Signalling Saltfleet - on the bench

[Dave-5-5-7]

On 06/04/2020 at 21:39, Junctionmad said:

As an EE I can design electronic switches that outperform  and outlive any “ relay “. If you wished it could survive conditions that would have extinguished all life on Earth. 
 

It’s all a matter of spec ( and cost ) I used to work in space and defense 

 

to me it doesn’t make sense to use relays to switch semiconductor leds !!!! 
 

buy hey as they say whatever floats your boat. 
 

To me relays are less suitable , require more assembly and wiring ( hence unreliability ) etc 

 

dave 

 

Like I said, I have a lot of them, I prefer physical switching where possible, and it's fun. I have always had an interest in electronics, to a point where I'm 2 years into a degree in Electronics and Electrical Engineering just for fun and I'm a full radio license holder and my preferred method are data modes and television. 

[Dave-5-5-7]

2 hours ago, micknich2003 said:

To prove I actually made it, here are a few pictures.

 

22 hours ago, micknich2003 said:

Just to throw a spanner in the works, I will stick with this.

 

That it exceptional. Beautiful work 

[micknich2003]

Dave, thanks for the kind words, building it was more repetition than anything, just a case of getting stuck in, from memory, a lot of it was built in British Railway's time.

[Dave-5-5-7]

5 minutes ago, micknich2003 said:

Dave, thanks for the kind words, building it was more repetition than anything, just a case of getting stuck in, from memory, a lot of it was built in British Railway's time.

Aye, a lot of my paper work and circuit diagrams have been done on Network Rail time. Been spending time in a little Gate box on a quiet branch line, two hours in between trains. 

 

[LNERGE]

35 minutes ago, Dave-5-5-7 said:

Looks like a McKenzie & Holland Type 13. I know what you mean thought. I have 3 kids, other half,  00 gauge railway, NR job and heritage rail job. Don't have the room for a signal box hence why I'm tying the two together. I do have a mate who has a signal box based on a miniature frame, 5 inch garden railway. 
 

It was originally fitted with Leytons finest slab locking tucked up right under the front floor beam. The tray brackets were blacksmiths nightmares and whilst it did the job it was intended to do relocking it would have been my nightmare.  

 

It now has LNER Standard trays and the box floor has been altered accordingly. It will be much easier to work on now.

 

Looking forward seeing more of your railway in due course. 

[DY444]

On 06/04/2020 at 12:12, The Stationmaster said:

But can you see what electricity is, or isn't, going where & when at certain states of the circuit?  That is the beauty of working with relays - ok they are very 'steam age' in some respects but like many other things from the steam age they have the benefit of simplicity.  All a matter of horses for courses but whatever ever you use the first part is to make sure that your circuitry and controls are both designed to do the correct job and actually do the correct job.  And if the circuitry doesn't do the correct job finding out why and then putting it right.  

 

For example I have seen numerous examples of folk using solid state controls for colour light signalling on layouts and they haven't even got the aspect sequences correct (there are obviously also examples of those folk who have got the sequences right).  Getting correct aspect sequences using relays is a doddle.

 

My view is that layout builders who get the aspect sequences wrong (or indeed any other facet of signalling practice) do so because they don't understand aspect sequences rather than it being a feature of the technology employed and so if you understand them then getting them right using electronics and computers is a "doddle" too.  If you also understand electronics and computers then you can include testing, diagnostic and reporting tools to assist in debugging interlocking logic and tracking down faults, which is the approach I've taken.  I also think those who go to the trouble of building relay based interlockings are almost certainly people who understand signalling principles very thoroughly.  

Edited April 8, 2020 by DY444

[LNERGE]

I have just had a fantastic session with my six year old lad on the model railway. I set him a task of delivering two fuel tank wagons from one part of the layout to another. The trip started at the diesel depot and involved joining the main line for a while then taking a branch then, after collecting the tanks and running round, taking them back to the diesel depot. All sounds simple? There were five other trains running on the mains. All he had to do was wait for a gap in traffic and swing the necessary  points.. The interlocking ensured they restored the main line signals. The abc braking stopped the trains as required and he could carry on just concentrating on the task in hand. With the points reset behind him the railway comes back to life. The points are track locked. The signals are interlocked with the points. All he has to do is ensure when he restores the protecting signals the approaching train is not too close to them to be unable to stop. Without interlocking/abc braking I'm sure I'd lose even more of my grey hair.

[Junctionmad]

On 07/04/2020 at 20:06, Mallard60022 said:

Why is there always someone that has to 'have a dig' when this poster is obviously having a whale of a time and loves his wires and whizzy things? If you know about other things then be generous, not condescending. I for one am envious of this particular project. My signals, if they ever get to work, are Semaphores so will probably be operated by bits of string and some wire!

Phil

chill , there bro.  I wasn't having a dig , merely a comment , its seems counter intuitive to me , but as I said , whatever floats your boat etc 

[Dave-5-5-7]

On 08/04/2020 at 21:27, Junctionmad said:

chill , there bro.  I wasn't having a dig , merely a comment , its seems counter intuitive to me , but as I said , whatever floats your boat etc 

A valid point, if I was starting from scratch, and buying new then it would all be eletronic, however as I've previously put, I have a lot of relays so I will be utilising them. Plus I prefer them. 

[Dave-5-5-7]

Little bit of an update, relay cabinet is coming together. A couple of amendments have been made to the diagram including an additional branch to an off scene power station. 

 

Amended diagram complete with switch markings and indicators. Corrections made to CCTV Crossing and addition of CFPS branch. 

 

Relay cabinet under construction. Most are 24v 4P2W and 12v 2P2W relays. Control cabling in place and tested. Feeds to signal heads will be going in next. 

[imt]

Oh dear!  I KNOW nobody likes a smartarse!  But aren't your AHBs on the wrong side of the road????  I ask in fear and trepidation since I have been reading Simon Paley's excellent book and his AHB on p131 (fig. 177) is the same.  Has he made the same "mistake", or is that how you professionals draw them?  The ORR publication on the whole subject https://orr.gov.uk/__data/assets/pdf_file/0016/2158/level_crossings_guidance.pdf shows them the other way round on p54 since it is from the point of view of signage.  Gulp.  Am awaiting incoming!

[Dave-5-5-7]

18 minutes ago, imt said:

Oh dear!  I KNOW nobody likes a smartarse!  But aren't your AHBs on the wrong side of the road????  I ask in fear and trepidation since I have been reading Simon Paley's excellent book and his AHB on p131 (fig. 177) is the same.  Has he made the same "mistake", or is that how you professionals draw them?  The ORR publication on the whole subject https://orr.gov.uk/__data/assets/pdf_file/0016/2158/level_crossings_guidance.pdf shows them the other way round on p54 since it is from the point of view of signage.  Gulp.  Am awaiting incoming!

 

Prize for you, you are correct and I'd not noticed. I flipped a section of an old diagram I'd drawn and obviously forgotten to flip the crossing back. Well spotted. 

Of course anyone asks and I was "just testing" ha ha 

[jimsig15]

Cracking effort Dave. Looking really good. 

[imt]

26 minutes ago, Dave-5-5-7 said:

Prize for you, you are correct and I'd not noticed. I flipped a section of an old diagram I'd drawn and obviously forgotten to flip the crossing back. Well spotted. 

Of course anyone asks and I was "just testing" ha ha 

 

Phew!  I am a fascinated amateur who laps up all the stuff on this thread.  Is there a write up on "track circuits with acceptance switches" anywhere you know of.  I use "Tokenless Block" which relies on track circuits and has an "Accept" on the Block Instrument.  Is it the same and just more modern?

[The Stationmaster]

2 hours ago, imt said:

 

Phew!  I am a fascinated amateur who laps up all the stuff on this thread.  Is there a write up on "track circuits with acceptance switches" anywhere you know of.  I use "Tokenless Block" which relies on track circuits and has an "Accept" on the Block Instrument.  Is it the same and just more modern?

Quite a lot of difference between Acceptance Lever (or Switch) working and Tokenless Block.

 

Acceptance Lever block needs continuous track circuiting through the entire single line section (as does a single line worked to Single Line Track Circuit Block Regulations) and Acceptance Lever block is what is known as a closed block system in that it requires a positive action (the operation of an Acceptance lever or Switch) in order to accept a train when the train is offered).  The acceptance Lever at the 'box in advance when reversed automatically releases the Section Signal at the 'box at the rear, entry, end to the section.

 

The system is well suited to comparatively short sections of single line but can become very expensive for longer sections because of the cost of installing track circuits although nowadays the use of axle counters instead of track circuits would considerably reduce the cost.

 

Both systems have the obvious advantage of dispensing with the need for tokens etc which avoids speed reductions at crossing places where automatic token exchange isn't provided plus it also removes the need to balance tokens (by taking them in a special carrier from one end of a section to the other) where the number of movements don't balance.  So in system and operational terms they deliver advantages over the traditional token and tablet systems.

 

In contrast Tokenless Block doesn't require continuous track circuits (which makes it massively cheaper over long sections of single line -  a major reason for its adoption on BR).  In the BR form it is also effectively what is known as an 'open' block system because it doesn't necessarily require the presence of a Signalman in order to accept a train - the WR version can be left, once the Accept Switch is turned to Accept' and the Signalman need not then be present for a train to be accepted (the idea being that he could then go and perform other duties, although that very rarely happened in practice).  The work is then done only by the Signalman  at the 'box in rear who simply presses the 'Offer' button on his instrument and the block will automatically clear to 'Train Accepted' releasing his Section Signal, and the block instrument will go to 'Train In Section' as a result of the operation of a short track circuit when the train passes the Section Signal.  The instrument at the 'box in advance also automatically goes to 'Train In Section' (again very different from a closed block situation where theh Signalman in advance would have to place it to 'Train On Line').  

 

The block is restored to normal by the Signalman when the train has arrived at the 'box in advance - to do this the commutator is reset to 'M Norma;' and the 'Train arrived' button is pressed to clear the block.  In the original WR installations it was also necessary for the train to operate a treadle in order to release the block.   However originally on the WR system the Signalman need not do this immediately after the train has arrived (unless things are busy movements wise and another train is waiting or approaching) but provided he has ensured that the train is complete he can be doing other duties before clearing the block.  Once the block is back to normal either Signalman can set then their instrument to 'Accept' depending on train service etc requirements.

 

The logic of the WR system was pretty near flawless although the same could not unfortunately  be said for its reliability especially in its early years.  I spent nearly 4 years of my railway career with it on my patch and it inevitably had a tendency to fail at the most inconvenient time - i.e. the middle of the night.  the reason for this was generally because the acceptance circuit proving was so unnecessarily complicated on some stretches including various things which while admirable didn't really make a massive additional contribution to safety.  With an accept circuit going through as many as 20 proving contacts spread through not quite as many miles there was a lot to potentially go wrong - and it did.  One of the Westbury S&T Techs completely rewired one accept circuit taking out all the extraneous bits and made it very acceptably reliable.  Overall I liked the system, apart from its ability to fail when least wanted.

[St. Simon]

4 hours ago, imt said:

Oh dear!  I KNOW nobody likes a smartarse!  But aren't your AHBs on the wrong side of the road????  I ask in fear and trepidation since I have been reading Simon Paley's excellent book and his AHB on p131 (fig. 177) is the same.  Has he made the same "mistake", or is that how you professionals draw them?  The ORR publication on the whole subject https://orr.gov.uk/__data/assets/pdf_file/0016/2158/level_crossings_guidance.pdf shows them the other way round on p54 since it is from the point of view of signage.  Gulp.  Am awaiting incoming!

 

Woops, you're right, I got it wrong, but sure how I managed it, I'll correct for any future releases!

 

Thanks for spotting it!

 

Simon

[phil-b259]

On 06/04/2020 at 12:28, Titanius Anglesmith said:

 

+1.  On my patch of "real" railway we have a mixture of relay interlocking and electronic.  The electronic systems keep us entertained with a variety of problems that relays are simply immune to.  The relay sites "just work".

 

Or not!

 

While relay interlocking are helpful in fault finding, the downside is they are susceptible to relay contacts becoming high resistance over time and thus causing failures (sometimes quite obscure ones) over time. Electronic interlocking don't suffer from this limitation.

 

That said, fault finding a relay interlocking is a definite skill and one which requires far more understanding of the interlocking than a 'replace a module' answer to everything that tends to occur with electronic solutions.

 

Just as the move from signalmen setting points then clearing signals individually in favour of 'Entrance Exit' panels (and subsequently IECCs and control centres equipped with ARS) actually saw a removal of a certain skill set, the same is true in the S&T world with the move to electronic modules.

[Titanius Anglesmith]

1 hour ago, phil-b259 said:

 

Or not!

 

While relay interlocking are helpful in fault finding, the downside is they are susceptible to relay contacts becoming high resistance over time and thus causing failures (sometimes quite obscure ones) over time. Electronic interlocking don't suffer from this limitation.

 

That said, fault finding a relay interlocking is a definite skill and one which requires far more understanding of the interlocking than a 'replace a module' answer to everything that tends to occur with electronic solutions.

 

Just as the move from signalmen setting points then clearing signals individually in favour of 'Entrance Exit' panels (and subsequently IECCs and control centres equipped with ARS) actually saw a removal of a certain skill set, the same is true in the S&T world with the move to electronic modules.

 

Yes we do have our fair share of relay failures but it’s rare for them do be really elusive (assuming the failure hasn’t self-cleared by the time the technician gets there, which our relay failures have a knack of doing). Our electronic failures on the other hand can keep us guessing, and that situation is steadily getting worse as the system ages. 

[LNERGE]

Trimley to Felixstowe Beach was direction switch at one end and direction lever at the other.

[imt]

On 23/04/2020 at 15:45, The Stationmaster said:

Quite a lot of difference between Acceptance Lever (or Switch) working and Tokenless Block.

 

Mike, we met at Pendon though I doubt if you will remeber me from the crowd.  Thank you again for giving of your knowledge and, what is often more important, your experience.  You helped me in the past sort out my Tokenless Block working, and I now have that working in my electronic control panel for my small layout - I am very happy with it.  Photo attached.

 

I am not sure that I really understand the difference still, it sounds more like semantics than reality - but that is probably because I don't have any experience of the real thing.  What you seem to be saying is that switch/lever requires positive interaction between the signallers, whereas TB is more passive - i.e. it is normal for the receiving signaller to set his route and leave the the system hanging on the remote sender by setting his instrument to "Accept".

 

I can see that Dave has switches on his panel for "going to" and "coming from" some point.  It would no doubt also be nearly impossible on such a busy panel to set a route and leave it hanging on the action by somebody else.  So I guess there is some positive exchange - telephonic or bells (but this is an electronic panel so surely not bells?).

 

Perhaps you should PM me if you have the time else I am highjacking Dave's thread and he knows all this anyway!

Edited April 24, 2020 by imt

[The Stationmaster]

21 hours ago, imt said:

 

Mike, we met at Pendon though I doubt if you will remeber me from the crowd.  Thank you again for giving of your knowledge and, what is often more important, your experience.  You helped me in the past sort out my Tokenless Block working, and I now have that working in my electronic control panel for my small layout - I am very happy with it.  Photo attached.

 

I am not sure that I really understand the difference still, it sounds more like semantics than reality - but that is probably because I don't have any experience of the real thing.  What you seem to be saying is that switch/lever requires positive interaction between the signallers, whereas TB is more passive - i.e. it is normal for the receiving signaller to set his route and leave the the system hanging on the remote sender by setting his instrument to "Accept".

 

I can see that Dave has switches on his panel for "going to" and "coming from" some point.  It would no doubt also be nearly impossible on such a busy panel to set a route and leave it hanging on the action by somebody else.  So I guess there is some positive exchange - telephonic or bells (but this is an electronic panel so surely not bells?).

 

Perhaps you should PM me if you have the time else I am highjacking Dave's thread and he knows all this anyway!

Marvellous panel layout - smashing job.

 

The big differences between Acceptance Lever and Tokenless are -

1.  The lack of track circuits on the single line between the crossing places at either end of the section which made tokenless a lot cheaper to install.

2. The lack of any sort of positive need in Tokenless Block for trains to be offered and accepted between signal boxes - Signalmen can simply work to the timetable and need only communicate if/when it is altered.  In turn this means -

3. The man at the advance end of the section has no need to be present when a train which has been accepted enters the section, he need only be present once it has left the section and to set the instrument ready for the next train.

4. Obviously in both cases a Signalman has to be present to set the route and clear signals and, in the case of e semaphore signals to replace them to danger.

 

If you're still noy happy by all means drop me a PM and I'll try to explain a bit further.  and yes, a great day at Pendon and I do remember talking, in the car park I think it was.

[Pannier Tank]

On 07/04/2020 at 22:13, Dave-5-5-7 said:

I'm a full radio license holder and my preferred method are data modes and television.

 

QRZ?

[Dave-5-5-7]

On 25/04/2020 at 16:02, Pannier Tank said:

 

QRZ?

Greetings, M0YAA (transferring to G7HJR when the paperwork goes through) IO93WN. 

 

73

Edited April 26, 2020 by Dave-5-5-7

[Dave-5-5-7]

Signalling work has stalled for the day whilst I finish installing the fiddle yard, which has now been completed, all I've done is to clear the c**p from the "block shelf" and align the CCTV camera for Church Hill crossing (when it goes in). 

 

Excuse the mess on the shelf above, that's where the panel is going so it's current a mass of cables, soldering kit, components and other random tools. 

 

Edited April 26, 2020 by Dave-5-5-7

[Dave-5-5-7]

On 25/04/2020 at 13:34, The Stationmaster said:

Marvellous panel layout - smashing job.

 

The big differences between Acceptance Lever and Tokenless are -

1.  The lack of track circuits on the single line between the crossing places at either end of the section which made tokenless a lot cheaper to install.

2. The lack of any sort of positive need in Tokenless Block for trains to be offered and accepted between signal boxes - Signalmen can simply work to the timetable and need only communicate if/when it is altered.  In turn this means -

3. The man at the advance end of the section has no need to be present when a train which has been accepted enters the section, he need only be present once it has left the section and to set the instrument ready for the next train.

4. Obviously in both cases a Signalman has to be present to set the route and clear signals and, in the case of e semaphore signals to replace them to danger.

 

If you're still noy happy by all means drop me a PM and I'll try to explain a bit further.  and yes, a great day at Pendon and I do remember talking, in the car park I think it was.

I use Transient TCB at work, at least I will when the line reopens and I can actually pass the box out, mine is a bit of a miss match. It's basically transcient TCB, with train describer. The code will flash up on a display, and the signalman will turn the accept button to the right and "Train coming from" will flash for a few seconds and illuminate. This mimics the system checking the circuit is correct for an authority to be issued. Box in rear locks release, signals clear, train runs. Once train arrives signalman turns switch back to centre and the system clears. In order to send, signalman enters code into TD, moves switch to left and presses "SEND" once box in rear acknowledges the locks release and MS938 can be cleared.