Signal lever frame, electromechanical locking from Newport West signal box

Signal lever frame, 16 lever, electromechanical locking, by Siemens - Ferreira, ex Newport West Signalbox.

This lever frame is an example of the first and only type of route-setting power lever frame to be used in Britain. The first prototype frame of this type was installed at Winchester Cheesehill on the Didcot, Newbury and Southampton Railway in 1922, followed by large installations at Newport East signal box in 1927 and Newport West signal box in 1928. No further installations of this system were made.

This power lever frame was designed by R J Insell and L M G Ferreira of the Great Western Railway. It was fully electric and was designed to reduce the number of levers that signallers needed to pull to set routes for trains. Instead of each lever controlling individual points and signals, they controlled a route and all of the associated signals and points. This is a similar principle to the push button based NX panels that came to dominate signalling in the second half of the 20th century.

Behind each route lever was positioned a vertical row of four lights. With the lever in the normal position the top (red) light was displayed. To set a main route the lever was pulled to the first check-lock position and if all track circuits were clear the bottom (white) light illuminated. The points required to move in the route now operated and once in the correct position the third from top (orange / yellow) light illuminated, the check-lock on the lever was released allowing it to be fully reversed, passing through the second check-lock position without stopping. Once reversed the signals cleared and the red light was replaced by a green light (second from top). When the train had occupied track circuits in the route the signal automatically reverted to danger, the green light was replaced by red and the white light extinguished. To cancel the route the lever was first replaced to the second check-lock position. Once signals had been proved at danger and all point controlling track circuits clear the white light illuminated and the lever could be moved to the normal position, passing through the first check-lock position without stopping.

This lever frame is part of a much larger installation at Newport West which was decommissioned on 09/12/1962.