There should be. Saying that, Lu signals are 2 aspect but in a lot of sections there should be repeaters for the next signal (identified by a yellow plate beneath the signal). check this page for LU signalling https://districtdave.co.uk/html/signalling.html
not as such no they have repeater signals that will show a green or a yellow if its a yellow start braking as the next signal is red. On normal signals it is either a red or green. North of queens park you go onto national rail signalling systems which is the standard british 3 aspect so will have red yellow and green.
That's the thing: I saw the red, assumed it must be the repeater for the main signal at danger beyond- and got popped as I passed it. (In the dark, there's no way to read the signal plate until it's too late to stop). There was no yellow signal at all.
Ok so in terms of signals and sighting. If a signal is placed at a distance where the driver cant see it in enough time to stop then a repeater will be installed. A repeater has 2 aspects a yellow and a green Yellow - The next signal is read (the one the repeater is repeating) so as soon as you see the yellow you need to start braking Green - the signal ahead is green so carry on at line speed if there is enough sighting time from the driving position to seeing the signal that is displaying a red then a repeater is not needed. ANY signal showing a red you stop at red = stop hope this helps.
