented, with high-quality digital renders, and clear and quickly comprehensible to a lay person. It must look like an architect's presentation, not an engineer's drawing. The submission must have enough detail to satisfy the rules and as little as possible beyond that, especially as if shortlisted you will need to address all the points you had no time to consider at Step One.

9. Is there scope to diss the other likely designs? I'm normally quite keen on this, it's usually possible to predict popular solutions and point out in the technical submission why they are the wrong answer. Just bear in mind that hardly anyone will read the technical submission.

10. Don't waste time on anything other than the simplest engineering calculations. The chance of winning doesn't repay the investment of time. Having said that, don't design anything you don't feel confident you could make work at a later stage, somehow. For Calgary, entrants need to finalise their concept within the next week, spend two weeks on the digital images, a couple of days to dash off the technical report and other data required, and that still leaves time to get it in the post by the deadline.

11. Design something you've never designed before. Never done a suspension bridge? Do one now. The basic equations for an unstiffened suspension bridge (or a stressed ribbon) can be written on a single line - how hard can it be?

12. Above all, have a good idea! An okay idea won't cut it in an open contest, it has to be striking, memorable, very well-presented, and able to stand out when surrounded by dozens of others, many of which will have all these qualities while being completely unbuildable or maintainable. Spend time thinking through different concepts. Spend time not thinking about them, so that the back-brain can do its job. Inspiration is unlikely to come from studying the designs of others - that just provides knowledge to use as a resource and test possibilities against. In my experience, there's a lot of hard effort put into working through concepts, developing them in different directions, but inspiration usually comes suddenly and unexpectedly.

Note this section is headed "how to compete", not "how to win". With an open competition like this, the odds are so low of winning that there's clearly no guaranteed strategy. With a smaller invited competition, there is a good chance of knowing who the other entrants are, and what they might enter, so the tactics may differ.

Some predictions for St Patrick's Bridge, Calgary

1. Calatrava will not enter.

2. There will be at least 100 entries.

3. At least two shortlisted entries will be from locals.

4. The winner will be a collaborative engineer/architect team; there's no chance of one alone winning.

5. This bridge will be built within budget; the Peace Bridge will not.

I'd be very interested in other opinions on this post!

17 August 2009

St Patrick's Bridge design competition announced

The City of Calgary is to get not one, but two hugely expensive landmark footbridges. I've addressed Santiago Calatrava's Peace Bridge design previously, but now a sibling is on its way.

Unlike the Peace Bridge, where the city council went straight to the top brand designer, the second CAN$25m bridge will be the subject of an open international design competition organised by the funder, the Calgary Municipal Land Corporation (which is itself owned by the city). Entries are required by 14 September.

The proposed structure must bridge 180m across the Bow River, touching down on St Patrick's Island mid-river.

It will be very interesting to see how a proper competition stacks up against the direct appointment of a star designer. Will it offer anything better for the same money? (I'd hope it will offer at least a more rational structure).

Unfortunately, the competition may not attract great designers: the risk is that there will be dozens of entrants, competing for what appears to be minimal reward - there's no prize-money, and plenty of hoops to jump through before landing a design contract. The jury is unidentified, and the judging criteria unclear. None of the lessons of recent failed design competitions have been learned here, that's for sure.

13 August 2009

Bridges news roundup

Beautiful Chinese Pedestrian Bridge
Beauty evidently in the eye of the beholder

OFF Architecture's visionary eco-bridge spans the Bering Strait
Heavily-promoted runner up out of 135 entries to ideas competition

Contest seeks design of proposed titanium pedestrian bridge at University of Akron
Yes, they are being serious

Historic bridge must be demolished, says university
Braunstone Gate Bridge in Leicester sold in preparation for demolition

Integral and semi-integral bridges
New book by Martin Burke published, proposing a more holistic approach to integral bridge design

Fury as pretty 19th century railway bridge is rebuilt using red brick by 'penny pinching' rail firm
Daily Mail splutters with anger over Cornish bridge repaired on the cheap

11 August 2009

Sheffield Parkway Bridge dropped

In the latest in a long line of recent RIBA bridge design competition failures, plans for an "iconic" footbridge over Sheffield Parkway have been dropped. The winning design, by Tim Nørlund Jensen and Ramboll Whitbybird, is apparently to be ditched because of "increased costs".

Nørlund and Ramboll fought their way past 108 other entries in order to win the competition in January 2008. The architect claims not to have been paid for working on a number of design developments requested by the client, Yorkshire Forward, other than his original £7,000 honorarium. That may say more about the inevitable risks of working without a formal contract than anything else, however. The risk that a winning designer may not get appointed to do the follow-on design work is inherent in many bridge design competitions, particularly the open format preferred by the RIBA.

There's no information on the extent to which the costs have increased, with Yorkshire Forward only saying: "The Parkway Bridge is currently undergoing a design review as a result of the increased costs for the original structure. The current economic downturn and subsequent prioritising of investments have resulted in different options for the bridge being considered."

Presumably, these "different options" include having no bridge at all, suggesting that the business case for having the scheme at all was somewhat lacking. If so, it's another slap-in-the-face to the dozens of competitors who entered the contest with a good faith assumption that this was a serious project with a genuine likelihood of being built. A comment on a previous post suggested a cheaper bridge is in the works.

Ironically, the winning design has just been included in a RIBA 175th anniversary exhibition at Manchester's CUBE gallery.

Of the seven RIBA competions I discussed in 2008 and again in 2009, none have yet been built, and only two remain under active design development.

10 August 2009

Back in action

The Happy Pontist has returned from holiday, and normal service will resume shortly. Well, actually, it may take a little while, what with the backlog of everyday life and paid work that has built up.

While that happens, a few brief items ...

I'd not previously been aware of the T Evans Wyckoff Memorial Bridge in Seattle, opened late last year, but it has been pointed out to me in view of its resemblance both to Calgary's Peace Bridge, and to the similar Buro Happold bridges in Edinburgh and at Harthill.

The Peace Bridge itself has received a thumbs-up from Calgary's planning commission, notwithstanding concerns over exactly what shade of red it should be.

Elsewhere, a 40-foot bridge has been built in Liverpool from toy Meccano. And the world's longest suspension footbridge is proposed for Barnards Castle.