English: Royal Mail Travelling Post Office (TPO) - information board. In 1830 an agreement was made between the General Post Office and the Liverpool and Manchester Railway (L&MR), according to which mail had was carried by train between Liverpool and Manchester using the L&MR. These special trains eventually became Travelling Post Offices (TPOs) > 1560877. TPOs were equipped with letter boxes > 1560871 so that mail could be posted whilst the train stood at a station. The first mail was sorted in a moving train in January 1838 and 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 with the inaugural train leaving Paddington station at 20:46 on February 1855. In 1968 the Post Office introduced the two-tier letter service and since then the TPO's have sorted only First Class mail. During the 1970's some marginal TPO's were withdrawn on economic grounds but the overall size and shape of the network remained largely unchanged until the mid-1980's. After initially suspending the transport of mail by rail on 9 January 2004, Royal Mail reversed this decision over the Christmas season that year and began again operating some TPO trains. In 2009 the contract for the mail trains reverted to DB rail. In 1963 £2.3 million was stolen from a Glasgow to London TPO train. Picking up and dropping mailbags without stopping was a feature of the TPO service and a few examples of the mail bag pickup apparatus can be seen on preserved railways > https://www.geograph.org.uk/photo/1560886. Coaches equipped with said apparatus had a large net which was made of heavy duty rope. This net was fixed to a hinged metal frame on the exterior body and could be extended to catch mail bags, enclosed in strong leather pouches to as a protection from being damaged and suspended from line side posts. The bags were projected through an opening in the coach body side and landed on the carriage floor. In order to despatch mail from a moving TPO folding metal brackets were fitted at body side doors, enabling bags to be hung from the carriage and scooped up by lineside nets. The last lineside apparatus exchange took place on the British Railways network at Penrith in October 1971. Since then only three locations in Great Britain have been able to operate the exchange: the Great Western Society at Didcot in 1975, the Great Central Railway in 1982, and most recently the Nene Valley Railway in September 2000. The lineside apparatus equipment at the Nene Valley Railway is on loan from the Locomotive Club of Great Britain (LCGB). A second lineside apparatus was installed in February 2008 by Hallet's Halt > https://www.geograph.org.uk/photo/1561021 just east of the new Yarwell Junction station.