Travelling Post Offices in the United Kingdom

A Travelling Post Office (TPO) was a type of mail train in Great Britain where the post was sorted en route. The last Travelling Post Office services were ended on 9 January 2004, with the carriages used now sold for scrap or to preservation societies.

Following an agreement in 1830, made between the General Post Office and the Liverpool and Manchester Railway (L&MR), mail had been carried by train in Great Britain, between Liverpool and Manchester, via the L&MR. The passing of the Railways (Conveyance of Mails) Act 1838 required railway companies to carry mail, by ordinary or special trains, as required by the Postmaster General; however this act did not set the charges for such services.

These special trains eventually became Travelling Post Offices (TPOs). TPOs were employed in many British Commonwealth countries; and the Army Post Office had its own TPOs.

TPOs were equipped with letter boxes so that mail could be posted whilst the train stood at a station. The post-marks from TPOs are valued by philatelists.

Mail was first sorted on a moving train in January 1838, in a converted horse-box, on England's Grand Junction Railway. It was carried out at the suggestion of Frederick Karstadt, a General Post Office surveyor. Karstadt's son was one of two mail clerks who did the sorting. In 1845 the service was extended via Derby to Newcastle upon Tyne by the Midland Railway; and soon after reached Scotland.

The first special postal train was operated by the Great Western Railway between London and Bristol. The inaugural train ran on 1 February 1855, leaving Paddington station at 20:46, and arriving at Bristol at 00:30. In 1866, apparatus for picking up and setting down mailbags without stopping was installed at Slough and Maidenhead.

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