Reverse Curves - R2 w/long straights or R3 w/short straights?

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LittleRedTrain

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Hi folks, wondering if someone could give me some advice.

To avoid a pesky conifer tree, my railway has to go through two S bends.
Obviously, I know that these are best avoided, and there should be a straight section between them, however, I have two options:
[*]Use R2 curves, which allow me to have a 300mm straight section between them. [*]Use R3 curves, but make do with a shorter 150mm straight section between them The XTrackCad diagrm below shows the two options, R2 at the top, R3 at the bottom. Regardless, the end will have to be an R2 curve followed by R3 point, so all stock must be able to traverse R2 anyway.
f4d091ee30bb44b9af4432811972e055.gif

Can anyone recommend from experience which option would provide the better quality running?
I'm erring towards the R3 curves but was wondering if the short straights between them would be too short.

Thanks
Daniel
 
Translate that in your mind into reality - and 150mm straights are still 6"... I'd go for the R3 version for appearance. Most stock should run fine through it anyway, it's more about it looking daft by the time you get to R3.
 
I would use the R3s. I have one direct coupled S curve and it does not look too bad with R3s and runs perfectly.
 
Hi , in my opinion -i would go with r3 + small straight -- the loco and stock , are not as tight against each other - less chance of buffer lock regards Dave
 
I have a couple of switchbacks here's the first, the track is an R3 curve at this point with no straight in the middle of it
f54e156d83ee4838bab2c13db4e01cf1.jpg

And here's the loco running through it. R3 curves.
c4260a04ad8c417daf12631b85c776ab.jpg

This switchback has a straight in it
296af2fa8b8342acb4e8576b90a9fa2c.jpg

And with a loco running through it.
091d4daafded4095bb84c615ce543d55.jpg

Both switchbacks work equally well, neither has let me down. Hope this helps
 
And here's how it'll look 'in the flesh'.
16eb6cbbed38401480421684b4b3b0e5.jpg

1675aa13727f49e5aad996a750f7e501.jpg

I found if I pushed the start of the s-bends to join the end of the curve over the pond, I could still get in the 300mm straight sections (or close enough) anyway.

Thanks Again
Daniel
 
Looks great - I always think a lazy curve looks better than a long straight anyway.
 
I can think of another option. It's straight on one side.............and kinda jagged on the other; makes a sort of 'zizzing' sound as it's pushed back and forth. Might raise SWMBO's blood pressure a tad though. :rolf::rolf:
 
Fortunately I don't have a SWMBO at the moment, (which means I can get away with leaving out pre-clamped sections of track on the conservatory floor ;)) so I did contemplate that option.

However, the conifers add a bit of colour to the garden and a bit of extra privacy.
I am resigned, however, to having to cover the section of track beneath them when not in use, because of the 'gunk' they will inevitably deposit!
 
Track cleaner loco will keep that under control.
 
The only S curves that are a complete no-no for me are with Radius 1 - although a minimum of a 300mm straight between makes them just about acceptable for smooth running and they cause no problems.
That said my vote too is for the Radius 3. What Stockers said about lazy curves looking better than long straights is absolutely right, next time I build a railway...
 
Personally i think R3 is the tightest curve to use, though i must say that with my 1:20,3 american 4-axle-stuff its hard on the edge.
For shorter cars and locos, R2 will be fine, too.

In this case, i would always prefer the R3 solution.


if u have to go for curves with bigger angles, u can use the bow-trick: sweep into the curve with a piece of R5, then use a piece of R3 and then run the base of the curve with R2.
In some cases, this technique must be used because of the space u have, but sometimes the R5-R3-R2-trick looks even better then going immediately from straight to R3.
Especially in "S"-curves its better to splitt the diameters then to use too long straights. But i would EVER use a straight. Best is to have a straight of the longest fix axle-distance u have.
With R3 curves and 150mm straight u should get a nice flow for most LGB-cars (2-axle) and alsmost all 2 truck cars (if not too long "per se").

But we shouldnt start overdoing, eh?


Greetings,

Frank
 
I have several LGB R5-R5 and R5-R3 S-bends with no straights between. These cause no problems, although I do only run 0-4-0, 0-6-2 type locos and a few bogie coaches, but no big machinery. However, I am about to introduce back to back R3 points on a curve (i.e. curved sections form part of main oval and straight sections branch off tangentially in opposite directions) to create a new extension and I'm wondering whether I should include a short straight between them (the shorter the better) - or could I get away with direct point to point connection? Any views?
[Apologies for slight thread drift, but I think it's a related problem]
 
I have several Ss all made out of 10/16foot diameter.
All my American locos including Dash9s and Fn3 stuff go through just fine.
Obviously the bigger the better.
 
LittleRedTrain said:
Thanks all for your quick replies, looks like a resounding vote for R3s, so I'll go with those.
Click to expand...
I'd have said the same. I don't think the actual length of the straight matters, it just allows the bogies to settle down a bit, bearing in mind that pre-formed track gives an artificial start to a curve. Flexi track naturally bends into a transition curve, which is what the 1:1 railways work with.

So, R3s will not restrict the type of stock you run, unless you have your eye on some of the US monsters.
sorry, forgot the obligatory, gratuitous photo :laugh:

647dfd64071e4a8a9d4dc4f4ce09393f.jpg
 
Rhinochugger said:
I'd have said the same. I don't think the actual length of the straight matters, it just allows the bogies to settle down a bit, bearing in mind that pre-formed track gives an artificial start to a curve. Flexi track naturally bends into a transition curve, which is what the 1:1 railways work with.
Click to expand...
I think the only time the straight matters is if your track cross level isn't level.
If you cant/superelevate your curves and have a reverse curve a vehicle could be trying to lean both ways at once at the transition. A bit of slack in the bogie mountings may help but a straight and level section (cross level, gradient doesn't matter) as long as the longest vehicle is a good idea.
 
BrianC said:
I am about to introduce back to back R3 points on a curve (i.e. curved sections form part of main oval and straight sections branch off tangentially in opposite directions) to create a new extension and I'm wondering whether I should include a short straight between them (the shorter the better) - or could I get away with direct point to point connection? Any views?
[Apologies for slight thread drift, but I think it's a related problem]
Click to expand...
You should have no problem with a direct back to back.
 
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