Mid-Cornwall Lines - 1950s Western Region in 00

[The Stationmaster]

Lots more food for thought there Mike, which I will digest in due course.

 

I actually looked at the arrangement you suggest for the Chapel Sidings, as this is how it is shown on a later (1979) SRS diagram and also on George Pryer's 1992 diagram. We decided to stick with the earlier arrangement but in the light of your comment I will have another look.

 

Look again at George's 1992 diagram and the lie of No.36 crossover

[St Enodoc]

Look again at George's 1992 diagram and the lie of No.36 crossover

 

Yes, that's the one I was thinking of.

[The Stationmaster]

Yes, that's the one I was thinking of.

 

So the alteration I suggested will bring it exactly into line with the way No.36 is arranged

[St Enodoc]

So the alteration I suggested will bring it exactly into line with the way No.36 is arranged

...and exactly how we had it in an earlier iteration of the diagram .

[The Stationmaster]

...and exactly how we had it in an earlier iteration of the diagram .

 

Do I sense a need for a document control system?     

[St Enodoc]

Do I sense a need for a document control system?     

Got one - several large piles on the desk and the round file on the floor.

 

Seriously, what I will do at the weekend is update v2 of the diagram to become v5 and see how that looks. Then I can rework the locking using the lessons I have learned over the course of this week.

 

Thanks.

Edited October 6, 2016 by St Enodoc

[St Enodoc]

Three useful acquisitions this week.

 

First, the S4 Society point blade and vee filing jigs arrived at my daughter's house in Sussex. Many thanks to Alan (islandbridgejct) for facilitating this on my behalf.

 

Secondly, I am now the proud owner of an NCE PH Box, which is the heart of the Power Pro system. I will convert over from the SB5 as soon as possible so that I can make use of the full range of macros. I will then reconfigure the SB5 as a dumb booster providing power just to the accessory bus.

 

Thirdly, I received some more old Hornby Dublo buffer stops via a well-known auction site. These are ideal for off-stage sidings as they are robust, the buffers themselves are sprung and the projection of the buffers means that DG couplings don't get all tangled up with them. I now need just a few more for the future Polperran fiddle yard.

Edited October 8, 2016 by St Enodoc

[Andrew P]

Some really good stuff going on Down Under, sounds good.

[The Stationmaster]

Got one - several large piles on the desk and the round file on the floor.

 

Seriously, what I will do at the weekend is update v2 of the diagram to become v5 and see how that looks. Then I can rework the locking using the lessons I have learned over the course of this week.

 

Thanks.

 

I'll  try to get the scans done tomorrow (Sunday) but the GWR one is very straightforward provided I don't include copies of the examples (which show a particular GW quirk of the late 1920s - on one example - which really would confuse the issue).  Farnham show today took much of my attention plus, at the show, the first shots of a new GW engine to have a good look at, and eating out later this evening so I'm told.

Edited October 8, 2016 by The Stationmaster

[St Enodoc]

I laid the first three B8RC points for the Penzance loops today, which connect the Up end throat to loops 11, 12 and 13. I need to build two more B8RC points for loops 8, 9 and 10 and also two A5R points for the link between loops 13 and 14 that will allow trains to enter and leave the Paddington loops at the Up end. Once all these are in place I can fit the point motors; wire up the motors, decoders and track; then build and program the Penzance point control panel before I move on to Penzance Down end.

[St Enodoc]

Well, with the help of many valuable comments and suggestions from The Stationmaster, both here and off-line, I think we have arrived at the final (?) version of the Porthmellyn Road signal box diagram - thanks Mike.

 

There are a few changes to the arrangements of the pointwork from the previous version, notably round the Chapel Sidings, and to the configuration of some of the signals. I've also renumbered the levers consecutively from 1 to 54, as this will make things easier when working out the interlocking using SigScribe4. That is the next job.

 

I will try to eliminate conditional locks as far as possible to keep the interlocking as simple as practicable but I think I will still need conditional locking on discs 24, 25, 26 and 34 to allow parallel moves on routes controlled by these signals. However, if that leads to excessive complication in the interlocking I will think again.

 

All this has stopped me from building any more points so far this week, but we will see what the next couple of evenings brings.

Edited July 21, 2023 by St Enodoc
images restored

[St Enodoc]

As it happens, I didn't get any more points built this week, as I was concentrating on getting the Porthmellyn Road signal box interlocking sorted out with Graeme's help. We have now sent the details to Harold Fanshawe at Modratec and, subject to any comments and suggestions he may have, I will be able to place an order for the lever frame soon. In due course there will be two more frames to be ordered, for Treloggan Junction and Pentowan, and I might order another to replace the existing electrically-interlocked frame at St Enodoc when I modify the station to suit the new layout..

 

Not building any points didn't mean that I didn't do anything on the layout this week though. First, I changed over from the SB5 to the PH Box and recreated the route setting macros. At the moment the SB5 is disconnected, as I had forgotten that the PH Box doesn't come with a power supply. I have used the one from the SB5 in the meantime. I will be able to pick up another power supply in a week or so together with another control bus cable to connect the PH Box and SB5 together. Once that's done I'll reconfigure the SB5 to "booster only" mode and use it to power the accessory bus, leaving the PH Box just for the track buses.

 

Today I spent a pleasant first half of the afternoon making up and connecting wiring harnesses for about ten point motors, then fitting them with cranks. Things got a little more frustrating when I decided to fit two motors at the Paddington throat to allow me to remove the Blu-Tac that was locking the points in place temporarily for the continuous runs.

 

I had no problems with the installation per se other than the severe lack of space in which to work. I thought that the Paddington throat was tight but this was tighter due to the very narrow baseboard and the small distance between the L-girders. Anyway, I got it done although I had to use through bolts on one of the motors as I just couldn't reach underneath to get screws in from below.

 

As a result of all that, I didn't have time to fit the motors to the other five points that are already laid.

 

No photos this week. It was bad enough getting the point motors in, never mind trying to poke around with the camera as well.

[St Enodoc]

Another busy week meant that I still haven't built any more points but today I fitted the motors to the remaining five points that I've already laid at Penzance Up end. I tested these on DC and all was well.

 

On Tuesday I should be able to pick up the power supply and control bus cable to connect the PH Box and the SB5, so then I will be able to separate the track bus and accessory bus power supplies.

 

Beyond that there won't be much activity on the layout for a couple of weeks as some other things are going to take up my spare time, including the BRMA National Convention next weekend in Launceston, Tasmania and the weekend after that the annual Singapore Cricket Club Rugby Sevens tournament. Chilli crab and Tiger beer here we come!

[Barry O]

Chilli crab...mmmh!!!

[St Enodoc]

Chilli crab...mmmh!!!

Not to mention roti prata and curry, soft-boiled eggs and kaya toast, Hainanese chicken rice, curry puffs, etc. etc.

[Andrew P]

Not to mention roti prata and curry, soft-boiled eggs and kaya toast, Hainanese chicken rice, curry puffs, etc. etc.

Do you have Sticky Toffee Pudding for desert?

 

Layout sounds like it's coming on well.

[Stubby47]

"The annual Singapore Cricket Club Rugby Sevens tournament".

 

That should be an interesting mix of rules...

[St Enodoc]

Do you have Sticky Toffee Pudding for desert?

 

Layout sounds like it's coming on well.

No, I don't like sticky toffee pudding. Treacle sponge is better, but in Singers you can't beat ice kacang or even a fresh durian.

 

Layout progress has slowed down recently but is still moving.

Edited October 23, 2016 by St Enodoc

[St Enodoc]

"The annual Singapore Cricket Club Rugby Sevens tournament".

 

That should be an interesting mix of rules...

Yes, it sounds a bit bizarre, doesn't it? Not quite as bad as the so-called International Rules matches we have down here from time to time, which are a mash-up of Australian Rules and Gaelic Football.

Edited October 23, 2016 by St Enodoc

[islandbridgejct]

May I interject to wonder how the nice man with the handlebar moustache from the BoT ever approved that direct connection from the down main across the branch loop and into the sidings? Was the final slip interlocked with no. 13 (in your diagram) to prevent a move from main to sidings, and ensure that a train could only move from the down main into the loop? I should have thought there'd be a standard double junction with a slip to allow a train from the branch platform to access the up main.

 

What about the reverse direction? How would you stop a train running from the loop or branch platform out onto the down main wrong road? Was it just controlled by signal?

 

I note from the SRS diagram that what you're doing is prototypical. I just thought it wouldn't have been allowed.

 

Alan

[St Enodoc]

May I interject to wonder how the nice man with the handlebar moustache from the BoT ever approved that direct connection from the down main across the branch loop and into the sidings? Was the final slip interlocked with no. 13 (in your diagram) to prevent a move from main to sidings, and ensure that a train could only move from the down main into the loop? I should have thought there'd be a standard double junction with a slip to allow a train from the branch platform to access the up main.

 

What about the reverse direction? How would you stop a train running from the loop or branch platform out onto the down main wrong road? Was it just controlled by signal?

 

I note from the SRS diagram that what you're doing is prototypical. I just thought it wouldn't have been allowed.

 

Alan

 

Very useful thoughts Alan.

 

On the real Par there was originally no signalled move from the Down Main to the Loop or Up Sidings, although there was later after the junction was modified to a single-lead layout rather than the single slip. I copied the later arrangement to simplify shunting of Down goods trains which could go straight into the Loop rather than occupy the Branch platform. However, now you mention it I'm not so sure so I'll think again.

 

In the other direction, I need 13 to be able to lie either way when 19 is reversed, so I think it has to be done through the signals.

 

Thanks.

Edited October 23, 2016 by St Enodoc

[St Enodoc]

I picked up the PH Box power supply and the extra control bus cable today. I also got the latest V1.65B firmware chip for the SB5.

 

First I changed the chip, then configured the SB5 to act in booster mode only. Next I made up and connected a booster common cable to keep the booster cases at the same potential. Finally, after separating the track and accessory buses I connected them up to their respective boosters - the PH box for the track and the SB5 for the accessories.

 

On the left is the SB5, which is now connected only to the accessory bus by the clear wires. It's connected to the PH Box at the front by the control bus cable and at the back by the green booster common.

 

Next to it is the PH Box. The booster section is on the left, with the power input and track bus cables, and the command station section is on the right, with the cab bus cable. The two halves are not connected internally, only by the control bus cable on the outside.

 

After setting all this up I was pleased and relieved to find that it all worked exactly as it should.

 

In case anyone is wondering, I took the photo with the power switched off which is why there are no LEDs lit on the boxes.

 

I might tape over the cab bus sockets on the SB5 to stop anyone plugging in a cab inadvertently.

Edited July 21, 2023 by St Enodoc
images restored

[Andrew P]

Nice set up you have there, re that tape, I had to do that after one of my operators tried plugging my Prodigy lead into the wrong socket at a show, it's a good idea.

 

All the best and keep the pics and info coming.

[The Stationmaster]

May I interject to wonder how the nice man with the handlebar moustache from the BoT ever approved that direct connection from the down main across the branch loop and into the sidings? Was the final slip interlocked with no. 13 (in your diagram) to prevent a move from main to sidings, and ensure that a train could only move from the down main into the loop? I should have thought there'd be a standard double junction with a slip to allow a train from the branch platform to access the up main.

 

What about the reverse direction? How would you stop a train running from the loop or branch platform out onto the down main wrong road? Was it just controlled by signal?

 

I note from the SRS diagram that what you're doing is prototypical. I just thought it wouldn't have been allowed.

 

Alan

 

I'm trying hard to see the problem and the only one I can see in all of that is that there is a ground disc shunting signal reading towards a hand point which isn't protected by a STOP board.  But I not only bet it wasn't alone in that but there were locations where running signals (3ft arms of course) did exactly the same, we even had one at our local branch junction where a 3ft arm read into two dead end sidings and the only way the route was decided was by a hand point.  So as such it was not an uncommon situation and provided everybody did their job properly it was a heck of a long way from being dangerous in any way.  In fact in my view by far the greatest risk arises from a train crossing from the Down Main to the Branch (platform) exceeding the permitted speed and derailing.

 

The site at Par was very constricted and there was definitely no room for a double line junction between the Main Lines and the Branch (platform) hence the original arrangement with a single slip (as at Porthmellyn Road) and the later arrangement with the Main Lines facing crossover and the added (shunt) route into the loop/sidngs.

 

I'm a bit puzzled about the question of how you would stop a train from the Loop or Branch (platform) running out onto the Down Main because the answer is there in the drawing at Post 587 above - lever 13 would be released by lever 19 but 50/44 would lock 13.  The only risk from 25 would be a SPAD but when you consider that 13 and 22 would only both be reversed for a planned movement either for a shunt to the Down Main or for an incoming move from the Down Main the likelihood becomes minimal if you start applyng risjk assessment methods.  In fact you might just as well ask how dangerous it is to have a 'Limit of Shunt' board in the Down Main with a risk that it could be ignored - effect no different at all in many respects from an errant move towards the Down Main.  So are all LOS boards a potential risk area - answer is 'yes', but it is a considered and measured risk and is necessary in order to handle traffic requirements.

[St Enodoc]

I'm trying hard to see the problem and the only one I can see in all of that is that there is a ground disc shunting signal reading towards a hand point which isn't protected by a STOP board.  But I not only bet it wasn't alone in that but there were locations where running signals (3ft arms of course) did exactly the same, we even had one at our local branch junction where a 3ft arm read into two dead end sidings and the only way the route was decided was by a hand point.  So as such it was not an uncommon situation and provided everybody did their job properly it was a heck of a long way from being dangerous in any way.  In fact in my view by far the greatest risk arises from a train crossing from the Down Main to the Branch (platform) exceeding the permitted speed and derailing.

 

The site at Par was very constricted and there was definitely no room for a double line junction between the Main Lines and the Branch (platform) hence the original arrangement with a single slip (as at Porthmellyn Road) and the later arrangement with the Main Lines facing crossover and the added (shunt) route into the loop/sidngs.

 

I'm a bit puzzled about the question of how you would stop a train from the Loop or Branch (platform) running out onto the Down Main because the answer is there in the drawing at Post 587 above - lever 13 would be released by lever 19 but 50/44 would lock 13.  The only risk from 25 would be a SPAD but when you consider that 13 and 22 would only both be reversed for a planned movement either for a shunt to the Down Main or for an incoming move from the Down Main the likelihood becomes minimal if you start applyng risjk assessment methods.  In fact you might just as well ask how dangerous it is to have a 'Limit of Shunt' board in the Down Main with a risk that it could be ignored - effect no different at all in many respects from an errant move towards the Down Main.  So are all LOS boards a potential risk area - answer is 'yes', but it is a considered and measured risk and is necessary in order to handle traffic requirements.

Thanks Mike, as always - clear, concise and comprehensive.