BNSF UP and others modelerThe question is, is it protypically logical to have a train hit an s curveal most directly after a super elevated curve?
From a prototypical standpoint there is no difference between a "super elevated curve" and an "S curve".
They are all curves. The question is how long are they and how much curve there is. Are they all the same radius? Are they all the same length? Do you want the track speed the same on all the curves? Is the S curve just a left hand curve followed by a right hand curve or is it a crossover?
The short answer is sure, there can be a series of curves where left hand and right hand curves follow each other. Happens all the time.
Dave H. Painted side goes up. My website : wnbranch.com
Most of the curves on my layout are superelevated to some degree, but speeds are relatively low, so it's unlikely that passengers will be wearing their soup.Other than in the towns through which the track passes, most of my track is curved and I also like the look of a train gliding through an ess-bend, too.
In the photo below, the track at the distant left is curved and superelevated, as is the track on the distant bridge and the curve leading to the straight track climbing the hill. The track in the foreground is also superelevated...
...here, the curve continues, superelevated...
...and further along...as the track nears the right edge of the picture below, it begins to curve in the opposite direction....
....with the superelevation shifting...
Here's an overview...
...and as seen from the top of the hill...
If your track is on risers (it doesn't have to be on a grade) it's easy to add superelevation.
Draw a pencil line on each riser where they attach to the crossmembers of the layout structure - this is to ensure that the risers will be at the proper height after the superelevation is imparted.
Place (or run) a train onto the curve - it should extend completely through the entire length of the curve, even if you'd never run a train of that length. Next, unscrew, from the crossmembers, all of the risers supporting the curve. The roadbed will likely sag somewhat, depending on the thickness of your sub-roadbed - I used 3/4" plywood, so the sag was minimal. Now, select the riser closest to the mid-point of the curve, raise it so that the pencil line aligns with its crossmember, then push the bottom of the riser towards the outside of the curve, thereby imparting some degree of superelevation to the track. Manually adjust the amount of offset until the train looks good to your eye...a noticeable tilt that you'd consider appropriate to the speeds at which trains would pass through that curve. Line-up the inside point of the pencil mark on the riser with the top of its joist, and then clamp or screw it in place. The outside end of the pencil mark will now be somewhat above the joist.
Next, pick a riser mid-way between the one you just attached and the beginning or end of the curve. You'll notice that the pencil line on it is now also not-level, as the entire sub-roadbed of the curve has twisted with the re-positioning of the riser at the mid-point of the curve. This twist diminishes as it gets farther away from the mid-point of the curve, which imparts the vertical easements into and out of the curve.Without applying any outward force, carefully lift it until the inside end of the pencil line aligns with the top of its riser, and fasten it in place. Repeat this procedure for the riser on the mid-point between the first-done centre one and the other end of the curve. You should then be able to repeat this operation for all intermediate risers, taking care to only lift until the pencil line on the inside of the curve aligns with the top of itts joist. Do not apply any force outwards.Each portion of an ess-curve is done in the same manner, and as long as the distances are great enough between the changes of direction, the superelevation will automatically transition to suit the curves.
It's a pleasure to watch a train snake through the curves, tilting in and out as they respond to the superelevation.
Wayne
So quite honestly, the only reason I want it is because curvy track like that can squeeze in an few cars per train versus having straight track. I see now with all of the prototypical problems that would be encountered, its best to leave the track straight and not make matters worse for passengers, like the prototype passenger train company which shall remained unamed...
I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.
To avoid having to construct a tunnel, possibly, but it doesn't sound like something you'd see just 'cuz. Are you contemplating this on level ground, no prominent features through or around which the tracks must go? If it's on flat ground, nothing nearby that can't be blown up, excavated and removed, or simply rolled/slid out of the way, why have the S-curve at all?
And yes, absolutely, you'd have to provide the same super on the S-curve as on the gradual curve in the way of super if you wish to maintain the same speed, and if you need the same effect on objects borne by the cars. However, methinks you're going to have the galley awash in soups and gravies, salads and crockery strewn everywhere, and some peeved passengers if this were the real world and you expected to run through it all at speeds higher than about 20 mph.
IOW, what is your aim or objective with the S-curve? What need or requirement do you have for the final product that would make such a curve, placed close to a super-elevated curve, necessary?
Well...
I have about 5-6 ft to play with. The question is, is it protypically logical to have a train hit an s curveal most directly after a super elevated curve? And if yes, would there have to be super elevation on the s curve as well to continue to handle the speed the train is at?
Depends on how big is the S curve.
Superelevation is dependent on the speed and how long the curve is. EVERY superelevated curve has a transition from the tangent to the full superelevation.
For an S curve it would be level, transition to superelevation, superelevation, transition back to flat, trainsition to superelevation, superelevation, transition to out of superelevation, flat. If your S curve is a total of 10 ft long or more you will have room to do all that. otherwise you will have to start cutting out the superelevated parts, then the transitions. If the S curve is real short then you might only get a fraction of the superelevation in before you have to back it out.
IMO, leave the track straight. Unless you have short switchers and rolling stock, ess curves are a disaster waiting to happen, as far as derailments. Avoid them at all costs...or make them less gradual by placing as long a straight section of track between the curves as possible.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I plan to have an s curve on my layout a bit ahead of some super elevated curves. But then I realized that might not be prototypical/safe on the prototype to have trains flying straight from super elevatated trackage into an s curve. Would they super elevate the s curve too? Or would trains HAVE to slow down...
My other alternative is to just scrap the s curve and leave that track straight. I'm perfectly open to that too if thats my only choice...