Gibraltar Straits Crossing

Gibraltar Straits Crossing Proposed

Gibraltar Straits Crossing Proposed

© Cubanito / Wikimedia Commons

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

Channel Crossing Proposed

Channel Crossing Proposed

© B2 Archive

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

Other long-span bridges


Çanakkale Dardanelles

Çanakkale Dardanelles Bridge 2023

Çanakkale Dardanelles Bridge 2023

© ÇOK AS

© B2 Archive

World Record Longest Bridge Spans


Çanakkale Dardanelles Bridge, 2023, Turkey, 2,023m
Akashi Kaikyo Bridge, 1998, Japan, 1,991m
Humber Bridge, 1981, England, 1,410m
Verazzano Narrows Bridge, 1964, USA, 1,298m
Golden Gate Bridge, 1937, USA, 1,280m
George Washington Bridge, 1931, USA, 1,100m

There is a new world record for the longest main-span suspension bridge. After decades of planning and four years of construction the 1915 Canakkale Bridge over the Dardanelles Strait in north west Turkey has opened for traffic. At 2,023m main span it succeeds the Akashi-Kaikyo Bridge in Japan and is a glorious celebration of the development of Turkey.

The official opening will be in 2023 to mark the 100th anniversary of the founding of the Republic of Turkey. It will also be the 50th anniversary of the opening of the Bosphorus Bridge (18th July Martyrs’ Bridge) in Istanbul, the first bridge to link Europe and Asia.

If someone asks you: What is the world’s longest span bridge? You can say: “the 1915 Canakkale Bridge over the Dardanelles Strait”.

Bill's Proposed Bridge Design


Bill Brown first designed a bridge over the Dardanelles at Çanakkale nearly 30 years ago (B2 illustration shown above) and he would be overjoyed that his invention of the twin-box girder deck design would become a reality on the new bridge.

Bill and his firm Brown Beech were formally commissioned to prepare designs for The Dardanelles Bridge project following the success of the Second Bosphorus Bridge (Fatih Sultan Mehmet Bridge) and the expansion of the major road system. KGM recognised the need for bridges over the Dardanelles Strait and the Izmit Bay to improve communication and connect communities across Turkey.

In the early 1990s Bill and his team of consulting engineers and bridge designers at B2 were developing innovative designs with aerodynamic-box deck sections that continued the work that began with his Severn Bridge and Bosphorus Bridge designs. His introduction of the world’s-first concept of the twin-box deck (and multi-box) was the key.

Çanakkale Dardanelles Bridge

World record span suspension bridge under construction in Turkey

Key Facts

1915Çanakkale Bridge (official name)

World’s longest suspension bridge

Part of a new motorway easing the traffic load on Istanbul

Location

Near Gallipoli, North-west Turkey

Across the Dardanelles Strait

Linking Sütlüce, in Europe and Lapseki on the Asian side

Designers / Engineers

Parsons, Takfen and COWI (detailed design)

Original design concept by Dr William (Bill) Brown, B2

Mott MacDonald (Technical advisor)

Description

Steel suspension bridge

2,023m main span

3,563m total length + 1045m of approach viaducts

Main contractors

A Turkish-Korean joint venture

Comprising: Limak and Yapi Merkezi (Turkey)

Daelim and SK Engineering (Korea)

Construction of the 1915Çanakkale Bridge


The bridge is currently being constructed 10km south of the town of Gallipoli in north west Turkey. Not only will it be the longest central-span suspension bridge in the world at 2,023m, it will also have the highest towers for a suspension bridge at 334m. The aerodynamic twin-box girder deck will be 45m wide.

The towers have been built on piers in the Dardanelles Strait which is approximately four kilometres wide at this point. The cable spinning is underway and the deck will be erected later this year.

The bridge will form part of an 88km three-lane motorway project that connects to a route west of the Sea of Marmara, opening up communications and connecting communities in this part of Turkey and easing the traffic load on Istanbul.

These images show the 3D renders of the bridge and construction videos courtesy of Çanakkale Motorway Bridge Construction Investment Management Inc. (Çanakkale Otoyol ve Köprüsü İnşaat Yatırım ve İşletme A.Ş) and ©ÇOK AŞ

© ÇOK AS

Long-span bridges in Turkey


Tinsley Viaduct

Tinsley Viaduct 1968

Tinsley Viaduct 1968

© B2 Archive

The Bridge


The two-level Tinsley Viaduct carries the M1 motorway and a main road over the heavily developed Don Valley. It was the first steel structure in Britain to have road traffic on two levels.

The 1,036m long viaduct has the six-lane M1 motorway on the top deck, with the four-lane A631 road and services (gas, electricity and water) on the lower deck.

The decks are of continuous composite construction. A prestressed reinforced concrete slab 215mm thick is supported by two main longitudinal steel box girders, with transverse cross girders and cantilevers at approximately 3m centres. The structural steel has an especially high anti-corrosion specification.

Tinsley Viaduct

A two-level box girder viaduct

Key Facts

Two-tier road bridge

Carries the M1 motorway on the upper deck

Industry continued unabated during the construction period


Location

Sheffield, England

Across the River Don


Consulting Engineers

Freeman Fox & Partners


Description

Twin-deck box girder bridge

1,036m total length


Main contractors

Cleveland Bridge & Engineering Company


Construction

Began in 1965

Lower deck opened 25 March 1968

Upper deck opened 19 October 1968


The first two-deck steel viaduct


Dr William Brown was Principal Designer at Freeman Fox & Partners in the 1960s.

One of the bridge projects he worked on with the design team was the Tinsley Viaduct with 20 simply-supported spans up to 49.7m long, and two end spans. The spans over the Don Valley are carried on 17 pairs of high tensile steel box columns. Each has a rocker support to accommodate thermal movement and subsidence, with a jacking facility to rectify any settlement. The 17 piers and four abutments are of reinforced concrete, founded at depths of 4.6 to 9.1m.

Other long-span bridges


Tsing Lung Bridge

Tsing Lung Bridge Proposed

Tsing Lung Bridge Proposed

© Ryan McManimie

The Bridge


The Tsing Lung Bridge was designed and planned between 1999 and 2002 to provide a second road link to Lantau Island in Hong Kong and the International Airport at Chek Lap Kok. A suspension bridge with a steel superstructure was proposed with a main span of 1418 metres. Each side spans would be 220m long.

Bill Brown and B2 worked in an engineering team for the review, design and proposed bridge construction with Chodai of Tokyo and Maunsell of Hong Kong. Bill was tasked with preparing the essential design drawings and continued his design development of the twin-box deck and undertook extensive wind tunnel testing. He created an advanced shallow streamlined deck to carry a three-lane highway for the Hong Kong Highways Department. The bridge was originally planned for completion in 2008 but has yet to be constructed.

Derivatives of Bill’s twin-box bridge deck design have subsequently been used on other bridges in China. He attempted to patent his designs and continued design protection up until his passing in 2005.

Tsing Lung Bridge

Proposed bridge to Lantau Island in Hong Kong

Key Facts

A proposed suspension bridge with a twin-box deck

6-lane roadway


Location

North Lantau to Tsing Lung Tau, Hong Kong

Across the Ma Wan Channel


Designers / Engineers

Bill Brown, Brown Beech

Chodai

Maunsell


Description

Suspension bridge

1,418m main span

Twin-box vented bridge deck


Other long-span bridges


Java Bali Bridge

Bali Straits Crossing Proposed

Bali Straits Crossing Proposed

© B2 Archive

The Bridge


Bill Brown applied his multi-box deck innovation when he was commissioned in 1996 to submit designs for a suspension bridge spanning the Indonesian islands of Java and Bali. Bill advised that the new Bali bridge should become a dual-box suspended span of 2,100 metres. He proposed an initial two-lane deck that could go on to accommodate two further curved-bottom boxes for greater stability and a final total of six lanes. This would reduce the initial capital cost of the bridge to a minimum when traffic and toll income is lowest. As traffic volume increased, toll revenue would fund the addition of bridge capacity.

Bali Straits Crossing

Proposed bridge linking Java and Bali

Key Facts

Two traffic lanes, expandable to six lanes


Location

Across the Bali Strait, Indonesia

Linking Java and Bali


Designers / Engineers

Dr William Brown

Brown Beech & Associates


Description

Steel suspension bridge design with multi-box innovation

Planned 2,100m main span


Other long-span bridges


Izmit Bay Bridge

Izmit Bay Bridge 2016

Izmit Bay Bridge 2016

© Ozkan Ulucam

The Bridge


Following the successful construction of the Second Bosphorus Bridge (Fatih Sultan Mehmet Bridge), which opened in 1988, the Turkish Ministry of Works commissioned Bill Brown to design long span suspension bridge schemes across Izmit Bay and Canakkale Straits. In 1994 he presented his Izmit Bay Bridge: a 1,540m single span with an aerodynamic box girder deck.

In 2009 the project was revisited by the Turkish Ministry with an increased desire to see the project realised and improve Turkish infrastructure. Japanese company, IHI, who had built the Second Bosphorus Bridge, won the tender to construct the superstructure of the bridge. They commissioned Danish firm, COWI, as consulting engineers working alongside architects Dissing+Weitling. They followed the Severn-type bridge design that Bill had originated and a 1,550m single span bridge began construction in 2013. The overall length was 2,682m and it was designed with expansion joints and towers on gravel beds to resist a powerful earthquake. On opening in 2016 it was named the Osmangazi Bridge.

Izmit Bay Bridge

Also known as the Osmangazi Bridge

Key Facts

The longest bridge in Turkey

The sixth-longest suspension bridge in the world by the length of its central span

Location

Dilovası/Altınova, Turkey

Across the Gulf of Izmit

Part of the Istanbul-Izmir expressway

Designers / Engineers

IHI Corporation

COWI (Consulting engineers)

Dissing+Weitling (Architects)

Dr William Brown (preliminary design)

Description

Suspension bridge

1,550m main span

2,682m total length

Main contractors

IHI

Construction

Began 30 March 2013

Open 1 July 2016

Longer bridge spans


Bill Brown had been constantly refining his bridge deck designs following his breakthrough innovation in 1960 of the streamlined box girder for the Severn Bridge. In the 1990s he was focussing on designs that would increase the distance that could be spanned. He carefully considered the aerodynamics with the aid of his own wind tunnel and the latest computer software, but it was his vast bridge engineering experience and creative mind that forged the design concepts. The preliminary design for Izmit was presented with visualisations.

The Turkish road network would be significantly developed around the bridge and two decades later Turkey would have a significant improvement in its connectivity between Istanbul and Izmir, east of the Sea of Marmara.

Long-span bridges in Turkey


Wye Bridge

Wye Bridge 1966

Wye Bridge 1966

© Willum Griffith

The Bridge


As part of the Severn Bridge project, Bill Brown and the Freeman Fox team worked on a separate bridge and viaduct over the River Wye. This shorter, four-lane road crossing acted as a continuation of the main Severn Bridge and the M4 motorway. It became the M48 motorway when the Second Severn Bridge opened in 1996.

Bill had shown that, by getting the shaping and stiffened plates right on this project, he could produce a suspended structure that was up to 25% lighter than a more traditionally constructed crossing. It was a similar welded box to the main structure and indeed its design phase had influenced the decision to use a box girder deck on the main Severn superstructure.

Wye Bridge

Linking South Wales and England

Key Facts

Cable-stayed suspension bridge

Part of the Severn Bridge project

Advanced box girder deck


Location

Monmouthshire, Wales

Across the River Wye

Linking Wales and England


Consulting Engineers

Freeman Fox & Partners


Description

Cable-stayed Suspension Bridge

235m main span

1,153m total length


Main contractors

Cleveland Bridge & Engineering Co. Ltd.


Construction

Opened 1966


Crossing the Beachley Peninsula


The viaduct connecting the Wye Bridge to the Severn Bridge took the entire crossing right over the Beachley Peninsula near Chepstow. The Wye Bridge was constructed of steel with reinforced concrete piers. Its main span was 235 metres long and its road deck consisted of a continuous steel box girder measuring 14.6 metres wide.

Together with the completed Severn Bridge, it was opened on 8 September 1966 by Her Majesty the Queen, receiving significant publicity in engineering and national media across the world. It was another triumph in suspension bridge innovation for Bill and Freeman Fox.

Other long-span bridges


Volta Adomi Bridge

Volta Adomi Bridge 1957

Volta Adomi Bridge 1957

© Sopotnicki

The Bridge


In 1955, Bill Brown joined his Freeman Fox colleagues, Gilbert Roberts and Colin Blackwell, to work on the design of the Adomi Bridge, a trussed arch spanning the Volta River at the Akosombo Dam in Ghana. He spent ten months living in Ghana and working on site. He enjoyed this very much, despite contracting dengue fever, and the intimidating sight of crocodiles swimming in the river around the site of construction. The two-hinged suspended-deck road bridge was 334 metres in length and comprised a single-span steel arch. Due to the presence of the crocodiles, the deck sections were pulled into place sideways, lifted, and lowered on inclined hangers.

A classic truss configuration was created for the Adomi Bridge. The design called for top-quality manganese steel for the structural welding, which was a new approach from the more generally accepted use of mild steel. The construction project went well, and the bridge over the Volta River opened in 1957 to international acclaim.

Volta Adomi Bridge

Connecting western and eastern Ghana

Key Facts

Near the Akosombo Dam

Replaced the busy ferry service, where delays of a few days were possible


Location

Adome, Ghana

Across the Volta River

Near the Akosombo Dam


Consulting Engineer

Sir William Halcrow & Partners

Freeman Fox & Partners

Steel arch bridge designer: Bill Brown and Colin Blackwell (FFP)


Description

Single-span steel arch suspension bridge

245m arch span

334m total length


Main contractors

Dorman Long

Cleveland Bridge


Construction

Began 1955

Opened 1957


Other long-span bridges


Triangle Link Bridge

Triangle Link Bridge 2001

Triangle Link Bridge 2001

© B2 Archive

The Bridge


The Triangle Link fulfilled the desire to have a fixed link between the islands of Stord and Bømlo in Norway. Two of the three bridges were suspension bridges and the suspended main cable work was engineered and erected by Bill Brown’s firm, Brown Beech, and the Norwegian contactor, HMV.

Bill Brown devised the method of cable spinning to construct the main cables of each of the suspension bridges. The cables were spun using Bill’s innovative air-spinning technique with controlled tension. A carrier wheel shuttled forward and back from one anchorage up over the towers to the far anchorage. The cables consist of seven bundles, each with 420 individual 5mm wires.

The spinning of the main cables for the two bridges was completed in less than two months and its success was estimated to have given a cost saving of NOK 10million (£1million).

Triangle Link Bridge

Three bridges connecting Norwegian islands

Key Facts

Consists of three bridges

Connects Stord and Bømla Islands to the mainland

Two are suspension bridges with Severn-type single box girder


Location

Hordaland and Bergen, Norway

From Stord to Bømlo, and to the mainland at Sveio


Designers / Engineers

Design: Aas-Jakobsen

Cable: Brown Beech (B2)


Description

Stord Bridge main suspended span: 677m

Bømla Bridge main suspended span: 577m

Spissøy Bridge 283m beam bridge


Main contractors

Triangle Contractors, a joint venture between NCC and HBG Steel Structures


Construction

Stord Bridge opened 28 December 2000

Bømla Bridge opened 30 April 2001

Spissøy Bridge opened 28 December 2000


Other long-span bridges