Multi-track superelevation question


A

a300mech

New Member
Hello,
I'm in the very early planning stages of a Pennsy layout. I was thinking of incorporating a representation of horseshoe curve, which brings me to my question...

On multi-track curves in general, is each track superelevated individually, or is it more common for the entire width of the roadbed to be graded at an angle so that as each track is laid they are all automatically superelevated?
I hope that makes sense. I tried a search but couldn't find anything regarding this. Thanks in advance for any info.
 
I don't have the answer to that.

However, looking at your screen name I assume you know what stator vanes, APU's, and pitot tubes are?

P.S. Welcome to the forum.
 
To answer your question each track is done separately.

7-8-200121.png
 
Mac, I know what a pitot tube is! :)

A300, Mark is correct. Think about the radius of multi-track curves. The outermost track has the widest radius and the innermost track has the most narrow radius. If they did one grade for all the tracks, the super elevation would be the same for all the tracks, which would defeat the purpose of superelevation. The outside track have the greatest angle of elevation and the inside track are generally close to level. The other tracks would have superelevation based on the caluculated centripetal forces of the curve radius. Superelevation of adjacent tracks is calculated very carefully and the grades are set to ease the train through the curve without having the natural lean of the train interfere with a train on the adjoining track.
 
Thank you to all who replied. It does make sense to each track separately, and now I understand why. :D

macjet...How did you guess? LOL Yes, I must plead guilty. I'm one of those dreaded airline mechanics. ;)
You're screen name seems to hint at aviation as well.
Couldn't have anything to do with McDonnell Douglas could it? :D
 
a300mech said:
macjet...How did you guess? LOL Yes, I must plead guilty. I'm one of those dreaded airline mechanics. ;)
You're screen name seems to hint at aviation as well.
Couldn't have anything to do with McDonnell Douglas could it? :D
Click to expand...

I'm on the other side of those squawks but nothing as big as an MD.:D CE-680 is the largest so far.

The screen name was a combination of my new Macbook and a Learjet type that I received in the same week.

Welcome again. There are a lot of guys here with a ton of info.
 
I use to have a 50 Mercury coupe w/a pitot mounted in the grill w/a 200 mph speedometer on the dash. Use to scare the hell out of people when I was doing about
60mph on a windy headwind. LOL

Larry
 
A little off topic, but the other day they were talking about a Boeing 757 that went down due to a wasp building a nest in the pitot tube. Caused mass confusion when the inst's went wonky after take off.
Too bad I fly so much for work... I hate leaving the ground! :)
 
LOL, Mac. My brother is a pilot and I've done lots of walk arounds with him before we take off so I'm pretty good at knowing where stuff is on airplanes. Other than that, I'd probably never make it through my first solo without nose diving into something. :) The CH-47 is my favorite helicopter. A California ANG sh*thook saved my life when I was working a bad flood in California. Got me and two other people out of the Russian River just before the roof we were standing on would have been headed out to the Pacific. :eek:
 
Yes indeed, those 'hooks were and are great birds and our ANG pilots and mechanics were some of the best in the world. The flood I was working lasted four days and we had 1,000 people that needed to be evacuated. We had one dry spot in town in front of the fire station and there was probably 10 feet of rotor clearance between the building and wires on the other side of the LZ. The wind was blowing about 35 knots and those guys made 21 flights in a little over eight hours, placing the 'hooks right in the center of the LZ each time. We got everyone out and I was on the last flight out as it got dark. I was never so glad to be in a drafty, noisy, shaking metal tube in my life. :) I made it a point to get over to their air ops base and shake as many hands as I could find. Most people have no clue about what those ANG pilots and mechanics go through to help in natural disasters, let alone combat. Merry Christmas to all the men and women who are still keeping them flying today.
 
My goodness! Aviation, and model railroading. Well it's a combo that seems to work for a lot of us! :D

I'm very glad to have fallen in with you all, and a very merry Christmas to everyone!
 
I to am glad to have stumbled across this site and all you great model railroad
enthusiasts also merry Christmas.

a300mech said:
My goodness! Aviation, and model railroading. Well it's a combo that seems to work for a lot of us! :D

I'm very glad to have fallen in with you all, and a very merry Christmas to everyone!
Click to expand...
 
A300, I was building aircraft and ship models at the same time I was doing trains when I was younger. I still have one F4U Corsair I built when I was about 14. It's not very good, looking at it now, but I thought I was world's geatest modeler when I built it. :) It seems like anything that moves attracts modelers so there's a lot of crossover between train, plane, and ship buffs.

Dom, glad to have you here. Merry Christmas to you and yours as well.
 
Back to the original topic here...

What is superelevation? Is this the term for the tracks leaning towards the center of the curve (such as banking on a NASCAR track)?

I had not seen that term used yet.
 
ken_23434 said:
Back to the original topic here...

What is superelevation? Is this the term for the tracks leaning towards the center of the curve (such as banking on a NASCAR track)?

I had not seen that term used yet.
Click to expand...

Well, I'll try to give you a general answer. The other fellows will have specific info.
Yes it is in essence banking the track towards the inside of the curve. This helps keeps the train on the track allowing higher speeds through the turn? Also, I believe for passenger trains it prevents the uncomfortable feeling of leaning to the outside of the turn.

Now I've just thought of another question..Is there a rule of thumb for how much superelevation is to be used for a given curve? For instance given a 24" radius turn you would elevate the outside track how much?
And, I'm "assuming" we're all talking HO scale here. :D
If such a formula exists it would be great to know it. When I built my last layout over 15 years ago, I just eyeballed it, till it "looked right".
I'd like to do it better this time if possible. :)

Happy new year to all, and I hope you all got the train goodies you wanted!
a300mech
 
Here's the prototype Superelevation formula: Height = 4 * Speed * Speed / Radius In Feet. Reducing this to HO, it would be about .045 inches of super elevation on a 24" curve. This would be typical for mainlines with trains speeds faster than 60 miles per hour. As A300 wrote, superelevation is used to allow higher train speed through curves and reduce both discomfort to passengers and damage to freight. Since HO trains really don't have enough mass to make superelevation have any real use, a standard 4" for curves would look about right.
 
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