Great Southern Railway (Fictitious) - Signalling the changes...

[Penrhos1920]

On 25/03/2024 at 16:46, Skinnylinny said:

. They've enough to deal with now that I'm getting back into organ practice too (well, as best I can with a MIDI keyboard, and an old church organ pedalboard that I've managed to acquire and am planning to MIDI-ify...) but at least that I can do on headphones!

Hauptwerk or Grandorgue?

[Skinnylinny]

  

15 hours ago, Dana Ashdown said:

A real wooden case would be even better!

It would, although I lack the required woodworking skills, and no longer have access to the laser cutter since moving to Glasgow-ish. 
 

13 hours ago, Penrhos1920 said:

Hauptwerk or Grandorgue?

GrandOrgue at the moment, as I don't have the cash to drop on a copy of GrandOrgue, and I'm sort of cautiously dipping my toe back in for as little spend as possible. The 61-key MIDI keyboard cost me £60, while the pedalboard has cost me the grand total of £1.04 on eBay and the price of a decent takeout dinner for a friend to drive it up to me! It will require a bank of microswitches, and the use of an Arduino which I already have, to MIDI-ify it.

[Skinnylinny]

The frame now has lever numbers (Also 3d printed), and work has started on printing the block instrument. All the circuitry fits inside, although I've had to temporarily substitute momentary toggle switches while I await the push-buttons arriving. I've also set up a temporary trackplan board to make testing easier. 



Now to decide what type of wood veneer to use - mahogany or cherry. Or possibly walnut. All three are rather nice!

I ought to start thinking about signals, I suppose...

[Skinnylinny]

Yes, I ought to start thinking about signals... As I've mentioned before, the history of Linton Town includes the company contracting out the supply of signalling equipment to Messrs. Saxby & Farmer. As such, I'd rather like to have split-post signals, although I'd prefer to have the spectacles mounted on the same spindles as the arms (similar to the NER designs), rather than lower down the post, which was S&F's more common modus operandi at the time. I've been having trouble getting any useful drawings of similar signals, too. I suspect that I may have to "bash" mine together from a mixture of MSE parts intended for S&F and NER signals, and Ian MacCormac's parts.

What I'll need on the visible part of the layout will be something like this: 



I'm not going to lie, I'm rather nervous about the bracket for numbers 16-19! While I'm a big fan of 3D printing in various situations, I think that metal kits will likely be rather more able to stand up to the rigours of operation. I have previously made some laser-cut signals out of MDF, card, and acetate, but I can't decide whether they look too chunky or not.

Unfortunately, at the moment, the layout boards are packed up, so I don't have any brilliant photos of them, but these are what I do have!

[Skinnylinny]

A brief step away from signals... I have had a very empty, nicely-built (not by me!) Roxey LSWR lavatory brake tricomposite sat on a shelf, glaring at me, along with a packet of the Ratio carriage seating strips. My previous attempts at using these were... somewhat abortive, so I spent a few minutes drawing up some rough approximations in CAD. Given these will be inside compartments with small windows, I came to the conclusion that filament printing would suit absolutely fine, so I've drawn up a few different types of seats (first, second and third class, with central or offset lavatory doors). 





I was wondering if they'd be useful to anyone else? I can pop the files on Thingiverse or similar, and they're fairly quick and easy to print. Certainly they saved me a lot of effort!

[Michael Hodgson]

On 25/03/2024 at 11:20, Skinnylinny said:

 

 

 

 

Excellent job, and I do like the wood finish. 

 

You'll have to decide whether you are working the instrument to your fiddle yard operator who uses an identical one, or to a simulator of some sort (or possibly both options).  One way of modelling bells I've usd that isn't too loud is to take the bell from an old fashioned GPO telephone and modify that to single-stroke working.

 

Your wiring of the instrument is unlikely to justify following full size practice, as that includes complexity such as minimising the number of telegraph line wires between signalboxes and a latching design for safety so that the instrument keeps its last indication in the event that line wires come down in a storm (generally one wire with earth return on this style with miniature signal arms), and separate power supplies at each end.  I've used non-protoypical circuitry for simplicity using home made miniature 3-position instruments, as did Tri-ang with their short-lived RT268 block instrument.

 

 

One thing you'll have to decide with this two-position style of instrument is how to represent the "Normal" condition of the line in your block working, the third position of a more modern block when there's no trains about.  There were differences between companies in their rules.  Some instruments had additional aids such as reminder flaps or indicators to reduce the risk of errors (such as in the GER flap instrument, or in the Harpers blocks used in Ireland)  https://collection.sciencemuseumgroup.org.uk/objects/co209395/telegraph-block-instrument-great-eastern-railway-telegraph-instrument

The complexity of design could complicate which plungers you pressed to work the bell depending on the state of the block/message you were sending, since this could affect the instrument's indication.

 

Some railways equated Line clear (miniature arm in the off position) to be the Normal position, as logically the line must be clear if it isn't its occupied.  This probably made sense to railwaymen who had been brought up with Time Interval before block working was introduced, when signals had only been at Danger for a short period after train had passed.

 

Other railways equated Train on Line (miniature arm at Danger) with Normal position, as it was seen as safer to regard the line as blocked except when it had been specifically established as clear for the passage of a particular train.  The miniature arm should then show the same indication as the signal outdoors.  I believe the SR inherited both practices at grouping and perpetuated the old procedures in different Divisions of the company.

 

As you're modelling a fictitious company, you've got that choice to make.

 

 

[Skinnylinny]

39 minutes ago, Michael Hodgson said:

 

Excellent job, and I do like the wood finish. 

 

You'll have to decide whether you are working the instrument to your fiddle yard operator who uses an identical one, or to a simulator of some sort (or possibly both options).  One way of modelling bells I've usd that isn't too loud is to take the bell from an old fashioned GPO telephone and modify that to single-stroke working.

 

Your wiring of the instrument is unlikely to justify following full size practice, as that includes complexity such as minimising the number of telegraph line wires between signalboxes and a latching design for safety so that the instrument keeps its last indication in the event that line wires come down in a storm (generally one wire with earth return on this style with miniature signal arms), and separate power supplies at each end.  I've used non-protoypical circuitry for simplicity using home made miniature 3-position instruments, as did Tri-ang with their short-lived RT268 block instrument.

 

 

One thing you'll have to decide with this two-position style of instrument is how to represent the "Normal" condition of the line in your block working, the third position of a more modern block when there's no trains about.  There were differences between companies in their rules.  Some instruments had additional aids such as reminder flaps or indicators to reduce the risk of errors (such as in the GER flap instrument, or in the Harpers blocks used in Ireland)  https://collection.sciencemuseumgroup.org.uk/objects/co209395/telegraph-block-instrument-great-eastern-railway-telegraph-instrument

The complexity of design could complicate which plungers you pressed to work the bell depending on the state of the block/message you were sending, since this could affect the instrument's indication.

 

Some railways equated Line clear (miniature arm in the off position) to be the Normal position, as logically the line must be clear if it isn't its occupied.  This probably made sense to railwaymen who had been brought up with Time Interval before block working was introduced, when signals had only been at Danger for a short period after train had passed.

 

Other railways equated Train on Line (miniature arm at Danger) with Normal position, as it was seen as safer to regard the line as blocked except when it had been specifically established as clear for the passage of a particular train.  The miniature arm should then show the same indication as the signal outdoors.  I believe the SR inherited both practices at grouping and perpetuated the old procedures in different Divisions of the company.

 

As you're modelling a fictitious company, you've got that choice to make.

Thank you! Unfortunately, that's only a computer render, and I haven't applied the "wood"  finish to the 3D print yet!

For home working (by myself) I expect it'll end up with a simulated signaller up the line (if at all), but for exhibitions, the idea would be to communicate between fiddle yard and layout by bell codes. However! To save the sanity of those around the layout, I intend to use recorded bell beats, with a choice between a small speaker or an earphone (both with volume control).

As to the wiring, I do have a set of the Triang instruments, although they haven't made their way back into the daylight since the house move. I rather fancied having proper coil-operated arms, but trying to get the bits these days is not easy. At the moment, the example print is designed around servos. Not ideal, but good enough for now. I suppose if I did want to go for bells, bicycle bells might be a suitable option, coming in a variety of shapes, tones, and materials.

I have to admit, I'd assumed that the instrument would usually be at "danger" unless the line were explicitly cleared by the signaller in advance. That said, I can see the logic in assuming the line is clear if there's no train on it!

[Michael Hodgson]

On 20/04/2024 at 12:33, Skinnylinny said:

Yes, I ought to start thinking about signals... As I've mentioned before, the history of Linton Town includes the company contracting out the supply of signalling equipment to Messrs. Saxby & Farmer. As such, I'd rather like to have split-post signals, although I'd prefer to have the spectacles mounted on the same spindles as the arms (similar to the NER designs), rather than lower down the post, which was S&F's more common modus operandi at the time. I've been having trouble getting any useful drawings of similar signals, too. I suspect that I may have to "bash" mine together from a mixture of MSE parts intended for S&F and NER signals, and Ian MacCormac's parts.

What I'll need on the visible part of the layout will be something like this: 



I'm not going to lie, I'm rather nervous about the bracket for numbers 16-19! While I'm a big fan of 3D printing in various situations, I think that metal kits will likely be rather more able to stand up to the rigours of operation. I have previously made some laser-cut signals out of MDF, card, and acetate, but I can't decide whether they look too chunky or not.
 

My instinct has always been to go for metal for strength, but if you have a 3D printer and the knowledge to use it, you do have the advantage that if you break something you can print off another one.   A downside of anything with moving parts is that it will entail different components and an assembly job, so becomes a hassle.   I suppose it then comes down to how clumsy you are = how often you think you're likely to need to do that.  So I'd still be aiming to try and provide some protection where possible - by placing close to an overbridge for example.