Gibraltar Straits Crossing
© Cubanito / Wikimedia CommonsGibraltar Straits Crossing Proposed
Gibraltar Straits Crossing Proposed
The Bridge
In 1995, Bill Brown spoke at an engineering conference in Gibraltar about a proposed bridge over the Strait of Gibraltar. It represented engineering challenges on a whole new scale, including another vast distance to span, strong winds, powerful currents, earthquakes and a very busy waterway. Nonetheless, he devoted much time to considering how such a bridge might be constructed.
In 1983, two years before he left Freeman Fox, Bill had presented initial suspension bridge designs for the Strait of Gibraltar to the governmental powers that be, focusing on ten spans measuring 2,000 metres each. He planned to position the bridge over the shallower seas of a subterranean ridge between Punta Paloma in Spain and Cap Malabata in Morocco. The total crossing would be 28 kilometres long. He would anchor the towers to the seabed using deep-sea oil-drilling platforms. A collapsible water-filled skirt would provide enough ballast to avoid and lessen the impact of ship collisions.
The new plans that Bill presented in Gibraltar in 1995 were based on work already carried out for the Messina Bridge. Once again, he used the concept of curved underbellies and box shaping to ensure smooth wind flow. Added stability came though the addition of perforated slots on the vented deck sections. This bridge still remains hypothetical; however the work Bill put into his designs helped clarify his research and moved international knowledge about suspension bridge design and innovation several crucial steps further forward.
Proposed Gibraltar Straits Crossing
Linking Europe and Africa
Key Facts
Proposed 28.8km bridge
10 suspended spans, each of 2000m
Approach viaducts of 6,400m and 2,400m
Location
Linking Spain and Morocco
Across the Strait of Gibraltar
from Punta Paloma in Spain to Pointe Malabata in Morocco
Designers / Engineers
Dr William (Bill) Brown
Freeman Fox & Partners (1980s)
and Brown Beech (1990s proposals)
Description
10 steel suspension bridges
Each 2,000m main spans
28,800m total length including approach viaducts
Other long-span bridges
Channel Crossing
© B2 ArchiveChannel Crossing Proposed
Channel Crossing Proposed
The Bridge
In 1981 Bill Brown presented a proposed 30km Link into Europe: a planned crossing of the English Channel with 12 suspended spans each 2,500m long. Bill and his colleagues at Freeman Fox had been developing a new deck design able to withstand the long spans required for this vast crossing. Although the tunnel was constructed and opened in 1994, the bridge was presented as a feasible option. The deck would carry six lanes of traffic and a central rail line.
Bill revisited this design between 1996 and 1998 and incorporated his multi-box deck designs and wind deflectors in a new proposal. He also designed new pier protection for the 310m-high towers that would be sited in the Channel.
Proposed Channel Crossing
Multi-span suspension bridge design proposals across the Strait of Dover
Key Facts
30km multi span
12 suspension bridges of 2,500m each
1981 and 1998 proposals
Location
Across the English Channel
From Folkestone to Sangatte
Spanning the Strait of Dover
1981 Design and Engineering
Dr William (Bill) Brown
and Sir Gilbert Roberts
Freeman Fox & Partners
A patented vented-deck design
1998 Design and Engineering
Proposal by Brown Beech (B2)
Featured Dr Bill Brown’s unique multi-box deck design
310m-high towers
Innovative pier protection