Atomic Systems

Fodda wrote:

Inthernet wrote:This thread seems to have mushroomed into quite something else! My particular issue is with the 185 minute scenario. I'm crossing the bridge Northbound at 50mph. There are two very closely spaced signals at the end of the bridge. I do not remember if I was given a yellow caution but the one after that was red, without enough braking distance.

Right! I can confirm this on the 185 min scenario. I was following the Northern Lights train north over the bridge, all lights are green so I stay at line speed (50 over the bridge in my 166). Coming to north end of the bridge I see a two aspect signal showing green. On passing this and then clearing the brick bridge portal, I then see the three aspect signal at the north bridge end showing a red aspect. At 50 it's too late to prevent the SPAD, and I've not seen a yellow signal for a few signals before this. Looking at the view 9, I can just see the Northern Lights northbound train just clearing the block north of the bridge.

So there IS something amiss with the signalling on the bridge which didn't show a yellow before I could see the red.

I surmise that this problem is intermittent, depending on your speed to the bridge. Some are reaching the bridge after the Northern Lights northbound has cleared the whole bridge section and therefore they won't get the red at the north bridge end as the express will have already cleared the next section... They'll probably get a yellow there. Those of us who're that little faster out of Edinburgh will arrive on the northern section of bridge whilst the express is still in the following section and see all greens followed by a red which we can't stop at.

Fixes are:

1. Check the signals over the bridge and fix 'em... (Preferred option)
2. Drive more slowly on the section leading to the bridge and hope that the express has cleared the after-bridge section before you get to the north end of the bridge... (OK)
3. Assume you'll have a red signal as you exit the north end of the bridge (regardless of the greens you get all the way over) and slow down accordingly to avoid a SPAD. (Annoying if you forget or the express has cleared and you approach a yellow (or even green) with the brakes on doing 20 or so.

That's my tuppence-worth. Discuss.

Russardo wrote:Since this is turning into an interesting discussion on signalling I thought I would ask my own question, which I only just came across the other day. At my local station there is a distant signal / repeater (2 colour aspect green or yellow) which was showing green (i.e. the next signal, which I think is protecting the junction where the line goes down to single track, is showing a proceed aspect). However, when the train passed the distant / repeater it changed to yellow like a "normal" signal would change to red after a train passed. Why is this? Surely the distant / repeater doesn't have its own block and the next signal will still be showing a proceed aspect, so why does it change to yellow? I'm sure I wasn't imagining things!