Railway block code

The railway block code is a system of bells used to send simple messages about train operations from one signalbox to another. Although codes varied from region to region the following shows a few selected UK bell codes:

• 1 bell - call attention
• 2 bells - train entering section
• 2 - 3 bells - is line clear for light engine
• 3 - 1 bells - is line clear for stopping passenger train
• 4 bells - is line clear for express passenger train
• 2 - 1 bells - train arrived