Fixing a Leak (not just a washer)

For several months the Kent Underground Research Group, one of many KAS affiliated organisations, have been assisting the Crossness Engines Trust. They have been using their expertise in the excavation of difficult areas in the search for an underground leak. Every day round about midday water flows into a disused sewer. The sewer had been filled with sand when the engines were decommissioned some years ago. As all the obvious reasons for the influx of water had been tried and explored the only option left was to excavate the tunnel filling. At the same time that this work was being carried out other members of the group were clearing out the sand filling of one of the pump cylinders. When this is finished the Trust will be able to further their work of restoration of a second beam engine.

An electric winch constructed by the group’s engineer, Paul Thorn, is used to lift the buckets of sand from the excavation site up to the floor of the engine house. From there it is wheel barrowed to a dumper truck and driven to an area where the Trust is constructing a nature area.

The exploratory work on the old sewer has now been finished and we have ascertained that the water emanates elsewhere. Resulting from this discovery we are now digging into one of the original filter chambers. This chamber had a continuous bucket chain hoist and was used to remove large items from the sewers prior to the residue being pumped into the underground reservoir. In earlier times the reservoirs were emptied into the river on the outgoing tide.

One member of the group has explored some of the disused sewers in an inflatable dinghy. After air tests using a miner's lamp he was lowered into the void with his boat. The original intention was to photograph the original sluice gates to the river. However, once down there the spirit of exploration got a hold and he explored the adjacent tunnels whilst the surface crew went from vent to vent to keep a check on his progress.

It should be pointed out that before any of the group’s activities are carried out a proper risk assessment is made and measures are put in place to deal with any emergency. KURG members carry a £5,000,000 insurance and indemnity policy. We have carried out exploratory work for local authorities, developers, the National Trust and Canterbury Cathedral. If you do come across underground features on sites we can usually help in surveys and excavation.