PNEUMATIC TUBE SYSTEMS
These started in the days of the Telegraph and Telegrams. As most information was paper based the GPO used pneumatic tubes to distribute the information between large offices, outside bodies or internally within a building. Street tubes connected buildings, whilst House tubes were installed within a building. House tubes could be found around the UK in various large GPO buildings and also in large exchanges. The papers were placed in tube shaped carriers, which were slightly smaller in diameter to the tubes, to allow for bends.
Street tubes involved the use of lead and steel underground piping between the buildings, whilst the House tubes used brass pipework. At the end of the tube would be collection and sending terminals. The systems operated on compressed air and/or vacuum.
There was also a system called Ticket tubes, which were oblong shaped tubes, used for sending Trunk call records. In this system the tickets were blown down the tubes, obviating the need for carriers.
Most of the large London Post Offices had Street tubes terminating at the GPO West building, usually known as the Central Telegraph Office (CTO) in St. Martins Le Grand, London. GPO West was opened in 1874 and demolished in 1967. The CTO was the Telegraph hub of the UK and had telegraph connections world wide, employing 5000 people at one point.
These GPO systems are no longer in use today, but pneumatic tube systems can still be found in Hospitals, where samples can be sent to the Pathology department from any department that had a tube terminal.
Last revised: August 20, 2023