To enable B & V to construct 4nr sewage tanks there is a requirement to install 2nr sheet pile walls. A leader rig was used to install the sheet piles fed by the 38t excavator with Movax attachment.

3 sided open cofferdam measuring 18m x 15m x 15m. L604 x 9.0 to 9.5m sheet piles was installed to a level of 104.0mOD and 103.3mOD, which left the piles projecting 1m above the existing ground to act as a safety barrier. A twin waling beam was installed at a level of 102.0mOD to reduce the deflections due to the proximity of the existing sewage pipe.

A 30m run of various types of piles ranging from 12.0 to 13.7m sheet piles was installed to act in cantelver to retain the existsing ground in order for the silo base to be constructed.