# single rails for points/closures?



## SE18 (Feb 21, 2008)

Anyone following GRR and downloaded the turnout templates? (June 09 issue).

I had to reduce to fit my outdoor 32mm track

Anyway, I noticed he's using code 332 brass and using single rails for point/closure.


I used to do that for code 148 and smaller scale turnouts but never for large rails, especially 332.

I guess the trick would be to have a long-enough unspiked run to allow bending, plus a strong throw


I need a bunch of new turnouts and am considering the GRR methods (I forgot name of the author)

Anyone here do similar?


Thanks


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## Dwight Ennis (Jan 2, 2008)

I haven't seen that issue. However, I did watch a video the other day (one of many) where one of the owners of FastTracks is building an HO scale module of the CNJ Bronx ferry terminal, which had some very unique and crowded trackwork. A couple of the turnouts required very short point rails. His solution was to use a rail joiner to act as a pivot for each point rail. Something similar may work in large scale as well.  

I think I'd go a different route on Code 332 though - maybe a copper-clad tie soldered (or better yet, screwed) to the outer rails at the pivot point, and drilled to accept small flathead screws that would go through it from the underside and thread into the endpoint of the point rails. Much stronger and not subject to the fatigue of a rail joiner.


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## Jerry Barnes (Jan 2, 2008)

My SVRR switches use a slide on joiner for the pivot. Works fine.


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## Paul Burch (Jan 2, 2008)

Old Pullman turnouts are built that way although there is a partial cut underneath at about the same point that most turnouts would have some kind of joiner in the point rails. The Old Pullman turnouts are a little stiff.


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## Allegheny (Jan 2, 2008)

Dwight,

I think you would find that a threaded connection at a pivot point like that would work loose over time. If you wanted to go that route, I'd suggest either using high grade loctite, epoxy, or better yet, silver solder to keep the screw firmly attached to the rail base.

Just my $0.02


Brian


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## Pete Thornton (Jan 2, 2008)

My SVRR switches use a slide on joiner for the pivot


I've built switches using a solid, bending point rail, but it puts a lot of strain on the lever and on the spikes holding the whole thing together. 

The prototype uses a rail joiner with bolts that aren't quite as tight as the usual ones! I use a rail joiner, as Jerry says, with 'dimples' on the underside. 










I drill a small indentation in the underside of each rail and bash the joiner with a center punch. The green arrow points to the joiner, and the yellow circle shows one 'dimple'. The other is hidden by the tie.


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## Brendan (Jan 12, 2008)

I've built 6 turnouts using the method described. Although I built mine on a base board. I use Code 215 rail. I did have doubts but there's no problem I use a cupboard door latch mounted across the throw bar to lock the closure rail in place. They provide real smooth operation.


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## Dwight Ennis (Jan 2, 2008)

If you wanted to go that route, I'd suggest either using high grade loctite, epoxy, or better yet, silver solder to keep the screw firmly attached to the rail base.
Agreed for sure. I'm reasonably sure Loctite would do the job. It would be hard to silver solder to the pivot rails without adhering it to the copper-clad as well. 'Course one could remove the copper-clad from that area. Still, I think I'd try the easier route with Loctite first.


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## toddalin (Jan 4, 2008)

If I were doing it (not that I've ever done it), I would simply cut the rail at the point that you want the pivot and solder a thin strip of brass along the web to reconnect both pieces back together. The thin brass would be flexible and take off the strain of trying to bend a whole piece of rail.


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## Pete Thornton (Jan 2, 2008)

cut the rail at the point that you want the pivot and solder a thin strip of brass along the web to reconnect both pieces back together


Hmmm... You might be under-estimating the side thrust of a 1:20.3 brass loco negotiating your switch. I'd use a very thick piece of brass if you are going that route - or how about a rail joiner, as I mentioned above.







(Incidentally, I think my rail joiners are Llagas Creek stainless steel, so they are much more rigid than a piece of brass. On sharp radius switches I've had to 'ease' them a little with a screwdriver to make the rails pivot.)


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## toddalin (Jan 4, 2008)

Posted By Pete Thornton on 05/30/2009 8:11 AM
cut the rail at the point that you want the pivot and solder a thin strip of brass along the web to reconnect both pieces back together


Hmmm... You might be under-estimating the side thrust of a 1:20.3 brass loco negotiating your switch. I'd use a very thick piece of brass if you are going that route - or how about a rail joiner, as I mentioned above.







(Incidentally, I think my rail joiners are Llagas Creek stainless steel, so they are much more rigid than a piece of brass. On sharp radius switches I've had to 'ease' them a little with a screwdriver to make the rails pivot.) 


"Thin strip" is relative to the thickness of the actual rail. But I can't imagine that it would need to be all that thick because the rails would still butt up to each other.


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## ohioriverrailway (Jan 2, 2008)

I opted for a thin brass strip soldered under one part of the rail, then a 2/56 tap and screw into the points. It's worked good for 5 years now . . .


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## Pete Thornton (Jan 2, 2008)

But I can't imagine that it would need to be all that thick because the rails would still butt up to each other.


I'm not sure what the 'butt up to each other' does - I was referring to the side thrust on the curve. A 30 lb loco trying to turn a corner exerts a lot of force on the outer rail with the wheel flanges, and will try to roll the rail over or push it out of gauge. The spiked/solid rail will be OK, but your thin piece of brass is taking all the strain for the whole length of the point rail. And it will be flexing every time you move the points which will weaken it.


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## toddalin (Jan 4, 2008)

Posted By Pete Thornton on 06/02/2009 8:41 AM
But I can't imagine that it would need to be all that thick because the rails would still butt up to each other.


I'm not sure what the 'butt up to each other' does - I was referring to the side thrust on the curve. A 30 lb loco trying to turn a corner exerts a lot of force on the outer rail with the wheel flanges, and will try to roll the rail over or push it out of gauge. The spiked/solid rail will be OK, but your thin piece of brass is taking all the strain for the whole length of the point rail. And it will be flexing every time you move the points which will weaken it.


The only point to flex is the unsupported spot at the "butt" and this would be extremely short. Guess you'll never know unless you try it.


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## SE18 (Feb 21, 2008)

the GRR article did not mention any sort of artifice for getting the rail to bend; it is continued next month; excuse me 2 months from now as it is bimonthly; I'm sure he must be using a strong throw and locking mechanism as 332 is quite large


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## RimfireJim (Mar 25, 2009)

It is not only the size of the rail that affects the deflection force, but also the material's modulus of elasticity (E), or "Young's modulus". The deflection force is directly proportional to "E". "E" for aluminum is 10E6 psi; for brass, 17E6 psi; for nickel silver, 18E6; for stainless steel, 28E6 psi. These values are pretty much independent of specific alloy. You can see that brass requires almost twice the force to deflect as aluminum (all other factors being equal), and stainless steel almost 3X. Experience with one material may not be applicable to another material.

Note that "E" relates to _elastic_ deflection, where the material is not permanently deformed. It is a stiffness property, not a strength property. It doesn't have anything to do with how much force is required to deform the material, and vice versus, i.e., the strength of the material doesn't have anything to do with how stiff it is. 


-Jim


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## Pete Thornton (Jan 2, 2008)

The only point to flex is the unsupported spot at the "butt"


Todd - sorry to belabor it, but you're still not seeing the problem. (And I'm only replying again so that the others will get the point.) 

When a train goes round a curve, there's a *sideways* force on the rail, completely seperate from the downward pressure. That's why they have flanges. 

A large metal loco, like the USATrains Hudson or even a Bachmann K-27, will exert a lot of force* sideways* on the top of the rail. That's how the gauge gets widened on a curve if the rails aren't spiked down properly. As it is acting on the top, the rail tries to "roll over" like your pet dog.


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## SE18 (Feb 21, 2008)

thanks, Jim 

Very instructive. I'm 250 alum so sounds like the turnout plan in GRR will be no problem


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## toddalin (Jan 4, 2008)

Posted By Pete Thornton on 06/03/2009 8:16 AM
The only point to flex is the unsupported spot at the "butt"


Todd - sorry to belabor it, but you're still not seeing the problem. (And I'm only replying again so that the others will get the point.) 

When a train goes round a curve, there's a *sideways* force on the rail, completely seperate from the downward pressure. That's why they have flanges. 

A large metal loco, like the USATrains Hudson or even a Bachmann K-27, will exert a lot of force* sideways* on the top of the rail. That's how the gauge gets widened on a curve if the rails aren't spiked down properly. As it is acting on the top, the rail tries to "roll over" like your pet dog.




I see the "problem" but don't see it as a problem. The web provides plenty of space to install a piece of brass that would be plenty strong and could easily keep the railhead from "kicking out." Do you really think that this piece of brass would be any weaker than those puny little screws used in the LGB points that snap off simply by overtightening them? Try it and see for yourself.


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## Pete Thornton (Jan 2, 2008)

this piece of brass would be any weaker than those puny little screws 


I think the piece of brass would have to be quite big, and it would get progressively weaker as it was made to flex. 

However, I'm only making observations, not trying to pick a fight. I'd be interested to see how long it lasted compared with the screws.


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