"Leicht Weit / Light Structures"

Jörg Schlaich & Rudolf Bergermann's "Leicht Weit / Light Structures" (Prestel, ISBN 3-7913-2918-9, 2005, 328pp) [amazon.co.uk] is a mammoth coffee-table slab documenting the ever-fertile genius of one of Germany's best known design firms. It came out a few years ago now, an offshoot of a series of exhibitions of Schlaich Bergermann's work held in 2003 to 2005, but I re-read it recently and it more than deserves a mention here.

Schlaich and Bergermann began working together in 1968 in the office of Leonhardt und Andrä, collaborating on a number of television towers, and lightweight structures such as the Munich Olympic stadium roof. In 1980, they set up their own firm, Schlaich Bergermann und Partner. Schlaich had followed his mentor Fritz Leonhardt in becoming a professor at Stuttgart University, and was as prodigious as Leonhardt in his ability to bridge consultancy and academia, contributing to a staggering range of innovative designs.

Presented throughout in dual German and English, the book marries a series of essays with a lengthy survey of SBP's work written by Annette Bögle. The chapter headings give a good idea of quite why SBP are so important: concrete towers; cable net and steel lattice towers; concrete shells; cable nets; grid shells; textile membranes; air-inflated roofs; cable-suspended roofs; highway bridges; railway bridges; footbridges; solar power plants; and more. If they ever deign to descend into the world of mundane civil engineering, little trace of it is to be found in this book.

The essays are generally illuminating, and include contributions from luminaries such as Marc Mimram and David Billington. An interview with Schlaich offers amusement when he is quoted as describing the "wild ones" who "outdo each other with puffed up and squashed blobs, often just satires and caricatures of misinterpreted 'role models' - with no connection between form, function and flow of forces". This is juxtaposed with a picture of a Frank Gehry building design, surely the antithesis of this statement - although, of course, Gehry has often collaborated with SBP.

Schlaich's own essay on lightweight construction identifies it as important for its combination of social, ecological and economic benefits, while clearly noting that it has limits including the paradox that the lightest weight permanent form often requires the heaviest construction methods to build. However, Schlaich sees this as an advantage, particularly where increased labour costs are recognised as beneficial due to the increased employment generated.

Indeed, the essay exemplifies his engineering ethic quite clearly: socially and environmentally aware, an attitude seen both in their early Hooghly Bridge design, with its multitudes of rivets well-adapted to local working requirements, as well as their recent keen interest in solar power structures, and their potential to alleviate energy-poverty at low cost.

"Light Structures" is copiously illustrated with both photographs and diagrams, and the structures included are generally well explained. Most of their best bridges are included although there are some curious omissions such as the Löwentor cable-net footbridge and the Obere Argen Valley Bridge.

Both those were, however, well-covered in Alan Holgate's "The Art of Structural Engineering: The Work of Jörg Schlaich and his Team" (1997), another bulky coffee-table monograph which could be considered to be either competing or complementary. Hopefully I'll cover that one on another occasion.

"Leicht Weit / Light Structures" is an essential book for anyone interested in innovative structural engineering. It's well written and well illustrated, and an excellent survey of some of the most innovative work of the late twentieth century, including in the bridge engineering field.

Max Eyth: "The Bridge Builder"

Last year I reviewed both Peter Lewis's "Beautiful Railway Bridge of the Silvery Tay", and John Rapley's "Thomas Bouch: The Builder of the Tay Bridge", both about the 1879 Tay Bridge disaster, in which 75 people died. The tragic story of the bridge's collapse is a familiar cautionary tale, although I suspect most bridge engineers know little of the detail other than that the bridge was under-designed for wind load. Construction defects, poor design detailing, and inadequate maintenance all played their part, as did economic pressures.

Max Eyth's "The Bridge Builder" (Sampson Low, 1937, 218pp) is a long out-of-print novelisation of the disaster, originally written in German and published in English translation. I was attracted to it by the back cover blurb, which describes "the deep absorption of the engineer in the wonderful thing that has been conceived in his brain and given material form before his eyes; his artistic delight in the beauty of a perfect mechanical creation; his sense of responsibility for its soundness and durability; all this is set forth with a terse conciseness and a deliberate restraint that are at once emotional and convincing, and give the book undeniable literary value".

Books with a bridge engineer as the central character are few and far between, let alone those claiming to offer special insight, so this seemed like it might be especially interesting to a curious Pontist.

Max Eyth was himself a noted engineer (albeit a designer of agricultural machinery). He appears in the first person in the novel as the narrator of the story of the only barely fictitious "Enno Bridge". However, the main protagonist is one Harold Stoss, a German engineer whose mastery of structural theory is of great service to his employer, William Bruce, civil engineer for the North Flintshire Railway.

Bruce is the stand-in for the bold lead engineer Thomas Bouch, while Stoss's closest real-life counterpart is the Cambridge mathematician Allan Duncan Stewart, who carried out the calculations for the bridge's metalwork and later went on to assist Benjamin Baker in the design of the Forth Bridge.

In the first chapter, Eyth encounters Stoss, and a third German expat engineer, in lodgings in Manchester. As narrator, Eyth reports secondhand on his friend Stoss's experiences, receiving news of developments at the Enno Firth through occasional visits and letters. Only after the bridge is complete does Eyth travel to see it for himself.

All the secondhand reportage gives the book an oddly detached and uninvolving style. Most, if not all, the technical detail is an accurate account of the Tay Bridge story, with a series of bold engineering decisions paving the way for eventual catastrophe. Stoss becomes increasingly anxious about whether he has fulfilled his duties properly, particularly in regard to the treatment of wind load. Speaking of Bruce/Bouch's daughter, he comments that "she kissed me into a lower co-efficient of safety". His mingled joy and fear as he pushes the boundaries of design should be familiar to any engineer who has lain awake late at night pondering the risks associated with innovation.

The engineering is interspersed with plenty of incidental detail, but I still finished The Bridge Builder thinking it was rather unsatisfying. The distancing effect of the uninvolved narrator is the main issue, and the somewhat episodic nature of Eyth's intersections with events leave everything quite disjointed as well.

It would be interesting to see what a more contemporary writer would make of the Tay Bridge story. I can easily imagine it as a courtroom drama, focussing on the real-life debate on where to place the blame. However, although the Tay Bridge Court of Inquiry reached rather firm and unequivocal conclusions, history suggests that the bridge fell for a number of coincident reasons, which may be less suited to the imperatives of drama. A simple re-telling of events might be sufficient, particularly if it got closer to the heart of Bouch himself, who was both the hero and villain of events, with a tragic end.

Jolyon Gill

Sad news to report - Jolyon Gill, an independent UK bridge engineering consultant who I'm sure several of my readers will know, died yesterday, of a stroke.

Gill worked for Freeman Fox and Partners, the renowned long span bridge designers, and was head of their successor Hyder's special structures group until 2001. He then moved to Faber Maunsell (now part of Aecom) to become their UK head of bridges and special structures. In 2003, a "reappraisal of business objectives" led to his departure, to set up his own firm Jolyon Gill Consultancy Ltd. He was always active in the wider bridge engineering community, for example working on the second edition of the IStructE's guidance manual for bridge access gantries, and serving on the Editorial Advisory Panel for the ICE's Bridge Engineering Journal.

I mentioned him briefly here on a previous occasion, for his talk at a symposium on learning from bridge failures. He struck me as someone both with a sound grasp of the way in which the wider world impacts upon the purely technical, as well as a desire to move beyond conventional wisdom.

Bridge of the month

There's already a Bridge of the Month competition which you should take a look at it if you haven't already.

Now there's a new Bridge of the Month newsletter, from Bill Harvey, the masonry arch bridge specialist perhaps best known for his Archie-M arch analysis software. The first issue is available online [PDF] and features Llanelltyd Bridge. It discusses the geometry of the arch, the difference between a three-centred and an elliptical arch, and the difficulty of modelling and hence analysing a bridge with irregular, distorted arch geometry.

You can subscribe to receive future newsletters at http://eepurl.com/ccAyL.

Bridges news roundup

Research seeks design guidelines for composite bridges
Researchers in Bristol carrying out prototype tests on bridges with precast beams and polymer composite "slab".

Iconic new bridge could be built in Rhyl next year
Foryd Harbour Bridge competition winning design now submitted for planning consent.

Derry peace bridge ready for May
£13m suspension bridge held up by bad weather.

Miraculous escape after lorry flips over on bridge and is held upside down over 200ft drop ... by a single punctured tyre
I am not normally a reader of the Daily Mail, but had to share this, the pictures are great!

2011 China Bridge trip

Now, this sounds like just the most fantastic holiday ever, for a pontist so deeply committed as to be practically certifiable.

Eric Sakowski, of the great website highestbridges.com, is organising a three-week trip to China to visit dozens of bridges including the eight highest spans in the world, and many more truly spectacular structures, often in remote parts of the country that Westerners almost never visit.

The tour runs from 5-26 August 2011, and costs less than US$4,000.

Eric's trip preview really has to be read to be believed, and his advice for anyone else looking to make a similar trip is also well worth reading.

Sadly, the Happy Pontist won't be going.

Blogwatch

Time is still keeping me from longer posts, so instead, what are the other bridges blogs up to?

Bridge Photo of the Day has returned after an absence of several months, with a series of wintry Alaskan bridges, although sadly it looks like the archive of photos from before their hiatus has disappeared.

My perennial favourite, Tabikappa, seems to visit an inexhaustible supply of interesting bridges in Japan, particularly pedestrian suspension bridges. There was a series of great postings on particularly ramshackle examples that I've mentioned before, but more recent ones have included several unusual asymmetric spans.

Tallbridgeguy is one of the few blogs to discuss bridge design rather than just depict it, and has recently used various posts to focus on the theme of sustainability in bridge engineering.

Frame and Form is an irregular Spanish blog (with English translation). I particularly enjoyed two recent posts on bridges designed by Anta, which are unusual yet simple and attractive.

Bridgehunter provides a database of historic bridge structures in the United States, campaigns for their preservation and restoration, and always makes for interesting reading. Recent highlights include their Top Twelve threatened but saveable bridges, as well as a roundup of preservation success stories from 2010.

From Korea, Bridgeworld publishes a wide variety of short features on bridges, often unusual ones. I particularly liked the stressed ribbon bridge examples they showed recently, a variation on this design that's not often seen.