The cost of the project was £1.4 million, and seven lives were lost during construction.

Between 200 and 250 people worked on the line during construction.

During construction 600-800 men died and only 310 ever received any pay.

Seven workers were killed at various times during the construction.

In addition, there will be around 2,000 jobs during construction.

During the construction, service on the surface line will continue.

In all, 156 soldiers lost their lives during the construction.

Another low figure is the average $600 a house for security services on 250 houses during construction.

During design and construction, the team was at its largest in numbers.

That strategy does create other problems, though, like where to live during construction.