A Strait of Gibraltar crossing is a hypothetical bridge or tunnel spanning the Strait of Gibraltar that would connect Europe to Africa.
The governments of Spain and Morocco appointed a Joint Committee to investigate the feasibility of linking the two continents. This resulted in the much broader Euromed Transport project 2003 - 2009.
Contents |
Several engineers have designs for a bridge spanning the Strait of Gibraltar on various alignments and with differing structural configurations. Professor T.Y. Lin’s proposal for a crossing between Point Oliveros and Point Cires featured a 14-kilometre length, deep piers, 3000-foot towers, and 5000-metre spans, far exceeding the longest current bridge span.[1]
In 2004 architect Eugene Tsui published his concept of a floating and submerged bridge connecting at a three mile wide floating island in the middle of the Mediterranean Sea.[2]
In 2004 The Science Museum included an image of the concept of the proposed Gibraltar Straits road bridge.[3]
Futurist author Arthur C. Clarke described a bridge across the Strait in his 1979 science fiction novel The Fountains of Paradise.
| Overview | |
|---|---|
| Location | Strait of Gibraltar |
| Status | Proposed |
| System | Railway tunnel |
| Operation | |
| Owner | Spanish and Moroccan governments |
| Technical | |
| Line length | 39 kilometres (24 mi) |
| Lowest elevation | ~300 metres (980 ft) below sea level |
Various Gibraltar tunnels have been proposed. The earliest record one was in 1930 with the first modern tunnel under the Straits of Gibraltar was a proposal by Spain in 1930. But there was one major problem discovered by the engineers hired by the Spanish government, in that the material under the straits was of extremely hard rock making normal tunneling almost impossible with the technology available.[4] One engineering solution was to prefabricate a tunnel in concrete sections and fix these sections to the floor of the straits by cables. This tunnel would handle both automotive, truck and train traffic. Nothing came of this proposed engineering solution.[5]
A 2008 geological study cast doubt on its practicality. However in March 2009 a contract was issued for a joint system linking the Moroccan "Société Nationale d'Etudes du Détroit de Gibraltar" SNED with its Spanish counterpart, the "Sociedad española de estudios para la comunicacion fija a través del Estrecho de Gibraltar S.A" SECEGSA
The idea of a tunnel for petrol/diesel powered road vehicles has been discounted due to the currently very difficult engineering challenge of ventilation to remove exhaust gases from a tunnel some 14 kilometres (8.7 mi) long. A three-year study for a railway tunnel was announced in 2003. SNED and SECEGSA commissioned several sea-bed surveys.
The strait depth extends to 900 metres (3000 ft) at the shortest route, but only about 300 metres slightly further west, where the European and African plates meet. The shortest crossing is about 14 kilometres (8.7 mi), whereas the proposed route runs west of Tarifa and to the east of Tangier, is not straight, being some 23 km. The tunnel is likely to be about 34 km in all, and an additional rail line would be needed to link the Spanish end of the tunnel near Tarifa to Algeciras, where the current Talgo train-hotel service currently terminates.
The project would be financed by two publicly-owned companies, SECEGSA Spain and SNED in Morocco, with the assistance of the European Union. It is yet not clear if this will be a Euromed project or a commercial consortium.
A report [6][7][8] on the feasibility of the tunnel was presented to the EU in 2009 and a further study of the Project global assessment and evaluation is under development by a Group of specialized Consultants composed by Systra, Amberg and Cowi.
In December 2003, Spain and Morocco agreed[9][10] to explore the construction of an undersea rail tunnel to connect their rail systems. The tunnel would have linked Cape Malabata near Tangier with Punta Paloma 40 km west of Gibraltar.[11] In late 2006, Lombardi Engineering Ltd, a Swiss engineering and design company, was retained to draft a design for a railway tunnel.[12] According to the company, the main differences between the construction of this tunnel and that of the Channel Tunnel, linking France and Great Britain, are the depth of the sea and the geological conditions. The area under the Strait is less stable than that under the English Channel, as an active major geologic fault, the Azores-Gibraltar Transform Fault, bisects the Strait, and severe earthquakes have occurred in the area. The presence of two very deep Quaternary clay channels in the middle of the Strait also makes construction complex,[6] causing doubts about the feasibility of the project and proposals for an exploratory tunnel.[13]
It is projected to carry 9 million passengers in its first year of operation, expected to be 2025. No official figures about the cost of the project had been announced by 2007, but previous estimates were at least five billion Euros.[14]
The proposed rail tunnel would be 40 kilometres (25 mi) long, 300 metres (980 ft) deep,[7] and its construction could take 15 years. An earlier plan was to link the two continents via the narrowest part of the strait, but this idea was dismissed as it is 900 metres (~3000 ft) deep. Even 300 m is deep since the deepest undersea tunnel, the Eiksund tunnel is 287 m (942 ft) below sea level.
Terminals might need to be constructed for trans-shipment of road vehicles, like those at Cheriton and Frethun.