ENGINEERS have managed to build an underpass beneath the busy A12 Blackwall Tunnel Approach without disturbing the daily flow of traffic. The new 2012 Olympic link was completed by engineers working round-the-clock in just 28 days without closing off the six-lane dual-carriageway above them

By Mike Brooke

ENGINEERS have managed to build an underpass beneath the busy A12 Blackwall Tunnel Approach in East London without disturbing the daily flow of traffic.

The new 2012 Olympic link between Old Ford and Hackney Wick was completed by a squad of 50 engineers working round-the-clock in just 28 days, all without closing off the six-lane dual-carriageway above them.

It was done using a 'jacked box' method which involved a pre-constructed concrete box 'pushed' through the ground beneath the A12.

Tunnelling techniques were used to excavate the ground while a series of hydraulic rams then pushed the box into the excavated tunnel face.

The underpass forms part of the new Olympic Loop Road being laid out across the massive 2012 site which is to criss-cross the canals and tributaries of the River Lea between Bow, Hackney Wick and Stratford which will be left as a 'road legacy' for East London after the Games.