Signals at (Lincoln) High Street

March 83

High Street crossing and Central station

High Street crossing and the western end of Central (now, just plain Lincoln) station. An annex has been added to the signalbox to house the level crossing controls - it had motor-operated gates in 1983.

The up home bracket, from the other side of the level crossing.

The signalbox interior. Here, the diagram is suspended above the block shelf.

The signalbox diagram, with Central station to the left.
The coloured track sections denote track circuits, where a small electrical current through the rails is used to detect trains on the lines. The grey ovals are indicators which light up when a train is present on the track circuit in question. Each track circuit is identified by a code letter, shown on the diagram adjacent to the corresponding oval indicator.

The block shelf. These block instruments are older, GNR/LNER models which require separate instruments for every line. Because there are five separate lines through the station (one up and two down platforms, and the two through lines in the centre) as well as the double line to East Holmes, there are seven instruments. The ones with the control handles are for the sections on which trains approach this box; these are known as pegging instruments. The others, with needles only, are non-pegging. The smaller boxes are bell instruments.

Two of the non-pegging instruments. The one on the left is for the up main (through) line, the other for Platform 5. Both of these selctions run from here to Pelham St Jct. Because permissive block is also used in the platforms here, the latter has line occupied against a yellow background instead of train on line, just like the Greetwell Jct instrument in Boultham Jct. To the left of each block instrument is the corresponding bell and tapper unit.

A pair of pegging instruments. These are for Platform 6 and the down main, which run from Pelham St Jct to here. Again, the platform line is worked by permissive block. In the centre is the bell unit for the down main.

The level crossing controls. The left-hand lever opens or closes the gates; after they have been closed across the road, the right-hand lever can be operated to lock the gates and allow the signals to be cleared.

The rear of the up homes bracket, with the line to East Holmes beyond. The latter's level crossing, and down home, can be seen in the background.

The down main home - an underhung bracket known colloquially as a "gallows signal". It is also unusual, for an upper-quadrant, in that the arm is operated by a rod rather than just wires. This is because its arm is driven from the right-hand angle crank on top of the bracket, from where a rod is needed to push downwards on the right-hand side of the signal head. The signal wire from the counterbalance lever at the base of the post pulls the left-hand angle crank downwards (clockwise); the rod from there turns the right-hand crank in the same direction and hence raises the signal arm.