Great Western Railway telegraphic codes

The Great Western Railway (GWR) pioneered telegraph communication over the 13 miles (21 km) from Paddington to West Drayton on 9 April 1839 using the Cooke and Wheatstone telegraph equipment.

Although this early system fell into disuse after a few years, from 1850 a new contract with the Electric Telegraph Company saw double-needle telegraphs working at most stations on the line; these were replaced by single-needle machines from 1860.

[2] Although used primarily as a safety device to regulate the passage of trains, it was also used to pass messages between the staff.

In order to do this quickly and accurately, a number of code words were used to replace complicated or regularly used phrases.

Note: many of these codes could have an extra letter to identify variations, such as Scorpion C (a 45 ft (14 m) carriage truck), or Scorpion D (a 21 ft (6.4 m) carriage truck).