Catch points
Catch points
Does any one have any advise on how to construct a a catch point? I will need one on my diorama project, I am sure there are many different types, but for my layout it is needed for a siding leading onto a single track mainline.
I had a look on Exacto scales website to see if they did a template but could not one.
I had a look on Exacto scales website to see if they did a template but could not one.
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Re: Catch points
Functionally this is a trap point, not a catch point. Depending on the expected speed a trap point can be a single blade, a pair of blades or a complete turnout.
If this is just a slow speed siding a single blade on the side away from the main line should be enough. There is no need of special templates, just use the switch section of any turnout as far as the heel. Usually it would be an 'A' switch. I'll see if I have a template section I can post here.
Regards
Keith
If this is just a slow speed siding a single blade on the side away from the main line should be enough. There is no need of special templates, just use the switch section of any turnout as far as the heel. Usually it would be an 'A' switch. I'll see if I have a template section I can post here.
Regards
Keith
Re: Catch points
Thanks Keith, sounds like single blade would do as speeds would be very slow at this point of the line.
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Re: Catch points
Attached drawing shows a set of A switches, just use whichever switch suits and put a plain rail opposite to it.
Regards
Keith
Regards
Keith
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Re: Catch points
My method of constructing a trap point was to use a set of switches from an Exactoscale A7 turnout. Fortunately I had the switches as spares since otherwise it is a bit expensive since the rest of the kit is not used. If you ask Exactoscale nicely they may even just sell you the bits required.
Terry Bendall
Terry Bendall
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Re: Catch points
jhock wrote:Thanks Keith, sounds like single blade would do as speeds would be very slow at this point of the line.
The GWR always used single-blade traps up to the 2nd World War, although they were constantly nagged by the Railway Inspectorate to use double traps.
When upgrading the DN&S for extra war traffic (in preparation for D-Day), the GWR did put double traps in the lengthened loops on that line, maybe because the government was paying for the work.
My impression was that other members of the Big Four habitually used double traps, but no doubt there were exceptions, espcially on low-speed lines in out-of-the-way places, or if inherited from pre-grouping companies that used single traps.
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Re: Catch points
I think the Caledonian Railway wasn't alone in using single rail traps in low speed situations, and, as here, building them into a turnout to save space (Auldbar Rd, north of Forfar)
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Re: Catch points
Further to my previous note, Keith Ettle has kindly written to me to point out that there were two double tongued traps at Churston, certainly from the time of the rebuilding just before WW1. He points out that David Smith’s book on GWR point and crosing work has details of double tongued catches or traps. Nevertheless, it is my impression that double traps do seem to have been a rarity on the GWR. Is anyone aware of any other examples dating from before WW2?
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Re: Catch points
Trap points built into turnouts were also used by the LNWR. There are pictures in Richard Fosters Birmingham New Street showing at least two turnouts with single blade trap points built into the stock rails.
There is also a good site for photos of Warwickshire railways. This links also shows a couple of trap points in New Street;
http://warwickshirerailways.com/lms/lnwrbns_str413a.htm
Jol
There is also a good site for photos of Warwickshire railways. This links also shows a couple of trap points in New Street;
http://warwickshirerailways.com/lms/lnwrbns_str413a.htm
Jol
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Re: Catch points
There's a great one on the far right of this photo of Birmingham Moor Street:
Birmingham Moor Street Trap Point
Seems strange to have opposing switch rails, wouldn't it be damaged if it were ever used?
Birmingham Moor Street Trap Point
Seems strange to have opposing switch rails, wouldn't it be damaged if it were ever used?
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Re: Catch points
Simon_S wrote:There's a great one on the far right of this photo of Birmingham Moor Street:
Birmingham Moor Street Trap Point
Seems strange to have opposing switch rails, wouldn't it be damaged if it were ever used?
The trap points on the WHR either side of the flat crossing over the Cambrian Coast line are of this sort. I wondered if they were designed to ensure that any vehicle which overran then trap point are stopped upright and as quickly as possible by the rails hard against the back of the wheels. As for doing damage if used, I think that was accepted as inevitable what ever the design.
Will
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Re: Catch points
All trap points were designed to divert a runaway away from the most dangerous side (i.e. usually away from the main line). In some situations it wasn't a good idea to divert a runaway to either side , hence the opposing switch rails. Any trap point would, if used, at least cause damage to the sleepers, and very likely to the rails as well. The only exception to this would be where a full turnout is provided, often leading into a sand drag.
Allan F
Allan F
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Re: Catch points
Double-traps were quite common on LT for reversing sidings between running lines.
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Re: Catch points
Double-traps were quite common on LT for reversing sidings between running lines.
But note this arrangement is quite different from the 'wide to gauge' traps shown in the Moor St picture.
The wide to gauge traps create an immediate strong braking effect by forcing the rails at standard gauge in between the back to back of the wheelset, unless the vehicle is light enough to climb out, or going very slowly the rails will be forced from their fastenings and the wheelset likely damaged as well.
With the LUL version the wheelset will just run through the open blade with minimal restriction and as the gauge widens out will drop onto the ballast, at which point the traction motor and/or gearbox will likely drop onto the 4th rail and these will be the bits suffering the damage.
Regards
Keith
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Re: Catch points
Catch points to one rail only within a turnout are not that uncommon I thought?
A rather nice prototype one here: http://www.derbysulzers.com/24047freight.jpg and one in model form by yours truely......
A rather nice prototype one here: http://www.derbysulzers.com/24047freight.jpg and one in model form by yours truely......
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Mark Tatlow
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Re: Catch points
martin goodall wrote:Further to my previous note, Keith Ettle has kindly written to me to point out that there were two double tongued traps at Churston, certainly from the time of the rebuilding just before WW1. He points out that David Smith’s book on GWR point and crosing work has details of double tongued catches or traps. Nevertheless, it is my impression that double traps do seem to have been a rarity on the GWR. Is anyone aware of any other examples dating from before WW2?
Martin,
When researching the track layout for Hallatrow we found a photo, in the Wild Swan book on the Camerton Branch, showing a double tongued trap point within the point for the up sidings to protect both the up and down lines through the station. The photo was taken in the 1930's but the caption states that these sidings the laid during the pre WW1 re-build.
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Re: Catch points
Mark Tatlow wrote:Catch points to one rail only within a turnout are not that uncommon I thought?
The photo of Mark's layout shows an almost identical arrangement to the one I have used in the goods yard on my Burford layout.
I don't have a photo to hand immediately which I can scan and post here, but it can be seen in one or more of the photos in my article in MRJ No.71, if you have that issue.
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