News Article

Love in a pneumatic climate

Last Updated: 14 Feb 2018
Topics: Our history
On Valentine's Day, our Historian Tony Comer shares a story about a technology of old that helped GCHQ communicate between offices and also spark some romance.

News article - 14 Feb 2018

In the Harry Potter series, Arthur Weasley is fascinated by working out how Muggles function without magic.  Part of my job is to answer questions from younger members of staff who are fascinated by how we used to work before there were computers on every desk.  Most of the communication channels we use today have equivalents: rather than using Instant Messenger like today, we had Opscomm links: a 75 baud1 (yes, not megabaud, or even kilobaud: just baud) teleprinter circuit with our stations to enable our HQ to chat to operators. We didn't have emails, but we could send signals, and depending on the priority of the message (there were four levels: Routine, Priority, Operational Immediate, and Flash) you could get information to the other side of the world very quickly.  But what happened if you wanted to send an original document?


A glass tube, approx 30cm long, 7cm wide, with closeable padded ends
A Lamson Tube last used at GCHQ Scarborough. None at GCHQ Cheltenham survived. ©GCHQ 2018
Well, at Headquarters in Cheltenham, as at Bletchley Park before, we had a Lamson tube system.  A network of pressurised pneumatic pipes linked more than forty "tube stations" in various offices and buildings to a central tube exchange room.  When you wanted to send a document to somebody, you rolled it up, put it into a carrier, aligned two rings on the carrier to show the address of the tube room you wanted to send the document to, and put the carrier into the tube at the station.  The message would speed through the pipes to the exchange where it would be put into the tube connecting the exchange with the destination tube station.  It meant that within a couple of minutes the document could be anywhere on site that it needed to be. The system had one particular advantage over modern networks: you could put suitably shaped confectionery into a tube and send, for example, an éclair to a colleague. Such use of the system was, of course, frowned upon, and occasionally stern memos would be circulated warning staff that personal use of the Lamson tube network was not permitted.

So why am I telling this story on Valentine's Day?  Well, an example of unofficial and forbidden use of the system happened when one of our colleagues was too nervous to propose to his girlfriend in person and so sent his proposal by tube instead. It would have been very neat if she had replied by the same means but she didn't: she came to his office instead and embarrassed him by accepting the proposal very publicly. They married, and lived very happily ever after, and all thanks to the aid of a Lamson tube!




1 Bauds measure the speed of a comms link: 1 baud is one bit per second. 75 baud is prehistoric: home modems in the 90s were 56 kilobaud; few city-dwellers today will have slower than 2 megabaud internet links.