After our unexpected success in exploring Finsbury Park reservoir, fellow explorer Nick and I continued our drive South, and rolled in to Sheerness just before dawn. History (amended and abridged from here and here) Thamesteel is a large former steel foundry and steel rolling site in Sheerness, on the Isle of Sheppey in Kent. Construction was given the go-ahead in 1971, and completed in 1972 at an initial cost of circa £10m (over £100m in today’s money). The works, owned…