Catch points or no catch points?

[11B]

Hi all

 

Your views please?

 

Having decided to replace my track with bull head rail I have a question and would be grateful of your thoughts/views?

 

I have a siding that runs next to the main running line on the entrance to my station that is a branch line terminus, like there was at Lakeside (Windermere) only access would be out onto the main running line in the direction of the station. But back in the days of steam would there have been some sort of catch point or trap point to protect the running line?

 

Thanks

 

Ian

[TheSignalEngineer]

Any siding onto a passenger running line would have a trap point.

[Trog]

Any siding onto a passenger running line would have a trap point.

 

Except those sidings that have a de-railer instead, if only because on the railway there has to be an exception to every rule.

[TheSignalEngineer]

Except those sidings that have a de-railer instead, if only because on the railway there has to be an exception to every rule.

Usually because there wasn't room for a trap.

 

A separate trap would not be needed if the siding points led to another siding as well as the passenger line. In this situation the points would be locked towards the siding when a move on the passenger line was signalled.

[Peter Kazmierczak]

Even if it's a dummy trap point, well worth including.

 

Some otherwise excellent layouts are (at least in my mind) spoilt by not having these features.

[Pteremy]

My first thought on this - which may not be the right one - is what is the risk that you would be protecting against in this context? Would a short stub, continuing the main siding, be more likely than catch points? Might be better aesthetically as well? 

[Right Away]

Just as PK says above, I have fabricated a "false" catch point from a siding onto a running line as a temporary fix.

Apart from being permanently set for permitted movements (which one can try to ignore) it looks fine and together with its associated dummy, to my mind is better than having no perception of runaway protection.

[Trog]

My first thought on this - which may not be the right one - is what is the risk that you would be protecting against in this context? Would a short stub, continuing the main siding, be more likely than catch points? Might be better aesthetically as well? 

 

The risk would be wagons in the siding moving towards the running line so that they were foul of traffic on that line.

 

As TheSignalEngineer mentioned setting the signal locking up in a way that points leading into another siding, also function as a trap is another way to do it. Provided that there is a need for that other siding, otherwise a simple trap point or blade is the simplest and cheapest way of doing it.

[BR60103]

There may also be some consideration of what the trapped wagons might run into. Does the trap point send them towards the station platform?

 

It's not only wagons. There is video somewhere of a locomotive ignoring a signal and running through the catch points on a preserved railway.

[brossard]

Oh that sinking feeling:

 

 

The catch point looks like the pair I'm just building.  Should be done tomorrow - I'll post a pic.

 

http://www.rmweb.co.uk/community/index.php?/topic/46962-which-direction-should-catch-points-go/ Post 15

 

John

[Right Away]

Excellent example of the need for trap points.

What was the signalman doing? A red flag from the box may have averted this especially as it's on the driver's side.

[kevinlms]

Excellent example of the need for trap points.

What was the signalman doing? A red flag from the box may have averted this especially as it's on the driver's side.

Well, the driver didn't get the 'Right Away'.

 

[LMS2968]

From what I heard, he did. The bobby could not clear the starter since he had not set the road, so he gave the driver permission to pass the signal at danger, thinking there was a signal failure. The driver did not check that the road was properly set, and after a long whistle, set off through the traps.

[Ken.W]

There may also be some consideration of what the trapped wagons might run into. Does the trap point send them towards the station platform?

 

It's not only wagons. There is video somewhere of a locomotive ignoring a signal and running through the catch points on a preserved railway.

As shown in video posted above, traps usually derail away from the adjoining line being protected

[The Stationmaster]

From what I heard, he did. The bobby could not clear the starter since he had not set the road, so he gave the driver permission to pass the signal at danger, thinking there was a signal failure. The driver did not check that the road was properly set, and after a long whistle, set off through the traps.

 

And to just add to that lot of stupidity the Driver kept the regulator open, and didn't brake, not only after the tender had dropped off the road but even after the engine started to drop off   

[brossard]

Here are the catch points I mentioned:

 

 

Gibson sleepers (because I got a good deal on them), Peco chairs and rail, JLTRT tiebars.

 

John

[jim.snowdon]

Here are the catch points I mentioned:

 

P1010001-018.JPG

 

Gibson sleepers (because I got a good deal on them), Peco chairs and rail, JLTRT tiebars.

 

John

And with enough switch opening to drive a double deck bus through sideways

 

The switch throw ought to be about half what the picture shows.

 

Jim

[Trog]

If fitting a trap like those shown above in Brossard's post to a line where adjacent tracks make derailing the stock in either direction iffy say a siding with another line either side. What you do at 12" to the foot is install a single rail down the middle of the 4' as a guard rail so any derailed stock is kept in a reasonably straight line.

[brossard]

And with enough switch opening to drive a double deck bus through sideways

 

The switch throw ought to be about half what the picture shows.

 

Jim

 

You are right Jim, the gap is large and matches Peco's.  I have experimented with smaller gaps but I have found a blade spacing of 27mm to be about right.  We are lumbered with a slop of 2mm in 7mm FS.  CG = 29.6mm (depending on flange width) minus slop of 2mm gives a minimum blade spacing of 27.6mm (rounded down to 27mm).  If you go larger, flanges can hit the blades.

 

John

Edited March 11, 2018 by brossard

[TheSignalEngineer]

If fitting a trap like those shown above in Brossard's post to a line where adjacent tracks make derailing the stock in either direction iffy say a siding with another line either side. What you do at 12" to the foot is install a single rail down the middle of the 4' as a guard rail so any derailed stock is kept in a reasonably straight line.

Or use a wide to gauge trap which keeps the stock straight up by acting like a retarder at low speed.

[Mike Storey]

In many cases on the SR, sand traps were used instead, where a normal set of points would be set against the conflicting move, into a very short spur with a sand drag, both diverting from the potential collision and ensuring the runaway would be safely stopped with less likelihood of complete derailment. In my research for my Queenborough layout, I found examples of these dating back to pre-nationalisation, at Queenborough, Sheerness, Grain, Hoo Junction, Canterbury West, Hove, Brading, and Falmer. i.e. not always on gradients. I did not look elsewhere, but that may be a plausible compromise between a simple trap point and a separate alternate route siding (for which there might be no other purpose).

[uax6]

Here are the catch points I mentioned:

 

P1010001-018.JPG

 

Gibson sleepers (because I got a good deal on them), Peco chairs and rail, JLTRT tiebars.

 

John

 

Aren't the tiebars set up wrong here? Surely the right hand blade should be in contact with the stock rail, so that you can pass over the trap? At present it's almost a wide to gauge trap, but not quite!

 

Andy G

[brossard]

Don't think so Andy.  The Tortoise motor will fix the blades where they need to be.

 

John

[uax6]

Is only one of the blades going to be moved by the motor then?

 

Andy G

[brossard]

Nope, both, this is a turnout without the crossing.  Peco's version only has one blade, perhaps that's what you're thinking of.

 

John