 While construction of the Chesham line was underway , the Metropolitan Railway was also expanding to the northwest , and in 1892 the extension to Aylesbury and on to Verney Junction opened . The Chesham line became a branch line , with most trains operating as a shuttle service connecting to the main line rather than as through trains to London . The opening in 1899 of the Great Central Railway , Edward Watkin 's connection between London and Manchester , as well as the highly successful Metro @-@ land campaign encouraging Londoners to move to the rural areas served by the railway , led to an increase in traffic in the area , although the Chesham branch was less affected by development than most other areas served by the railway . In 1933 the Metropolitan Railway was taken into public ownership and became the Metropolitan line of the London Underground . London Underground aimed to concentrate on their core business of passenger transport in London , and saw the rural and freight lines in Buckinghamshire as an expensive anomaly . The day @-@ to @-@ day operation of the Chesham branch was transferred to the London and North Eastern Railway , although London Transport retained control . In 1960 the line was electrified , and from then 1962 on was operated by London Underground A Stock trains . 
