The Channel Tunnel at Thirty

 by Diarmuid Bailey

In May the world's longest undersea tunnel will celebrate its thirtieth year open. With over 500 million people having used this megaproject over this time it has stood as a testament to the evolution of construction and the lessons learnt from it have restructured the industry. Drawing in 1,300 workers, it stretches 50 Km under the sea, took 6 years to construct and was centuries in the making. This is the story of how the seventh wonder of the modern world, The Channel Tunnel, was built. 

The Channel Tunnel, or Chunnel as it is affectionately known, is in fact three separate tunnels; two rail tunnels taking on average 500 trains a day and a central service tunnel for emergencies and ventilation. Estimated to cost £5.5 billion in 1985, at the time it was the most expensive construction project ever proposed, the final cost was over £9 billion, equivalent to £21.8 billion in 2021. With record unemployment, key industries collapsing and massive civil unrest, neither government was in a position to fund such an ambitious project, this meant it had to seek private investment. Everyday people, including my Grandfather, invested their money to see this project finished, alongside banks such as CTG and FM. The project stalled throughout construction with fears that it would never open, however the first train, carrying 75 people, crossed through the tunnel in 1994 and they haven't stopped since.   

 

As early as 1802 there were plans to connect the two countries, shortening the 6 hour dangerous ferry ride taken by most. At the time it would have connected the two countries through a road with horse and carts using the narrow tunnels to traverse a similar route the trains do today. Many thought that this strategy was merely a ploy by the French government to be able to invade so the idea lost traction with the public.

The idea was revisited in the late 1950s and early 1960s, with a series of bridge and tunnel designs being adopted, work even began on a tunnel in 1974 before being called off. Some of the most interesting were a bridge-tunnel-bridge, suggested in 1963 and 1984, with two artificial islands linked to land by two bridges and each other by a tunnel. It was designed for rail and road with hotels and services on each island, a more touristic experience than a windowless tunnel under the sea. The plans were proposed by Euro-Route at a high cost and quickly were rejected by both governments for a more affordable option, a tunnel. As a competitor to Euro-Route, FranceManche proposed a dual-purpose rail tunnel for fast trains and shuttles with a lower cost than the bridge-tunnel-bridge it quickly won support. 

Construction broke ground in 1988 utilising the prior efforts of earlier attempts it began with the excavation of the tunnels. The service tunnel took the lead with the two rail tunnels following along allowing for the route to be tested before the expensive mistakes were made. Sticking in the chalk layer allowed for a cheaper cost as it provided a watertight layer and an easier material to drill through creating quick progress. One of the most difficult tasks was making sure that both the British side and French side matched up. With 5 Tunnel Boring Machines (TBMs) dug from France and 5 TBMs from England it was a challenge to navigate the thin layer and stay on course requiring specialist lasers to guide the two tunnels to meet. Hands were joined, metaphorically and physically, in December 1990 when the two service tunnels joined up with the rail tunnels being completed shortly after. The dirt excavated by the Tunnel Boring Machines was used to build the ventilation outputs at the foot of the White Cliffs and to create a nature reserve off-putting some of the effect the construction had on the environment.

Since the Channel Tunnel has opened, there have been a number of controversies around its ongoing operations. Despite how the people vote the UK is now attached to Europe physically. Brexit has been one of the biggest political impacts on the tunnel in recent times. The arrangements for the construction and operation of the Channel Tunnel were agreed through the 1986 Treaty of Canterbury signed by the French President, President Mitterand and then British Prime Minister, Margaret Thatcher. However following Britain’s departure from the European Union in December 2020, a new legal framework was needed to govern the operations of the tunnel. In 2021 it was suggested that the French authorities wanted full control over the length of the tunnel, in relation to safety and security, with the European Court of Justice settling disputes. This move was being opposed by the British government as an attack on sovereignty, with the House of Commons European Scrutiny Committee describing the 2021 French proposal as a “power grab”. Furthermore, the question of illegal immigration has plagued the tunnel's ongoing operation. Illegal immigrants were using the tunnel for clandestine passage into the UK from centres in northern France and most notably from Sangatte, where the tunnel opens. A few attempted to walk through the Tunnel or cling to the trains themselves, but most tried to hide in freight containers or trucks using the tunnel. Sangatte has since closed, considerably reducing the use of the Tunnel for illegal immigration. The problems with illegal immigration led to both the UK and French government spending tens of millions of pounds on tightened security measures around the opening to the tunnel.

The Channel Tunnel has stood as a testament for engineering between both countries and its position in the 21st Century, so far, shows how extraordinary it was. With over ten million passengers being transported each year and one million tons of freight being imported through the tunnel it is a vital connection to Europe that ensures a successful relationship of trade for both parties. Despite political  adversities the tunnel has persevered and will continue to prosper into the many decades after its thirty year anniversary.