Block instruments and bells

[SHMD]

Now for the four Pillars.

Actually the two left ones should be paired together as should the two right ones. They are linked at the top but I can't think of a way of (me) machining them in one go.

 

The CAD drawing..

..showing the pillar in half profile so I can measure the cut depth.

 

Here's the toolpaths overlaid onto the simulated finished work piece.

 

The software said the job would take ~25 minutes to cut.

(It doesn't even attempt to guess my setup time though!)

 

One things for sure...   ...this will be interesting!

 

 

Kev.

 

[SHMD]

Well, after a very frustrating day of trying to understand the CAM software and then failing to realise that the Laptop/CNC software had lost the config for the Router - I decided to write my on CNC code.

 

This eventually worked and here are the results :-

 

First, setting the tool hight and the job datum position...

(The "Sharp Point" was found - and recycled - from that cornucopia that is the metal bin at work!)

 

Here, eventually, is a Pillar half way through being machined.

 

..nearly finished..

 

..and after more than a days work..

Here, you can see how the Pillars fit into the base.

Quite a snug satisfying fit with very little play.

 

Now, one step above the base... ...several more to go...

 

 

Kev.

 

[SHMD]

 

Another step up - the Base for the main cabinet.

Again, this fits beautifully together.

 

 

 

 

 

This took a lot of work.

I also had to machine both sides (my first time) but, unfortunately, I didn't register them together very well - nearly 2mm out!

 

So, although this piece is scrap - it does show great promise.

 

 

Kev.

 

[clecklewyke]

On 16/04/2020 at 07:53, SHMD said:

So, although this piece is scrap - it does show great promise.

 

Only 2mm out - that’s precision modelling by my standards!

 

 

Any progress to report, Kev? I’m going to need four block instruments.

ian

[SHMD]

Yes! I messed up with my clamping and ran out of wood.

 

The good news is I'm just about to start on the main cabinet's left hand side wall. If that's good then the right hand side will quickly follow on.

 

 

 

Kev.

[uax6]

You do know that the pillars that the case sit on are actually metal don't you?

 

I've taken some photos of my single line instrument if you would like me to put them up here?

 

Andy G

[SHMD]

4 hours ago, uax6 said:

You do know that the pillars that the case sit on are actually metal don't you?

 

I've taken some photos of my single line instrument if you would like me to put them up here?

 

Andy G

 

Hi Andy,

 

Yes I know they are metal and I also know they are joined together at the top front-to-back.

What I don't know (is most things ) what they were made of. They are heavily oxidised, after 130 odd years, but were they zinc - as in diecast - or brass? Either way I will be painting them the dull grey-ish that they are now.

 

Yes please to the photos.    

There are plenty on the net but are low resolution and I have not found any photo showing what's behind the needle or what's in the cabinet with the Instrument panel swing out.

 

 

Kev.

 

[SHMD]

The Left hand cabinet side is done.

 

It's pretty simple but as I had to remove a lot of material it took ages. 

(18mm down to 9mm work piece thickness using a 3mm cutter to simplify things.)

 

 

 

Who would have thought that this was hiding inside that piece of wood!

 

 

 

Kev.

[SHMD]

The Left, Right and Back sides of the Block Instrument needed to be drawn together.

Or I really doubt that they would line up.

 

Another really important consideration was to "adjust" the proportions until I get what I think looks right. This was not easy.

I have no drawings, or prototype to take dimensions from, so everything has been guessed but I spent ages trying different proportions to the bottom and top halves of the "face" of the instrument.

 

 

Anyway, lets create the CNC file to machine the Right Hand Panel.

I use VCarve Desktop.

 

As with most CAD/CAM programs - it does things "differently" to how I want to do things so learning it was (is) not that intuitive!

On two occasions now, I was so unhappy with its' created toolpaths, that I manually wrote the CNC file!

Having said that, I think I would still recommend VCarve.

 

 

..and now for a bit of fun.

(I know what is behind the rotary switch, but I have never seen what is behind the top two needles.)

 

 

Kev.

 

[t-b-g]

Those proportions look good to me.

 

If you go back to page 4 and follow the link, you will get some ice photos of the insides of a real block instrument.

 

I will find out for myself soon, having been successful in bidding for a couple of GCR examples at an auction. I have one of each kind, with and without the knob.  I just have to wait until we can start getting out and about to collect them.

 

They may get used if (a big if) the O gauge garden railway ever gets going. Otherwise I will measure them up for dimensions to make smaller replicas for the indoor/exhibition layouts.

 

 

Edited May 3, 2020 by t-b-g

[SHMD]

How on earth did I miss that link!  

 

Thanks so much indeed.

 

 

Kev.

[tomparryharry]

One exhibition addition you might consider is a headphone jackplug, and a set of headphones.

 

"Aahh, the tinkle of bells in a signalbox......"  It would find it very annoying, very quickly. 

[t-b-g]

7 minutes ago, tomparryharry said:

One exhibition addition you might consider is a headphone jackplug, and a set of headphones.

 

"Aahh, the tinkle of bells in a signalbox......"  It would find it very annoying, very quickly. 

 

If you look back a few pages, you will find that even fans of block bells acknowledged that unless the volume was dealt with properly, they could be annoying at shows. A few ideas as to how to deal with the problem were put forward.

 

The idea of listening to the bells via headphones wasn't one of them, so you may have hit upon something! Put the bell in a sound proofed box, with a microphone. If it is via an earpiece in one ear, the operator can still hear the rest of what is going on with the other ear. It would also mean that operators siting a few feet away can only hear their own bell, instead of both, which adds to the realism.

 

Having said that, I think the general feeling was that the thread was not so much about whether block bells are a good thing or not but was more about how to get hold of some and whether a manufacturer might ever produce them like Triang used to. It moved on to folk coming up with ways of making them for themselves. I think most people contributing are more concerned with home based layouts rather than exhibitions, so you are probably safe from being annoyed!

 

 

[St Enodoc]

52 minutes ago, t-b-g said:

It would also mean that operators siting a few feet away can only hear their own bell, instead of both, which adds to the realism.

Hearing all the bells is the main reason I don't use them Tony.

[SHMD]

 

I'm pretty sure I will get fed up of the noise of bells after just a few tries of trying to churn out a bell code as fast as I remember them by real signallers.

It doesn't stop me from wanting them to work though or occasionally wanting a "play".

 

No, I will just carry on running my model railway, according to the local rules set out in the sectional appendix - which basically just refers to Rule 1 in the main section!    

 

 

Kev.

 

[t-b-g]

I never used to bother with bells until I learned when I got to operate a big layout with 12 stations that had them. Even then, I wasn't hooked. Too many bells all going off together and constant "Was that you" called from one station to another. It was, however, where I learned the basics of working hem.

 

Then I got to operate Buckingham. As I knew the basics, I could just drop onto a station and run it, as if I had known it for years.

 

The timetable and the operating system, including the bells, were and are just so absolutely natural and an integral part of the joy of the layout. Now, even when I operate a layout that doesn't have bells, it just feels as if something is missing. I find myself muttering "ding, ding" under my breath! It is a bit of a standing joke amongst my friends. Many see the bells as a joke and make comedy "Ding " noises or Quasimodo references every time they are mentioned. 

 

I would never suggest or dare to say that those who don't like block bells and block instruments should be forced to use them, or should even try them if they have no interest in that type of operating. But I wouldn't want to go back to asking the next operator "Can you take the express now?" when the real railway had a perfectly good way of doing it that I can replicate in model form.

 

But at the risk of upsetting folk, dare I suggest that "I don't like/want/enjoy block bells" or "Should model railways use block bells?" is not really what the thread is about.

 

2 hours ago, SHMD said:

How on earth did I miss that link!  

 

Thanks so much indeed.

 

 

Kev.

   

I thought you must have missed it! Glad to help.

[uax6]

18 hours ago, SHMD said:

 

Hi Andy,

 

Yes I know they are metal and I also know they are joined together at the top front-to-back.

What I don't know (is most things ) what they were made of. They are heavily oxidised, after 130 odd years, but were they zinc - as in diecast - or brass? Either way I will be painting them the dull grey-ish that they are now.

 

Yes please to the photos.    

There are plenty on the net but are low resolution and I have not found any photo showing what's behind the needle or what's in the cabinet with the Instrument panel swing out.

 

 

Kev.

 

I'm guessing that they might be nickel-plated brass, but I've not really payed too much attention to them.

I'm in work now, but tomorrow morning I'll get the block out of the exchange and risk the management by placing it on the dining room table so that I can take some close ups of it for you.

 

It's a shame mine is a single line version, I'd love to swap it for a double line one (I could then use it back to back with my penguin block)... or have another to work it too...

 

Andy G

Edit:

The insides of an LNWR block is very different to the insides of others....

Edited May 3, 2020 by uax6

[SHMD]

Thanks so much Andy,

 

All pics are extremely useful and I thank you (and your very understanding misses) for allowing some serious (a-hem) research to take place.

 

The single line block instrument will be useful because I have seen so few examples of them on the net. It will also allow comparisons to be made with the double line block instrument to see which components were common, why and/or why not. Better views might also ensue too.

 

If I could make a request, or two...

A full frontal photo with everything open giving side on views of the front two doors, and the side elevation of the needle coil, whilst giving an unimpeded view of the cabinets' full back panel.

..and..

All other shots will be of great interest too.

 

 

A simple daft question, is the bell round or oval?

At first I thought it was oval but now the dimensions seem to indicate that it is round.

 

Ploughing through all this info is a bit like archaeology. You begin to discover why things were the way they were, and can even spot different styles in the workmanship.

Fascinating.

 

 

Kev.

[uax6]

Your request shouldn't be too difficult, hopefully my poor photography skills will get you what you want!

 

I'm sure the bell is round. It has a lovely ting to it!

 

I'll try my best to do a full survey of it for you.

 

Andy G

[tomparryharry]

The key mechanism is pretty much identical to a Morse key.

[Pacific231G]

1 hour ago, uax6 said:

.

 

It's a shame mine is a single line version, I'd love to swap it for a double line one (I could then use it back to back with my penguin block)... or have another to work it too...

 

Andy G

Edit:

The insides of an LNWR block is very different to the insides of others....

I'm probably being dense but, apart from tokenless block instruments used by the W.R. how did a single line block instrument that wasn't part of a token machine function? I thought the token machine was the block instrument on a single track line. 

 

Let's see if I've got this right  so can explain it in simple English.

On a double track line,  in 'our' box, each instrument connected to another box (one each side unless ours is a junction box) has a commutator and a lower needle (to confirm the state of the circuit)  for the line towards us. When the other box offers us a train and the  line is clear we can accept it and confirm that by setting our commutator (and their upper needle) to line clear. The other box can then clear the train to enter the block and lets us know by sending train in section on the telegraph. We then move the commutator to  train on line, until the train arrives intact and clears the block. We then send train out of section on the telegraph and confirm that by restoring the commutator to 'normal/line blocked' and the other box can then in due course offer us another train.  

Conversely, when we offer a train to the other box and they can accept it they confirm that by moving their commutator to line clear, and the upper needle in our instrument shows that. We can then signal the train to enter the block and send train in section on the telegraph when we expect to see our upper needle moving to train on line until it clears the section.

In simple terms each instrument has a commutator to set a needle in the instrument in the other box and a needle that their commutator sets in ours (the lower needles just confirms that the appropriate indications are being sent)   but the two circuits are independent of one another as are the two lines of track.  

 

Assuming I've got that right so far,  what I don't understand is how that works with a single track as the section cannot be in two states at once, it's either occupied or not so can't (or can it? ) be blocked/normal in one direction and clear or train on line in the other and you surely couldn't have line clear in one direction and train on line in the other though the normal block instruments could be set that way.   So how does an instrument that indicates the state of a line where there can be both up and down trains (not at the same time) operate and is it part of the token (or tablet or even ball in India) instrument?

[uax6]

My single line instrument is for working a one directional single line under Absolute Block conditions. Something like a fully signalled relief line. The box in rear offers the train on on his instrument (I'm guessing it didn't have a commutator, just the bells and needle) and I answer on mine, giving line clear on my commutator, swinging both my (single) needle and his to line clear. On receipt of train entering section I turn my commutator again and put the needles to train on line. When the train passes, train out of section is given and the block put back to line clear...

 

You'll see better tomorrow when I post pictures...

 

Andy G

[Pacific231G]

1 hour ago, uax6 said:

My single line instrument is for working a one directional single line under Absolute Block conditions. Something like a fully signalled relief line. The box in rear offers the train on on his instrument (I'm guessing it didn't have a commutator, just the bells and needle) and I answer on mine, giving line clear on my commutator, swinging both my (single) needle and his to line clear. On receipt of train entering section I turn my commutator again and put the needles to train on line. When the train passes, train out of section is given and the block put back to line clear...

 

You'll see better tomorrow when I post pictures...

 

Andy G

Thanks Andy. That makes sense. We tend to see main lines as always being in pairs, which they generally are, but not always. There are also a few places, south of Princes Risborough is one example, where a main line divided into two separated single  lines. I don't know whether that example was long enough to be divided into several blocks (but I can probably find out) and there may have been others.

There were also railways that used separate instruments for up and down lines so a simple wayside box would have had four, two for each direction though I think the block bells would have been separate.

 

Because most of our modelled lines are single track I'm trying to think how one could operate them in  a railwaylike way but without the physical tokens that for some reason our miniature drivers seem not to be ale to handle. A simplified tokenless block system seem the logical answer. I 'm not sure I even want to know how the innards of a token machine actually work

(I'm actually trying to think how to do this for a French BMVU - single line manual block- system- their systems were almost all tokenless- but the instruments for that are far more complex and involve relays and the few modellers there exploring it are turning to Arduinos etc. ) 

Edited May 3, 2020 by Pacific231G

[uax6]

I've an article out of an old Railway Modeller, that describes working single lines with a token in model form. The token takes the form of a Large jack plug, which is inserted into a jack at the far end of the section and allows the controller at that end of the section to control the single line. Being only one plug, the end that has it drives the train towards itself...

 

You could, if you have multiple single lines one after another, use stereo jacks, wire the first section as say tip and ring, and the second section as tip and sleeve. A third section could be sleeve and ring.

 

Not fool proof, but a bit closer to reality...

 

Andy G

[Pacific231G]

1 hour ago, uax6 said:

I've an article out of an old Railway Modeller, that describes working single lines with a token in model form. The token takes the form of a Large jack plug, which is inserted into a jack at the far end of the section and allows the controller at that end of the section to control the single line. Being only one plug, the end that has it drives the train towards itself...

 

You could, if you have multiple single lines one after another, use stereo jacks, wire the first section as say tip and ring, and the second section as tip and sleeve. A third section could be sleeve and ring.

 

Not fool proof, but a bit closer to reality...

 

Andy G

Hi Andy,

Do you know hold old? I have a good run of early RMs.

There was an article in the March 1948 MRC by C.W.Aatkin  describing what amounted to a tokenless block system. He'd faced the same problem of wanting to operate a single track line in a way that for the operators would simulate a token block system without actually having tokens.

 

 

A wiper on the arm connected to the knob bridged the two or three contacts in each of the instruments three positions. In the "normal" token in position each local controller had control of its station as far as the shunting limit but the "token" section between was dead. After the usual exchange of bell codes, with the knob actinf as plunger, both operators would turn their pointer to up or down token out as approrpriateand the offering end would then keep control of its own shunting area, and get control of the token section and the accepting station's approach as far as the home signal. If the pointers were not in agreement than the token section would remain dead.   Aatkins suggested that the home signal at each station could close a switch to extend the sending station's control all the way into the platform but  I think I prefer the convention  that an operator drives a train towards them not away but that would simply involve reversing some of the wiring.

 

 

Edited May 3, 2020 by Pacific231G