27 July 2021

Email subscriptions update

Hello!

Yes, it's me.

This is a quick note aimed at the 314 readers who subscribe to get updates from the Happy Pontist via feedburner. That email subscription service is going to be switched off in August.

I am looking to transfer all email subscribers to the alternative platform follow.it instead. If you think you'd rather no longer receive emails from the Happy Pontist, that's fine, just click on any emails you get from follow.it to unsubscribe.

Obviously, blog posts are few and far between right now, but I'm not shutting the blog, so hopefully there will be more to come!

13 May 2021

Yorkshire Bridges: 33. Western Bank Bridge, Sheffield


Ah, it was good to get out and see an actual bridge again.

I'm not quite sure how I missed this beauty on my previous visits to Sheffield, but never mind.

It was built in 1969 to a design by Ove Arup and Partners and architect Yuzo Mikami. I say "it", but actually there are two bridges here, as shown in the cross-section below.


The bridges carry the steeply sloping A57 Western Bank highway above a pedestrian concourse area in the University of Sheffield campus. They are two-span structures, supported on single bearings below their tetrapodal centre pier, and a pair of bearings at each end.

The bridges were built in a period when the University campus was expanding, and the growth in road traffic had led to the highway being upgraded to a dual carriageway. Up to 10,000 pedestrians were reported to be crossing the road every day before the bridges were introduced.

The reinforced concrete slab decks vary in depth, being 1.2m deep over the central support and 0.84m at the abutments. It's a subtle feature that is not immediately obvious visually due to the large footway cantilevers on the edges of the deck.

Both decks are slightly curved in plan, but as can be seen in the photos, the main bridge deck slabs are straight, with the edge cantilevers varying in width to provide the curve.


From above, there is very little of interest to see. The interest is in the space created underneath the bridge. From below, this is a concrete roof held up on finger supports and providing some shelter from the weather. Glass blocks allow light through the central strip, and recently new lighting has been installed to make this a more attractive space at night.

It's a classic of modernist design, with some similarities to both Kingsgate Footbridge (1963) and Drochaid a' Chaolais Chumhaing (1984). The attraction is in its balance between the monolithic and the skeletal; it's clearly one "thing", like a sculpture, rather than one thing sitting upon another thing, like a conventional two-span road bridge.

The tetrapod supports have an interesting blend of straight and curved geometry: the outer edges form an inverted pyramid, while the inner surfaces of each arm are profiled with the curves of two intersecting hyperbolas. I'm not 100% convinced about the way the arms meet the deck slab and wonder whether a different detail would have been preferable e.g. having the arms project slightly from the side faces of the slab to give more of a "cradling" effect.

The sloping faces in front of the abutments were a conscious design choice, not so much to provide seating as to avoid the "tunnel" effect common to subways with vertical walls. The aim is to integrate the bridge with the adjacent landscaping. I guess the central tetrapods represent a similar visual impulse.

The block seating around the supports is not original. I wonder to what extent it was added to stop drunken students from bashing their heads into the angled support struts?

The concrete appears to have weathered well, and I'm left wondering why such a well-designed bridge isn't a little better known.


The article about the bridge in Arup Journal is well worth reading, including some excellent photographs, design drawings, explanations of the structural analysis, and an unexpected anecdote about students in mini-skirts.

The bridge was rewaterproofed, repaired and had new bearings installed in 2016.

Further information:

08 May 2021

"Link it! Masterpieces of Bridge Design" by Chris van Uffelen

There ought to be a name for this sort of coffee-table architecture book, churned out seemingly by the dozen every month, heavy on the photos, light on text, and filled with an uncritical gosh-gee-whizz approach to its subject. Publishers like Braun have a formula that works, whether the book is about bungalows, home conversions, factory design, corporate gardens, cinema architecture, bamboo architecture, apartment buildings, or, eventually bridges. And all those examples are just a small part of the output from one author, Chris van Uffelen.

Something similar can be found on architectural websites like Dezeen, Archboom, Architizer and Designboom: an ever-growing torrent of archi-gloss, much of it unedited from designer's self-promotional submissions. And make no mistake: it is responsible for a genuine and substantial dumbing down of how "design fans" perceive the built environment, such that even the worst examples of toxic architectural bloat are slurped down like nectar by an audience increasingly addicted to the hyperreal and incapable of rational analysis.

None of which is to say that I find nothing of value in "Link it! Masterpieces of Bridge Design" (Braun Publishing, 2014, 208pp).

This is essentially a sequel to van Uffelen's "Masterpieces: Bridge Architecture + Design" (2009), which I reviewed when it came out. I say "van Uffelen" as if he wrote these books, but they are actually put together by "Editorial Office van Uffelen", who provide publishers with the complete ready-made coffee-table service, even if much of that is simply emailing suitable architects and asking them to submit their marketing material. A disclaimer at the end of the book makes clear that if anything is incorrect, it's the fault of the design firms, not editors or publisher.

So: there's almost nothing in the book that you can't find freely on the internet, and essentially you're paying to fund the marketing efforts of the designers who participate in the publication. And yet ... there are plenty of structures and projects in this book that I was unaware of and intrigued to discover.

"Link It!" includes a smattering of generally remarkable bridges that should be well-known to dedicated pontists: Dublin's Samuel Beckett Bridge; the Millau Viaduct; the Hovenring; the Passerelle Simone-de-Beauvoir; Calgary's Peace Bridge; Jerusalem's Bridge of Strings; etc. I am sure these will be interesting and attractive examples of bridge design for the non-specialist (who are obviously the book's core audience).

Beyond that, there are bridges in China, Austria, Germany, Canada, the Netherlands, Belgium, Denmark, Indonesia which are interesting, in some cases attractive, and often have features that a designer could take inspiration from, or in others spot details to avoid. The quality of the designs is, inevitably, uneven, and each bridge has minimal explanation and certainly nothing in the way of criticism. There are, thankfully, only a handful of complete stinkers amongst those that have actually been built.

I mention that because the book also features a number of unbuilt bridges, generally with little or no detail on when they may be built, or whether they will happen at all. Some clearly won't, like the daft "Bouncing Bridge" proposed in Paris, the deliberately conceptual "Hydraspan" proposed for San Francisco, or the notorious Kazimierz Ludwinow Pedestrian Bridge, in Krakow, Poland.

There are a few designs which I would hope even the more cynical pontist would find appealing. Examples include the Wupperbrucke in Leverkusen, Germany; the timber truss Enniger Bridge in Switzerland; the Phyllis J. Tilley Memorial Footbridge in Texas; and the Green School Millennium Bridge, in Bali. Sadly, it's not hard to think of plenty of other fine bridges that didn't make the cut.

The photographs throughout the book are generally of an excellent quality that show off the subject matter to its best, although they are often the "day-before-opening" images beloved of the architectural press, showing the bridges pristine and generally unsullied even by people or traffic.

In summary, it's best to see this sort of book as a glossy brochure, assembled without any expert curation; but which can still provide some pleasant browsing if not taken too seriously.

02 May 2021

"The Architecture of British Bridges" by Ronald Yee

Where does engineering end and architecture begin? That's the question I was left with after reading Ronald Yee's wide-ranging and informative "The Architecture of British Bridges" (Crowood Press, 2021, 224 pages).

Books on the bridges of Britain tend to fall into three camps: big national surveys; more selective surveys following the author's specific tastes; and studies of niche topics like railway bridges. The new book by specialist bridge architect Ronald Yee surprised me by coming closest to the first camp.

The core of the book is a survey of bridges from around the UK, not comprehensive but very well-chosen. This is bookended by an introductory chapter on the architecture of bridges, and two final chapters on bridge parapets and lighting. There is a useful index but nothing in the way of references or bibliography.

Since much of the first chapter is given over to a layperson's guide to different structural forms, there are actually only three or four pages which specifically tackle the architecture of bridges. I had definitely hoped to read more about this, given the author's own area of expertise. There is a bit of a gap in the market here, as most books and articles about bridge aesthetics are written by engineers, not the architects who now play such a key role in bridge design.

Yee's own architectural approach is one that is very closely aligned to the engineering: he is not one for the outlandish or decorative. His approach to the book's topic is to "show, not tell", allowing the idea of good bridge architecture to emerge through example rather than through a didactic approach.

The message I got from the main part of the book is that Yee sees architecture and engineering as being to some extent complementary and to some extent inseparable. Bridges from all periods are described straightforwardly, with the same attention given to how they work (structurally), as to their place in history, their visual appearance, or their local context. Yes, they may have specific architectural attributes (the description of Chester's Grosvenor Bridge includes its "archivolts of red Peckforton sandston ashlar" and "a frieze and cornice with rectangular modillions", amongst other features; Stirling's Forthside Footbridge's "visual effect is gymnastic and an undeniably spectacular sight"), but these are never anything other than part of the wider story.

This leaves many of the individual bridge entries a little dry, even where the bridges themselves can be seen to have some degree of special interest. In other cases, Yee ventures more of an opinion and I'd certainly like to have seen more of this.

The key strength of the book lies in how well the entries have been curated, and illustrated with generally excellent photographs. Given that Yee is well known for his sketches and drawings, I'd love to have seen more of those - they are few and far between.

I have read many books about bridges in Britain, but I still found plenty here that I was unaware of or which has not been celebrated previously in print. It surveys an excellent range of often exemplary bridges, at all scales great and small.

Presenting the bridges in a gazetteer format, structured by materials and bridge typology, does mean that much is left unsaid about architecture: the way in which bridge design in Britain moved through phases of craft construction, master builders, the era of "scientific" engineering, and the slow and then more rapid rise of architects as the leaders of the design narrative. Yee's book therefore leaves room for some very different treatments of the subject, and hopefully others will step into the breach.

22 April 2021

"Transporter Bridges: an Illustrated History" by John Hannavy

Transporter Bridges by John Hannavy (Pen and Sword, 268pp, 2020) is, I think, the first book to bring these unusual structures together in a comprehensive record. Subtitled "An Illustrated History", this is indeed a highly pictorial and well-detailed account of what was a very short-lived type of structure. Nineteen were built between 1893 and 1916, before the growth in motor traffic made them a less attractive form of river crossing.

The concept of a transporter bridge dated back to the mid-19th century. At a time when tall boats still used major rivers, there were essentially four ways to transport vehicles across such an obstacle. Ferry boats were common, but could only carry a few vehicles at a time, and could be unreliable. Fixed bridges were the highest-capacity, most reliable solution, but expensive both in construction and land-take. Moveable bridges were, in their earlier years, complex and expensive, and suitable only for moderate spans. The transporter bridge could cover longer spans, but carrying loads more in line with those on a ferry.

Hannavy documents early proposals for transporter bridges in detail: H.N. Houghton's idea for a railway crossing in New York (1852); J.W. Morse's plan for a similar crossing (1869); Charles Smith's proposal in Middlesbrough (1873); and others.

However, the first proposal to be built was the Viscaya bridge at Portugalete near Bilbao, completed in 1893. The designers Alberto Palacio and Ferdinand Arnodin took out patents for the transporter concept, and Arnodin went on to complete eight more such bridges.

Hannavy's history covers most of the transporter bridges with relative brevity - I say relative as they all get plenty of detail. He takes the story right up to recent decades where new transporter bridges have been proposed (e.g. at Royal Victoria Dock, Nantes, Marseilles and Brest). Of these, the Royal Victoria Dock Bridge is the only that was built, but its transporter gondola was never installed.

Beyond the basic history, the book discusses the "Systeme Arnodin" in detail, and there are chapters covering five of the few surviving transporter spans at length as fine examples of the type: the Viscaya bridge, Newport Transporter Bridge, the Tees Transporter Bridge, Crosfield's Warrington Transporter Bridge (and its now-demolished sibling), and the Rochefort Bridge. A further chapter considers the Widnes-Runcorn Bridge, which was closed in 1961. All five of the transporter bridges ever built in the UK are therefore given close attention.

Each of these is covered thoroughly, with quotes from contemporary journals and an excellent variety of historic and recent photographs. Hannavy's research has clearly been in-depth. The chapter on the Rochefort bridge is particularly interesting, as it mainly documents the massive refurbishment project undertaken to prolong the life of the bridge and to restore it closer to the original Arnodin design.

In addition to the main chapters, the book concludes with a series of one-page summaries of all the known transporter bridges both built and unbuilt.

This is, without any doubt, the definitive book on transporter bridges, and essential for anyone with an interest in them. More generally, it should appeal to those with a broader interest in historic bridges. It is not entirely faultless, unfortunately, as there is no bibliography and no referencing of any sort. This is a shame for any serious researchers, but probably not a big issue for the more general reader.

18 April 2021

"Bill Brown's Bridges" by David Boxall

I've remarked in the past how few books there are on the great bridge designers of the 20th century, other than one or two of the earliest decades such as Robert Maillart and Othmar Ammann. Even many bridge design professionals will struggle to name designers comparable with the likes of the nineteenth century's Telford, Stephenson and Brunel.

In the 20th century, the increase in scientific understanding of structural design and consequent specialisation made large projects more and more the province of a broad team rather than a singular man and his support office. This was especially the case where the scale or sensitivity of projects required decision-making to be collective rather than dictatorial.

Of course, it was always the case that the big names were often just those who fronted up the work of a broader team. That's nothing new, although it does sometimes seem as if in the late 20th and early 21st century the only entities that can be credited for a bridge design are the engineering corporation or the architect. Individual engineers, not so much.

With all that in mind, I was keen to read "Bill Brown's Bridges" by David Boxall (301 Publishing, 2015, 148pp, available from b2.co.uk), a biography of one of Britain's most successful suspension bridge engineers, who worked on the Forth Road Bridge, Severn Bridge, Erskine Bridge, Humber Bridge, two bridges over the Bosphorus straits, and on unbuilt proposals for the Messina Strait Bridge. Brown has been credited with the aerodynamic box girder design for the Severn Bridge, which radically changed the economy and feasibility of major suspension bridges.

Boxall runs a marketing and design agency, but was previously manager of Brown Beech Associates. This book is very much an "official biography", produced with the cooperation of Brown's wife Celia, and its aim is to document and cement the legacy of one of Britain's most successful bridge engineers.

Born in south Wales in 1928, Brown studied engineering at Southampton and then completed a PhD at Imperial College. His family background was technical in that his grandfather and father were both cabinetmakers. On graduating from Imperial in 1951, Brown was fortunate to go straight into employment with the engineer Gilbert Roberts at Freeman Fox.

Roberts was one of the top engineers of the day, responsible for the structural design of the Dome of Discovery for the Festival of Britain. He had worked with Sir Ralph Freeman on the design of the Sydney Harbour Bridge (1932), and on a suspension bridge on the Zambia - Zimbabwe border (1939).

Over the course of eighteen years until Roberts retired in 1969, Brown was exposed to progressively more challenging engineering and greater levels of responsibility. By the time he became a partner in the Freeman Fox firm in 1970, he had worked on some truly exceptional projects.

His early years included work on major cranes, and a major steel arch structure, Adomi Bridge in the Ghana (1957). Developments in welding and higher-strength structural steels during the 1950s were to prove essential for what would follow in the 1960s.

Freeman Fox's design team, led by Gilbert Roberts, were appointed (alongside Mott, Hay and Anderson) to develop designs for both the Forth Road Bridge (1964) and Severn Bridge (1966). These were spans well in excess of the largest suspension bridge recently built in the UK (Tamar Bridge, 1961). It had been two decades since the collapse of the ill-fated Tacoma Narrows bridge, but aerodynamic concerns remained high in engineers' minds.

Both the Severn and Forth bridges were initially designed to be built using the truss decks then seen as the norm. Fortuitously, an accident in wind tunnel testing during design of the Severn bridge led to a model being mostly destroyed. The book recounts that for the replacement model Brown sketched out a very different slender box-girder geometry, that could be built quickly out of plywood and used for the remaining testing. Severn went on to become the first large suspension bridge built using an aerodynamically stable box girder, a major innovation.

What the book doesn't say is that the slender box-girder concept was not new to the Severn crossing: German engineer Fritz Leonhardt had proposed the same idea for the Tagus suspension bridge in 1960, albeit with two separated box girders rather than just one. Indeed, much of the development of welding and stiffened steel plates for bridge construction had been undertaken in Germany.

The book goes big on Brown's role here (and elsewhere) as an innovator, but says nothing about the Severn Bridge's legacy of problems: fatigue in the inclined suspension hangers, issues with the quality of welded plate, and the need for expensive strengthening. Innovation is never without risk, and on this scale, the consequences can be significant.

Box girders were also used by Freeman Fox for the nearby Wye Bridge, the Erskine Bridge, and for the West Gate Bridge in Melbourne, Australia. The latter collapsed, killing 35 people, in October 1970, and Brown was amongst the senior Freeman Fox staff summoned to testify at the subsequent inquiry in Australia. Boxall records partner Dr Oleg Kerensky's view that the collapse was the fault of the contractors, and that the design had been sound. This is misleading: Freeman Fox's design calculations and site supervision were condemned as completely inadequate by the inquiry.

At the time the West Gate Bridge collapsed, Freeman Fox had already been working on plans for a new suspension bridge across the Bosphorus for three years. This adopted both the aerofoil deck from the Severn Bridge, and also the triangulated layout for the suspension hangers, an idea which had seen little if any use elsewhere.

Completed in 1973, the first Bosphorus Bridge was the longest span outside the USA at the time it was built, and is quite possibly Roberts and Brown's finest achievement. Freeman Fox took on significant overall responsibility for guiding and supervising the project, not just its design, and Brown relocated to Istanbul for most of the construction phase.

By the time of the even longer Second Bosphorus Bridge (1988), Brown had left Freeman Fox and set up his own firm, Brown Beech Associates (in a huff, to paraphrase the book's account). His role this time was as the client's technical advisor, rather than as designer. This bridge adopted conventional vertical hangers, unlike the triangulated ones used on Severn and the previous Bosphorus span, and a few years later the latter bridge had its hangers replaced with vertical cables as well.

In his later years, Brown worked as a consultant on a number of structures, including the Messina Strait Bridge and the Storebaelt East Bridge, both developing concept design proposals and advising on more specific issues such as cable-spinning techniques. He passed away aged 76, in 2005. The book includes a gallery of images of nine key structures that he worked on, and they truly are an incredible CV.

I think it's fair to say that this official biography is a partial account - broader and more balanced accounts of the development of twentieth century suspension bridges are available elsewhere. However, the book is well written, well illustrated and well presented. There are dozens of great photographs of some truly epic bridges, and it's great to see a twentieth-century British bridge engineer recognised in this way.

There was a period from the completion of the Severn Bridge to the completion of the Humber Bridge when it appeared that Britain had firmly re-established itself in the vanguard of long-span bridge design, and as part of the Freeman Fox team Bill Brown was clearly central to that.

13 April 2021

"Fowler's Bridges" by Aidan Bell

Sir John Fowler is best known (with Sir Benjamin Baker) as one of the engineers responsible for the Forth Railway Bridge, completed in 1890, a masterpiece of Victorian civil engineering. During his illustrious career, Fowler was responsible for many other bridges and railways, including much of what is now the Circle Line on the London Underground.

Aidan Bell's book "Fowler's Bridges" (self-published and available from biblio.com, ISBN 978-1-5272-7661-1, 190pp, 2020) deals with the engineer's most famous works only in passing. Instead it is an in-depth study of the estate that Fowler developed at Braemore, near Ullapool in Scotland, and the bridges that he built there, many with Baker's assistance.

Fowler's life story is one of almost constant upward progress. Born in 1817, Fowler set himself on a career in engineering as soon as he left school. His first few years saw him apprenticed to John Towlerton Leather, George Leather and John Urpeth Rastrick. He rapidly took on increasing responsibility, before setting up independently at the age of 26 in 1843. It was the period of railway mania, and Fowler was in the thick of it, taking on chief engineer roles and promoting schemes in Parliament.

By 1849, Fowler was elected to the Council of the Institution of Civil Engineers, going on to become its President in 1865. By that time his consulting practice had grown substantially and was working on over 70 large projects each year. Fowler's army of assistants were based at premises in London, where he also had his main residence.

Also in 1865, Fowler bought the first of two estates near Ullapool in northern Scotland, Braemore, merging it two years later with the adjacent Inverbroom estate. This was to be his holiday home, and he would spend two months of each year there. A new house was built, with innovations including hydro-electric power for electric lighting, and many improvements were made to access around the estate. Fowler had become a proper Victorian gentleman, eventually adding a Baronetcy to his Knighthood, enjoying the Highland hunting life, and entertaining guests at what must have seemed a very remote place to some.

In this painstakingly detailed book, Aidan Bell recounts the story of Fowler's life and career, and documents the Braemore estate, providing detailed descriptions of several "miniature" bridges which Fowler had installed within the landscape. The estate was very different in character to many of those of the landed gentry, with its rough terrain and steep river gorges. The only comparable landscaped Victorian estate seems to be William Armstrong's Cragside.

Two of the estate bridges are relatively well-known: Corrieshalloch Suspension Bridge, and Auchindrean Bridge. The bridge at Corrieshalloch stands out for its situation above a waterfall, allowing visitors spectacular views of the river gorge. The Auchindrean bridge spans a less dramatic location, but is notable as the largest lenticular bridge surviving in Scotland today. It has similarities to Brunel's larger Saltash bridge.

The other bridges are less spectacular, but interesting in how Braemore was treated very differently to other Victorian estates. As an engineer, Fowler seems to have had little interest in the sort of faux-classicism that decorated the property of other wealthy landowners. The Braemore bridges are economically appropriate solutions to difficult terrain, rather than ornamental. They are for the most part aesthetically unspectacular, encouraging the visitor to look away from the bridge and admire the scenic grandeur instead.

Bell's book is heavy on detail. Many of the bridges no longer exist, but each bridge site is described in detail, with photographs and even diagrams to illustrate the structural behaviour of each bridge. It is, to be fair, so much detail that it is likely to be too much for the casual reader, but I certainly enjoyed its thoroughness. The book may be best suited to anyone with an interest in Fowler himself, or Scottish historic bridges generally, or the way in which an estate's development illustrated the expertise and philosophy of an engineering owner.

For me it raises interesting questions around taste. The desire of others to ornament their lands with the mock-Palladian, columns and porticos and pediments taken out of context and plopped down amidst soft green vistas seems to be a taste that has survived today. Prince Charles is perhaps the most notorious modern proponent of a belief that beauty can be found mainly in the past, and that the tics and tropes of the classical are a timeless aesthetic, rather than a pastiche shorn of meaning when taken out of context.

As an engineer, Fowler is more likely to have seen the problem that needed solving as one of spanning an obstacle, rather than decorating a view. The functional nature of the Braemore bridges suggests a love of a more natural landscape, and a desire to make his intrusions into it as modest as was possible. It seems an aesthetic approach to admire and emulate: bridges creating new spaces to admire the surroundings rather than to function primarily as sculpture. There are designers still working today who could benefit from that philosophy.