By train from Europe to Africa - undersea tunnel project takes a leap forward

. Spain and Morocco set up engineering study project
· Major hurdles, but service could be running by 2025

Giles Tremlett in Madrid
Friday October 20, 2006
The Guardian

The excavation of a tunnel joining Europe and Africa deep below the Strait of Gibraltar could start as early as next year after Spain and Morocco commissioned preliminary engineering studies.
Veteran Swiss tunnel engineer Giovanni Lombardi has been called in by the governments of both countries to draw up a project outlining how work could proceed towards creating the only direct physical link between the two continents.

Exploratory tunnelling could start after his report, which will be based on recent detailed studies of the geological patterns under the strait, is handed in next year. "We are just beginning the work, but I would say this is more difficult than the Channel tunnel," Mr Lombardi told the Guardian yesterday.

"The main difference is the depth of the sea but the geological conditions are also different."
Actual construction of the 25-mile twin rail tunnel could take 15 years from when preliminary studies and the exploration tunnels were finished, Mr Giovanni said.

Spanish engineers involved in the project have said that if no major geological or technical problems arise rail passengers could be travelling to and from Africa by 2025.

It would be a twin rail tunnel with a service tunnel between and is projected to carry 9m passengers in the first year, rising to 11m after 10 years. It could also carry 8m tonnes of goods in 2025.

A final decision on whether the tunnel will be excavated, however, depends on both financing and political will. The border between Morocco and oil-rich Algeria is currently closed, for example, thereby reducing potential traffic.

There are no costings for the tunnel as yet, but estimates made several years ago put the minimum price at more than €5bn (£3.36bn). The 31 mile Channel Tunnel, although relatively easier to build, eventually cost £10bn.

If the tunnel to Africa was linked to the existing high speed rail line at the southern Spanish city of Seville the travel time between Madrid and Tangier could be as low as four hours.

Spain first began studying the idea of a transcontinental tunnel in the 1970s. A joint Spanish-Moroccan body was founded in 1991, inspired by the building of the Channel Tunnel, to start surveying the seabed under the strait.

Those studies have been hampered, however, by sea conditions in the strait.

Engineers have had to invent new boring methods in order to cope with the fierce underwater currents at a point where the Atlantic Ocean meets the Mediterranean Sea.

They have already decided that the tunnel cannot cross the narrowest part of the strait because, at 900 metres, it is too deep.

A rail tunnel at that point, between Spain's Punta Canales and Morocco's Cirea Point, would have to start many miles inland so that the gradient would not be too difficult for trains to climb.

The current proposed route for the new tunnel lies to the west, where the seabed is, at 300 metres, relatively shallow.

Even that is much deeper, however, than the Channel Tunnel where the sea bed lies just 50 metres below the waves. As a result, the gently sloping tunnels will emerge at least three miles inland from the coast on either side.

They will cross the African coastline under the area around Malabata Point, near Tangier, and reach European soil somewhere under Spain's Punta Paloma.

The strong currents and depth mean that bridges have been ruled out as a way of connecting the two continents.

Some engineers, however, favour the idea of building a huge barrage that would also control water flow into and out of the Mediterranean.

The geological layers under the Strait of Gibraltar are horizontal, meaning the tunnel has to cross through many different rock strata. "That is quite a complex geological situation," said Mr Lombardi.

Underwater clay deposits that have recently been discovered near the Moroccan coast have further complicated the project.

Mr Lombardi said he would also have to take into account a history of earthquakes in the region, including the 1960 quake in the Moroccan city of Agadir and the 1755 quake centred near Lisbon, Portugal.

Mr Lombardi, aged 80, has built many tunnels in Switzerland and was recently called in to redesign the Mont Blanc tunnel after 41 people died in a fire there in 1999.