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