Editing Talyllyn Railway (section)

==Operation==
{{See also|List of Talyllyn Railway rolling stock}}
The line has six steam locomotives for passenger trains and four diesel locomotives, which are primarily used for shunting and to haul works trains. It is unusual for all steam locomotives to be operable at the same time, as at least one is normally scheduled for overhaul.<ref>{{cite web |url=http://www.talyllyn.co.uk/node/661 |title=Talyllyn website – 100% availability |publisher=Talyllyn Railway Company |access-date=6 September 2014 |date=29 August 2007 |author=Willans, Karen |url-status=dead |archive-url=https://web.archive.org/web/20141221203929/http://www.talyllyn.co.uk/node/661 |archive-date=21 December 2014 |df=dmy-all }}</ref> The railway also owns 23&nbsp;carriages and vans, including all of the original carriages and the brake van built for the railway.

[[File:Brynglas.jpg|thumb|left|Brynglas block-post]]
The railway is [[Single track (rail)|single track]], so special measures have to be taken to prevent collisions. Before preservation, the railway operated a "[[Signalling block systems#One train working|one engine in steam]]" policy, but with growing passenger numbers it became necessary to install passing loops and a more stringent method of single line control was introduced.<ref>Potter, pages 130–131</ref> The line is worked by Electric Key [[Token (railway signalling)|tokens]] installed in 1973, which authorise the driver to enter a section of single line, and these are interlocked to prevent more than one token being withdrawn for a section at any one time. There is a loop at Pendre, which was used from the opening of the railway for shunting purposes, and further loops were installed at Brynglas in 1953 and Quarry Siding in 1963.<ref>Potter, pages 132–133</ref> When the Nant Gwernol extension opened in 1976, Abergynolwyn also became a passing loop.<ref>{{Cite web|url=https://www.talyllyn.co.uk/history/part-8-nant-gwernol-extension|title=History Part 8: The Nant Gwernol extension|publisher=Talyllyn Railway|access-date=15 June 2019|archive-date=1 January 2020|archive-url=https://web.archive.org/web/20200101184146/https://www.talyllyn.co.uk/history/part-8-nant-gwernol-extension|url-status=live}}</ref>

Each passing loop is controlled by a small [[signal box]], known as a block-post. These house the [[Lever frame|lever frames]] that control the points, the token equipment and telephones. The railway has few signals; instead it has stop boards at Pendre, Brynglas, Quarry Siding and Nant Gwernol, and the [[Signalman (rail)|blockman]] allows trains to proceed by use of flags.<ref>Potter, page 222</ref> There are colour light signals located at Tywyn Wharf, operated from the Control Office and disc signals controlled from the ground frame. Abergynolwyn has colour light signals, which are operated from the blockpost.<ref>Bate 2001, pages 128 & 186</ref> When the block-post is unmanned, it is the responsibility of the locomotive crew to change the token before proceeding.<ref>Rolt 1965, page 102</ref>