The company W T Henley has always been highly regarded for the manufacture of cable and electrical components and was clearly the company of choice when a system had to be devised as a countermeasure to the growing threat of German magnetic mines during the Second World War.  As a result, a new site was constructed in 1939 in Gravesend for W T Henley and a complex of tunnels was built underneath to provide air raid shelter for the company’s employees.

With at least six entrances, the air raid shelter was very clearly signed internally to ensure that there was no confusion when looking for your allocated space.  Cut into chalk and lined with prefabricated concrete, the shelter tunnels were well laid out, including first aid areas and numerous latrines – in the form of Elson buckets.

The tunnels remain remarkably well preserved and have seen use in the post-war era.