Its sole purpose was to divide what would otherwise have been a long block section of 4m 22c between South Cave and Little Weighton. There are no points to complicate matters, and the farm crossing can be ignored. Depending on its location, a Stop signal can be a Home or Starting signal, and visually, both are identical.Īs an introduction, I’ve chosen Weedley which consists of no more than a home and distant signal in each direction, these being the bare necessity of a signalling system. The former is painted red with a white stripe with a squared end, the latter is painted Yellow with a Black chevron and a ‘V’ end. These have full-size arms and can be further sub-divided into ‘Stop’ and ‘Distant’. Signals can be loosely divided as follows: The rear signalman, is now free to offer another train. ![]() ![]() On seeing this, the advance signalman sends the ‘Train Out of Section’ bell signal to the rear ‘box and restores the block needle to ‘Line Blocked’. The tail light is the advance signalman’s confirmation that the train is complete and is not divided. The needle will remain in this position until the train has passed through the section, complete with tail light. The advance signalman acknowledges this and deflects the needle the opposite way to show ‘Train on Line’. With the signals cleared and as the train is about to enter the advance section the rear signalman sends the bell signal ‘Train Entering Section’. On accepting a train, the advance signalman will deflect the needle to indicate ‘Line Clear’, the rear signalman now knows he can clear his signals and allow the train to proceed. When stood vertical, there is no train in the section and the needle will point to ‘Line Blocked’ – it’s always assumed the line is blocked. There is also a visual indicator, and this by means of a pivoted needle shows the state of the block section. In theory, no matter how many points are in advance of the Home Signal, this one signal will suffice.Īn example of block instruments at Gylberdyke signal box, Yorkshire, with visual indicators and bells. This is because apart from protecting the advance block section it must also protect the siding or crossover connections. Once points and crossings are brought into use the siting of this signal becomes more critical. ![]() When only one Stop signal is provided it’s known as a 'Home Signal', and almost without exception, will be sited a few yards rear of the signal box. The rear ‘box signalman now knows the line is clear, and safe for the passage of a train. Providing the above-mentioned conditions have been met, the advance signalman will repeat back these four beats. For example, when asking “Is Line Clear for an Express Passenger train?” the ‘asking’ signalman sends four consecutive beats to his colleague in the advance signal box. Signalmen communicate ‘box to ‘box using single stroke bells, known as ‘Block Bells’.
0 Comments
Leave a Reply. |