Sloane exchange, London

A comprehensive description of the 8400-line equipment at Sloane exchange, brought into service on July 28, 1928. The exchange is of the Step-by-Step Register-Translator type (usually known as "Director"), similar to the other London automatic exchanges. The impulse machines associated with the register-translators are of a reciprocating type, a.c. driven from a common motor alternator, the speed of which is controlled within plusmn2%.