 Construction work began on 2 May 1936 . The company hoped to have the line open in time to serve the large crowds expected on the August Bank Holiday , leading to a very tight construction deadline of three months . To try to meet the deadline , construction work was carried out both day and night . As the journey would take place entirely underground it was decided to line the wider , original tunnel with illuminated displays showing scenes from around the world . This led to the line becoming semi @-@ officially known as the " World Scenic Railway " . 
