New York and London are separated by 3,459 miles of ocean. By air, this distance takes 8 hours to cover. In recent times, engineers have proposed the construction of a maglev train between these cities. The train zips through a trans-Atlantic tunnel at a maximum speed of 5,000 miles per hour. Most audacious of all, the distance is covered in one hour. The engineering challenge of accomplishing the project is unlike anything seen before, comparable to that of landing on the Moon. According to retired MIT professor Ernst Frankel, “from an engineering point of view there are no serious stumbling blocks”. As always, an analysis of the design features proposed will help evaluate to what extent this statement is true.
The first design feature of inspection is the tunnel. Instead of building the tunnel along the seafloor, engineers have proposed another option. This involves submerging the tunnel “150 to 300 feet beneath the Atlantic’s surface”. In addition, the structure is firmly tethered to the seafloor by cables.
There are a few key advantages to this choice in design. To begin, the enormous pressure at high depths is avoided and the construction process itself is made easier. It is estimated that it would take 300 years to drill across the Atlantic seafloor. Secondly, the Mid-Atlantic Ridge is situated right below the tunnel and is known for its extreme volcanic activity. By making the tunnel float, the proximity between the tunnel and the volcanoes is reduced, although not eliminated. Thirdly, the cables provide “just enough slack to allow the tunnel to absorb the impacts of savage ocean currents and tidal flows”. This additional flexibility accrues stability to the tunnel.
Despite these advantages, there are serious drawbacks. Although construction is easier nearer the surface, it still poses significant obstacles. For example, only one of the 50,000 sections of the tunnel requires “enough concrete and steel to build a 10 story building”. Quantitatively, it would take 1 billion tonnes of steel to build the whole tunnel, which is what “all the world’s steel mills produce in a year”. Yet another fact to consider is that during extreme weather conditions, construction work would have to stop entirely. It is impossible to predict whether the tunnel can endure severe underwater earthquakes and currents.
The second design feature of inspection is the maglev train. For a train that is thundering along at 5,000 miles per hour, friction and air resistance are huge obstacles. These are overcome by the use of maglev and a vacuum. Maglev (short for magnetic levitation) is a phenomenon where objects are propelled by magnetic pulses in lieu of wheels. Hence, the train is essentially ‘floating’ and there is no kinetic friction between the train and track. Furthermore, a vacuum is created by pumping all the air. This ensures that there is no air resistance to slow the train down, allowing it to reach high speeds. In addition, the vacuum “save[s] the tunnel from the destructive effects of a sonic boom”, a phenomenon that has the power to destroy the tunnel.
One has to also consider the trade offs of this design. Removing all the air from the tunnel would take “100 jet engines, working 24 hours per day for two weeks”. This raises big questions related to the sustainability of the project. Another concern is safety. Any derailing of the train would cause the death of hundreds. At such high speeds, it is difficult to guarantee the complete safety of passengers.
No doubt, a maglev train connecting two continents would have a positive impact on the lives of many. It would mobilize businessmen, goods and services, increasing economic activity and globalization. On a human level, a student studying in the States could go back home for Thanksgiving in the matter of hours. As good as it sounds, is it worth spending $12 trillion (nearly 15% of the world’s GDP) on a tunnel that takes 100 years to build? There is no easy way to answer this question, but I do believe that mankind is destined to accomplish this feat in the future.