Unusual PW configurations thread both real and model.

[Grovenor]

4 hours ago, RailWest said:

I believe that the arrangement was altered at some date. The later arrangement is similar to that which existed in the 1950s/60s at Tipton St Johns, at the foot of the incline towards Sidmouth.

 

What I find more curious is the fact that, as the Bodmin installation was at the top of the incline up from Boscarne Jcn, why did they need a trap+fpl for incoming trains coming up the hill?

The catch at Bodmin was to catch anything that might leave the yard when shunting etc and throw it off before it could runaway down the hill. The fpl was to hold the catch closed for trains departing on signals.

Regards

[RailWest]

6 minutes ago, Grovenor said:

The catch at Bodmin was to catch anything that might leave the yard when shunting etc and throw it off before it could runaway down the hill. The fpl was to hold the catch closed for trains departing on signals.

 

Agreed. But that does not address the matter of the apparent earlier equivalent provision for arriving trains coming up the hill.

[Grovenor]

Its functionally the same, arriving trains trail through the catch, anything running out of the station gets derailed, unless its a signalled departure when the points are reversed and locked to avoid the catch.

[RailWest]

32 minutes ago, Grovenor said:

Its functionally the same, arriving trains trail through the catch, anything running out of the station gets derailed, unless its a signalled departure when the points are reversed and locked to avoid the catch.

Err, sorry no. The apparent original arrangement had a facing trap for incoming (uphill) trains which had to be closed for trains to enter the station. Other than preventing the train from entering the station against the signal (not done anywhere else), what possible purpose did it serve? Even Cornish wagons couldn't run away up hill :-)

[Pacific231G]

4 hours ago, The Stationmaster said:

But Coombe Junction had a trap point, not a catch point so it was a very different situation  and one where the point had to be closed to permit a train to pass in either direction.  Thus in your diagram above signals at the real Coombe Junction had both 1 and 25 (your numbering) released by 3 (your numbering)  -  the real world numbering changed over the years.

 

As ever there is a need not to confuse the purpose of (runaway) catch points with trap points (in the past often known as 'safety points').  No.3 on your diagram would have been a catch point if it had been a spring slotted point (and hence would have not needed to be pulled to release 25) but it was not - it was a trap point pure and simple.

 

As for trains standing on catch points all I would say is that a good many years ago when working in the West Country I had a good look one day at a spring slotted catch point when visiting one of our signalboxes which was only opened on rare occasions for diversions etc.  The number of wheel marks where vehicles on trains standing at the next 'box in advance's Home Signal had rolled back off the road was quite impressive.  Vehicles rolling back and derailing or partially derailing on catch points was not exactly a common thing but it did happen - hence the GWR's approach in putting a warning board (for Drivers) well in advance of the catch thus reminding them to get the rear of their train clear of the catch point.  

 

It is one reason why routes had length limits and why catch points were always carefully sited in relation to stop signals.  That particular catch point was a wartime job and the distances involved were short so as train lengths increased problems could occur.

 

 

Hi Mike

It's not my numbering. The numbering on the creative commons diagram is the same as in John Hinson's - possibly because the former was based on the latter- and so far as I can make out from the two very different locking tables on the Signal Record Society's webste appears to be that for the box that replaced an older one in the mid 1950s. Unfortunately the only images of the inside of the box I've found lack the definition needed to compare these diagrams with the actual situation

 

I'm now rather confused as I've always understood that catch points were on running lines to cach runaways on gradients whereas traps, whether in the form of derailers, catch type points or trap sidings, are to prevent stock in sidings and yards from inadevertedly getting onto running lines so they're not actually on rinning lines.  The steeply graded line from Coombe Jct up to Liskeard is definitely a running line so I'm not sure what else it could be for except to catch runaways. Is this perhaps is an example of reality being rather more complicated than the cut and dried definitions that modellers and enthusiasts are so fond of. It does seem that the Coombe Jct. arrangement is  a different way of dealing with the same situation as Bodmin North, 

[RailWest]

The box at Coombe Junction opened circa-1900 and closed in 1981. The layout changed a number of time of the years, including when the level-frame was replaced in 1956, hence any possible confusion over lever numbering.

 

>>>The steeply graded line from Coombe Jct up to Liskeard is definitely a running line so I'm not sure what else it could be for except to catch runaways.....

 

Simple IMHO ...it also permitted the signalman at Coombe Jcn to accept trains from Liskead and Looe simultaneously. Any train coming down from Liskeard which overshot 21 would 'simply' end up in the trap road (or possible the actual road!) rather than smashing into the side of a train arriving from (or going to) Looe. The lesser of the two evils.....

[The Stationmaster]

On 10/06/2019 at 23:57, Pacific231G said:

Hi Mike

It's not my numbering. The numbering on the creative commons diagram is the same as in John Hinson's - possibly because the former was based on the latter- and so far as I can make out from the two very different locking tables on the Signal Record Society's webste appears to be that for the box that replaced an older one in the mid 1950s. Unfortunately the only images of the inside of the box I've found lack the definition needed to compare these diagrams with the actual situation

 

I'm now rather confused as I've always understood that catch points were on running lines to cach runaways on gradients whereas traps, whether in the form of derailers, catch type points or trap sidings, are to prevent stock in sidings and yards from inadevertedly getting onto running lines so they're not actually on rinning lines.  The steeply graded line from Coombe Jct up to Liskeard is definitely a running line so I'm not sure what else it could be for except to catch runaways. Is this perhaps is an example of reality being rather more complicated than the cut and dried definitions that modellers and enthusiasts are so fond of. It does seem that the Coombe Jct. arrangement is  a different way of dealing with the same situation as Bodmin North, 

Two different points - two different reasons for them.

 

The point numbered 16 on the diagram you posted was partially  there for the purpose described by Railwest in his most recent post.  It was definitely a trap but if the Signalbox Footnotes were appropriately worded it would also have served as a catch point for breakaways from trains ascending the bank to Liskeard and in fact the 1969 Sectional Appendix describes it as a worked catch point   We don't have the Signal Box Footnotes although I wouldn't mind betting that the late Larry Crosier had a copy of them so they might be somewhere in an SRS archive. and that they working of them will compliment the description given in the SA.

 

The point at the other end - and the numbers I referred to - is at the boundary between the freight  only line from Moorswater  (actually classified  as a siding) and the passenger railway from Liskeard/Looe.  It is therefore a trap and, from the Locking Chart, clearly worked as one.  If it had been a catch point it would have had a spring slot as was the normal GWR practice in such situations where there was no need for an FPL.  But even after the new frame was provided at Coombe Jcn in 1956 it was locked and worked as a trap point  and that remained the case following the closure of Coombe Jcn Signal Box when it became operated by No.2. Ground Frame.  

[bradfordbuffer]

Is there a point to all the above posts? 

 

Sorry long day at work!

[AndyID]

2 hours ago, bradfordbuffer said:

Is there a point to all the above posts? 

 

 

That depends on how things turnout.

[bradfordbuffer]

4 hours ago, AndyID said:

 

That depends on how things turnout.

Now your just diverting off the subject keep it on track!

it's a punoff! 

[PaulS]

Fresh enquiry, thanks to YouTube cab video! Thoroughly enjoyed this trip from Tirano to St Moritz -
https://www.youtube.com/watch?v=QQHRP_sfBZk

 

At 1:08;30, just before the train reaches Alp Grüm (heading north), the single track becomes a 180 degree-plus loop, curving sharply. Less than a long train's length from the points, the two tracks converge to give inadequate clearance for two trains to pass each other, and round the bend separate fully to enter the station. There would appear to be room at the platform end for the divergence to happen there.

 

Google maps give an impression of this - https://www.google.co.uk/maps/place/Alp+Grüm/@46.3736189,10.0318493,207m/data=!3m1!1e3!4m5!3m4!1s0x47839d91d76ac5fd:0xfca6b3a9caceba7f!8m2!3d46.3745587!4d10.0311902 

 

Any thoughts why this should be?

 

[martin_wynne]

20 minutes ago, PaulS said:

At 1:08;30, just before the train reaches Alp Grüm (heading north), the single track becomes a 180 degree-plus loop, curving sharply. Less than a long train's length from the points, the two tracks converge to give inadequate clearance for two trains to pass each other, and round the bend separate fully to enter the station. There would appear to be room at the platform end for the divergence to happen there.

 

Any thoughts why this should be?

 

 

Hi Paul,

 

It allows a standard straight turnout can be used for the loop. The alternative would need a very long curved turnout on a sharply curving gradient. A curved gradient means a track twist, which makes it difficult or impossible to install moving switch blades.

 

Thanks for the link.

 

cheers,

 

Martin.

[jim.snowdon]

13 minutes ago, martin_wynne said:

 

Hi Paul,

 

It allows a standard straight turnout can be used for the loop. The alternative would need a very long curved turnout on a sharply curving gradient. A curved gradient means a track twist, which makes it difficult or impossible to install moving switch blades.

 

Thanks for the link.

 

cheers,

 

Martin.

It does make me wonder why they didn't just install the switches on the straight (where the turnout is) and interlace the two tracks until nearer the point where the divergence is actually needed, as per typical tramway practice. It would have saved the additional length of the second contact wire.

 

Jim

[PaulS]

Thanks for the clarification; it all makes sense now!

[Grovenor]

On 10/06/2019 at 20:42, RailWest said:

Err, sorry no. The apparent original arrangement had a facing trap for incoming (uphill) trains which had to be closed for trains to enter the station. Other than preventing the train from entering the station against the signal (not done anywhere else), what possible purpose did it serve? Even Cornish wagons couldn't run away up hill :-)

The earlier arrangement was functionally the same, the catch was for leaving the station. The facebook photo seems to be lost now but I did look at it carefully the first time.

[ATME]

On 05/02/2015 at 15:05, Brian Harrap said:

Not exactly a 'formation' but a little novelty to consider - speed humps for rail vehicles. Brian

Just seen this, I kept my boat in Ipswich Haven Marina for a few years and drove over this regularly. They serve no rail purpose at all! ABP wanted a speed bump on the access road to the Marina and lorry park and also another hump further round the Marina, and you can’t tarmac or concrete on top of steel especially checkrail so they just welded a hump to each rail. They were installed well after the last train used that route which leads to the still in use For road traffic swing bridge over the lock. 
I can remember container freight going via the north side to the docks. If you walk through the Marina to the far end where the old lock used to be, there is quite a complex track layout still in the concrete.
The last freight to that part of Ipswich was the BOC tanks the other side of Stoke Bridge. The sidings of which I remodelled as a junior track engineer.

Funnily enough, I just came across some drawings of the pway layout in Ipswich Docks at work. 

[Brian Harrap]

Thanks ATME thats interesting, while we're at it here's another puzzle picture, Spain this time.

Baron

Edited May 5, 2020 by Brian Harrap

[The Stationmaster]

Culvert or similar underneath?

[Philou]

I was thinking an area of soft ground? But culvert sounds good.

 

Cheers,

 

Philip

[Orion]

Her's an interesting bit of pointwork from Sweden. I thought single blade turnouts went out with the Ark, but this one was in existence between the wars. No exact date though.

[AndyID]

17 hours ago, Brian Harrap said:

Thanks ATME thats interesting, while we're at it here's another puzzle picture, Spain this time.

Baron

 

IKB enthusiasts?

 

[Brian Harrap]

Here's something unusual.

B

[iands]

4 minutes ago, Brian Harrap said:

Here's something unusual.

B

Perhaps an obvious question, I assume there is another one to make a pair? 

[bécasse]

3 hours ago, Brian Harrap said:

Here's something unusual.

B

Guided trolleybus system - as in Caen (where they call them trams but guided single-wire trolleybuses is more accurate)?

Edited July 7, 2021 by bécasse

[Compound2632]

It's a wagon turntable on a monorail system.