70 or so feet underneath London's streets lies the unused mail rail system, a hard to reach subterranean system of postal tracks, cloistered away from human eyes. That is, until a gang of intrepid urban explorers cracked a secret entrance.
After a precarious climb up a five-story drain pipe, the spelunkers at Silent UK plumbed the depths of this system, which has existed in various forms for over a century:
Originally designed using a pneumatic system in 1855, after years of testing, tunnel construction and usage its limitation began to show. The Post Office who were already unhappy with its high running costs, coupled with the fact the scheme only shaved four minutes from the delivery time by road decided in 1874 that they would no longer use the line, the Pneumatic Despatch Company being dissolved as the tunnels were closed [...] Even before the demise of the Pneumatic line, several plans had been put forward recommending a similar mail delivery system, most promoting usage of electrified lines [...]
The line was eventually finished in 1927 with the first letter through the system running on February 1928 [...] Although initially the system was a success, in its last years of service the line was continually [losing] money. On the 7th November 2002, Royal Mail announced the line had become uneconomical with losses of £1.2M a day and that they planned to close it should no alternate uses be found. This was to be the death of the Mail Rail with the line from Mount Pleasant to the Eastern Delivery Office closing on the 21st March 2003, the remaining section from the Western District Office to Mount Pleasant following on the 29th. Now it just sits there buried where light cannot reach, rusting away, the trains sleeping silently in and around the stations wanting to be used again. Sadly a dream which we all know will never come true.
You can see many more photos of these mostly inaccessible tunnels over at Silent UK. Hat tip to Spencer!