Tolcarn Junction was, for the first half of the twentieth century, a vital node in the Cornish rail network, especially in the summer season, yet it remains a place of semi-mystery, under-photographed and forgotten. Today the site lies beneath residential and industrial development and has been completely lost.
The Cornwall Minerals Railway (Treffry tramways) established a single track triangular junction here in the 1870s. There was the passenger line to Newquay and the mineral triangle leading to the Treamble line.
At the Newquay apex was Treloggan Junction, at the Par end, Tolcarn Junction and at the Treamble end lay Lane Junction. In the 1870s there was a signal box mid-way along the northern chord, named Tolcarn Junction. It was probably a small wooden affair, operating some semaphore signals and the junction points at the eastern and western ends of the triangle.
The east chord (Tolcarn to Lane) seems to have fallen out of use in the 1890s, meaning that whatever traffic was coming up from Treamble had to be worked via Newquay, or stored in a group of sidings which replaced the east chord (they were connected to the Par line).
All changed with the construction of the Perranporth line, and the overhauling of the line to Shepherds to complete it, in 1905. A new, standard Great Western box with a 43 lever frame opened in about 1903, for the work to begin and passenger services began in 1905. Newquay station was rebuilt at the same time.
The age of the mineral lines here had ended and passenger traffic now dominated both lines.
Longer and heavier passenger trains between the wars saw the need for larger engines, but there were no facilities for them. The 1905 turntable at Newquay could just manage a 4-4-0 and the loco depot at Newquay was to be closed to allow for platform extensions, so the solution was to reinstate the old triangle at Tolcarn for engine – turning and this was done in 1931.
This was not quite the end, for during the 1930s the GWR steadily improved and expanded the facilities on the Par to Newquay line. Crossing loops were lengthened and some doubling took place. The final phase was to be an expansion of Newquay station, including doubling of the track from Tolcarn to Newquay. The box got a new, 52-lever frame in 1938 in preparation for this. The work required the reconstruction of Trenance viaduct. The widening of the viaduct was complete in 1939, but the remainder of the work was suspended for the duration of the war. The double track finally opened in 1946.
In the 1950s, Tolcarn Junction was a hive of activity on summer Saturdays especially, with two branch lines, through trains, engine turning and carriage movements. Diesels did not need turning and the closure of the Perranporth line put paid to Tolcarn Junction: the box closed in November 1964.
A short distance down the Perranporth line from the junction was Trevemper siding, serving Trevemper mill. The siding occupied a stretch of the Treffry mineral line which had been by-passed in 1874. The section to Trevemper remained technically open after the Perranporth line closed, because of an unexpired private siding agreement. There was no traffic and the lifting contractor is said to have put paid to the whole thing by mistakenly lifting the track! Many thanks to Roy for this article