 In the late 1930s , war between Britain and Germany began to seem likely . Ramsgate 's location on both the English Channel and North Sea and its proximity to the Thames Estuary , its large port facilities , and its close proximity to RAF Manston made it a likely target for heavy aerial bombing and as a landing site for any German invasion of Britain . With this in mind the town 's borough engineer and surveyor , R. D. Brimmell , devised a scheme in 1938 for a network of tunnels beneath the town , to serve as a vast deep @-@ level air @-@ raid shelter for the town 's inhabitants . 
