From levers and buttons to computer screens

Tuesday 14th July 2026 Signal boxes are becoming something of an endangered species on the railway, not least on the London Underground, with modern technology enabling trains to be controlled from a computer screen many miles away from the tracks and in-cab displays for drivers rather than what is now regarded as old fashioned track side signals managed by staff from stand-alone signal cabins. Despite the gradual phased roll out of Computer Based Train Control (CBTC) on the sub-surface London Underground lines over the last few years traditional signal cabins can still be found on the outer reaches of the Metropolitan line at Harrow-on-the-Hill, Rayners Lane, Rickmansworth and Amersham. However their days are now very much numbered with CBTC almost ready for switch on in this section too so it was a delight to be able to pay a visit to both Rayners Lane and Harrow-on-the-Hill signal cabins last Thursday as part of a tour organised by the London Transport Museum Friends to see the…