Rayners Lane and Ealing Common

One of the aspects contains a 'shunt' aspect, a 45 degree black bar on a yellow background. When one of them is lit it tells the guard that the train is performing a shunt maneuver and that the train needs to be tipped out.



This is a Fixed Red Light, or FRL, a warning to drivers that they cannot proceed any further. The one you saw is a 'proper' FRL, as it has an associated trainstop attached which enforces the FRL, i.e. for movements to the eastbound platform from depot. There are other FRLs which are purely 'idiot lights', placed in locations where no sensible driver would expect to proceed further than their current position (i.e. Hyde Park Corner e/b). I say sensible because it happened once at Kings Cross.

Cough cough splutter....





A similar example of the use of the black bar as a harbour light repeater can be seen at Turnham Green w/b, where a guard in the rear cab would definitely not be able to see the junction indicator from his vantage point. Baker Street Bakerloo n/b is also a good example of one that is not used anymore.

my idea is that platform repeaters should now be removed they are a pain when they either fail or a bulb goes in them. but mr lul still wants them so the station supervisor knows when the signal has cleared for the last train so he can see it out and if the bulb fails it costs metronet and tubelines £500 a day when they dont work in fines ;D ;D ;D ;D ;D

You would think that by now the infracos would have worked out it was cheaper to fix minor problems on the day they happen, rather than getting fined for when the failure drags into the next traffic day.

It's not just for last trains either. Those keen individuals with large table-tennis bats need to know when the starter is green ;D

Lets see if we can get there this time ;D

Right, we all know that a platform repeater shows what the station starter shows (green for green, and yellow for red), and that a basic platform repeater for a basic signal, has a green light over a yellow - with only one lit, according to the aspect of the station starter.

The other type looks like this (apologies for poor quality):

In this version the green is bottom left, and can be lit on it's own if that is all the station starter is showing. The reason it is on the bottom here is because of the aspect above - a white bar (either direction) which is for a junction indicator, and, would appear in conjunction with the green. Yellow on it's own is for a red station starter, and the bottom right being for a shunt signal.

It's possible to have several greens with different junction indicators above them, if needed, but you will only ever get one yellow over a shunt. Similarly, it's possible that you may only see three of the possible basic four aspects - local needs will dictate.

Is that any clearer?

As for fixed red lights on running lines (found at the end of many reversing platforms, usually at the 'wrong end') - I didn't think these had train stops?!

Where a fixed red light is provided as the terminating point of a signalled route then a train stop is provided. Where a fixed red light is provided at a location where there is a possiblilty of an incident similar to the one that occurred at Kings Cross years ago then generally a trainstop is not installed.
To take an example both sorts can be found at Harrow on the Hill. The northbound platforms 3 & 4 both have fixed red lights at the south end. The one on platform 4 has a train stop because trains can be signalled into the platform from both ends i.e. from the south in most cases but also from the reversing siding to the north and in this case the fixed red light is the end of the signalled route.
There is no train stop associated with the fixed red light at the south end of platform 3 as trains can only be signalled into the platform from the south and in theory a train operator will only find himself looking at this fixed red light if he mistakenly changes ends in the platform after being told to reverse at Harrow. (and before anyone says I know a train in platform 3 cannot actually reverse at Harrow and must actually continue further north)