Absolutely first rate description of an absolute block signalling system. Really useful for modellers. Please take this as me trying to be helpful for completeness. It is certainly not a criticism. Your ‘catch points’ are actually ’Trap points’. Catch points are normally unworked points that prevent an unauthorised backward movement. For instance on severe inclines to prevent loose fitted breakaway wagons from running wrong direction down the incline. Loose fitted = unbraked. Your signals 3, 16 and 17 are your starter signals. The platform signals are merely stop signals and strictly classed as home signals. Home signals are in rear of the signal box and starters are in advance of the box irrespective of whether platforms etc. are involved. I hope that this is helpful. Best regards, Tony
Ah fab! Thanks so much for clarifying for us, really helpful. I had heard that trap points and catch points were interchangeable, so it's interesting to hear there is technically a difference.
This is a very nice simulation and would be great addition in a museum because it's giving a good feel of what a signalman had to do and how irreplaceable he was.
Nicely done and explained, I can appreciate the fun to be had from playing signalman and good on you for giving it a go. It's way too much for my head to deal with but I did enjoy watching and listening so thank you for sharing.
In one real world example I have seen at St Andrews, Fife, the sidings connection crosses the running line then connects to the loop which then joins the running line. I think the logic of that is to avoid a facing point straight in to a siding.
Hi there I have just come across your channel. Very intersting topics and examples . I look forward to following along and seeing how you progress. Regards Allan
Brilliant, best explanation Ive seen on you tube. It’s something that I would love to retro fit to my layout. Have added a few Dapol signals and was hoping to electrically interlock them with the points. if only the was a simple mechanical interlocking available
Have to say, only ran into this video now, and this is really interesting stuff. I was planning on just putting signals in, naively didnt realise it was this in depth 😂
There are rabbit holes everywhere in this hobby, we just have to decide which ones we're prepared to go down! For me, it's interesting to know the background, but the practical implementation is always going to be a compromise, and the trick is drawing the line somewhere you're comfortable with.
Apologies if I'm late to the show. Really fascinating aspect of model railways. What if there was a passing train and shunting work being performed wouldn't the two 14 points need to be switched independently?
No, because the road to the shed wouldn't be used as a headshunt for the siding and bay. So any shunting movement would use the mainline. At a larger station, a separate headshunt would be provided to allow the sidings to be shunted without blocking the main.
Thanks for making and sharing this video. I'm certainly one of the modellers who's happy to set a train off and let it run, but would like to know what should be going on in the signal box, so now I've a much better understanding! I'm DC but with some automation via Arduino or Pi and my signalling diagrams are bit sparse on detail so far, as I've not been sure what should go on them. Cheers. Mike
I'm far from an expert, I've just done a load of casual research on the internet (TH-cam and Google) to find out as much as I could. Glad you found it interesting!
I've never worked a Great Western signal box, so am unable to comment on the details of the signal levers, but on the lever frame boxes I have worked, the levers only listed the other levers that needed to be out of the frame to unlock them. They didn't list the 'put back' levers. I think that this is probably because in the normal course of working, all the levers would be in the frame, and would only be pulled to complete a movement. Once the movement was complete, all the levers would be put back in the frame, ready for the next movement.
That is a fascinating video, thank you for that. It's also at about the same point that I am in my own layout. May I ask how you produced the track diagram please?
I used a free piece of vector graphics software called Inkscape, as that allowed me to tweak and change the positions of everything as the concept evolved. Adobe Illustrator would have been easier, but I don't have access to that!
This is great! How many lines of code to recreate all that interlocking! It would be really interesting to try and recreate it on the real model in some form or other
The code is actually all available on Github if you're interested, and the interlocking wasn't actually too complicated. It's all done in Vue.js. And yes, I did get to the end and thought it would be wonderful if I could connect the browser up to the point motors somehow, but I'm not sure how I'd do that!
@@FrontingtonandBackwoodsRailway thanks, I didn’t spot the little GitHub link when I played with the simulator. If JS is your thing, it might be “straightforward” (stressing the quote marks) to get the same logic running in Node on a raspberry pi that then can be your point motor/signal controller. Alternatively, if you are running DCC on a controller that supports it, you could have your sunglasses controlled from your compute through this controller. I believe there are a couple of DCC projects on GitHub though I can’t remember their names this second If going the raspberry pi route, you could use actual switches as inputs and build a physical version of your box, with a buzzer instead of mechanical locks for simplicity, driven by the same logic running in Node.
Excellent ideas there, thanks. I wasn't planning on having the points or signals DCC controlled, but yes I'm sure a pi could be used to make that happen. I also like the idea of constructing it physically but using a pi (or Arduino?) to replicate the logic and sound a buzzer if there's a conflict. I'm tempted by that one!
JMRI I believe could cope with all the logic and ensure the interlocks worked and allows actual physical dcc control of points and signals. However JMRI takes a lot to get your head around for this level of control.
Absolutely first rate description of an absolute block signalling system. Really useful for modellers. Please take this as me trying to be helpful for completeness. It is certainly not a criticism. Your ‘catch points’ are actually ’Trap points’. Catch points are normally unworked points that prevent an unauthorised backward movement. For instance on severe inclines to prevent loose fitted breakaway wagons from running wrong direction down the incline. Loose fitted = unbraked. Your signals 3, 16 and 17 are your starter signals. The platform signals are merely stop signals and strictly classed as home signals. Home signals are in rear of the signal box and starters are in advance of the box irrespective of whether platforms etc. are involved. I hope that this is helpful. Best regards, Tony
Ah fab! Thanks so much for clarifying for us, really helpful. I had heard that trap points and catch points were interchangeable, so it's interesting to hear there is technically a difference.
by that logic signal 13 would be a starter signal
This is a very nice simulation and would be great addition in a museum because it's giving a good feel of what a signalman had to do and how irreplaceable he was.
Nicely done and explained, I can appreciate the fun to be had from playing signalman and good on you for giving it a go. It's way too much for my head to deal with but I did enjoy watching and listening so thank you for sharing.
Fun explanation, enjoyed the walk through. It'snice to have an explanation as you are simulating the movements.
Thanks you.
In one real world example I have seen at St Andrews, Fife, the sidings connection crosses the running line then connects to the loop which then joins the running line. I think the logic of that is to avoid a facing point straight in to a siding.
Hi there I have just come across your channel. Very intersting topics and examples . I look forward to following along and seeing how you progress.
Regards Allan
Brilliant, best explanation Ive seen on you tube. It’s something that I would love to retro fit to my layout. Have added a few Dapol signals and was hoping to electrically interlock them with the points. if only the was a simple mechanical interlocking available
Have to say, only ran into this video now, and this is really interesting stuff. I was planning on just putting signals in, naively didnt realise it was this in depth 😂
There are rabbit holes everywhere in this hobby, we just have to decide which ones we're prepared to go down! For me, it's interesting to know the background, but the practical implementation is always going to be a compromise, and the trick is drawing the line somewhere you're comfortable with.
Nice update you done lots going on liked very much.
A very interesting video I am looking forward to the track rodding video
Very interesting video.
I approve of signalling.
Apologies if I'm late to the show. Really fascinating aspect of model railways. What if there was a passing train and shunting work being performed wouldn't the two 14 points need to be switched independently?
No, because the road to the shed wouldn't be used as a headshunt for the siding and bay. So any shunting movement would use the mainline. At a larger station, a separate headshunt would be provided to allow the sidings to be shunted without blocking the main.
Thanks for making and sharing this video. I'm certainly one of the modellers who's happy to set a train off and let it run, but would like to know what should be going on in the signal box, so now I've a much better understanding! I'm DC but with some automation via Arduino or Pi and my signalling diagrams are bit sparse on detail so far, as I've not been sure what should go on them. Cheers. Mike
I'm far from an expert, I've just done a load of casual research on the internet (TH-cam and Google) to find out as much as I could. Glad you found it interesting!
@@FrontingtonandBackwoodsRailway A goed expert knows he's not an expert ;-)
I've never worked a Great Western signal box, so am unable to comment on the details of the signal levers, but on the lever frame boxes I have worked, the levers only listed the other levers that needed to be out of the frame to unlock them. They didn't list the 'put back' levers. I think that this is probably because in the normal course of working, all the levers would be in the frame, and would only be pulled to complete a movement. Once the movement was complete, all the levers would be put back in the frame, ready for the next movement.
Yes, my approach is probably overkill! But it makes the interlocking clearer, I think, which is useful for demonstration if nothing else.
That is a fascinating video, thank you for that. It's also at about the same point that I am in my own layout. May I ask how you produced the track diagram please?
I used a free piece of vector graphics software called Inkscape, as that allowed me to tweak and change the positions of everything as the concept evolved. Adobe Illustrator would have been easier, but I don't have access to that!
Very enjoyable if only you could come and run my layout 😊
Will you be planning to use this virtual signalbox simulator to run the points when they're all DCC'd up??
No, this is just for demonstration and playing around with. The points won't be DCC controlled. At least not for now.
This is great! How many lines of code to recreate all that interlocking! It would be really interesting to try and recreate it on the real model in some form or other
The code is actually all available on Github if you're interested, and the interlocking wasn't actually too complicated. It's all done in Vue.js. And yes, I did get to the end and thought it would be wonderful if I could connect the browser up to the point motors somehow, but I'm not sure how I'd do that!
@@FrontingtonandBackwoodsRailway thanks, I didn’t spot the little GitHub link when I played with the simulator. If JS is your thing, it might be “straightforward” (stressing the quote marks) to get the same logic running in Node on a raspberry pi that then can be your point motor/signal controller. Alternatively, if you are running DCC on a controller that supports it, you could have your sunglasses controlled from your compute through this controller. I believe there are a couple of DCC projects on GitHub though I can’t remember their names this second
If going the raspberry pi route, you could use actual switches as inputs and build a physical version of your box, with a buzzer instead of mechanical locks for simplicity, driven by the same logic running in Node.
Excellent ideas there, thanks. I wasn't planning on having the points or signals DCC controlled, but yes I'm sure a pi could be used to make that happen.
I also like the idea of constructing it physically but using a pi (or Arduino?) to replicate the logic and sound a buzzer if there's a conflict. I'm tempted by that one!
JMRI I believe could cope with all the logic and ensure the interlocks worked and allows actual physical dcc control of points and signals. However JMRI takes a lot to get your head around for this level of control.
The code should be pretty simple -- remember, back in the day, it was implemented mechanically.