You would be forgiven for thinking that here we have a photograph of the piping inside the ballast tanks of a WW2 submarine but no, this shows part of the low tension network at the Mullard Mitcham production facility.  Although this may look arcane and let's face it, the working conditions certainly are ( does it comply with PUWR regulations???),  this was considered state of the art in 1953 with the proud boast that the Mitcham Plant Department was the most up to date in the South of England.