LARGE suspension bridges rank among the world’s most sublime and heroic structures, and Bill Brown played a vital role in the design of the great series of suspension bridges over the Forth, the Severn, the Humber and the Bosphorus which were longer and more elegant than anything built before.

In an era when it has become possible to build cheaper cable-stayed bridges of increasing length, Brown remained the world’s foremost and ablest advocate of the long-span suspension bridge, and for more than 30 years he was engrossed with the design of by far the longest suspension bridge yet conceived — the awesome Strait of Messina crossing, with a central span of 3,300 metres.

Born in South Wales in 1928, Brown studied engineering at University College, Southampton, and Imperial College, London. He joined the famous engineering firm of Freeman Fox in 1956, serving as partner from 1970 to 1985.

At Freeman Fox he was working as No 2 to Gilbert Roberts on the Severn and Forth bridges, both adventurously long spans. When the Forth bridge was given prior approval they were able to refine the Severn Bridge design, producing the first of a new generation of aerodynamic bridge decks. The two went on to design the breathtaking span of the Humber Bridge, then the longest suspension span in the world.

Brown played a leading role in the first Bosphorus bridge linking Europe and Asia. Seen from the water, it is ethereal, almost ribbon-like in its slenderness, effortlessly carrying a nose-to-tail stream of heavy lorries. The opening of the bridge made Brown a national hero in Turkey, not least because it paid for itself within two years when earlier studies had suggested this would take 20. He was both engineer and project director of the equally elegant second Bosphorus bridge.

Bill Brown’s life-long mission was to make bridges lighter, leaner and more athletic, achieving not just grace of silhouette but also major savings in building materials and construction time. Pushing the boundaries of technology risks disaster. This came at Freeman Fox with the collapse of the Milford Haven box-girder bridge during construction, killing several workers. The blow was doubled by the collapse soon after of another box-girder bridge the firm had designed over the River Yarra in Australia, later established to be due to a construction error. Freeman Fox was never to recover, but it is a measure of Brown’s ability that he outrode these setbacks.

Brown inspired awe in his colleagues and sometimes fear in his juniors. He worked from first principles and was constantly sketching. He was also highly numerate and had an unsurpassed understanding of the way steel behaved at all stages of manufacture, fabrication and construction.

He patented a system of aerial cable spinning for the Storebaelt Bridge in Denmark linking the islands of Zeeland and Sprogø, which halved the cost of suspension cables. The construction of suspension bridges is weather dependent — his achievement was to shorten the time taken in making cables from which the bridge deck is suspended.

Brown regularly turned his talent to other forms of bridge construction. He led the design of the 80-metre swing bridge at Hull and co-ordinated the design and construction of the twin-leaf bascule bridge over the Golden Horn in Istanbul. He was also involved in the design of mountings for the William Herschel telescope in the Canary Islands. He devised the welded-boom concept which allows slender modern mobile cranes to carry enormous loads.

After leaving Freeman Fox, Brown started his own practice, Brown Beech & Associates in 1987 — Beech was not a colleague but his childhood home in Wales. He regularly tested models of his designs in a wind tunnel built in his office in High Street Kensington, achieving results which compared .favourably with those taken in much larger tunnels. As the force of the fan was potentially strong enough to suck in the windows they had to be kept open even on freezing winter days whenever a test was under way.

He was a constant traveller, and his knowledge of steel led to consultancy in Italy. On the Messina bridge the wind pressure and turbulence across the open sea were potentially enormous — all the more so as the crossing is a combined road-and-railway bridge. Brown conceived the idea of three parallel decks, rather like a trimaran, perforated to allow wind to pass through the structure. Bridge decks normally have a trapezoidal under-structure: for Messina Brown evolved a curved one, further streamlining it. At one time he spent two and a half years in Rome working on the project.

If the finance is found, the Messina Bridge will enable trains and vehicles to cross the strait in just three minutes. It is designed for a life of 200 years and to withstand winds of 216kph and an earthquake more severe that the one that devastated the city in 1908. The first international ideas competition for the bridge was held in 1968. Currently tenders are being invited for the contractor to be entrusted with the final design and .realisation of the work. When it finally opens, Bill Brown will deserve a key share of the plaudits.

Brown continued to work at a formidable pace until illness overtook him. He also worked on the design of a number of bridges that have not proceeded, including the 1,480-metre span Tsing Lung suspension bridge in Hong Kong, the 2,100-metre highway link from Java to Bali and the 1,440-metre highway span over the Dardanelles. He was also involved in the proposed bridge and tunnel crossing for the Strait of Gibraltar as well as the much earlier proposal for a bridge-tunnel crossing of the English Channel with 2,000-metre spans. His first bridge was the Volta River Bridge in Ghana in 1956, an arch. The Auckland Harbour Bridge of 1969 and the Erskine Bridge across the Clyde are also his.

He is survived by his wife, Celia whom he married in 1964.

William Brown, engineer, was born on September 16, 1928. He died on March 16, 2005, aged 76.