Miscellaneous: Operating Equipment & Practices

Telegraphs and Telephones: misc_equip234

Three Great Western Railway Omnibus Telephone Circuit Cards recovered from Birmingham area Signal Boxes. These give the details of the specific ring codes for all the individual telephones on each of the omnibus circuits. As each omnibus circuit was effectively a party line with all the telephones connected in parallel across a single pair of wires, the line was shared and calls to an individual telephone had to be identified with a specific ring code. The code would ring at all the telephones on the omnibus circuit, but the intended recipient would recognise their own ring code and answer the call. Some important locations had multiple telephones on different omnibus circuits, but where possible they were allocated the same ring code (for example see Birmingham locations, Bordesley South Box and Small Heath North Box on these Cards). See 'misc_equip233' for more details of the typical Great Western Railway telephones used on these omnibus circuits.

Robert Ferris

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