A 'Chunnel' for Spain and Morocco
Sunday, January 28, 2007
TANGIER, Morocco -- From the bustling waterfront of this African port city, Europe appears tantalizingly close: The coast of Spain shows on the horizon just nine miles away. Despite decades of dreaming, no one has been able to bridge the physical divide that opened between the two continents more than 5 million years ago, forming the geological bottleneck to the Mediterranean Sea.
In recent months, however, the governments of Morocco and Spain have taken significant steps to move forward with plans to bore a railroad under the muddy bottom of the Strait of Gibraltar. If built, the project would rank among the world's most ambitious and complex civil engineering feats, alongside the Panama Canal and the Channel Tunnel between Britain and France.
A Gibraltar transportation link has adorned official drawing boards for a quarter-century. After years of slow-moving studies and geological tests, Spain and Morocco gave the project fresh momentum last fall by hiring a Swiss engineering firm to draft blueprints for an underwater rail route. Numerous obstacles remain, and a final decision on whether to build is still a few years away, but optimistic engineers say the project could be completed by 2025.
Government officials on both sides of the Mediterranean say the tunnel would give the economies of southern Europe and North Africa an enormous boost. But the project is being driven at least as much by intangible benefits: the prospect of uniting two continents that culturally and socially remain a world apart despite their geographic proximity.
"We've already done a tremendous amount of work to make this dream come true, to go from an idea -- a concept that is just philosophical -- into something we can transform into reality," said Karim Ghellab, Morocco's minister of transportation. "It's not easy to predict a date yet, but it is a project that will happen."
Ghellab envisions a day when commuters will board a high-speed train in Seville, in southern Spain, at 8 a.m. and arrive at their workplaces in Tangier by 9:30.
Next stop, 90 minutes later: Casablanca, followed by the bazaars of Marrakech slightly more than an hour after that. Today, such a trip by ferry and rail would take at least three times as long. "It will completely change our world," Ghellab said.
Like the Channel Tunnel, the Gibraltar project would consist of twin tracks in parallel tunnels, with a service tunnel in between. But engineers said the technical challenges would far surpass those encountered in constructing the "Chunnel," which opened in 1994.
For starters, the water is exponentially deeper: nearly 3,000 feet at the shortest route across the strait, compared with just 200 feet in the channel. As a result, engineers have mapped out a different path, from Cape Malabata, Morocco, to Punta Paloma, Spain, that would run twice as far across the strait but through shallower water -- a still daunting 985 feet below sea level.
Compounding the problem is that the seabed around Gibraltar is much more permeable than the hard-chalk rock under the channel, which would require engineers to push the tunnel down by another 300 feet or so. The water pressure at that depth means the tunnel would leak heavily, no matter how well it was constructed, said Andrea Panciera, chief project engineer with Lombardi Engineering Ltd., the Swiss firm that is designing the Gibraltar link.
"This is the biggest difficulty," he said. "We have to go deep into the seabed, which is very, very soft, with a lot of water pressure on top of that."
Officials in Spain and Morocco said their governments are committed to the tunnels but acknowledged that engineering and cost hurdles won't be easy to overcome.