Friday, 1 July 2011

Track Diagrams: Llanfair P.G.

(Click on image to enlarge)

T - Tubular post signal
L - Lattice post signal
LG - Loading Gauge
tt - Turntable
CR - Crane
s.b. - Signal Box
L.C. - Level Crossing

This village on Anglesey, originally called Llanfairpwll would probably have remained little-known had not a Victorian committee with a flair for self-promotion extended the name to a jaw-breaking 'Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch'. More information here. The L.M.S. commonly simply used the abbreviation 'Llanfair P.G.', which was much easier to fit on an Edmundsen ticket.

Signalling was Absolute Block. On the Down, there was a lattice post Home protecting the crossing, Starter and a fine L&NW lower quadrant Advanced Starter. The Up had two Home signals, the one protecting the crossing on a short post to improve sighting (presumably because the station footbridge would otherwise impair an approaching driver's view).

The Down Advanced Starter and the first Up Home (I'm not sure whether it was 'Home 1' or, if 1/4 mile in advance of the second Home, it would be called an 'Outer Home') each carried a 'White Diamond'. This indicated to train crews that 'Rule 55' was exempt and the Fireman did not have to trudge to the signal box when detained at the signal to remind the Signalman of his train's presence. Track Circuits on the line approaching the signal would indicate 'Occupied' to the Signalman and electrical 'Block Controls' would prevent the Signalman from inadvertently allowing a second train to approach.

I didn't spot the down Distant but the Up Distant was a Colour Light. Under A.F. Bound, who joined the LMS as Chief Signal & Telegraph Engineer in 1929, there was a long-term program of risk reduction by converting semaphore Distants to colour light signals to reduce the chances of a 'missed distant'. Bound also prioritised the introduction of track circuits and block controls, dealing with the biggest risks and the more important lines first.

The small goods yard is served by a single wagon turntable, neatly giving access to a goods shed, two loading dock roads, a high-level loading dock and a crane. The London and North Western was rather addicted to wagon turntables and was not averse to connecting Up and Down sidings with wagon turntables and a line crossing both main lines at right angles (a potentially damgerous practice) but here the use of the wagon turntable is both economical and efficient - that would have certainly appealed to the feared Chairman of the London and North Western Captain Mark Huish (1808 - 1867)!