Page:The Working and Management of an English Railway.djvu/108

There are many other electrical appliances used in railway working, such as "Train-starting indicators," from platform to signal-box, to inform the signalman that trains are ready to start from certain platforms; "Route indicators" for junction cabins, by means of which signalmen are advised beforehand of the route an approaching train is required to take where the roads diverge; "Vehicles on line" indicators, to show the signalman when a line is fouled by a vehicle being detached from a train and left standing on the line; "Shunting indicators" for station yards, and a variety of other electrical apparatus of a similar character. There is, however, one special appliance which merits a somewhat more detailed description, viz., the "Electric lock" for sidings. This apparatus has been designed to lock and unlock sidings at a distance from the signal-box too far to be worked by rod and lever. There is an instrument at the signal-box, and another at the siding, each containing an electro-magnet capable of actuating an armature which constitutes the lock, fixed in connection with the locking bars of the signal frame. The normal state of the apparatus is "Signals at signal-box unlocked, and siding locked," by the constant flow of a current of electricity through the electro-magnets. If a train, arriving at the signal-box, has to call at the siding, the breakman, or person in charge, intimates the fact to the signalman, who, by the insertion of an ordinary carriage key into the electrical apparatus, disconnects the wire. This has the effect of locking the signals at the signal-box and unlocking the lever at the siding, and the key can only be inserted when the signals are at "Danger." There is a code of bell signals drawn up for the guidance of the men, but it will be