You'll find easements discussed in the Dec. 3 1880 edition of the Railroad Gazette.
Talbot first covered them in issue 5 of the University of Illinois 'Technograph' in 1891, and had the reference book I mentioned out by the end of the 19th Century.
I think we may be at the point where Sheldon writes the follow-up to his post on flanges and discusses fact and fiction in curve layout. TL; DR to the original post is that spiral transitions are of nearly 150-year-old antiquity in the USA, originally involved transition from tangent to fixed radius (not full spiral layout through the curve), and at model scale can be relatively short and compressed and still retain positive benefit.
I fail to see why there should be any more difficulty arranging a superelevation spiral if equipment can negotiate the 'built-in' transitions in the Kato superelevated sections. We know superelevation, unlike vertical-curve easement, is for appearance and not to enhance physical speed or reduce running wear.
Lastspikemike When I was a boy trainspotting from the railway bridge the clatter of buffers on an unbraked freight train was exciting to listen to as the locomotive braked the train to a stop. There was also a guards van or brake van at the end of the train, with brakes. That was around 1960 and the UK was still using steam to haul freight.
When I was a boy trainspotting from the railway bridge the clatter of buffers on an unbraked freight train was exciting to listen to as the locomotive braked the train to a stop. There was also a guards van or brake van at the end of the train, with brakes. That was around 1960 and the UK was still using steam to haul freight.
There was still some steam pulling freight trains here in 1960, on the N&W J class 4-8-4's pulled 100 car trains thru Appalachia, with easements, super elevation, air brakes, automatic signaling and automatic couplers. The UK was only 80 years behind......?
Sheldon
Lastspikemike The "run off" for any superelevation on a model railroad takes up a lot of space. Most home layouts won't have the space. This thread was about easement for curves, originally. There is inadequate space for proper easements also. The real question is how much extra work is worthwhile to mimic these prototype features in a manner that is just not realistic. Since you cannot reproduce the actual functionality you are in search of visual effect evoking reality. Is the result worth it or will most viewers fail to notice. Will you fail to notice? Depends what you expect from your modelling. I just like to run the trains. This is in the same class of issue as intricate model details like door handles and grab rails that are really too small to realistically model at 1/87 but seem to be worth the trouble to some. My Intermountain F7B kit came with such details I just left off, mind you I was only building it to consist with a BB A unit which lacked such detail anyway. I concluded it was practically impossible to insert the door latches into the tiny holes on the kit. I did use the brass wire hand rails from the F7 dress up kit though. The styrene model hand rails were not worth the effort to install. Same with some tiny styrene details on Proto 2000 tank cars and so on. Sure some of this level of detail can be added to your model railroad but ask yourself first is it worth the effort?
The "run off" for any superelevation on a model railroad takes up a lot of space. Most home layouts won't have the space.
This thread was about easement for curves, originally. There is inadequate space for proper easements also.
The real question is how much extra work is worthwhile to mimic these prototype features in a manner that is just not realistic. Since you cannot reproduce the actual functionality you are in search of visual effect evoking reality. Is the result worth it or will most viewers fail to notice. Will you fail to notice? Depends what you expect from your modelling. I just like to run the trains.
This is in the same class of issue as intricate model details like door handles and grab rails that are really too small to realistically model at 1/87 but seem to be worth the trouble to some. My Intermountain F7B kit came with such details I just left off, mind you I was only building it to consist with a BB A unit which lacked such detail anyway. I concluded it was practically impossible to insert the door latches into the tiny holes on the kit. I did use the brass wire hand rails from the F7 dress up kit though. The styrene model hand rails were not worth the effort to install. Same with some tiny styrene details on Proto 2000 tank cars and so on.
Sure some of this level of detail can be added to your model railroad but ask yourself first is it worth the effort?
I generally agree with the premise behind your question, not necessarily about superelevation but about the concept of how much realism is worth the effort.
If I were to superelevate my curves, I would probably just run an extra bead of caulk along the outside edge of the curve, thereby raising the roadbed at a slight angle when I installed it. A more secure and consistent way would be to use strips of wood or styrene, provided you can locate the correct thickness in sufficient quantities.
But generally, realism in layout trackwork is a function of space. I wouldn't bother superelevating curves on a 4x8 layout, mainly because I would not even think of modeling a high speed mainline on a 4x8. Others might, but then your point about the effort being worth it becomes more relevant.
If I had a 20 x 40 layout and high speed main line, I probably would.
But I build branch line and short lines, never high speed, so I might only do it for one curve...the longest curve where it would realistically be more appropriate.
- Douglas
LastspikemikeThe "run off" for any superelevation on a model railroad takes up a lot of space.
It's not that much.
Lastspikemike There is inadequate space for proper easements also.
I don't know how much space a "proper" easement would take with our model curves, I've never bothered calculating it. I just do enough to look good and get the benefits of smoother running, which does not take much space.
When I add easements and superelevation to a 15" radius (N-scale), 180° curve, it adds less than 2" to the width of the curve and less than 4" to the depth.
LastspikemikeThe real question is how much extra work is worthwhile to mimic these prototype features in a manner that is just not realistic.
Well, most of our curves are nowhere near realistic, so I guess we should all just model straight track.
LastspikemikeSince you cannot reproduce the actual functionality you are in search of visual effect evoking reality.
While it's true that modeling superelevation is all about the visual effect, with easements, as has been said before, you do get the actual functionality as well.
Lastspikemike ATLANTIC CENTRAL Lastspikemike When I was a boy trainspotting from the railway bridge the clatter of buffers on an unbraked freight train was exciting to listen to as the locomotive braked the train to a stop. There was also a guards van or brake van at the end of the train, with brakes. That was around 1960 and the UK was still using steam to haul freight. There was still some steam pulling freight trains here in 1960, on the N&W J class 4-8-4's pulled 100 car trains thru Appalachia, with easements, super elevation, air brakes, automatic signaling and automatic couplers. The UK was only 80 years behind......? Sheldon Yes, there was a rather expensive war that nay have delayed UK conversion from steam. Coal production was also a factor until the 1980's in fact.
ATLANTIC CENTRAL Lastspikemike When I was a boy trainspotting from the railway bridge the clatter of buffers on an unbraked freight train was exciting to listen to as the locomotive braked the train to a stop. There was also a guards van or brake van at the end of the train, with brakes. That was around 1960 and the UK was still using steam to haul freight. There was still some steam pulling freight trains here in 1960, on the N&W J class 4-8-4's pulled 100 car trains thru Appalachia, with easements, super elevation, air brakes, automatic signaling and automatic couplers. The UK was only 80 years behind......? Sheldon
Yes, there was a rather expensive war that nay have delayed UK conversion from steam. Coal production was also a factor until the 1980's in fact.
It is not the late use of steam that puzzles me, it is the failure, long before that war, to adapt a list of proven technologies to improve safety and productivity? Again - Air Brakes? Automatic Couplers?
Lastspikemike On the subject of useful modelling of realism I take it all are agreed that model superelevation would be limited to creating a maximum height differential across the gauge of 1-2 mm......
On the subject of useful modelling of realism I take it all are agreed that model superelevation would be limited to creating a maximum height differential across the gauge of 1-2 mm......
Yes, 1/16 of an inch, or about 6 scale inches (1.75 mm), maybe just a little more (my brain is not very "metric adjusted") on the broadest curves with long easements.
But across the short distance of the track gauge, the is a noticeable angle of inclination as the rolling stock/loco sits on the track resulting in about 10 degrees of "tilt".
In real life, if you are close to a train, it is always noticable when the train is on a superelevated curve.
On my last layout I had 0.03" (0.08mm) high superelevation on the R22" curves of my mainline (that included easements on both ends) and it was noticeable. I don't think I would go much higher than that on such a small radius curve but might, if the radii were much wider.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
ATLANTIC CENTRALIt is not the late use of steam that puzzles me, it is the failure, long before that war, to adapt a list of proven technologies to improve safety and productivity?
You must be refering to the Boeing 737MAX. Warning light on the angle-of-attack sensor? Optional? (Make them buy convenience package A, a trick learned from Detroit)
Minimize the cost and time to train crew on MCAS so rather than a simulator they used a one-hour Ipad session. Good cost savings there, aye.
So, How far have we come?
Cheers, Ed
On my two Free-mo modules, each has a 60" radius curve with an 18" easement.
Superelevation is created by gradually increasing thicknesses of Evergreen styrene, until the max of .040" is reached in the true curve.
That gives a .022" superelevation of the outer rail, which is 2" in the real world.
Going with what Douglas said, you don't notice it until you notice it.
I am very happy with the results. It looks great, and there has never been a derailment on these modules.
Because next to nothing in our rolling stock/locomotive world has full equalization, the twist in the track in the easement COULD be a derailment problem. By keeping the rise minimal, that danger is lessened. And by keeping the easement long, the same is true.
HOWEVER. I have NOT proven there will be a problem with higher superelevation. That is up to others, who build to that height. Or who choose a different easement length.
Ed
gmpullman ATLANTIC CENTRAL It is not the late use of steam that puzzles me, it is the failure, long before that war, to adapt a list of proven technologies to improve safety and productivity? You must be refering to the Boeing 737MAX. Warning light on the angle-of-attack sensor? Optional? (Make them buy convenience package A, a trick learned from Detroit) Minimize the cost and time to train crew on MCAS so rather than a simulator they used a one-hour Ipad session. Good cost savings there, aye. So, How far have we come? Cheers, Ed
ATLANTIC CENTRAL It is not the late use of steam that puzzles me, it is the failure, long before that war, to adapt a list of proven technologies to improve safety and productivity?
He MIGHT be referring to the deaths per working hour for the operating personnel of a Boeing 737MAX compared to the operating personnel of a British pre-war train.
7j43k On my two Free-mo modules, each has a 60" radius curve with an 18" easement. Superelevation is created by gradually increasing thicknesses of Evergreen styrene, until the max of .040" is reached in the true curve. That gives a .022" superelevation of the outer rail, which is 2" in the real world. Going with what Douglas said, you don't notice it until you notice it. I am very happy with the results. It looks great, and there has never been a derailment on these modules. Because next to nothing in our rolling stock/locomotive world has full equalization, the twist in the track in the easement COULD be a derailment problem. By keeping the rise minimal, that danger is lessened. And by keeping the easement long, the same is true. HOWEVER. I have NOT proven there will be a problem with higher superelevation. That is up to others, who build to that height. Or who choose a different easement length. Ed
Not sure I understand your description? If you raise the outer rail .040" how is the superelevation only .022"? Don't you keep the inner rail level?
Another good argument for equalized trucks........
But in my experiance, the NMRA suggested 6 scale inches, about 1/16" (.062") is not a problem with 15" to 18" long easements on curves 36" radius and above.
Prototype superelevation "generally" ranges from 4" to 8".
I use N Scale.
When I started laying track, I read a lot about superelevating N track. I followed the easiest advice, which was to lay strips of masking tape under the outer rail. The layers of tape gradually increased from one to five and back down again.
Five thicknesses of masking tape seemed to give just the right elevation to the outer track.
The tape is completely covered with ballast so it's not seen. The results looked very good to me. The trains look great around the curve, with just enough lean to make it look realistic.
It was not at all difficult.
York1 John
ATLANTIC CENTRAL Not sure I understand your description? If you raise the outer rail .040" how is the superelevation only .022"? Don't you keep the inner rail level?
I guess I should have written that better. The styrene pieces go out on the end of the ties. So the amount of lift at the outer rail compared to the inner is .66/1.2 of the length of the tie.
Lift at outer tie = .040"----lift at outer rail = .022" (compared to inner rail). It IS true that I also lifted the inner rail, but I decided that was negligible. It is, in fact, .008", compared to its height in the flat section.
And equalized diesel trucks, and equalized steam engines....
Ain't gonna happen. So you better make your track accept non-equalized rolling stock and locomotives. And consider that typical 4 wheel freight trucks need equalization the least, because of their short wheelbase.
What I try very much to do, however, is to do 3 point suspension on rolling stock. It's not just for tracking, though. It's also to eliminate the jelly-wobble of some cars. I did it to a string of 35 Red Caboose coil cars, and got a couple of compliments on how they "tracked".
But in my experiance, the NMRA suggested 6 scale inches, about 1/16" (.062") is not a problem with 15" to 18" long easements on curves 36" radius and above. Prototype superelevation "generally" ranges from 4" to 8". Sheldon
Here's a pretty detailed examination of superelevation:
https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/19085/Superelevation.pdf
Superelevation on typical freight railroads maxes out around 4". That's the max, not necessarily the typical.
I do know BN cut way back on the superelevation on the old Burlington Zephyr race track, because they weren't running trains that fast anymore, and it was being a REAL problem for their coal trains.
Each of us who do superelevation have a "look" we're after. And they won't all be the same. Works for me.
7j43kand it was being a REAL problem for their coal trains.
what was the problem? flange rubbing/wear?
greg - Philadelphia & Reading / Reading
7j43k ATLANTIC CENTRAL Not sure I understand your description? If you raise the outer rail .040" how is the superelevation only .022"? Don't you keep the inner rail level? I guess I should have written that better. The styrene pieces go out on the end of the ties. So the amount of lift at the outer rail compared to the inner is .66/1.2 of the length of the tie. Lift at outer tie = .040"----lift at outer rail = .022" (compared to inner rail). It IS true that I also lifted the inner rail, but I decided that was negligible. It is, in fact, .008", compared to its height in the flat section. Another good argument for equalized trucks........ And equalized diesel trucks, and equalized steam engines.... Ain't gonna happen. So you better make your track accept non-equalized rolling stock and locomotives. And consider that typical 4 wheel freight trucks need equalization the least, because of their short wheelbase. What I try very much to do, however, is to do 3 point suspension on rolling stock. It's not just for tracking, though. It's also to eliminate the jelly-wobble of some cars. I did it to a string of 35 Red Caboose coil cars, and got a couple of compliments on how they "tracked". But in my experiance, the NMRA suggested 6 scale inches, about 1/16" (.062") is not a problem with 15" to 18" long easements on curves 36" radius and above. Prototype superelevation "generally" ranges from 4" to 8". Sheldon Here's a pretty detailed examination of superelevation: https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/19085/Superelevation.pdf Superelevation on typical freight railroads maxes out around 4". That's the max, not necessarily the typical. I do know BN cut way back on the superelevation on the old Burlington Zephyr race track, because they weren't running trains that fast anymore, and it was being a REAL problem for their coal trains. Each of us who do superelevation have a "look" we're after. And they won't all be the same. Works for me. Ed
Well now it makes perfect sense and if you are modeling a modern freight railroad I agree.
In the "olden days" most mainlines were built for the fastest passenger traffic and drawbar forces were limited anyway, and mitigated by pushers in many of the places where stringlining on a superelevated curve mightr be a problem.
Freight trains were generally shorter and lighter than today, and railroad were looking for speed in the 30's thru the 60's.
I consider the 1/16" number to be generally the maximum, with the idea being to get into the 5-10 degree tilt range that was visually obvious on the prototype.
1/16" under the rail? 1/16" under the tie ends? I never got that fussy, maybe a test or drawing is in order?
gregc 7j43k and it was being a REAL problem for their coal trains. what was the problem? flange rubbing/wear?
7j43k and it was being a REAL problem for their coal trains.
I suspect stringlining of very long trains at slow speeds.
ATLANTIC CENTRAL gregc 7j43k and it was being a REAL problem for their coal trains. what was the problem? flange rubbing/wear? I suspect stringlining of very long trains at slow speeds. Sheldon
I tried finding the article, but couldn't. As I recall, the problem was a tendency to tip the inner rail.
When the train is going at any speed that isn't the theoretical "perfect" speed, there will be sideways forces on the rail top, as delivered through the flanges (once you've run out of wheel tread). If you're going a lot slower than the design speed, you also will get a "lot" of sideways thrust. And if you are running 100 ton cars (as opposed to passenger cars), that too will increase the sideways thrust.
Beyond that, if the flange is rubbing on the inside of the curve, you wear both the flanges and the rail.
I don't believe they had real stringlining, where the train would tip over into a curve. I think they had derailments, where the rail just sorta disappeared out from under the car(s). That is: rolled over.
And then some lucky lads and lasses got to make it all better again. Quickly, if you would be so kind.
ATLANTIC CENTRAL 1/16" under the rail? 1/16" under the tie ends? I never got that fussy, maybe a test or drawing is in order? Sheldon
It's not hard to figure on paper:
1/16" under the tie end will give you .034" lift at the outer rail (3" in the real world).
Slide it farther in, under the rail, and you get .041" lift (3.6" real world).
That's more than I've got, but I suspect if I'd done the above, I would've been happy enough with the results.
Lastspikemike Not required under the conditions experienced in the UK.
Not required under the conditions experienced in the UK.
And as I said, I full well admit I have no knowledge of understanding of how or why their railroading is so different.
And given that we all make choices about how to spend our time and mental energy, I'm pretty sure I will never really know.
Lastspikemike 10% superelevation, which is a lot for prototype, is 1.65 mm elevation difference across the gauge. Get real. To ease that properly requires scale hundred feet which is 350 mm or over a foot just to ease the superelevation from maximum to level which is nowhere near prototype distance.
10% superelevation, which is a lot for prototype, is 1.65 mm elevation difference across the gauge. Get real.
To ease that properly requires scale hundred feet which is 350 mm or over a foot just to ease the superelevation from maximum to level which is nowhere near prototype distance.
Again Mike, I live in the USA and build houses for a living, and play with garden tractors as one of my other hobbies. My brain was trained, and works in inches, fractional or decimal.
Yes 100 scale feet, 13.79", just slightly more than one passenger car length, less than the easements I use on my 36" radius and larger curves. My easements are between 15 and 18 inches long.
Oh, that's right, the easement and the superelevation runout are generally the same length. It works just fine.
So I guess I have plenty of room for 5-10 DEGREE superelevation.
Civil engineering is in my skill set. To build a house, you first have to survey the location and set the elevations......
Remember this track plan? The SMALLEST mainline or passenger track curve is 36" radius. A great many of the curves are in the 40's.
ATLANTIC CENTRAL ...but I have never understood the slow development of things like air brakes, automatic couplers, or larger equipment in other parts of the world?
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
ATLANTIC CENTRAL So I guess I have plenty of room for 5-10 DEGREE superelevation. Sheldon
For a 10 degree superelevation, you will be raising your outside rail by .114".
That is a 10" superelevation in the real world.
For a 5 degree superelevation, it's .057", or 5".
ATLANTIC CENTRAL ...but I have never understood the slow development of things like air brakes, automatic couplers, or larger equipment in other parts of the world? Gidday Sheldon, an over simplified “Bears eye” answer is “Landmass”. The Brits and the Europeans did not have to move freight anywhere near the distances that was necessary in North America, therefore overall speed was unimportant. I would also suggest that national pride was a factor. Cheers, the Bear.
Thanks, many times the distilled simple answer conveys the most information.
ATLANTIC CENTRALThanks, many times the distilled simple answer conveys the most information.
Bear isn't paid by the word. He makes his point and carries on.
I agree, the best answers come in this form.
-Kevin
Living the dream.
7j43k ATLANTIC CENTRAL So I guess I have plenty of room for 5-10 DEGREE superelevation. Sheldon For a 10 degree superelevation, you will be raising your outside rail by .114". That is a 10" superelevation in the real world. For a 5 degree superelevation, it's .057", or 5". Ed
We are all doing some different math here, and I'm not sure I have the energy, but here goes.
Using the tie width, 1.125" on the piece of Atlas track in my hand. And using a trig calculating program because I can:
If I raise the outer edge of the ties .125" (1/8") that creates an "angle B" (angle of tilt) of 6.34 degrees and would be 10.87 scale inches measured at the tie ends, not at the rails.
That same angle of tilt, measured at the rails makes the outer rail .0724" (close to the 1/16" - .0625, number I used earlier) above the inner rail.
.0724" x 87 = 6.2988" scale inches of superelevation.
The NMRA suggests that 6 scale inches is a workable number and "typical" or mid range among prototype practice.
So ok, maybe I was being too general saying 5-10 degrees, lets be more specific at 6-7 degrees.
But still, my 1/16" number measured at the rail or out at the tie ends, is a workable range.
1/16" measured at the tie ends, is only 3 dgrees of tilt. And only 3" of superelevation at the rails.
SeeYou190 Bear isn't paid by the word. He makes his point and carries on. I agree, the best answers come in this form. -Kevin
I agree, Kevin, but am probably going to stray from that method, with more words and more pictures, too.
When I decided to add superelevation to some sections of my track (much of it on both curves and grades) I used my "this oughta be pretty easy" method.
With the track on 3/4" cut-out plywood roadbed, atop risers to create a means of moving a train from the main level of the layout to a partial upper level, I simply marked each riser with a pencil line at the same level as the top of the open grid framework to which they were attached, then removed the the screws which held them to the grid.
Next, I assembled a train on the curving grade, then selected the riser closest to the mid-point of the 45' long grade, elevating it so the pencil line was even with the top of the grid member to which it had been attached. I then pushed the bottom of the riser towards the outer edge of the curve, which caused the outer end of the pencil line to rise. I then applied a C-clamp to temporarily affix the riser in place, with the inner end of the pencil line even with the top of its grid-member.
After crawling out from under the layout, I visually assessed the amount of tilt on the train that was parked on the grade, and after trying a few re-positionings, decided on the look I liked best. The riser was then re-screwed into its new position.By doing so, all of the risers on either side of that one were automatically also offset, each to diminishing degrees from that one at the mid-point. All I had to do was carefully lift each one, without further off-setting it, then re-fasten it with screws.Since there are five curves on this grade, off-setting the risers depended on which way each portion of the track curved. I did include superelevation on two of the three bridges, basically offsetting the bottom of the supporting piers until they looked suitable (one was on straight track).
All of the curves have uncalculated easements (done "by-eye") and easements into- and out-of each of the five curves, the "calculations" done by the offset of each riser nearest the centre-point of each curve.
The grade starts at this flanger sign...
...with the left rail at this point raised .030" (just a tad under 3" in HO scale).
As the track reaches the bridge, the superelevation is now .040" ...
...increasing to .050" here...
...then dropping down to .030" as the track straightens-out...
The track, now straight, continues to climb, and as it crosses this short bridge, the track's superelevation is 0.0"
About 4' past that little bridge, the right rail is superelevated .015", and 2' later, it's .022", and in another 2' it's at .044", continuing at that level as it navigates the curve.As the curve of the track eases, the superelevation decreases to about .033", then .015" and then zero...
...the track then nears the next curve, with the left rail elevated .018", then a little further on, to .062"...then dropping to .042" as it nears the straight portion of the bridge.
At the middle of the bridge, the right rail is elevated by .012", and that increases to .055" as the track curves to the left
...and then the final curve, with the left rail elevated .038", decreasing to .022", then .011", almost at the top of the grade.
While the measurements mentioned were eyeballed on a dial caliper, they're reasonably accurate, but my point is that the adjustments to the offset of the risers supporting the roadbed was done strictly on a "if it looks reasonably realistic, then it's good-enough" basis. The measurements merely confirm that the superelevation is within reason. None of the track on this grade sees fast trains...I'd guess an HO scale 30mph at most, and for heavy trains, even with helpers/pushers, somewhere between 10-20mph.
My apologies if this post is boring, but I thought that there's been too much controversy over the methods or necessity needed to add this feature.
Wayne
Wayne, thank you for that detailed explaination. In the end, your maximum superelevation was similar too, and/or just under my suggested .0625".
And was simply talking in general terms.
OK, I'm worn out. Maybe I will post something when I get started on the benchwork in a few weeks. Otherwise I'm on to my other hobby, the first of next month is the GRAVELY mow-in, and my baby is going to the show.
ATLANTIC CENTRAL OK, I'm worn out.
OK, I'm worn out.
Rich
Alton Junction
Soupy's not much into replying. The last time he replied to a post was June 21.
If he's still lurking, he should be learning a lot about superelevation.
And about British trains. And about camber on roads.
I have taken to just scrolling past posters or replies that don't interest me. Even topics.
And when I get even more exasperated, I go play with trains instead of being here.