TED-Ed: How the world's longest underwater tunnel was built

The English Channel, a crucial maritime passage, posed significant challenges for crossing due to its rocky shores and stormy weather. In the 1800s, engineers proposed various designs, including an underwater tunnel. Despite technological advancements, political and economic obstacles delayed the project. By 1985, private funding enabled construction, leading to the creation of three tunnels. The project faced engineering challenges, such as water seepage and precise alignment. After 2.5 years, the tunnel was completed, becoming a major transportation route. However, it also became a site of conflict due to refugee attempts to enter Britain.

What was one of the main reasons the English Channel was considered dangerous for most of its history?

• Frequent pirate attacks

• Rocky shores and stormy weather

• Lack of navigation technology

• High traffic congestion

What technological advancement made the Channel Tunnel more feasible?

• The invention of the steam engine

• The discovery of sonar technology

• The development of the tunnel boring machine

• The creation of reinforced concrete

What was a significant challenge faced by engineers during the construction of the Channel Tunnel?

• Lack of skilled labor

• Water seepage through fault lines

• Inadequate funding

• Political opposition from both countries

How did engineers ensure the two sides of the tunnel met accurately?

• Using traditional compasses

• Relying on visual alignment

• Using underwater drones

• Employing satellite positioning systems and paleontologists

When did the Channel Tunnel officially open for public service?

• May 6th, 1994

• December 25th, 1993

• July 14th, 1995

• January 1st, 1996

What is one of the modern challenges faced by the Channel Tunnel?

• Declining passenger numbers

• Refugees attempting to enter Britain through the tunnel

• Environmental concerns

• Increasing maintenance costs

What does the history of the Channel Tunnel remind us about humanity?

• The importance of maintaining borders

• The potential to overcome barriers

• The need for technological advancement

• The significance of economic growth