Bridge criticism 2: No disparaging please, we're engineers

In a previous post, I noted that bridge design competitions often throw up designs that are uneconomic, unmaintainable and in some cases even structurally unfeasible. Yet there is a surprising lack of visible criticism of such designs: engineers generally like to keep their heads below the parapet.

One reason for this might be that engineers are ethically constrained, separate from their nervousness of the legal and commercial consequences. Do the professional bodies encourage or discourage open criticism of our peers?

In the UK, the Institution of Civil Engineers’ code of professional conduct [DOC] asks that:

“When commenting on another person’s work, members must advise that person of their involvement … members must not act maliciously or recklessly … members should take account of the broader public interest”

The ICE don't appear to contemplate the possibility of comment in journalism (let alone a blog!), where to contact everyone before commenting on their work would be a little over-the-top. But it's clearly only fair that those criticised should have a right of reply.

The ICE code draws upon the Royal Academy of Engineering’s Statement of Ethical Principles [PDF], which says that:

“Professional engineers … should be alert to the ways in which their work might affect others and duly respect the rights and reputations of other parties … Professional engineers … should uphold the reputation, standing and dignity of the profession”

That seems to put a somewhat old-fashioned notion of professional dignity above the rights of the public or wider community. Surely there are public interest issues which outweigh the rights of engineers to stand aloft from the fray?

IABSE’s Ethical Principles are considerably more specific:

“Members shall not disparage other engineers or scientists … Constructive criticism should be regarded as contributing to integrity and truthfulness”

Although the IABSE is against disparagement, it makes clear that constructive criticism is acceptable and may contribute both to the public interest and to the profession’s integrity. Indeed, it could be argued that criticism of a particularly poor design has the effect desired by the Royal Academy of upholding the profession’s reputation, by discouraging unworkable and absurd designs.

Personally, I think the public interest has to come first. If a design deserves criticism, it should receive it. The public (and, it seems, many clients) have no way to judge the engineering merits of structural engineering proposals, and it must be the case that better, more open public debate on these matters will ultimately lead to procurement of higher quality designs, and fewer cases of project failure.

Bridge competition debris part 5: Stratford-upon-Avon

Late last year I briefly discussed with a fellow bridge designer how difficult it can be to trace the history of design competitions. The advent of Google makes it tempting to think that all knowledge is at your fingertips, but of course this isn't the case at all. Websites disappear (competition websites are often taken down after the project fails and the promoter loses interest), and much of the rich history of the bridge design competition predates widespread use of the internet anyway.

Some help is at hand: sites like europaconcorsi and e-architect take an interest in archiving designs that were never built, and can be a useful if incomplete resource.

In 2008, I offered a set of four posts of "bridge competition debris": the winners and losers from New Islington, Bootle, Sheffield Parkway and River Douglas, with the aim of bringing together images that otherwise are hard to find and may eventually be inaccessible. I thought that would be that, but now think there is scope to continue further.

So the next in this continuing series is the 2006 Stratford-upon-Avon footbridge competition, run (like all those above) by RIBA. There were over 60 expressions of interest, with 5 competitors shortlisted. After the winner had spent some time developing their design (and the client had spent over £300k), the project was cancelled in July 2008 as costs had risen more than 50% above the promoter's original £2m budget.

The Warwickshire County Council website currently features plenty of detail on the competition, including consultation documents, reports, and a copy of the winning design's presentation board.

So what about the designs themselves? The client shortlisted a good set of teams, although it's very unfortunate that they missed the opportunity to let new talent have a go.

The winner was a good choice - minimal, unintrusive in the setting, and a good opportunity on a small-span footbridge to push the limits of design somewhat. It's a shame that costs derailed it. The Wilkinson Eyre design has very obvious similarities to their Floral Street bridge [PDF]. I think at this scale it looks over-fussy and over-deep. In a similar manner, the Flint and Neill design has echoes of their cranked stress-ribbon Kent Messenger bridge. Whitbybird's scheme seems very much out of scale with the site to my eyes.

As always, click on any image for a full-size version. Please note that while there are definite references on the web linking two of the designers to their images, I can't find definitive links for the other three, and have guessed the designers' identities based on what I know of them.

Winner

Schlaich Bergermann & Partners / Ian Ritchie Architects


Shortlisted

Arup / Wilkinson Eyre


Buro Happold / Spence Associates


Flint & Neill / Dissing + Weitling


Whitbybird


Others

In asking for expressions of interest, RIBA were looking for details of potential competitors' past experience, not actual bridge designs. But judging from the example below, they must have received at least one ...

Public House / Webb Yates [PDF]

Bridge criticism 1: Of heads, and parapets

Late last year, I attended a talk by architect Cezary Bednarski, which ran through his experiences in the bridge design competition arena. I've covered some of the issues raised previously, but there's one that I wanted to return to.

A topic that arose repeatedly related to the various occasions when Bednarski had lost a competition and lost it to a design which in his view was a very poor choice. He offered as examples the notorious Krakow footbridge (pictured left, click any image for a larger version), Glasgow, and a competition for temporary bridges in Rome. Other examples of bizarre competition winners include Cambridgeshire Landmark East and River Wear. These mostly offer examples of exotic, ambitious designs where their very structural feasibility should have been in doubt from the start.

There has been ample criticism both of a competition process which frequently delivers designs beyond the budgetary constraints of a project's promoter (e.g. Stratford-upon-Avon, pictured right), or which will saddle them with expensive maintenance costs for years to come (e.g. Trinity Footbridge). But where precisely does the fault lie? With the competition clients, organisers, jurors or the entrants? I actually think at least some of the fault lies elsewhere.

Several of these competition designs were criticised in the press after the winner was announced. However, in most cases serious criticism only appeared after the project had failed (e.g. when the Glasgow bridge scheme, pictured left, went massively over budget). Is there perhaps a failure of the bridge design community as a whole to speak up about designs which are likely to be unusually challenging or high risk?

For several of the competitions mentioned above, there was no specialist landmark bridge engineer involved on the jury, and it is possible that whoever did judge them had no realistic way of benchmarking the likely costs and risks of the designs put in front of them. In many cases, the shortlisted entries are not made public, so there is no possibility for anyone else to assist by making informed comment.

If there's an appropriately knowledgeable and empowered bridge specialist involved in the judging, then in theory the absence of wider input should not matter. But I still wonder whether competitions would benefit generally from greater transparency, and the opportunity for a promoter to receive wider comment on the merits of the entries. One of the aims of this blog is to see whether a space exists for constructive public criticism of the merits of bridge designs.

Of course, that's where the problems begin. The heads, and parapets, of this post's title, and the unwillingness of bridge designers to stick the former above the latter.

Criticism of others' designs is far more common in the architectural field, indeed it's something that's positively encouraged from an early stage through the use of the architectural crit as part of an architect's education. There are very few analogues in structural engineering, although I'll address some that do exist in a future post.

Engineers are traditionally reluctant to publicly criticise the work of their peers. There are several reasons: simple politeness, commercial pressures, legal constraints, etc. All three of these can be found at work here on the Happy Pontist whenever comment is made on the merits of a particular bridge design. Legally, there is the risk of committing libel if criticism goes too far. Commercially, the critic can upset someone who may otherwise be a future client or commercial partner.

In a follow-up post, I'll look in more detail at one: ethics. Could it actually be unethical to criticise designs? That might seem ridiculous, but the engineering institutions promote precisely that view.

Bridges news roundup

Iron Bridge set for revamp
Removal of utilities to return bridge to 18th century condition

Forth Bridge on track to join pyramids and Taj Mahal
Old rail bridge may become World Heritage Site

Forth Bridge payment plan blocked
New road bridge struggles to agree funding

Rebels too late - Calgary bridge contract already signed
Councillors fail in attempt to open Calatrava bridge to competition (see previous posting for more)

Newport Transporter Bridge can't find enough cash
4% of needed funds granted - 96% still awaited (again see previous posting)

Jan Kaplicky dies aged 71
Kaplicky was known more for his buildings and general design work than his bridges, but his firm Future Systems' design for the floating bridge at West India Dock in London is undoubtedly one of the most noteable footbridge designs of recent decades, while other designs such as at Spencer Dock (pictured), Olympic Park and in Glasgow offered a very unconventional view of the possibilities for bridge design.

Williamette River Wave Bridge seeks support

Design options for a new light rail bridge over the Williamette River in Portland, Oregon, have been presented to the local design community by architect Miguel Rosales (see previous post for further details).



Only two options are currently being offered, a choice between a cable-stayed bridge or a "wave frame" span (arch, box girder, extradosed and truss options being previously rejected in a lengthy exercise). The latter, pictured above, is Rosales' pet scheme, an exotic curved Vierendeel truss bridge, which draws its inspiration from Schlaich Bergermann und Partner's Havel Railway Bridge.

The main difference is that the SBP bridge has a traditional stiffened girder web, while Rosales' variant omits the web to achieve transparency. Structurally, the resulting design is considerably less efficient, and I'd personally doubt the ultra-slender members shown on the visualisations are quite was is achievable.

The article at OregonLive.com suggests that Rosales impressed his audience with his even-handed approach to both options and his "precise, minute understanding of bridges, not just their design but also their engineering". Set aside for a second the semantic divorce between the "design" and the "engineering". It's always good to find an architect who really understands bridges, as there are plenty who have little sympathy for the structural and construction issues that are at the heart of all the great bridge design masterpieces. Having said that, the cable-stay is undoubtedly the more economic design for a light rail bridge of this span, and it's a shame more effort hasn't gone into making it more visually attractive.

I don't really think that these design options are being presented in an even-handed way. The images of the two options made public (and provided below) show that more care has been given to the detailing of the "wave" design. It's support piers have been shaped and fluted to make them look nicer than the more plain pylon columns shown for the cable-stay bridge, and the superstructure has been given a paler colour to make it look more slender. In a similar manner, an attractive post-and-wire parapet is shown for the wave bridge, but a solid opaque parapet for the cable-stay. And there is substantial scope to choose an alternative cable-stay pylon which would be much more attractive than that depicted.

If Portland does eventually get the "wave" bridge option, it will be an ambitious venture, and one to follow with interest.

Calgary Calatrava controversy caput

It seems the fight against two footbridges in Calgary to be designed by Santiago Calatrava has drawn to a close, with the news that Calgary city council have signed a $3.3m contract for the design despite ongoing opposition. The contract was placed without any competition from other designers, and represents about 7% of the estimated $50m capital cost for the two structures. See previous posts for more detail.

The Calgary Sun notes that opponents sought the money to be spent instead on more pressing projects in a time of recession. At least one local architect is reported (quite reasonably) as being unhappy about not having the opportunity to bid for the work.

A local columnist suggests writing to Calatrava asking him to turn down the project. A local councillor has apparently tried precisely that, saying: "Since this city council can't read the current state of affairs in Alberta I hope he can do us a favour and kindly say thanks but no thanks to this stupid offer".

Bridges news roundup

First footbridge to be built by 90-year old

I don't mean the first by any nonagenarian, just one in particular, architect Paolo Soleri, who is perhaps best known for his utopian eco-village Arcosanti. Hopefully the finished bridge will look better than in the only visualisation I could find (click for full-size version).

Bridge design fees hit new record

If only. But a fee of US$3.3m to design a footbridge (or possibly two - the story isn't clear) seems somewhat on the generous side. This is the latest story in the always entertaining Calgary & Calatrava saga, which also features this amusing quote from the city's transport team, attempting to justify their recommendation not to put the design contract out to normal competition:

"Over the past two decades Calatrava's designs have revolutionized bridge construction from dull, mechanical instruments into elegant objects"

I'll bet all the many other talented designers around the world who've been active over the same period love being treated as mere footnotes in bridge design history.

Wobbles in Wrexham

The image (click for full version) shows the bridge in question (taken from Tekla website). Council spokeswoman: "The bridge is, by design, a suspension bridge and will therefore inevitably be subject to a certain degree of movement." Well, it's technically cable-stayed rather than suspension, but never mind.

What seems odd about it on first viewing is that the mast, which is hinged at its base, is inclined towards the deck, where on many similar curved footbridges it inclines away (e.g. South Quay). The mast is shown as tied down towards the deck, when you'd expect a stay cable in the exact opposite direction. The local news story also makes what seems an entirely spurious connection to the notorious Millennium Bridge.

It's not entirely clear why this is news now, as the bridge would seem to have been wobbling ever since it opened two months ago.

Transporter bridge to reopen

Newport Transporter Bridge is one of only three surviving transporter bridges in the UK and one of only eight worldwide. It has been closed since August 2008 but the local council has agreed to find the money to repair and reopen it.

It's quite criminal that these irreplaceable historic structures are allowed to fall out of use (and beyond that into ruin), with at present the Middlesborough bridge being the only one working in the UK (Warrington's bridge has been disused for nearly 50 years and is likely to be lost as it serves no useful purpose at its original site). (Image courtesy of James Stringer).