The signalling around Salisbury (with the exception of the station

itself) was converted at the start of the twentieth century by the L&SWR from a conventional mechanical system to an electro-pneumatic set-up. Both Salisbury East (seen here) and Salisbury West signal boxes were purpose-built to accommodate the unusual equipment. Whilst the bells, indicators and plungers were conventional the points and signals were operated by sliding levers. Whilst the down line from Salisbury Tunnel Junction was worked under the conventional absolute block system, the signals between East and West were slotted which allowed block working to be dispensed with.