29 June 2015

10 essential bridges books: 6. The Work of Jörg Schlaich and his Team

I was keen to include in my list of 10 essential bridges books a monograph on a contemporary designer. You can fill a bookshop with monographs on contemporary architects, but you might struggle to fill a shelf with books on specialist bridge designers.

I had a few excellent candidates to choose from. There are at least three fine books on the work of Wilkinson Eyre (Bridging Art and Science (2002), Exploring Boundaries (2007) and Works (2014)). I have several gorgeous volumes on the amazing Swiss engineer Jürg Conzett, including the beautiful early survey Structure as Space (2006). I felt particularly disappointed to have to leave out Wolfdietrich Ziesel's Dream Bridges / Traumbrücken (2004), which is a gorgeous, generously illustrated book about a singular and imaginative designer, but I decided that perhaps Ziesel just has too many unbuilt bridges in his oeuvre.

In the end, the choice was easy: Alan Holgate's The Art of Structural Engineering: The Work of Jörg Schlaich and his Team (Axel Menges, 294pp, 1997). I've previously reviewed a more recent book on Schlaich Bergermann und Partner, Licht Weit / Light Structures (2005), but Holgate's monograph still has much to recommend it.

Jörg Schlaich is undoubtedly one of Germany's most important 20th century structural engineers, and I think, my favourite. The firm that he helped establish has been responsible for a vast array of hugely innovative and fascinating structural engineering, much of which has its roots in Schlaich's experiences working with Fritz Leonhardt on projects such as the Munich Olympics cable net roof. Schlaich Bergermann's work is generally united by a strong sense of ethics: a constant striving for excellence, a desire to minimise use of materials, and frequently a desire for their work to be socially constructive, exemplified by Schlaich's designs for solar power plants.

At the time of publication, Alan Holgate was a Professor at Monash University in Australia (now retired). He had previously authored Aesthetics of Built Form (1992) and The Art in Structural Design (1986), the latter of which is perhaps the most essential and simultaneously least-read book ever written for structural engineering students. Unusually for an author of a coffee-table book about an engineer, Holgate wrote from a position of deep engagement - he understood the engineering but was also able to position it within a wider context.

Much of The Work of Jörg Schlaich and his Team covers projects of seemingly peripheral interest to committed pontists: towers, shell and cable net structures, glass grid roofs, buildings and textile membranes. However, these projects provide numerous excellent illustrations of Schlaich's attention to detail, as well as explanations of how different designs were developed. Here, Holgate draws on the outcome of his own interviews with Schlaich, and does a splendid job of depicting the realities of the design process: often one of false starts and dead ends.

The chapters on bridges are wide ranging in coverage and scale, commencing with the gargantuan Hooghly Bridge and concluding with the intricate Kiel drawbridge. There are some amazing bridges featured. Personal favourites include the Obere Argen viaduct, with its under-deck cable propping system; elegant concepts for high-speed rail viaducts (later realised on the Erfurt - Leipzig/Halle line); and the delightful cable-net footbridge at Löwentor, Stuttgart.

The book is very well illustrated, both with photographs and technical diagrams. These are particularly helpful in drawing attention to Schlaich Bergermann's excellent facility for structural detail, perhaps the area where the firm most excels. Combined with Holgate's detailed, patient and (where necessary) critical text, I came away from the book both informed and inspired.

That, in essence, is what makes me recommend this book. Here is a firm who most engineers can never hope to emulate, but who offer a constant reminder that hard work and intelligence point the way beyond the mundane.

Update 30 June 2015:
A commenter has drawn my attention to the fact that this book might be a little expensive secondhand to describe as "essential". It's certainly not worth paying hundreds of euros, pounds or dollars for, but it is still worth snapping up if you see it at a reasonable price.

23 June 2015

10 essential bridges books: 5. Bridgescape: The Art of Designing Bridges

It seems that bridge designers have been dissatisfied with the appearance of bridges for as long as bridges have been designed.

Certainly in the twentieth century, as the divide between the disciplines of architecture and engineering became clearer, it has been a persistent preoccupation. In 1912, Henry Grattan Tyrrell published Artistic Bridge Design: A Systematic Treatise on the Design of Modern Bridges According to Aesthetic Principles, opening his preface with the words: "A lack of artistic treatment is the greatest fault of American bridges". Tyrrell cited various reasons for poor visual quality of bridges, including price competition, lack of architects' involvement, legal hindrances, but top of his list was simply that engineers were not taught about aesthetics, and little or no literature was available to assist them. Tyrrell's book therefore extensively presented examples of good design, alongside clear guidance on what did and did not work well.

More recently and most notably, Fritz Leonhardt's Brücken (1982) offered a well illustrated survey of bridge design accompanied by a framework of ten key issues which together form a good basis by which designers can evaluate their own work.

Concern over a lack of attention to the visual aspects of bridge design has surfaced periodically in Britain. In 1964, the Ministry of Transport published The Appearance of Bridges, setting out broad principles such as expression of function, relationship to context, proportion, simplicity etc, and suggesting how they could be applied to common types of highway bridge. In 1994, the MoT's successor, the Highways Agency, made aesthetic considerations mandatory in their standard BA41 (latest version BA41/98) The Design and Appearance of Bridges, supplemented with an excellent companion book The Appearance of Bridges and other Highway Structures (1996).

Interest in bridge aesthetics has increased in the USA in recent years, including the establishment of a sub-committee of the Transportation Research Board. As well as their bridge aesthetics website, the TRB published the wide-ranging survey Bridge Aesthetics Around the World (1991) and a Bridge Aesthetics Sourcebook (2010).

Frederick Gottemoeller has been prominent in these efforts to raise American bridge design standards, and his book Bridgescape (John Wiley and Sons, 276pp, 1998) is an excellent source of good sense. Gottemoeller's view is that bridge aesthetics is to some extent objective, that engineers need to play a key role in improving the appearance of bridges, and that they can do so by learning aesthetic ability. His book is targeted not at "iconic" or "landmark" structures, but at the everyday, and most particularly at American highway bridges.


Gottemoeller's "ten determinants of appearance" seem prosaic: vertical and horizontal geometry; superstructure type; pier placement; abutment placement and height; superstructure shape; pier shape; abutment shape; colours; surface texture and ornamentation; and signing, lighting and landscape. However, this is precisely why I enjoy his book so much - it targets the types of bridge which are most common (and often designed most poorly), and addresses them in a manner which is straightforward to understand. His message is: anyone can do this!

Most of Gottemoeller's key guidance is well illustrated with simple sketches and relevant photographs, and often couched in terms of simple geometric rules, such as relating abutment height to end span length on multi-span viaducts. These are ideal for dunderhead engineers, who love rules and formulae, but behind the numbers there is a drip-drip-drip feed of deeper aesthetic principles - proportion, rhythm, the distribution of material to define the space that surrounds it. Readers who persevere seem likely to imbibe an intuitive visual understanding alongside what seems to be simple and algorithmic.

Bridgescape ranges far beyond being a simple manual for use in better distributing lumps of concrete. It encourages readers to come to terms with their personal aesthetic responsibilities, and gives them a simple design language to make their journey less painful. It offers plenty of real-world examples, both good and bad. It tackles issues of cost, and discusses how design engineers can collaborate with others - especially with the general public, that perennial bugbear of the American design process.

Some of the advice is local or specific to certain types of bridge, but most of it is broadly useful. It's one of the books on bridge aesthetics where I can remember the content most clearly, and that's a testament to the author's patient, straightforward explanation. I think there should be no highway bridge designer without this book on their shelf, and more widely it should be of interest to anyone concerned with creating simple, effective, visually appropriate bridge designs.

(Footnote: I've reviewed the 1st edition of this book. However, the 2nd edition from 2004 is the one to get, with updated material and far more photographs in colour).

19 June 2015

Totally awesome bridge design competition


I imagine that shortly after the Tintagel Castle Bridge Design Competition was announced yesterday it was possible to hear the sound of an enormous chorused "slurp", as bridge designers everywhere (and I do mean everywhere) licked their lips at the prospect unveiled before them.

Tintagel Castle is one of the historic treasures of Cornwall, a spectacularly situated 13th century ruin, perched upon a rocky headland, and reachable only via lengthy steps and a short bridge. It is protected within the custody of English Heritage, who have decided that it is time for a new bridge, to be situated some 28m above the existing span. This will provide greatly improved access to the site, as well as opening up impressive new views. EH are running a design competition to find a £4m bridge which they hope will be both "elegant" and "structurally daring" (mercifully, the word "iconic" is absent).

It's difficult to think of a more challenging site. It is of huge visual and historic sensitivity, with the Castle and surrounding landscape garnished with a substantial number of official protective designations. In addition, access for construction will be extremely difficult - it is far from straightforward even to bring in plant for site investigations, let along for building works.

The bridge design competition will have two stages: an open prequalification stage, followed by a concept design stage for up to six shortlisted teams, each of whom will receive a £5,000 honorarium. Expressions of interest must be submitted by Tuesday 21st July, and the shortlist is expected to be announced in late August. A competition winner should be declared in January 2016, and English Heritage expect to open the new bridge in 2019.

It's a marvellous opportunity for talented designers to show what they can do, and I hope the selection process and competition judging will allow some truly exceptional teams and concepts to emerge.

Photo courtesy of Matthew Kirkland (Creative Commons license).

17 June 2015

10 essential bridges books: 4. Highland Bridges

Out of many bridge guidebooks in my collection, Gillian Nelson's Highland Bridges (Aberdeen University Press, 224pp, 1990) [amazon.co.uk] is my favourite.

In her introductory essay, Nelson discusses the three basic types of bridge: beam bridge, arch bridge, and suspension bridge. It seems to me that the remainder of the book then goes on to comprehensively demonstrate how futile such simple categorisations can be.

The book is a product of the author's own extensive explorations of the Scottish Highlands, and documents a truly fabulous variety of bridges both historic and modern. It is arranged geographically, so that, for example, all the bridges of Lower Speyside form a chapter. Each bridge is given a map reference, and, where necessary, directions by which to find it. The text combines factual details on the nature and history of the bridges with the author's own opinions, and there are a good number of photographs.

These may seem like the basic essentials for any guidebook, but it is amazing how few books in this field manage to do such a good job. Highland Bridges is both reasonably comprehensive, detailed and yet highly readable. It is a friendly book, suitable for readers both lay and expert, and of the type that makes you immediately wish to plan a bridge-viewing journey.

This book introduced me to a number of bridges which I would not otherwise have encountered, mostly notably the astonishing Craigmin Bridge, but also the beautiful Maryhill House footbridge. Its coverage is generally excellent, with both the famous and the unknown given equal space.

What jumps out at me the most is the sheer variety of types of bridges to be found in the Scottish Highlands. There are many beautiful stone arches and quite a few charming suspension bridges, but also a staggering range of oddities, such as the fortress-like concrete Findhorn Bridge; the intricate Dredge designs at Whin Park and Bridge of Oich; rare timber trestles at Broomhill and Aultnaslanach; and much, much more. I think there are few areas of the United Kingdom so well equipped with such fascinating, intriguing and bizarre bridges.

16 June 2015

Bridges news roundup

I've not rounded up any bridges news for a while, so here are a handful of things that caught my eye recently ...

Expert slams Garden Bridge business case
Apparently, the Garden Bridge project is a fiasco dressed up in a farrago, disguised as a farce.

The case for exempting projects from open procurement
Should pet projects like the Garden Bridge be permitted an exemption to normal competitive procurement, especially when it leads to things like the absurd procurement process by which Heatherwick Studio beat off two other designers to proceed with what had always been their own design proposal?

A Folly for London
Here's a lovely idea, a free, open, presumably not-pre-decided-at-all competition to come up with an idiotic idea whereby central London can be permanently ruined. Satirical, of course.

Boris agrees to underwrite Garden Bridge’s maintenance costs
Having previously promised that taxpayers will never have to cover the running costs of the Garden Bridge, London's mayor has had a change of heart. It's hard to see now why anyone else would cover those costs, when they know the London taxpayer is underwriting it all.

Design of new pedestrian bridge linking East Perth to Burswood revealed
Interesting new design in Perth, Australia. And look, it's got trees on it!

This Robot Can 3-D Print A Steel Bridge In Mid-Air
I expect that 3d printing of steel will never be an economic alternative to more conventional construction, but this is a genuinely exciting project, and I'd love to see more being made of robotics to help build complex structures.

14 June 2015

10 essential bridges books: 3. The Architecture of Bridges

Back in 1949, the Museum of Modern Art was taking bridges seriously as a subject for their attention. Elizabeth Mock was MoMA's director for architecture and industrial design, and a committed advocate for modernism. The Architecture of Bridges (MoMA, 1949, 128pp) [amazon.co.uk] has been described by the Encyclopaedia Britannica as "the first major book on bridges to give a modern viewpoint".

It was a significant occasion. Most books on bridges prior to this point were historical in their intent, such as Henry Grattan Tyrrell's History of Bridge Engineering (1911) or Charles Whitney's Bridges: A Study in Their Art, Science and Evolution (1929). Where those authors did provide information on what was happening in the present day, it was largely focussed upon the large and most heroic spans that provided the key milestones in early 20th-century bridge engineering.

Mock's book was probably the first authored from an entirely different perspective, recognising that as large-scale industrial structures, bridges could embody key tenets of modernism, such as form following function, exposure of structure, and elimination of detail.

Mock wrote:
"Beauty is not automatic; technical perfection alone is not enough. A great engineer is not a slave to his formulas. He is an artists who uses his calculations as tools to create working shapes as inevitable and harmonious as the natural laws behind them. He handles his material with poetic insight, revealing its inmost nature while extracting its ultimate strength through structure appropriate to its unique powers".
She was not alone in her mid-century recognition that engineers could be more than calculators. Architecture critic Sigfried Giedion had championed the Swiss bridge designer Robert Maillart, including him in his seminal book Space, Time and Architecture and exhibiting photographs of his bridges at MoMA in 1946. Artist and designer Max Bill also published a comprehensive overview of Maillart's work, Robert Maillart: Bridges and Constructions, in 1949.

The Architecture of Bridges also heavily features the bridges of Maillart, but is wide-ranging in overall scope, and critically acute. It features a who's who of (mostly) 19th and early 20th-century bridge engineers, and cheerfully mixes the well known (Stephenson, Brunel, Leonhardt) with the obscure, wherever it can find aesthetic merit. It features a number of essentially generic bridges alongside the more famous examples, for example, typical highway overbridges from the USA and Germany, offering a keen appreciation of their aesthetic successes and failures.

The book establishes a coherent critical vocabulary which remains relevant today, being bold and perceptive in its judgements. Many others have followed after, although primarily from a position as engineers themselves (Mock paved the way for the writing of Fritz Leonhardt, Frederick Gottemoeller and David Billington, amongst others).

I think The Architecture of Bridges remains significant today precisely because it is a fine example of a viewpoint from outside the engineering field which nonetheless shows a good understanding of engineering issues and uses these to address a broader audience. If it seems at first glance to be essentially a picture-book, it hides within its many picture captions a well thought-out and provocative aesthetic philosophy.

I admire it as much for this as just for the way it documents so many interesting and exciting bridges.

MoMA's entanglement with modern engineering did not end here, either. In 1964, the Museum published Twentieth Century Engineering, which entirely omits the architectural criticism but includes many exceptional photographs of industrial and civil engineering work, bridges and buildings but also dams, radio telescopes, tunnels, masts, water towers and much more.

07 June 2015

10 essential bridges books: 2. Living Bridges

In 1996, London's Royal Academy of Arts hosted an exhibition titled "Living Bridges: The inhabited bridge, past, present and future". The exhibition presented a host of real and never-realised inhabited bridges both from history and more modern times, and also played host to a speculative bridge design contest, the Thames Water Habitable Bridge Competition.

It was an eye-opening exhibition, and the accompanying book (Prestel, 1996, 158pp) [amazon.co.uk] was (and is) a splendid companion. It's a thoroughly well-researched account of the inhabited bridge from mediaeval to modern times, and extremely well-illustrated.

Early inhabited bridges included fortified bridges, and also chapel bridges. The fortifications were essential to ensure that a bridge's primary purpose in enabling trade could not lead to the spans providing a too-convenient route through a city's defensive walls. The chapel often recognised that bridges were built to combine religious favour with a practical purpose. Several early inhabited bridges incorporated both features, as at London Bridge and the Pont d'Avignon.

Another common feature of early inhabited bridges was an association with businesses requiring proximity to the river, such as watermills. The Pont de Blois incorporated no less than five watermills at one time. Other businesses took advantage of the opportunity to front onto one of a city's most used thoroughfares, while residences took advantage of the direct route to the river for sewage. Including buildings on a bridge was attractive to those who built and owned the structures, as income from rent could help towards the costs of maintaining the bridge.

Living Bridges features extensive accounts of these early bridges, accompanied by period illustrations and numerous reproductions of paintings, lithographs etc. Bridges which have survived to the present day are represented with photographs. It's a goldmine of interesting information which I don't believe is covered in such depth anywhere else.

In addition to well known bridges such as the Ponte Vecchio, Ponte de Rialto and Pulteney Bridge, the book features a number of speculative proposals including John Soane's 1776 Triumphal Bridge or Gustave Eiffel's 1878 scheme for the Pont d'Iena in Paris.

These ideas often seem megalomanical by today's standards, with examples of a tendency towards the gargantuan including Raymond Hood's "skyscraper" bridge in New York, and Cedric Price's proposal to bury much of the River Thames in a lengthy culvert. Although such ideas were more than a little crazy, they reflect a wider sense of the inhabited bridge as a utopian vision insensitive to any reasonable context. Many inhabited bridges seem visually attractive in their own right, but have the effect of blocking views both of riverbanks and along a river.

City rivers are now valued primarily as open space within a crowded urban context, and the idea of depositing a new building into such a context seems more than a little foolish. Nonetheless, Living Bridges offers numerous examples of modern proposals to do precisely this, with some kind of romantic attraction to visions of Old London Bridge trumping common sense again and again.

For such a niche subject, this is an ambitious and thought-provoking book, which ably explains the attractions of the habitable bridge while exposing its many flaws. Long since the Royal Academy exhibition, proposals for inhabited bridges continue to emerge, most of them absurd, but this excellent survey of the subject remains the definite resource for understanding what such bridges have been in the past, and might still be one day in the future.