Green’s Dictionary of Slang

Pipe, The n.

the Rotherhithe Tunnel, London.

[UK](con. 1950s) http://spitalfieldslife.com/ 2 Aug. 🌐 His round was Rotherhithe which meant driving through the tunnel [...] One day, we had to go back through ‘the pipe’ as they called the tunnel in Mile End [etc.].