Electric Railway Journal · Vol. 67, No. 23 · June 4, 1927 · pp. 1003-1004.

Daylight signal and semaphore.

A Signal School in a Tunnel. Classes for employees are held by London Underground Companies in unused section of South Kensington tube twice a week -- Models of many kinds of signal apparatus are available for study.

Opportunities for practical and technical training of signal linemen, fitters and installers are provided in a new school recently established by the London Underground Companies. Appropriately enough, the school is located in an unused section of the underground system at South Kensington. It is open to apprentices and signal linemen and to other employees who are interested in the work of the signal section and wish to prepare themselves for examination for better jobs. The method of training is to give a lecture in the school and to follow this by examination and experiment with the apparatus. The lecture room has a capacity of about 60 students. It is fitted with desks, blackboard, lantern and screen. Operation of the apparatus is explained and demonstrated by a qualified technical staff.

Monday evenings are devoted to exposition for apprentices of general principles, rules of signaling and operating practice. On Friday evenings the work is more advanced and covers all signaling, including the most recent a.c. installations. This is for the benefit of linemen and others who wish to keep in touch with the latest practice. At the end of each session an examination is held embracing both technical and practical work. The school is used also for the examination of individual linemen before they are placed in actual charge of signal sections on the railways.

An experimental track circuit for testing and demonstration purposes has been installed. By lowering or raising the water level in a nearby tank the effect of wet or dry weather on a track circuit can be demonstrated. On a bench running the length of the room is a miniature track. In front of the bench are arranged signals and train stops which are controlled from this track.

One end of the room is fitted up to represent a signal cabin complete with seven-lever power frame and illuminated diagram. The power frame controls five signals and one switch. A length of full-sized section of permanent way runs along the school on the lower level. In conjunction with this, signals and apparatus are connected up in the same manner as on the railways.

[Top left] Above, signal interlocking frame with the casing removed; [Top right] Above, electro-pneumatic tunnel signal; [Middle] At right, the classroom of the London Underground signal school is provided with a projector and screen. Seats and desks accommodate 60 students; [Bottom] Below, experimental track circuit tank and fog repeater.

Switch mechanism and train stop showing circuit breaker box.

Sources

Electric Railway Journal, McGraw Hill Company, Digitized by Microsoft, Americana Collection, archive.org.