Signal from Liverpool Overhead Railway
The signals at each end of the Liverpool Overhead Railway were mechanically operated but the rest of the route was covered by the first electric automatic signalling system ever used on a railway. It had to be approved by the Board of Trade before it was installed. In 1921 coloured lights were added to the signal system to improve safety. The drivers could see the lights from 1000 metres away, even in bright sunlight. The Railway Signal Company Ltd of Fazakerley, Liverpool, installed this innovative system which had an excellent safety record.