The Pneumatic Railway

The world’s first hyperloop

In 1909, the Post Office began to consider ways to quickly and safely transport mail across london. They would eventually settle on the electric driverless railway we now call Mail Rail, but not before experimenting with pneumatic power.

Air powered, or pneumatic, means of propelling containers predate not only electric railways, but even the first steam powered railways. The first recorded suggestion of using air to move things though pipes was from French Engineer Monsieur Denis Papin in 1667.

His proposals never led to production, but in 1810 a proposal was made for a similar system specifically for movement of letters. Once more, it was not developed as it was considered too complicated and expensive. However, from then on various ideas were experimented with.  

In 1853, a small diameter pneumatic powered tube system was successfully developed to move messages over a short distance at the Central Telegraph Office (now the site of the BT Centre in Central London). This was expanded and developed over the following years and by 1869 a variation developed by German company Siemens linked several postal buildings in London. This provided a means of internal communication within post offices in various UK towns and cities.

These pneumatic tube systems became common place in the UK for many years and some will remember them in use for sending short messages or moving cash in supermarkets. The Postal Museum also has a working example of pneumatic tubes for visitors to interact with, speeding messages across the gallery.  

The Pneumatic Tube in The Postal Museum’s exhibition gallery

At a similar time to the development of the small diameter pneumatic tubes for messages, consideration was being given to larger scale versions that might be used for movement of letters in bulk.  

In 1855 Rowland Hill, Secretary of the Post Office, requested an investigation into a ‘tubular conveyance of mail’ system using air power. It was found to be feasible but was not taken further as it was going to prove too expensive to develop.

The 1855 scheme however, was arguably the first consideration towards what later become Mail Rail.

The Pneumatic Despatch Company

A further proposal was put forward in 1858 for a larger scale rail-based pneumatic system, this time by a private company called the Pneumatic Despatch Company.  

Proposed layout for the London Pneumatic Post. Prepared in 1858 by by T.W.Rammell, Engineer to the Pneumatic Despatch Company (POST 30/766)

An experimental, above ground, version was built at Battersea in a series of pipes to prove the technology could work.  

The Pneumatic Despatch Company built an experimental tube on the banks of the Thames at Battersea, adjacent to the Victoria railway bridge. Illustration from The Illustrated London News, 24 August 1861

The company wanted to secure a contract with the government owned Post Office, which would offer them the financial security they needed. The Post Office was initially interested and in 1863 a short section of this pneumatic railway was built linking the North Western District Office at Eversholt Street with Euston Station, allowing movement of letters between the sorting office and the mainline trains.

There were numerous difficulties and failures, but when it worked it did see a remarkable increase in speed of moving the post. Technology developed and changed during the trials and the size of the tunnels and cars that carried the letters increased to allow for greater volumes to be accommodated.

By 1866 the cost of development and running was such that the Pneumatic Despatch Company was running at a loss. However, after a pause in development, work continued a few years later and by 1874 the system was extensive, running from Euston Station to the Post Office Headquarters at St Martins Le Grand with an interchange at Holborn where the mail was transferred from the smaller system to the larger one. However, despite the relative success the Post Office once again failed to commit to the system, and the company was unable to secure sufficient funding to continue. The company failed and the railway came to an end. That was almost the end of the story.  

The history of the pneumatic railway was re-visited in 1909 as part of the commission into what became Mail Rail, but the old pneumatic tube system was to make itself known again in dramatic form in 1928. 

The Holborn Explosion

After the abandonment of the pneumatic tube system in 1874 the tunnels were occasionally used for cables to be laid for the telephone network, thanks in part to the link between Holborn, where the large Kingsway telephone exchange was situated, and the Central Telegraph Office, close to St Martins Le Grand. In the early 1920s, fires occasionally broke out in some of these tunnels following build-up of flammable underground gases. The post office engineers would regularly ventilate the tunnels to prevent potential fires.  

On the morning of 20th December 1928, two post office engineers, W C Fisher and A L Standley, arrived outside the West Central District Office at High Holborn and lifted the manhole cover to start ventilation of the tunnel.

A third colleague, Percey George Thrower, arrived with an electrically powered blower to help speed the clearing of the gases. Thrower descended into the tunnel and began to set up the blower. A spark, probably generated by Thrower himself, possibly with a lighter, ignited some of the gases. It caused a large explosion and blew Thrower from the hole he was in. Fire broke out and travelled through the underground tunnel along Holborn.

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At each manhole the gases exploded blowing the manhole covers and causing further destruction. The road surface above collapsed into tunnel across a large area, stretching from St Giles Circus at the junction with New Oxford Street and High Holborn to the junction with Kingsway further down New Oxford Street.

The destruction was extensive and properties and the road surface badly damaged. Thrower, the engineer that had entered the tunnel sadly died in Charing Cross Hospital from his injuries. An investigation followed and extensive work took place to make the abandoned network safe. 

Uncovering the past

In 1930, close to Euston Station, work was taking place to excavate part of the former tunnel network and in doing so four of the rail cars from the pneumatic tube were discovered. Three were reportedly removed complete and one was cut in half to get it out. Two of the complete cars have since been lost, one probably destroyed in bombing in the Second World War. The two half sections, and one of the complete railcars are now part of The Postal Museum’s collection. 

The story of the pneumatic railway is one of Victorian innovation, experimentation, and at times disaster, but one whose evolution and development can be linked directly to the story of Mail Rail today.