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Discussion Starter #1
I have started the outside loop on my railway and wanted some input as to whether it’s worth putting in super elevation. I was once told for Gauge 1, half a level bubble is correct. When I built the club’s portable I put in super elevation only to find that no one even notices it or if they do, they ask why I put the Popsicle sticks under the track.
 

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Dan
Watching an Accucraft GS4 running at 200+ smph on trackage without super elevation, not sure what purpose it would serve other than to give you some additional work and maintenance. Then there is the entrance and exit taper necessary to ease the engine in and out of elevation to the curves. What if you had a reverse curve coming out of the elevated curve woud you have to have a long straight to allow for transition to level trackage?
 

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Good evening,
we had on our track elevation made ca. 7mm at the outer track and ca. 1m from zero rising to elevation at the end of the radius, perhaps pics say better than my description
greetings from Peter
 

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Super elevation adds a lot to any model railroad. My dad and I have super elevation on our scale S layout which makes it look very nice. We also use super elevation for our 7 1/2" gauge equipment at the club we go to since we haul the public, it provides a more stable feeling.

Really, it all comes down to what you like. If you have nice wide curves, super elevation is going to look great.
 

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Dan,
You should invite Tony Dixon up for a run. If his Britannia stays on the track after a couple of laps, then you know you don't need it.
I could be wrong, but I don't think the large track at the NSS is super elevated and nothing has come off yet!

Rob Meadows

Los Angeles
 

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Dan,
I reckon that anything over 12 foot radius really doesn't NEED it.
It may look good, but it adds an extra dimension of problems.
Besides, as you didn't add it to the first circuit, it will look funny to have one super elevated while the other is not.
I don't know about in North America, but in the UK some of the full sized railways did not use it at all.
But like most CEO's, I'm sure that you will do whatever feels good.
All the best,
David Leech, Delta, Canada
 

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Discussion Starter #9
"It will lessen the wear on wheel flanges and rails ??" by the time this happens, I will be buried beside it. I like the answer Rob gave about the large track at the Summer Steam-up. I like the reasoning David gave about the inside track not having it and it adds an extra dimension of problems. So being a good CEO and wanting to save the railroad money, I have decided the surveyors do not have to put in super elevation.
 

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Oh good,
That means we can come for a 'two track' steamup next week!????
In fact, AFTER the next lot of rain that is coming tomorrow, why don't you invite the 'crowd' over and give us each some track, screws and screwdrivers and we can help you get it finished.
David Leech, Delta, Canada
 

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I looked into this in some detail after my 232U1 broke its coupling to a fine rake of J&M Wagon Lit coaches, accelerated to a scale 300 mph (a guess) and came off the track at the next corner doing substantial damage. Curve radius is 3M but I suspect it was the transition into the curve rather than the curve itself that caused the problem.

The bank angle required to prevent any sideways force can be calculated fairly easily - it is tan-1(v^2/gr), where v is speed, r is radius and g is gravity. For a scale 200 mph this works out to approx 15%. Of course some sideways force is OK, just not so much as to topple the locomotive sideways. This, in turn, depends on how high the center of gravity is above the track. I guesstimated the center of gravity of the 232U1 and calculated that with a flat track, the machine would need to be doing just over 4 m/s or just under 300 scale MPH.

In the event, I decided it was easier to fit better coupling to the J&M coaches that try to super-elevate the track in a way that would survive the Seattle weather!
 

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Dan

In reality, super elevation for model railroads in any scale is cosmetic. Looks great. The physics does not justify the design and maintenance. If you have sharp curves [less than 15 ft radius], a transition spiral from tangent to the minimum curve radius is far more important. I put transitions in on my first IE&W because I had curves as tight as 16 foot radius. The current layout has 24 foot radius and the transitions are almost non-existent.
 

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Agree with Stapleton.
I have looked at the math and it is not necessary. We played around with it on Gaston's layout, and even a small amount has the trains running on the inside drivers
jim
 

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With superelevation, besides the horizontal transition/spiral in and out of a curve, you also need a vertical transition in and out of the superelevation, or you can run into more problems.

Many large scale locos do not have a compliant enough suspension to handle abrupt vertical transitions.

I vote for cosmentic and difficult to do right.

Regards, Greg
 

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Discussion Starter #15
OK, OK, you guys have convinced me, no super elevation. I do have transition curves and I do have tight radius curves, ruling radius is 12’3” on one inside curve, the rest being 16ft to 26ft. What I do have going for me is the level smooth track work. A lap is 265ft and David has an old Aster coach chassis that rolls very well. He can give it a push and it will do a lap and a half or more and that’s through 4 switches.
 

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Dan

Much more important; how well do long rigid wheelbased two axle cars do on the track. I am thinking of some British and German coaching stock and "utility" or freight vans. I found that their sometimes unforgiving suspension will find ANY fault in my track work. That is usually how I find rails that have a vertical bend in them from a "black walnut" assault from 40 feet up.
 

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OTOH, superelevation reduces the diameter of the curve... I think the idea with the popsicle sticks is a good one, you can keep your superelevation nice and smooth, and it's small enough it shouldn't cause any problems. It may not reduce the diameter much, by the time you get to trains the size of ours, yes, physics do matter to an extent. I used toothpicks in HO, and just the improvement in appearance was worth it.

Thanks! Robert
 

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Interesting discussion. May I add my personal experience? (Tough, I'm gonna dood it anyway!)

My track was 150-ft in a double-loop-back configuration with about 50-ft in the straight section before the curves of the loops. I "tried" to make the straight section have about 1 percent of grade down to the center and then 1 percent up to the other end. Each loop was about 50 ft of track with about 1/2 percent grade back to near the middle of the straight section. This was so that I could "Highball the Mainline" down-hill and HOPE that the uphill section would help slow the train before the curve of the loop-back. I ran only Live Steam with radio control.

I found that because the elevated structure of the layout was merely standing on concrete pavers laying on rather sandy ground, my attempts to maintain the specific grades were a futile effort as the ground absorbed and drained rainfall. i.e.: sometimes the grade would almost be the reverse of what I wanted (higher in the middle than the ends!)

It was fun to back a short train most of the way into one curve and then open wide on the throttle to peel out and fly at breakneck speeds 3/4 of the way through the straightaway and then close the throttle, slam the reverser the other way and open wide on the throttle again (well, sometimes the throttle was not moved at all!) in an attempt to slow the train BEFORE the curve of the loop-back. Watching the wheels spin backward while the train moved forward was quite entertaining.

I timed certain sections of the straight track and hit a scale 210 MPH near the middle! At the curve I could get the speed down to under 80 (S)MPH.

I wanted to superelevate the curves but found that without firmly attaching the track to something of the desired shape/form, the track tended to warp in any corkscrew shape it wanted and the amount of warp varied as the seasons changed. As it turned out, the curves tended to hold a superelevated form most of the time. I have no idea why, nor did I ever actually measure the amount of superelevation attained, but it was definitely a noticeable amount. A guess at this time (the track is all stacked in the garage at present, waiting on me to get around to rebuilding the elevated structure after a winter freeze/thaw/freeze severely damaged it) would be about 1/2 the rail height or maybe .1 to .15 inches. The track was pretty much fully floating in the ballast and it would tend to hold this amount of superelevation when the train went through because of the ballast. Over time the track could move the ballast enough to change its position, but it tended to hold a superelevated condition most of the time.

I never had a problem with transitions into or out of the curves and/or the uncontrolled superelevations. Only ONCE did it derail from the track because of irregularities and that irregularity was a total separation of the rails at one point in the curve (dumping a $4000 engine 4-ft to the ground!). (I did derail one other time, but that was blamed entirely on the ignoramus Switch Tender being too distracted by pride to notice the switch from the yard to the mainline was in the wrong direction! He should have lost his job, but the CEO would not fire himself!)

I will say that when the curves had a superelevated condition, it sure "felt better" to hit them at speed, as opposed to when the curves were "flatter".

A friend ran an "uncontrolled" Ruby around the track at adrenaline rush speeds a few times and it never derailed either.

I have posted this image before and I think it is possibly apropos here:


 

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Posted By JEFF RUNGE on 11 Feb 2011 12:37 PM
All I got from this thread so far is: the Laws of Physics don't apply to gauge one trains...... hehe

Not true... they do apply... but they don't scale.
 
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