The railway comprises a single line between its termini at Chinnor and Princes Risborough, with an additional intermediate siding and connection to Network Rail at Thame Junction (just outside Princes Risborough), which location for many years had a loop and served as our terminus. (Thame Junction was once where the line to Thame and Oxford diverged.)
The line is operated to a version of traditional One Engine in Steam (OES) signalling regulations. No train may occupy the single line unless its driver has what we call the token (which is a bit like a giant engraved key) as his authority. Since there is only one of these, he will not meet another Driver coming the other way!
The terminus at Princes Risborough has a run-round loop alongside our newly rebuilt platform 4 as well as a couple of sidings beyond the London end of the station. The commanding 1904 built signal box North of the platform – Princes Risborough North Box – was closed in 1991 and became derelict, but has been largely restored (forever ongoing!) and recommissioned to control the points and signals at that end of our line. The current signalling was brought into use in January 2023 and completed along with our “Chinnor Independent Line” between Princes Risborough and Thame Junction in June 2025.
At Thame Junction the connection to our siding (and via a boundary gate to one belonging to Network Rail) is worked by a small outdoor “ground frame” of levers which can only be unlocked using the single line token once a train has stopped there. There are no signals. This provides a simple and well proven system for control of such remote sidings.
At the other terminus, Chinnor, the points and signals are worked by levers in an even older 1890s built signal cabin (re-located to Chinnor in 2007). The most recent track and signalling work there has focussed on bringing the run-round loop up to passenger traffic standard. (It was formerly only of siding status.) This now allows us to run a loco round a passenger train without needing to ask all the passengers to get off every time – particularly welcome for some private charter and evening dining services.
The signals at each end of the line are mechanically operated semaphore and/or disc signals as once used on the Great Western Railway and the Western Region of British Railways. The equipment was rescued some years ago, and has been restored and installed by members of our Signal & Telegraph Department. The signals and signal box at Chinnor give the look and feel of a true GWR branch line station. At Princes Risborough we have followed a more British Railways (Western Region) era style.
The foot crossing of the railway at Chinnor, which is used by visitors to access the station, has staff operated gates which are supervised from the signal box and interlocked with the signals.
The line has two intermediate vehicular crossings at Wainhill and Horsenden Lane which are also operated by railway staff, and stand normally with their gates closed across the line. Depending on the timetable and the numbers of staff (all volunteers) available, the crossings may be worked by train crew or by a keeper based at the crossing. Each crossing is protected by Stop boards, and authority for trains to pass these is given by a green flag once the gates have been opened.
There are also several user-worked crossings. At these, it is the road or bridlepath user who is responsible for making sure there are no trains coming, and then working the gates so they can cross. Generally these are found on private roads giving access to a farm or between fields etc.
The Future
The Railway was extended and commenced services to our new platform at Princes Risborough in August 2018, running via a Network Rail siding for about ½ mile, requiring much procedural paperwork! Alongside this NR siding lay the derelict remains of the former Chinnor & Watlington line, closed in 1989 and largely hidden under trees and shrubs. Our volunteers lifted and replaced the track, as the sleepers were rotten and the rail worn. New pointwork was installed, and the signalling provisions made in 2023 are being completed. The line is expected to open and services transfer to it in July 2025.