TELEPHONES FOR TRACTION SYSTEMS
CENTRAL STATION SWITCHBOARD
Each Spring Jack and Line Annunciator is self-contained, and made in the form of a small box, so that should any repairs he necessary, all that is required is to take out the securing screws and the whole movement comes away without having any loose wires to deal with, and in restoring the movement there is not the slightest hesitation as to how the connections should be made, there being only one possible way.
The number of Through Switching Plugs and Cords varies according to the number of stations or
routes which have to be dealt with, and each pair of Through Cords is provided with a visible clearing signal, which normally shows “clear,” but while two lines are
put through and conversation is taking place shows “speaking.’’ The simple restoring of the telephones by the persons at the
sub stations, who have been conversing, returns the clearing signal again to ‘‘clear,’’ and at the same time rings a small bell,
this audibly indicating that the conversation is finished.
Last revised: February 05, 2011