This is a perfect video to introduce people to the basics and some of the terminology regarding signalling. Quality filming, editing and pacing when providing information. Gives anyone who wants to dip their toes in further into signalling a good starting point. Great work.
When showing one amber light on the signal that means stop at the next signal which is on red for danger Double yellows means one signal has one yellow so prepare to slow down Green light means you have a clear road ahead to proceed
You will also find a blue SPAD (signal passed at danger) signal at some locations. These are normally placed just after a normal signal at a critical location such as a complex and busy junction, the idea being to stop a train overshooting the main signal when it is showing red, and fouling the junction. We also have the Advanced Warning System which has been around since steam days and provides an audible and visual warning to the driver of the approaching signal's status.
Those were a short-lived attempt in the 1990s to rectify the problem of multi-SPAD signals arising from the Purley rail crash. However, Train Protection Warning System became more commonplace, so blue signals were obsolete.
The Junction Indicators are commonly known as "Feathers" and a signal can have 6 in total, 3 either side. For more than 6 diverging routes a "Theatre Indicator" is used which is a large glazed box on top of the signal which is capable of using a light pattern to show letters or numbers.
MORE DETAIL !!! Junction indicators (also known as "Feathers" or "Lunar Lights") must be further divided ! The Signal seen at 1:53 has a Junction Indicator in POSITION ONE. (That's ALWAYS Top left). The Right hand Signal seen at 2:09 numbered (L240) has Three Feathers in Position 1, 2 & 3 all of which are for tracks branching off to the left. Where POSITION 1 relates to the first track to the left. POSITION 2 relates to the second track to the left & POSITION 3 for the third & furthest track to the left. If there were 3 optional tracks to the right then the Indicators would be sticking out of the right side where a finger at 45 degrees would be indicator in POSITION 4. A finger at 90 degrees to the right is POSITION 5, & an Indicator at 135 degrees is POSITION 6. The need for definitive "POSITION" numbering from 1 to 6, is to avoid confusion between rail staff, when faults or other problems develop. Further the Signal number plate is also important. The signal seen at 0:08 has the number L406, where the "L" tells you it is a London Bridge signalling Centre signal. But above the number is a white section with a horizontal black bar, indicating this is a Fully Automatic signal. (Operated by the movement of trains across the various track Circuits). The signal at 0:50 on a gantry has just a black plate with the number W300. So a Wimbledon Signalling Centre CONTROLLED signal. So trains will trip the signal to Red when a train passes, but a Signalman has to "release" the signal before it will show a proceed aspect. There is a Further type not seen in the programme called a "SEMI" Automatic (This also has a white plate with a horizontal black bar with the word "Semi" written on it). Such signals are fairly rare, but usually protect the exit from a siding or Goods Yard that is NOT frequently used. Hence the Signal is normally in the "Fully Automatic" mode to suit trains passing on the main running line. But as and when the Siding or Yard needs to be used, the signal protecting the points, will be put in "Controlled" mode by the Signalman. So he can directly supervise access to or from the Yard. Very rare today I would think is the signal with a vertical white plate with a vertical black bar. This is an "Intermediate" signal. It can be a semaphore or a two Aspect colour light. This type will be found between two signalbox areas using normally "Absolute Block" and the signal with Intermediate plate will be controlled "remotely" by the Signalbox in ADVANCE. If this Signal is at Danger & delays a train for more than 15 minutes, the Driver can Sound the Horn and pass this signal at Danger, & proceed at Caution towards the next Controlled Signal ! A WHITE DIAMOND under a Signal alters what used to be called "Section K". (Trains detained at Signals). It was the rule that the Driver had to contact the signalman within 3 minutes if detained at a "Controlled" signal. The White Diamond modified this rule to Eight Minutes.
Great Video. Have you noticed at stations the 'OFF' indicator? This is placed at curved Station platforms or where the signal is obscured. It denotes that the signal is showing proceed.
@@Taitset the 'off' indicator is to let station staff know the condition of the signal at the end of the platform,..when signalling to the driver to start the train.
Indeed the off indicator is for the staff to let them know the state of the departing signal. It is an operational irregularity to dispatch a train against a red signal during normal working conditions.
seems on the underground they rely more on repeaters than bothering with double yellows, although those signals are also very close together and the trains run much slower than on the main line
this is truly piece of cake signalling. i've learned german railway signalling and it's so much harder with a speed limit indicator. not only that, also the signal types are divided into three types. HL Signal, HP Signal, and Ks Signal. Pzb signalling is quite complicated but it pays off.
I love your description! Long story short they can mean several things. Without going into all the operational reasons why sometimes trains don't use the 'big' signals shown in this video. A good starting point would be googling position signals to understand more about why. For what you describe 'ground position signals' sound likely what you have seen, but could be limit of shunt indicators too. Good luck!
Nice little video. Though I think you mean some signals are PREceded by a banner repeater, not proceeded by them. They also mirror the aspects of lower-quadrant semaphores, not just upper-quadrants.. but yeah, nice video :-)
You are absolutely correct on the spelling - Somehow I've never noticed they are different words before! Even growing up with my mother as an english teacher who is very quick to correct me on that sort of thing. :) I was under the impression that all banner repeaters rotated the same way, but looking now I can see that some of the mechanical ones do in fact go 'left side down.' Are there any of that type still in use today? I can't see any examples of a modern electronic one that goes that way.
@@Taitset Ah I see what you are saying now, I was just meaning that both upper and lower quadrant use a 45 degree angle as "off", as per banner repeaters, rather than looking at the specific rotation direction.
It actually says that on a green signal (clear) you can expect the next signal to be showing a 'proceed' aspect. A proceed aspect is any aspect other than Danger.
there is a few Signals here, but what about THAT BOARD that is black and about 12inches square, I am thinking there is some LEDS HERE to indicate a PLATFORM or a ROUTE ahead, I would like to know the Measurements. PLEASE
Do you refer to the box on the left hand side of the signal at 0:55 for example? That`s a route indicator, uses numbers and/or letters to tell the driver which route is set form the signal. Where there are a lots of routes available it is more practical than a tree of junction indicators. From this particular signal there are 5 routes available, Up Windsor Fast, Up Windsor Slow, Up Ludgate, Up Latchmere Curve and Down Latchmere Curve. The smaller rectangular one next to it is a CD/RA indicator, platform staff operates it when they dispatch passenger trains. CD tells the driver to Close Doors, RA is for Right Away, the train can depart.
Wondering if someone could measure this, PLEASE - might I suggest 2 pieces of dowel, one long for height other for across, while carrying these together there could be 2 rubbers in the form of a cross, so one can move across up or down the long one, the short one can move across the long one, PLEASE make sure you have a PRICE RECIEPT so everyone around can se it is not a WEAPON
@@graemewilson4126 That could be looked on as tampering with the signals so not a good idea. Why don't you ask Network Rail or one of the UK manufacturers which you can find on Google.
A random questions I got railway's by me that got 2 play forms but splits into middle lanes for frieght trains that split on the line use track switches who controls these as it got no Signal boxes
TLDR: Practically speaking, it means the same as a regular green aspect. Flashing green meant that the next signal is showing at least a green aspect. They were installed in the 1980s when British Rail wanted to introduce 140mph/225kph trains, because the existing double yellow signals did not provide enough warning to safely stop at speeds above 125mph/200kph. A flashing green signal told the driver that the next signal is showing at least a green aspect, so they could safely continue at 140mph. A normal green signal told the driver to slow down to 125mph so they would be able to stop in time if the next signal is double yellow. Since no trains currently run above 125mph, there is no practical difference between a flashing green and a normal green, but they left the flashing green signals in place where they were already installed because it wasn't worth the effort to remove them.
Just to be clear about the flashing Yellows...they were brought in around the 90's so passenger trains could approach a station at a higher speed that wouldn't affect brakeware and bringing the train to a softer stop....driver would see double flashing yellows 4 or 5 signals out from the station and start braking earlier and softer than he/she would if they were closer, saving on brakeware....and passenger complaints if braking harder sending passengers flying forward.
Not bad stuff at all, good illustrations, the bit about Flashing Yellows is a wee bit misleading...I explain that here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_cXTyHZDIkg.htmlsi=dyFaEqwIgB9paDJ-
