Single-needle block instrument
1845
Block instrument (sending/receiving) - Caledonian Railway
Clark's block signalling telegraph instrument, 1854
1854
Intermediate block instrument
Two-plunger block instrument pattern 288
Block instrument
Block instrument (sending)
Block instrument (sending/receiving)
Block instrument (sending/receiving)
Block instrument (permissive indicating)
Block instrument (lock and block)
1897
Lock & Block Type Telegraph Block Instrument
Telegraph Block Instrument, Markham North
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument; Tyers Patent; 2-position type
Train describer (receiving) Great Western Railway
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph block instrument
Block instrument, Great Central Railway (sending)
Telegraph Block Instrument, Signal Relay, Great Western Rail
Telegraph Block Instrument, Spagnoletti type
Telegraph block instrument, old form of bell instrument
Telegraph block instrument
Telegraph block instrument
Telegraph Block Instrument, Great Western Railway
Telegraph Block Instrument, Great Western Railway Spagnoletti receiving type
Train describer (receiving)
Single-needle telegraph block instrument
Tyer's One-Wire Three Indication Block Instrument
Block instrument with spagnoletti flag indicator (incomplete); GWR. Tyer's style
Three-wire block instrument
London & North Eastern Railway train describer
1923-1948
Telegraph block instrument, London Brighton & South Coast Railway
Lancashire & Yorkshire Railway Signalling School Model Railway Layout
1912
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Great Western Railway
Siemens Bros. block
Lock and Block Type Block Instrument
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Block instrument (sending)
Telegraph Block Instrument, Lock & Block Type, W R Sykes & Co
Block instrument (sending/receiving)
Telegraph block instrument, block bell, ground frame type
