Revealed: London’s secret underground railway system

Collectively dubbing themselves “Consolidation Crew,” individually with names like “Urban Fox” and “Silent Motion,” their mission was to “explore everything.”

What they did and still do is “place hack” — in other words, trespass on other people’s property.

In 2011, they made “an epic discovery of the highest order” — a “silent nocturnal city” some 25 meters (80 feet) below the streets of London, where the air was so still that calcium stalactites had formed. It felt, they wrote, ‘”like we were in an Indiana Jones movie — hot, sweaty and dank.”

Urban Fox and company went down a steep iron spiral staircase and into a series of extraordinary miniature man-made tunnels. Just as they had hoped, they’d found the defunct British Post Office underground railway network — the so-called “Mail Train.”

The extraordinary fact is that for much of its working life (pre-helicopters that is), the Post Office Railway was almost certainly the quickest way to cross London — ten kilometers in just 14 minutes. Of course, no one ever used it like that. The line wasn’t designed to carry passengers, just mail. As an old General Post Office poster used to exclaim, it was all about the ‘”Speed, Speed, Speed” of delivery.

The Postal Museum Deputy Director, Tim Ellison likes to tell the Post Office story in contemporary terms — as “the social network of its day — an incredible service on a scale that most people today wouldn’t possibly be able to imagine.”

A crucial part of it was having its own bespoke underground London railway. Its existence remains a revelation.