BACK FROM THE BRINK: The Belle Tout lighthouse on the Sussex coast was successfully moved back from the edge of the chalk cliffs last month.
The building was in a precarious position after a series of cliff collapses had left it only 4m from the cliff edge. The site is 1km west of Beachy Head, where a major collapse occurred earlier this year (Ground Engineering February).
The 17m high lighthouse was jacked up 650mm in the air and slid back 17m on four steel rails and greased skates by main contractor Abbey Pynford. Although the move took three days, slightly longer than originally planned, there were no major problems and in fact the force needed to shift the building just 2% to 3% of its weight rather than the original 10% estimate.
During the move, it was discovered that one corner of the 850t building had been supported on a previously undetected underground brick vault. Emergency repairs were needed before the structure was lowered onto its new foundations.
The contractor reported that the lighthouse was within 10mm of its intended location, despite arriving slightly on the skew.