There are many ways of counting...
Double Line Block Instrument
Pioneers in Automatic Train Control
Tyer Diagram Lamp Unit
Neutral Track and Line Relays
Domino Panels a revolutionary Control Device
For every requirement there's a Transformer by Tyer
Tyer Multi-Lamp Route Indicator
Tyer Colour Light Signals
Tyer Moving Iron Polarised D.C. Relay Type G.I.