Trap Points

Any aspect related to the structures and equipment on the Caledonian Railway Company.
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Alan K
Posts: 430
Joined: Mon Aug 13, 2012 10:41 pm

Trap Points

Post by Alan K »

Does anyone know how the Caledonian constructed trap points ( ie to prevent runaway wagons from getting onto a main line)? I've seen several in photographs which appear to be just using slightly longer sleeper timbers to accommodate the chairs which deviate to the outside. There doesn't seem to be an increase in the frequency of sleepers which might be expected if interlaced sleepering was used. But in view of the Caley's preference for having timber perpendicular to rail, I would have thought that would have been how it was done. Or didn't they use that type of check rail?
I'm not sure if the pictures I've seen weren't from later (ie LMS or even BR) times, and I can't find any photos which are definitely from the Caledonian era.

Alan
Last edited by Alan K on Fri May 30, 2014 10:11 pm, edited 1 time in total.
IBrown
Posts: 330
Joined: Sun Feb 03, 2013 5:36 pm

Re: Check Rails

Post by IBrown »

Alan K wrote:Does anyone know how the Caledonian constructed check rails ( ie to prevent runaway wagons from getting onto a main line)? I've seen several in photographs which appear to be just using slightly longer sleeper timbers to accommodate the chairs which deviate to the outside. There doesn't seem to be an increase in the frequency of sleepers which might be expected if interlaced sleepering was used. But in view of the Caley's preference for having timber perpendicular to rail, I would have thought that would have been how it was done. Or didn't they use that type of check rail?
I'm not sure if the pictures I've seen weren't from later (ie LMS or even BR) times, and I can't find any photos which are definitely from the Caledonian era.

Alan
Boxes Boarding and Covers .jpg
Boxes Boarding and Covers .jpg (202.91 KiB) Viewed 8890 times
Hi Alan,
The photo is one of Dave Lochrie’s borrowed from the Stretcher Rods thread:-
http://www.crassoc.org.uk/forum/viewtopic.php?f=6&t=415

and ‘No1’ I think is what you are actually asking about - trap points rather than check rails - which when lying in the normal, run-off position, will derail a train or vehicle making an unauthorised facing direction movement over them.

I don’t believe there could be a standard; for example these ones appear designed to drop the vehicle with one wheel in 4 foot and the other in the cess, just outside the right hand running rail. They appear designed to arrest a slow-moving vehicle quickly with minimum track damage. They do feature a few interlaced sleepers which you asked about.
Alan K
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Joined: Mon Aug 13, 2012 10:41 pm

Re: Check Rails

Post by Alan K »

Sorry - having a senior moment! Trap points is exactly what I meant. Any chance of changing the subject to 'Trap Points'?
The kind I've seen diverts both rails.

Alan
Alan K
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Joined: Mon Aug 13, 2012 10:41 pm

Re: Trap Points

Post by Alan K »

Thanks Ian.
That's what I was looking for - I missed these when they were originally posted. There are quite clearly interlaced sleepers present.
As you will have seen, I've just found that I can edit my faux pas, even when it's in the subject!

Alan
IBrown
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Re: Trap Points

Post by IBrown »

I’d said previously I didn’t believe there would be a standard ‘trapping arrrangement’. Most probably local circumstances would determine what went in, subject to Board of Trade Approval. An example is offered of two very different trapping arrangements at the same box, Springburn Park, on the Caledonian Hamiltonhill Branch. Part of another enquiry I think you will find it both relevant and useful here.

The photo is a crop of one image from National Archives Kew’s MT 6_1193_12_001, for the new Stobhill Hospital siding installation, treated by BoT as New Works and subject to the same planning, inspection and approval requirements as any new line. It shows the existing 1895 Caledonian trapping arrangements to protect the Up main line (rising gradient) at Springburn Park Goods and Mineral Station (top) and the proposed 1903 arrangement for Down main line (falling gradient) at Stobhill Hospital siding (bottom). The New Work was approved and a 1929 sketch shows the same layout carried forward into LMS days with very little alteration; the most notable being: additional ground signals; the Up main line end of the trailing connection into the Depot became catch points, set normal lie for the Depot and would turn a runaway on the Up line into the Depot. Within the Depot the facing points remained set normal for the headshunt, and continued to act as trap points protecting the Up line.



On another forum, others have commented on the unusual arrangement on the Down line with trap points within a double ended connection where the 3 sets of points were controlled by the same lever in the box (No5). Unfortunately the correspondence in the Kew item is silent on the thinking behind this trapping arrangement.
Attachments
National Archives Kew MT6/1193/12/ 1 Crop
National Archives Kew MT6/1193/12/ 1 Crop
MT 6_1193_12_001crop.jpg (66.37 KiB) Viewed 8864 times
Last edited by IBrown on Sat May 31, 2014 11:53 am, edited 1 time in total.
Dave Lochrie
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Joined: Mon Aug 20, 2012 9:38 pm

Re: Trap Points

Post by Dave Lochrie »

TRAP1.jpg
TRAP1.jpg (143.69 KiB) Viewed 8859 times
A clean close-up of the Brechin trap does confirm that they do employ interlaced sleepers. The Caledoniian used blades derscribed as nominally 30ft (standard Caledonian 32ft rail with an allowance for planing) and whilst a simple sleeper count shows this to be the overall trap rail length, it can clearly be seen that these are jointed just after the first non-slide chair, which looks to be a special of some kind.
TRAP2.jpg
TRAP2.jpg (140.28 KiB) Viewed 8859 times
This lower-angled shot is at the South end of the loop at Lesmahagow shortly after opening (note the young train-spotters assuming a surfaceman pose) and again you can just "see the join", as well as the usual Caledonian practice of covering all working parts.
TRAP3.jpg
TRAP3.jpg (130.21 KiB) Viewed 8859 times
As Ian says there seems no standard trapping arrangement and the final pic is a close-up from a pre 1914 postcard of Wilsontown. In this instance the trap on the loop is a single-bladed example and I have been unable to establish a pattern in the application of double or single traps, other than not finding many single traps in main-line locations (note the curve to the rodding from this angle).

Dave L
dumb buffer
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Re: Trap Points

Post by dumb buffer »

Auldbar Rd trap 3.jpg
Auldbar Rd trap 3.jpg (76.59 KiB) Viewed 8854 times
Auldbar Rd

I think the single sided trap was not uncommon in locations where
space was tight and/or
speeds were low and/or
economy was desireable (i.e. most of the time!)
Certainly I seem to recall a number of these at country stations on the main line

Allan F
jimwatt2mm
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Joined: Fri Nov 16, 2012 5:36 pm

Re: Trap Points

Post by jimwatt2mm »

Photos of the east end of Peebles CR station show a similar arrangement to that at Auldbar Road. Unfortunately my 'Peebles Railways' book is packed away at present, so I can't post a scan, however here is how I interpreted the arrangement on my layout.
Double trap points in 2mm finescale
Double trap points in 2mm finescale
Trap points in 2FS.jpg (55.18 KiB) Viewed 8833 times
Both switches are operated by the same lever as those of the turnout leading onto the main line.
Jim W
Alan K
Posts: 430
Joined: Mon Aug 13, 2012 10:41 pm

Re: Trap Points

Post by Alan K »

Thanks for the pictures. That's been most helpful - I'm sure that I can now reproduce an authentic looking set of trap points, even though it will involve a minor amount of butchery to retro-fit!
I'm impressed by the working switches on your layout Jim. Unfortunately, my trap points are too far away from the siding entry - I can get the ground signal to operate off the point switch using the rodding with spring assistance hidden under the boxed-in part, but getting the trap to work as well is a step too far...!

Alan
jimwatt2mm
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Joined: Fri Nov 16, 2012 5:36 pm

Re: Trap Points

Post by jimwatt2mm »

Alan,
I didn't have sufficient room for the trap points between the turnout dividing the sidings (in the photo) and that leading off the main line, so the photo of Peebles provided the ideal, prototypical solution. The main line turnout is on a separate board from the trap points and is operated by a memory wire actuator, while the trap point is operated by wire in tube from the lever frame. A micro switch operated by the lever switches on the current to the actuator. Had the turnout been on the same board then it too would have been operated by its own run of wire in tube off the same lever. The ground signal will have it's own lever, interlocked on the frame with that from the turnout.
As an aside, there was a photo in MRJ not that long ago of (I think) Bristol Barrow Road shed which showed a similar arrangement, but with double switched trap points on each road of the turnout.
Jim W
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