Sealing the challenge
With the hydraulics in the Thames Barrier now a quarter of a century old, there is some concern that the harder seals are now coming to the end of their lives
, according to Thames Barrier engineer at a meeting organised by the Institute of Materials, Minerals and Mining (IOM3). In all, there are around 13,000 seals, mostly nitrile, of 40 to 80 Shore hardness. It is estimated they would take 13 years to replace.
A decision must now be made as to whether it would be more economical to replace the ageing power packs or strip them out and replace the seals.
There is no question of replacing the main cylinders – believed to be the largest displacement hydraulic cylinders ever made, and specially forged for the job and supplied by Henry Berry and Company. Nor is there any problem with the massive gates or the rest of the construction, which showed itself stronger than the 98m long dredger Sand Kite, which ran into the structure 10 years ago, loaded with 3300 tonnes of shingle.
