super elevated curves

[rusty spike]

Been wondering if any modelers super elevate some curves on their layouts.I have done this in the past and plan to on my new layout,only on a few mainline curves......

 

[Irongrave]

I've done it a few times using parts of tires on the outside rail every 4 our so ties.

 

[lmackattack]

if you do it, consider that it may cause longer trains to "stringline" and derail. it looks cool if done right tho....

 

[jeffrey-wimberly]

I super elevated teh curves on my layout as it allows me to actually squeeze an 18" radius curve into a slightly smaller space. It sounds crazy but it works. I don't have any problems with cars stringlining even in a train with 30 cars.

 

[lmackattack]

Jeffry

Im talking 50+ cars with little weight in them. I have a shimmed 22" radius on a incline and can pull about 30 but with that amount of cars I can see the lighter cars leaning and wanting to jump the rail. Every layout is diffrent and I rarely run more than 20 cars.

Down at the club 150-170 cars is about the max we can go before we have trouble on the minimum 44" radius. and it does not have elevated curves. to bad gravity does not scale!!!

 

[NYC_George]

This curve has a 2% elevation. It’s the best running turn on the layout.

NYC_George

 

[Selector]

Super elevation has little practical use, although I can see what Jeff means. But on our layouts, virtually nil benefit....except that it looks darned good if you keep it minimal. Super Elevation can be overdone, and with the post warning of stringlining, I have heard that when too much is added, this can be a problem, particularly if the curve is also on a grade.

-Crandell

 

[Larry]

Over the years I've tried it many times w/no good results. Maybe I've been doing it wrong. No one has ever explained exactly where you flatten the rail after or before the curve. I've seen it on many club layouts & it really looks good, but have never been able to get close enough to that 1 area to see how it's done. Someone explain the process & I will put it on all my curves that's out in the open.

 

[jeffrey-wimberly]

Jeffry

Im talking 50+ cars with little weight in them. I have a shimmed 22" radius on a incline and can pull about 30 but with that amount of cars I can see the lighter cars leaning and wanting to jump the rail. Every layout is diffrent and I rarely run more than 20 cars.

Light cars can be a problem. All mine are weighted to NMRA recommendations. That makes for a heavier train but it's more stable.

 

[Selector]

Over the years I've tried it many times w/no good results. Maybe I've been doing it wrong. No one has ever explained exactly where you flatten the rail after or before the curve. I've seen it on many club layouts & it really looks good, but have never been able to get close enough to that 1 area to see how it's done. Someone explain the process & I will put it on all my curves that's out in the open.

Larry, it should start just prior to the onset of curvature. It would involve very complex geometry to have the super-elevation take place after a curve starts, and that is where most of us run into problems.

I have started a gentle rise of what will be the outer rail just an inch or so before the onset of the curve. Also, it works even better if your curves are properly eased because then you control for the two changes the frame of your engine must contend with...and the suspension (or lack thereof...), too.

If I had to put my finger on the likely trouble for most of us, it is in not knowing how to fiddle, patiently, with different track heights by shimming and prying the rails a hair here and there. I have solved vexing derailments whenever I introduce a new steamer to my rails by considering where the frame is in relation to the derailment, and it almost always points back a few inches from where the derailment first begins to happen in slow motion. Back down the frame is where the problem is, usually a sunken joiner or a low rail.

Believe me, I have had to be patient and persistent on several places, even ripping up 3' of nicely weathered rails and ballast in one case when fiddling wasn't producing the results. I had to reshape the roadbed a bit and then patch the rails. That worked. It taught me what to do on the other side of the layout where a modern diesel was coming out of the rails on a similar curve. I softened the beach sand ballast with water over 15-20 minutes, and the used a dentist's steel pick to gently pry up the outer rail in about 10 different places to raise maybe 12" or rail a whole half-millimeter. I then let the glue dry and harden, thus keeping the tracks oriented as I had just left them, and my next attempt with the SD75M worked much better. Fortunately, that 'fix' didn't also confound another engine that had been successfully negotiating those curves.

I use cardstock and somethings thin wood shims left over from stripwood model making. Others use masking tape cut into strips and overlaid in such a way as to create a very shallow and gradual two-ended ramp that runs about 105% of the length of the arc of tracks.

I hope this has been somewhat helpful to you.

-Crandell

 

[bkpigs]

Over the years I've tried it many times w/no good results. Maybe I've been doing it wrong. No one has ever explained exactly where you flatten the rail after or before the curve. I've seen it on many club layouts & it really looks good, but have never been able to get close enough to that 1 area to see how it's done. Someone explain the process & I will put it on all my curves that's out in the open.

Just as Crandell stated it should begin just before the curve. If you find a nice place to watch a mainline train run a turn from the outside of the curve you will see it lean just before it begins to make the turn. One thing to look at is not only do the prototypes raise the outside rail but it also looks as if they drop the inside rail. I would think this would result in the train leaning instead of "raising" one side. In theory this would create a smoother lean. Think of being in your car, if you raise one side only while going down the road to get 1.5% superelevation it will cause your shocks on that side to violently compress. Whereas if one side is lowered while the other raised, the change in elevation of the "uphill" side is cut down. This results in a less violent compression of the shocks meaning a smoother transition.

Just my thinking.

 

[rusty spike]

Larry, it should start just prior to the onset of curvature. It would involve very complex geometry to have the super-elevation take place after a curve starts, and that is where most of us run into problems.

I have started a gentle rise of what will be the outer rail just an inch or so before the onset of the curve. Also, it works even better if your curves are properly eased because then you control for the two changes the frame of your engine must contend with...and the suspension (or lack thereof...), too.

If I had to put my finger on the likely trouble for most of us, it is in not knowing how to fiddle, patiently, with different track heights by shimming and prying the rails a hair here and there. I have solved vexing derailments whenever I introduce a new steamer to my rails by considering where the frame is in relation to the derailment, and it almost always points back a few inches from where the derailment first begins to happen in slow motion. Back down the frame is where the problem is, usually a sunken joiner or a low rail.

Believe me, I have had to be patient and persistent on several places, even ripping up 3' of nicely weathered rails and ballast in one case when fiddling wasn't producing the results. I had to reshape the roadbed a bit and then patch the rails. That worked. It taught me what to do on the other side of the layout where a modern diesel was coming out of the rails on a similar curve. I softened the beach sand ballast with water over 15-20 minutes, and the used a dentist's steel pick to gently pry up the outer rail in about 10 different places to raise maybe 12" or rail a whole half-millimeter. I then let the glue dry and harden, thus keeping the tracks oriented as I had just left them, and my next attempt with the SD75M worked much better. Fortunately, that 'fix' didn't also confound another engine that had been successfully negotiating those curves.

I use cardstock and somethings thin wood shims left over from stripwood model making. Others use masking tape cut into strips and overlaid in such a way as to create a very shallow and gradual two-ended ramp that runs about 105% of the length of the arc of tracks.

I hope this has been somewhat helpful to you.

-Crandell

I have used a 22 guage wire under the outside rail and had good results with a continuos smooth curve...I also used some super glue on the inside ties to keep that side down...Jere