UK: Following successful trials, UK infrastructure manager Network Rail has granted full approval for the SL35 LED Light Engine which has been introduced by Howells Railway Products as a direct replacement for signal filament lamps.

The Light Engine is compatible with existing electrical and lamp proving systems, offering the reliability and long life of LEDs without the need to change the existing signal head. The existing lamp holder is used, but to further reduce failures the Light Engine is hard-wired into the signal. This means it does not use lamp holder contact springs to provide electrical connections.

According to Howells, a four-aspect signal can be converted in less than 15 min.