Automatic block signals and signal circuits

American practice

Ralph Scott  1908

Preface   Contents    Index

Preliminary considerations

Simple circuits

Normal danger circuits

Normal clear circuits

Semi-automatic circuits


The track circuit

Controlled manual systems

Motors, relays etc

Hall apparatus

Union apparatus

Electro-pneumatic and electro-gas systems

Electric locking

All-electric interlocking

Three-position signals

Electric railway systems




Sidan uppdaterad den 25 juli 2023