Kitabı oku: «Dan Cruickshank’s Bridges: Heroic Designs that Changed the World»

DAN

CRUICKSHANK’S

BRIDGES

Heroic Designs that Changed the World

Contents

Cover

Title Page

Preface

Introduction

CHAPTER ONE - EMPIRE

CHAPTER TWO - PIETY AND POLITICS

CHAPTER THREE - BRIDGES OF PARADISE

CHAPTER FOUR - INHABITED BRIDGES

CHAPTER FIVE - FORGING THE RAILWAY AGE

CHAPTER SIX - THE BIGGEST AND BOLDEST

CHAPTER SEVEN - STRUCTURAL PERFECTION

CHAPTER EIGHT - DEFINING PLACES

CHAPTER NINE - WORKS OF ART

CHAPTER TEN - MODERN MEGA-BRIDGES

Endnotes

Glossary

Select Biography

Index

Acknowledgements

Copyright

About the Publisher

PREFACE

Great cities are built on great rivers and so, sooner or later, great bridges arise – bridges that not only connect and transport but also that play key roles in creating and defining the character, nature and aspirations of the city. Bridges, among all their many attributes, are incomparable place-makers, man-made landmarks that vie with the memorable works of nature. This is most obvious in cities and towns, but is also the case in more remote places where so often it is bridges that excite, that stir the imagination, as they soar above chasms and canyon, knife across vast tracts of water – as they dare and achieve the almost unimaginable.

Humanity’s inventiveness and structural ingenuity in the creation of bridges, in the evolution of structural systems, in the utiliz ation of technology and materials, is on a par with the engineered excellence of the Gothic cathedrals of medieval Europe. Great bridges and great cathedrals both express – in the most sublime manner possible – the aspirations of their age, of the civilisation that built them. In Europe and America the genius of bridge building was – in the past – expressed most forcefully in mighty works, especially by the great railway bridges of the 19th century – utilitarian objects of supreme daring, forged of wrought-iron, steel, masonry in sweat and blood – that in the perfection of their function and their fitness for purpose achieved poetic beauty.

Now – in the early 21st century – there are few structural restraints that can stymie bridge-builders, there is little that engineers dare not aspire to, little that they cannot achieve. This has become the age of the mega-bridge where boundaries of ambition and scale are being regularly extended through ever growing technological prowess. This is impressive with unprecedented structures being realised. But often these mega-scale solutions are formulaic. Now, in many ways, the outpouring of ingenuity and creativity that distinguish the best bridges of the past is found not in huge creations but in smaller bridges where the challenge is not so much to achieve a crossing on an heroic scale but to do so in a manner that is consciously intended to delight and to give a place identity. In parallel to the rise of the mega-bridge is the evolution of the gem-like, small-scale bridge – often only a pedestrian bridge such as the Gateshead Millennium Bridge in England – that functions not just as a route but also as a work of art – as a creation that provides a promenade, that grants character, distinction and sense of place.

This book is a very personal journey into the world of bridges. I focus almost exclusively on those I’ve seen and experienced and so, naturally, the text dwells on those that exist rather than on great bridges that are no more, like Robert Stephenson’s seminal Britannia Bridge, Wales of 1846-50 that has been largely rebuilt and altered out of all recognition. This means, of course, that virtually all the works described can be seen – and enjoyed – by all who read this book and who – like me – are always thrilled and stirred by the sight of a good bridge.

Dan Cruickshank

August 2010.

INTRODUCTION

‘Always it is by bridges that we live.’

Philip Larkin, ‘Bridge for the Living’

From earliest times, mankind has built bridges, and still today bridge construction remains heroic, the most absolute expression of the beauty and excitement invoked by man-made constructions that are practical, functional, and fit for their purpose. Bridges that are leaps of faith and imagination, that pioneer new ideas and new materials, that appear both bold and minimal when set in the context of the raw natural power they seek to tame, are among the most moving objects ever made by man. They are an act of creation that challenge the gods, works that possess the very power of nature itself. They are objects in which beauty is the direct result of functional excellence, conceptual elegance and boldness of design and construction.

Like most people, I am addicted to bridges – to their raw, visceral punch, to their often astonishing scale and audacity, enthralled by their ability to transform a place and community and amazed by the way a bold bridge can make its mark on the landscape and in men’s minds, capture the imagination, engender pride and sense of identity and define a time and place. A great bridge – one that defies and tames nature – becomes almost in itself a supreme work of nature.

Bridges embody the essence of mankind’s structural ingenuity, they show how nature can be tamed by harnessing nature, how mighty chasms and roaring waters – the very embodiment of natural power and grandeur – can be spanned by utilizing the structural forces and principles inherent in nature; bridge design demonstrates – with startling and dramatic clarity – the structural potential of different materials and how these materials can be given added strength through design, through the use of forms that work in accordance with the structural laws of nature. For example, stone can be given additional load-bearing capacity and be used to bridge wider spans by being wrought to form well-calculated arches, and wood and metal can achieve great spans if used not as simple beams but when fabricated to form lattice-like, triangulated, trussed structures, where load-bearing capacity comes not through mass but from thoughtful engineering.

The most thrilling bridges are, in many ways, those not enhanced by superficial or extraneous ornament or cultural references. What moves and impresses is their honest expression of the materials and means of construction – their only ornament is a direct result of the way in which they are built and perform. A great bridge has an emotional impact, it has a sublime quality and a heroic beauty that moves even those who are not accustomed to having their senses inflamed by the visual arts.

Bridges are a great paradox, they not only use nature against nature, but magically the best examples do not defeat or damage nature but enhance it, and, in ways that are sometimes hard to fathom, achieve a deep harmony with their surroundings. For these reasons bridges have captured the imagination of people through the ages and now they are the only large-scale and radical examples of modern design and construction that the public generally applaud. All can see that bridges stand for something most significant, for the indomitable human spirit, the love of daring and of challenge, the power of invention.

Bridges, of course, inhabit worlds way beyond the merely physical and visual. Having excited human imagination they have, for centuries, possessed a powerful symbolism. They have been seen as links between this world and the next, as symbols of transition, and as metaphors for life and death on earth, and of the journey of the soul to the afterlife – the means of crossing the great divide. This symbolism and fancy have, occasionally, been reinforced by fact, for some bridges have, quite literally and rivetingly, been bridges between worlds and have possessed almost more meaning than physical substance. For example, the stone-arched Bridge of Sighs in Venice, built in 1602 by Antonio Contino (who had earlier worked for his uncle Antonio da Ponte on the Rialto Bridge, see page 158) that formed a covered way between the interrogation rooms in the Doge’s Palace and the adjoining prison. It has long been assumed that the small windows in the bridge offered convicted prisoners their last view of Venice or of life. The idea of the bridge as a metaphor for transition or for a journey of the spirit seems universal. In fifteenth century Peru, the Inca saw the rainbow as a bridge between their homeland and heaven, while some of the indigenous people of Australia conceive of the link between worlds taking the form of the vast, arching and bridging body of the rainbow serpent, a creature as it happens that is most similar to the Lebe snake, the bridge-like ancestor of the Dogon people of Mali, Africa.

The Zhaozhou or Anji Bridge, Hebei province, China, completed in AD 605: an object in which form is dictated by function to achieve beauty and eternal elegance.

Detail of one of the arched and open spandrels of the Zhaozhou or Anji Bridge. This is the world’s oldest surviving open-spandrel, segmental arched bridge built in stone. The joints between the masonry blocks forming the arches are reinforced by wrought-iron bars or cramps.

For all these reasons bridges have been applauded as heroic, sacred – almost mystic – works by all cultures. Bridges of great scale or span were venerated in Medieval Europe, either as pious works that glorified God or as almost impossible acts of daring that could only have been achieved with the aid of the Devil (see page 94). Great bridges were, people assumed, creations that could only be completed through prayer and divine guidance or by the sale of the soul to dark forces. They were places where you could meet angels and saints as if conducting you to Heaven, or the Devil himself collecting his toll. Similarly in China: the truly remarkable Zhaozhou or Anji Bridge in Hebei province, built between 595 and 605 AD to the designs of Li Chun and the world’s oldest open-spandrel segmental arched masonry bridge, is particularly rich in myth, legend and stories of the supernatural. This is mainly because its construction methods and ambitious scale – its main arch of segmental forms spans a mighty 37.7 metres – astonished most contemporary observers. Li Chun achieved the wide span of the bridge by using 28 parallel and abutting arches, each formed with massive, precisely cut and wedged limestone voussoirs whose joints were strengthened with wrought-iron cramps or bars. The arch-topped open spandrels not only reduce the weight of the bridge without weakening it but also – by creating additional openings through its body – protect the bridge from being washed away by the force of unusually high and powerful flood waters. These novel design features and construction techniques gave the bridge great strength but also the flexibility necessary to withstand earthquakes.¹

Li Chun – clearly a man of advanced practical know-how – was himself not ignorant of the worlds of magic and of the spirits. The bridge is of pure, simple and practical design yet the keystones at the crown of the main arch are embellished with carvings that show the leering and horned heads of the Taotie motif. These beings from the spirit world were intended to protect the bridge from floods and from the potentially malevolent spirits of the river that might resent the bridge, for it robbed them of some of their power over those mortals who wanted to cross the water. In a Taoist culture, where all is animated and nature is seen as the great guide and inspiration, everything is alive – not just the river but the stones from which the bridge is made and, indeed, the bridge itself.

One legend about the bridge is like those attached to many European medieval bridges of prodigious span or slender form: it was constructed by an inspired human, in this case the fifth century BC engineer and philosopher Lu Ban, working with the aid of spirits. Another legend is that two Taoist Immortals – perfected beings who are masters of time and space and travel between the earth and the distant stars – decided to test the strength of this unprecedented bridge by thundering across it in tandem. The bridge survived this ordeal just as it survived resentful water spirits and – perhaps more impressively – earthquakes and centuries of neglect. It still stands, still does the job for which it was built 1,400 years ago, and continues to inspire and astonish – a thing of perpetual delight and timeless beauty that contrives, despite all it has seen and suffered, to look eternally youthful and modern.

The Humber Bridge, linking Yorkshire to Lincolnshire, was opened in 1981, and was seen by the poet Philip Larkin as a great symbol of human existence. ‘Always’, he observed, ‘it is by bridges that we live’.

THE ART OF BRIDGES

Always bridges have been seen as things of breathtaking, elemental beauty, as audacious and epic engines of transformation. The profound role that bridges play, in all their symbolical and metaphoric richness, in our imaginations is revealed – and confirmed – by the works of poets, painters and writers. Shortly before the Humber Bridge in England opened in 1981 – a huge and daring suspension bridge whose span of 1,410 metres was until 1997 the widest in the world – Philip Larkin wrote a poem about the arrival of this new creation near his home town of Kingston-upon-Hull. For the first time ever, the mighty Humber Estuary, dividing those on its Lincolnshire south bank from the natives of Yorkshire on the opposite bank and defining the character of the area, had been bridged. Larkin pondered on the way the bridge transformed the landscape and communities and promised new life to all the area – even, as it were, to the dead: ‘Lost centuries of local lives that rose…Seem now to reassemble and unclose, All resurrected in the single span’. Larkin also saw the bridge – the act of bridging – as a great symbol of human existence, of the transition from the past to the present, from life to death and to rebirth: ‘Always it is by bridges that we live’.²

Larkin, although suspicious of change, clearly had a guarded enthusiasm for such bridges. So it is perhaps slightly disappointing that this particular great engine of transformation has never quite lived up to its promise and proposed purpose. The bridge remains magnificent and sound but not used by the numbers that were anticipated. The communities on each side of the Humber have not embraced the opportunity to mix quite as fully as Larkin and the bridge builders imagined. So in this case the bridge has taken on another symbolism, one somewhat removed from that envisioned by Larkin – and has become the personification of the ancient Greek concept of hubris, the excessive pride and daring arrogance that leads man to defy the gods, and by so doing, create the implacable mechanism of his own downfall.

Many painters, for reasons never fully explained, have not only included bridges in their works as seemingly peripheral objects, but have at times become obsessed by them, or by their apparent meanings. Indeed, for some artists, bridges have become veritable muses, objects that unleash the creative force of the imagination. In the romantically rude but also idyllic landscape that enfolds behind the Mona Lisa there is a bridge. It has several arches that appear semi-circular in form. It could be Roman. Why did Leonardo da Vinci include a bridge in this particular portrait? There are any number of possible answers, the least acceptable of which is that he was merely reproducing a landscape and details with which he was familiar, painting what he saw. The pioneering technique he used to render the landscape – depth is implied by the use of paler, misty-looking colours and by a softening of detail – gives all a naturalism and realism. But this is clearly a fictitious and unreal landscape and one pregnant with deep meaning – but what meaning?

Whatever the meaning, it matured over the years. Leonardo started the work in 1503 and seems to have taken around fifteen years to complete it, mulling over it, carrying it with him into France, putting it aside, then taking it up. It was his shadow, a thing haunting him. Is it really just a portrait of ma donna – my lady – or m’onna Lisa, the wife of the wealthy Florentine silk merchant Francesco del Giocondo? Perhaps, but also – in certain ways – it is surely more. The time and care indulged means that, among other things, the Mona Lisa is a self portrait of the painter’s soul. His soul, with a bridge nearby. As well as being a painter, Leonardo was an inventor of technically advanced machines, an architect and a military engineer. Without doubt he knew much about bridges and almost certainly loved them for their structural logic and power. He probably also saw them as emblems of human achievement, as Humanist creations that reveal the dignity, value, ingenuity and intrinsic worth of man. Even without reference to God, man was confirmed in his high status by such acts of genius and endeavour as bridge construction.

Bridges appear in the paintings of Botticelli, Raphael and, in particular, in the work of Canaletto. He paints not just bridges in Venice but also, in the mid 1740s, in London. The wonder-bridge at the time was Westminster Bridge – the first major bridge over the Thames built since London Bridge was completed in the very early thirteenth century (see page 16). The new bridge had inspired London-based artists from the moment construction started in 1739 on the designs of the Swiss engineer, Charles Labelye. Richard Wilson had, in 1744, painted its arches rising from the water. When Canaletto painted the bridge in 1746, he placed it in an almost Venetian context – showing the river packed with boats and large ornamental barges – and also produced a remarkable view of London framed by one of the arches of the bridge, complete with timber centering still in place.

This playful and inventive work by Canaletto seems to have challenged – and inspired – the London-based artist Samuel Scott who around 1750, when the bridge was nearing completion, produced an almost obsessive series of paintings. He portrayed the bridge in its setting and, more remarkably, produced over half a dozen studies showing details of, and views through, a couple of arches. Scott was evidently determined to out-do Canaletto at his own game, for not only did he emulate Canaletto’s unusual arch-framed view of the city but also embellished his images of the bridge with the trappings of daily life. Scott placed bustling or pondering people on the bridge and showed construction details – it was to be an emblem of urban vitality, of change, of London, and a vehicle for grasping new and unexpected views of the city.

In fact this was another favoured symbolic role for the bridge – an elevated and disinterested platform from which to see the world in revealing perspective, as if an Olympian god were looking down on the world of mortals. In September 1802 this was precisely the lofty position that inspired William Wordsworth – who was in fact given extra elevation by being perched on top of a stagecoach – when he wrote Upon Westminster Bridge. Apart from the reference in the title, the poem doesn’t mention Westminster Bridge directly but it is obvious that without the bridge – without the experience of passing over water atop a slowly moving vehicle on a still, late summer morning – nothing would have been possible, no insights or pleasures gained. Moved by the view of the metropolis offered by this relatively new vantage point, Wordsworth had a sudden vision of urban beauty and, in homage, created a hymn to London: ‘Earth has not any thing to show more fair…The City now doth, like a garment, wear/ The beauty of the morning: silent bare…Ne’er saw I, never felt, a calm so deep!/ The river glideth at his own sweet will:/ Dear God! The very houses seem asleep;/ And all that mighty heart is lying still!’³

One of a series of paintings by Samuel Scott showing Westminster Bridge under construction in around 1750.

As artistically ecstatic are the paintings by Pierre-Auguste Renoir and Claude Monet. Paris’s oldest surviving bridge – the Pont Neuf completed in 1609 – and the life it engendered over the reflective river inspired Renoir in the early 1870s to help forge the fleeting light effects and immediacy of Impressionism. A few years later Monet became entranced by the little Chinese-style timber bridge he had created in the early 1880s within his garden at Giverny, France, and painted it in different lights to create a series of studies that in a sense define his art.

For both these artists bridges were clearly admirable things, just as they were a few years later for Surrealist and Dadaist artist Marcel Duchamp. In 1917, when defending his decision to display a urinal as a work of art in a New York gallery, Duchamp explained that by placing the urinal at an unusual angle, in the novel context of an art gallery, and naming it ‘Fountain’, its familiar ‘significance disappeared under a new title and point of view’. Duchamp claimed to have transformed the essence of the object in an almost alchemical manner by creating ‘a new thought’ for it in the eyes of the viewer. He’d opened, in the prophetic words of William Blake, new ‘doors of perception’.⁴ And to those who argued that to display such a piece of off-the-peg plumbing as a urinal was just plain vulgar and could not possibly be art, Duchamp simply replied: ‘that is absurd. The only works of art America has given are her plumbing and her bridges’.⁵

It is not just poets and painters who have viewed bridges as potent symbols and metaphors. So have novelists. For example Thornton Wilder, in The Bridge of San Luis Rey, published in 1927, uses the sudden collapse of an ancient, creeper-built suspension bridge in Peru in which five people are killed, to explore the nature of God and religion. The fate of the bridge becomes a metaphor for the fate of man, a symbol of divine will. Were the deaths merely random, revealing that God has no plan and ultimately that life is arbitrary or was the bridge’s collapse the long-ordained and deserved termination of the lives it took?

Claude Monet was inspired in the 1880s to produce numerous versions of the play of light on the Chinese-style bridge in his garden at Giverny.

BRIDGES OF DEATH AND REDEMPTION

Perhaps the most relentless literary pursuit of the bridge as symbol is Ivo Andric’s The Bridge on the Drina, a novel published in 1945 and inspired by Bosnia’s history and quest for independence and identity. The novel focuses on the town of Višegrad and the Mehmed Paša Sokolovi Bridge over the Drina river and spans 400 years from the time the region, town and river were dominated first by the Muslim Ottoman Turks and then by the Christian Austro-Hungarian Empire. It chronicles the religious battles between the communities that co-existed in a border town on a river forming a frontier between different peoples – and the thread that holds the narrative together and that weaves through time is the bridge.

In the novel – and in reality – the bridge is a mighty work. The Ottomans were skilled and prodigious bridge builders who, like the Romans before them, understood that bridges and roads were the means of expanding, holding and controlling a sprawling empire and of linking and unifying the diverse peoples that it contained. The Mehmed Paša Sokolovi Bridge was completed in 1577 to the designs of the Ottoman court architect Mimar Sinan on the orders of the Grand Vizier of Bosnia. Sinan was the greatest architect of the Golden Age of Ottoman power, the designer of the spectacular mid-sixteenth century Süleymaniye Mosque complex in Istanbul that remains an exemplary essay in the creation of an Islamic paradise on earth.

Sinan’s bridge over the Drina was nobly conceived – it was to measure 180 metres and cross the water by means of eleven stone-built pointed arches, each with spans of between 11 and 15 metres. In the novel, the Vizier had, as a boy, been kidnapped into slavery in Bosnia and resolved to build a bridge at Višegrad to purge his memories of initiation into slavery aboard a boat while crossing the Drina. The tale woven around fact tells of the harsh conditions and chaos of the initial phases of construction – marked by episodes of gruesome cruelty – gradually giving way to order, to harmony, and to final completion when the bridge becomes a source of pride and prosperity for Muslims and Christians alike.

The bridge, with its mid-span meeting place, assumed the symbolic – in many ways actual – role of town centre and focus of activities that gave the community identity and cohesion. Then decline sets in, the bridge loses its importance as a trade route and finally – in the novel and in reality – soon after the start of the First World War ceased to exist as any sort of route at all because retreating Austrian forces blew up a number of its arches as the enemy approached. As Andrew Saint has observed of the way the bridge is presented in this novel: ‘Here is an engineer’s story, [it is] about courage, effort and technique; about the benefits a magnificent and useful monument can confer across generations; about amazement at its construction and pride in its endurance’.⁶ He could have added that the story also talks of the way bridges can bring prosperity and unite communities.

The real-life story of the bridge across the Drina after the publication of the novel (that in 1961 won the Nobel prize for literature) has bizarre and brutal twists worthy of the darker moments of Andric’s imagination. The three arches destroyed in the First World War were repaired, as were the five subsequently destroyed in the Second World War and by the 1990s the bridge was regarded as a major historic and architectural monument of Yugoslavia. Then descended the dark and ancient shadow of hatred and cruelty. There was division, fragmentation, a return to religious war, the imposition of the ghastly mechanisms of ‘ethnic cleansing’ and land appropriation by the most violent means imaginable. In 1992 a large group of local Muslims were herded to the centre of the bridge – to the place of creative and convivial gatherings in Andric’s vision of the history of the bridge – and then flung off ‘and shot at for sport by Serbs as they fell’.⁷ The bridge, now again a place of calm and beauty but more than ever haunted, currently belongs to the Republic of Serbia. Few visit it: the suffering it has seen is too great for most to bear.

One bridge nearby, with a comparable history and story, I have explored in detail. The bridge at Mostar was completed in 1566 and with a single and elegant stone arch spanning 29 metres and rising 19 metres above the water, is one of the great engineering marvels of the Ottoman empire – a testimony to the taste, culture and scientific skills of the Muslim world that created it. The construction technique was ingenious – the limestone blocks were finely cut and their joints strengthened by the use of wrought iron pins, set in lead to prevent them rusting, expanding and cracking the stone. As in Andric’s story of the bridge at Drina, the bridge at Mostar – with what many at the time believed was the longest stone-built arched span in the world – became a great source of local pride and brought prosperity and distinction to the town. It also became the focus of customs and rituals – notably offering young Mostar males of all persuasions the opportunity to publicly demonstrate their virility to all who might be interested by leaping from the crown of the bridge into the generally shallow water below.

The history, beauty and technical excellence of this bridge proved its undoing. The same vicious conflict following the break-up of Yugoslavia that led to the deaths on the bridge across the Drina also engulfed Mostar. The town had a complex and mixed community – Orthodox Christian Bosnian Serbs, Slavic Muslims and Roman Catholic Croats – and in mid 1992 this long stable but potentially volatile community fragmented. Fighting flared on opposite sides of the bridge, each the territory of neighbours now in conflict. Outside forces arrived and the bridge became a target – this was culture very much in the firing line. The bridge was obviously of military and strategic significance in the fighting – but it was also a symbol, an emblem of Muslim presence, of Islamic culture. As such some of the fighting factions found it intolerable. Despite attacks, the bridge managed to survive until November 1993 when Croat forces finally shelled it to destruction.

When the fighting gradually died down, and Mostar found itself stabilized as part of Bosnia and Herzegovina, it was resolved that this cultural wonder must be rebuilt. This was not only to reclaim lost beauty and history, but was to be an act of reconciliation that would give Mostar back its heart, its identity and its role as a trading centre. The European Union got involved, money was made available by various states and an exemplary reconstruction took place utilizing as many of the old stones as possible and using traditional building materials and techniques. By July 2004 the great wrong had been put right and the noble bridge rebuilt. I saw it a few months later. It looked superb, as if the last ten years had never been. Mostar has its wonderful bridge back, the ancient trade routes are reconnected, and customs revived. Even while I was there muscular young men were gaily tossing themselves off the top of the arch to splash into the water far below. But near the bridge I spied a stone standing against a wall, and on the stone was written, ‘Don’t forget’. The stark and powerful words provoked memories of ancient, prophetic texts, especially those touching on mortality and transience. I looked up the famous lines from the eleventh century Rubaiyat of Omar Khayyam: ‘The moving finger writes: and, having writ, moves on: nor all your piety nor wit shall lure it back to cancel half a line. Nor all your tears wash out a word of it’.⁸ Yes indeed, we are ‘weighed in the balance, and…found wanting’ (Daniel, 5:27). A bridge, for all its engineering wonder and potential symbolism, is in many ways just a bridge, a physical fact. The sign near the bridge at Mostar, I suppose, is saying that some things when lost cannot be found, that it is easier to mend a broken bridge than it is a broken heart.