Is there any plans to implement forms of approach control into London Commuter? On a few occasions I've been given a route which has a signifcant speed drop all under greens, this is very unrealistic. IRL you can only be signalled onto a diverging route with green signals if the speed reduction is equal or less than 10mph. Depending on the speed to be reduced different forms are sufficient but for the most extreme reductions (I can try and get the figures in mph) you will be brought down to a red and once in a position where you can see it, it will change up and give the route. If this was implemented it could also be used to double protect a conflicting move. For example you are on the 90mph on the down into Haywards Heath and a train is pulling out from the loop platform in front of you. You would be brought down to the signal before the station and that would switch up to a single yellow on approach then stop at the red in the platform. This is used routinley to ensure trains are effectively slowed to eliminate collision risk. Feel free to contact me and we can discuss the different forms of approach control I experience frequently Thanks, Kieran.
This makes a lot of sense. I have had many issues with this in BML. One example is from Victoria to Reigate. Before arriving at East Croydon, the speed reduces with very little warning to reduce speed from 60mph to 30mph to take a slower path into the station.
This is one of the points I was caught out by, extremely dangerous. From what I know the following methods can be used: Approach control from Red Ensures the driver recieves caution aspects and is brought down to a controlled speed down to the red, the signal should not come off until such a point that it is known the driver would have a clear view of the junction indictator. Approach Control from Yellow Less common but can be used if the difference in speed is greater than 10mph but not more than 30mph. However not more than 60mph junction speed, in this case different forms are used. In this case you'd be brought down until in sight of the 1 yellow and it would clear up, but it shouldn't be used if while braking for the signals you'd have to brake more to slow for the junction (the signals should get you below the diverging speed otherwise this form of approach control is not suitable). Flashing Yellows Used commonly to help keep the speed of the train up while giving advanced warning of diverging route. If multiple routes are available it can only be used for the highest speed diverging route, slower ones at the same location would revert to approach control Red/yellow etc. You'd get the flashin yellows then normally on approach to the single yellow with route indication if the route ahead is clear it will clear up to green on approach so you don't slow right down defeating the object of the flashing yellows. You have to be aware though that the single yellow might not clear up as the red on the diverging route may well be held red for a reason. An example I can draw expereience from is approaching Orpington on the Up. You get 2 flashing yellows, then 1 etc. This is for the 50mph junction onto the Up Slow into platform 4 at Orpington. I keep the speed about 45 approaching the single yellow then if it clears up to green keep it coasting (braking anyway if stopping at station, if not back up to 50mph). If it doesn't clear at that point, further brake will bring you down in good time for the after the junction. At some locations you can already read through to the next signal and see it is green even though you are approaching a single yellow so you know it will clear up, but reading through is a very bad practice for the most part. Splitting Distants I don't have any expereience with these and know little about them. I don't think there are any on the BML. Prelimnary Route Indicators 300 yards on approach to the two signals before OR the signal before and the signal with route information. Gives an early indication of the route set ahead, if not route is set yet (signal red) they are blank. They are normally used where a driver may need to brake the train to a stand before the junction if the route is incorrectly set. E.g. Southeastern High Speed (they are blank in game annoyinly). If you were in a 3rd rail DC train that should be going to Northfleet and the route had been set for the HS1, becuase of the PRI's you'd have plenty of time to brake to a stand from 70mph and question the route. Splitting Banner Repeater Have come accross these. Have them on approach to Grove Park after new signalling put in. Very handy. When you are being crossed over from DN Fast to Slow, you have to be under approach control as the junction speed is 40mph from 70mph. In this case, approach from yellow is used. You get 2 yellows, 1 yellow. In then can keep the speed at 40mph and keep and eye on the split banner repeater, if you see the bottom one come off you can keep the speed up at 40mph and safely cross the junction. Becuase the banner repeater classes as a route indiction and you see this before you see the signal coupled with the fact that the signals bring you to about the junction speed, this allows the signal to be cleared very shortly after passing the single yellow, so good example of when approach control from yellow can be used. Wow I waffled on a bit Kieran.
Absolutely Kieran. There are two threads in PC discussion where we've discussed the lack of appropriate approach control. Loads of approach red is needed especially around the 25mph junctions at East Croydon, Balham (only made that move in one of the scenarios though) and that 50 - 20 at South Croydon Jn which is used for all down slow services to Purley. The move from fast to slow at Selhurst is lethal too as you run on greens 60 to 30 and the signal for the junction is only visible from around 300yds. The move to platform 6 going south at Gatwick should be red on approach too for the 30. There's a couple of moves onto the DS crossings south of Gatwick which come as a shock.with no warning. Leaving Redhill and crossing to the DF is 70 to 30 on greens. There's plenty of slow speed crossovers which aren't in use on the current diagrams bit if TL arrived we'd be using more of them. I'm sure there are plenty more that I've missed, but I still don't get why DTG have nailed DB signals but not the signals on their own turf.
Completely agree with you. In the streams, the excuse is usually given that UK drivers must memorise all speed restrictions along the route. Of course, this goes without saying. However, it cannot be the case when a driver doesn't know which platform they are going to be directed into at rush hour, or which path signallers are going to make the train take at different periods of the day. In such instances, sufficient warning is needed. It can't just be a guessing game. DTG definitely need to look at UK signalling in greater depth. You are correct - so much work has gone into the German signalling, but British signalling seems left behind and over-simplistic in its implementation.
