2nd August: The Blackwall Tunnel

On this date in 1967 the second Blackwall Tunnel opened in Greenwich, London. The tunnel was originally opened as a single bore in 1897 by the then Prince of Wales, and supported a mix of foot, cycle, horse-drawn and vehicular traffic. By the 1930s, capacity was becoming inadequate, so the second bore opened in 1967, handling southbound traffic while the earlier 19th century tunnel handled northbound. 10 things you may not know about the Blackwall Tunnel:

1. The Northbound tunnel has sharp bends, although the Southbound one does not. This was to prevent Horses from bolting as soon as they saw the light at the end of the tunnel. The Southbound tunnel was built for cars so such precautions were not necessary.
2. 600 homes had to be demolished to make room for the first tunnel, including a house Sir Walter Raleigh once owned.
3. The Blackwall Tunnel is not a toll road, even though the nearby Dartford Tunnel is, because it was already an established route into London when the second tunnel was built.
4. The tunnel is part of the A102 road.
5. One London bus route runs through the tunnel - the 108, which runs between Stratford and Lewisham. Sometimes, when the tunnel is closed to other traffic, the buses still go through with an escort.
6. The entrance to the Northbound tunnel is a Grade II listed building since 1973.
7. The ventilation towers, designed by GLC architect Terry Farrell, were also listed in 2000.
8. In January 1979, the IRA planted a bomb in the tunnel, set to explode at midnight. Although the bomb did go off as police were searching the tunnel after the anonymous tip off, nobody was hurt in the explosion.
9. One of the worst London traffic jams ever was caused by a crane driver who ignored height restriction warnings and drove in anyway, breaking a reinforcement frame. The whole tunnel had to be closed at once. It might not have been so bad if not for the fact that the Limehouse Link Tunnel and the Queen Elizabeth II Bridge were also closed that day.
10. There could be a third tunnel one day. This is one of the proposals to make traffic flow even better.