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Banking of track

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Banking of track
Posted by Howard Zane on Saturday, January 14, 2017 1:46 PM

I recently had a visitor who commented on my banked curves and obviously not knowing anything about banking track. He claimed that this was the first pike he had visited with banked track and thought it looked stange. Oh well!

How many of you modelers bank your curves and what techniques do you use. Since I transitioned to code 83 flex track years ago, how I bank curves is simple...at least for me. Prior to installing track I just glue a strip of .040 styrene to underside of curved outside rail and install. Ballast fills the gap easily. I use to use .020 shims at ends of curves as it tranistions to straight, but with code 83, found this step not really important. In my hand laying track days, i'd just glue a styrene strip along the outside of curve and glue ties to it.

In a prior post I spoke of intenionally uneven track work. I found this combined with banked curves a fine step towards realism. I even bank curves on rough branch line track knowing quite well this most likely would not have been done....but it looks great!

By the way, the visitor was not a jerk, he just did not know. Most likey 99.9% of visitors to my pike are quite complimentary and are excellent guests. I'm actually sort of honored when questions about techniques are asked. But I could write volumes about comments.....and some are quite humorous.

HZ

Howard Zane
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Posted by Arto on Saturday, January 14, 2017 2:08 PM

I've banked my curves as well. It doesn't take much. Your shimming technique is probably easier than what I did. When I rebuilt/upgraded my existing layout durning the last few years, I used a digital level layed across the rails and banked the curves by adjusting the roadbed supports. The digital level really makes things easy since it provides readings in degrees, %, or inches of rise per foot of run with an accuracy of 1/10 degree. Very little banking (superelevation) is required for realism. I also use continously variable radius curves (aka ship or railroad curves). Unfortunately, variable radius curves (especially with superelevation) can cause derailment issues with some types of models such as articulated locos & cars. The track work must be perfect.

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Posted by 7j43k on Saturday, January 14, 2017 2:26 PM

I superelevate my curves by placing .040" shims at the outer end of the ties.  This is true for the main radius of the curve.  For the eased part, I use smaller shims.  It looks great.

It may well look strange to someone who is used to layouts where that is done.  I do not think it would look strange to someone who has done much train watching.  I noticed it a long time ago when I was a wee lad.  All by myself.  As my dad told me.

So, for me, it looks funny when layouts DON'T superelevate their mainline curves.

 

Ed

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Posted by Arto on Saturday, January 14, 2017 3:01 PM

7j43k

So, for me, it looks funny when layouts DON'T superelevate their mainline curves.

 

Ed

 

ditto 

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Posted by 7j43k on Saturday, January 14, 2017 3:51 PM

I will add that my mainline curves are 48" or bigger, and the curve easement is 18" long.  I don't recall there ever being a derailment on these curves.

However.

If I was running 18" curves, I would reconsider superelevation.  And try to keep easements, which are actually useful for our model trains.

 

Ed

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Posted by gmpullman on Saturday, January 14, 2017 4:08 PM

Howard Zane
I just glue a strip of .040 styrene to underside of curved outside rail and install. Ballast fills the gap easily. I use to use .020 shims at ends of curves as it tranistions to straight

Same method here. I am extremely pleased with the results. There was only one place where I had to reduce the height of the outside rail and that was a reverse curve where there was only about a foot of tangent between them. 

I'm pretty sure the railroads called it "superelevation" of curves. I understand on some curves the outside rail can be as much as 8½ inches higher! There are tie plates manufactured that cant the rail inward to reduce the "roll-over" effect and to keep the stress in line with the web of the rail.

Have Fun,

Ed

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Posted by BroadwayLion on Saturday, January 14, 2017 4:24 PM

Here is helix of LION. him super elevated the whople thing. Him put builders shims between the risers and the track deck.

PS LION said something about using risers between the ties and the tie-plates and got pasted by a gaggle of wildebeests who informed that such was not so. BUT I REALLY DID see it in official track specifications. Turns out I was looking at specifications for an elevated railroad so that the tie lay level on the structure. They just raise the tie plates.

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by selector on Saturday, January 14, 2017 4:26 PM

If our aim is to have our scenery and trains appear realistic, especially in imagery, I think it best to have at least some super-elevation.  I have always attempted to incorporate it into my curves, with some success.  I like the look, it seems intuitively correct, and the prototype does it.

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Posted by SLC RR on Saturday, January 14, 2017 4:55 PM

Howard Zane

I recently had a visitor who commented on my banked curves and obviously not knowing anything about banking track. He claimed that this was the first pike he had visited with banked track and thought it looked stange. Oh well!

How many of you modelers bank your curves and what techniques do you use. Since I transitioned to code 83 flex track years ago, how I bank curves is simple...at least for me. Prior to installing track I just glue a strip of .040 styrene to underside of curved outside rail and install. Ballast fills the gap easily. I use to use .020 shims at ends of curves as it tranistions to straight, but with code 83, found this step not really important. In my hand laying track days, i'd just glue a styrene strip along the outside of curve and glue ties to it.

In a prior post I spoke of intenionally uneven track work. I found this combined with banked curves a fine step towards realism. I even bank curves on rough branch line track knowing quite well this most likely would not have been done....but it looks great!

By the way, the visitor was not a jerk, he just did not know. Most likey 99.9% of visitors to my pike are quite complimentary and are excellent guests. I'm actually sort of honored when questions about techniques are asked. But I could write volumes about comments.....and some are quite humorous.

HZ

 

I had to bank a curve in my layout because a lighter, cheaper GP-9 "trainline" would not make good contact.  It was while the train was travelling uphill.  There was a 22" radius curve at this 2% grade.

All the others negotiated the grade without a sputter.  But the trainline would stall out.  The track was allready ballasted and glued, there were also a few small nails "brads" holding some of the ties of the flex track down to the plywood base.  I made some skinny shims by shaving a fat round toothpick into flat wedges, and inserted them under ties on the outside of the curve.  Finally, after adding shims over about a 2' length of track, the locomotive negotiated the curve without a stall.

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Posted by Arto on Saturday, January 14, 2017 5:38 PM

7j43k

I will add that my mainline curves are 48" or bigger, and the curve easement is 18" long.  I don't recall there ever being a derailment on these curves.

However.

If I was running 18" curves, I would reconsider superelevation.  And try to keep easements, which are actually useful for our model trains.

 

Ed

 

Excellent point Ed!

My sharpest curves are about 28" at the apex. Most are 30" to 36", some much larger (for short distances). Most of my curves are on grades. I'm sure that plays into the "trickiness" of derailment issues (which are now usually far & few between). If I ever build another layout I would prefer to have 60" radius minimum for mainline.

FWIW, the term "superelevation" is not a railroad term. It's used in other transportation engineering applications such as roadways.

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Posted by doctorwayne on Saturday, January 14, 2017 6:13 PM

I use superelevation on all of my mainline curves and used this simple method:

If you use open grid or L-girder benchwork, superelevation is easy to add, including the vertical easements into and out of the curve.
I use 3/4" plywood as a sub-roadbed, but any similar-type material, or even spline roadbed should also work.  Install the straight roadbed on either side of the curve by fastening the risers to the joists, except for the last riser beyond the ends of the curve.  Install risers to the underside of the curved roadbed, but don't fasten them to the benchwork just yet.  If your curve is on a grade, as most of mine are, raise the roadbed through the curve to the proper height, then mark a pencil line on each riser which corresponds to the top of the benchwork to which it will eventually be fastened.  If the track through the curve is to be level, adjust the risers accordingly, then make the lines.  Next, choose the riser closest to the mid-point of the curve, raise it to the proper height, then push the bottom end of the riser towards the outside of the curve.  Re-align the height line on the riser so that its inner end corresponds to the top of its benchwork member (the height line will be tilted, with the end on the outside of the curve somewhat above the benchwork).  I've found that the best way to establish the amount of superelevation is by placing a train on the curve, then adjusting the off-set of the bottom of the riser until it "looks right".  I use a C-clamp while I'm making the visual adjustments, then, when I'm satisfied with the appearance, that mid-point riser is screwed to the benchwork.  Because the roadbed is torsionally flexible, each riser on either side of the mid-point will now be off-set from the vertical, to diminishing degrees, as the distance from the mid-point increases.  Working from the mid-point of the curve, carefully raise each riser so that the inside end of the height mark aligns with the top of the benchwork to which it will be fastened, making sure to not change the angle of off-set, then screw the risers to the benchwork.  This allows the roadbed to form its own easements into and out of the super elevation.  I did all of mine with the trackwork in place.

Wayne

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Posted by cuyama on Saturday, January 14, 2017 6:49 PM

Arto
FWIW, the term "superelevation" is not a railroad term. It's used in other transportation engineering applications such as roadways.

That would be news to many railroads, past and present. Here's a page from a 1940s-50s Pennsy track standards book. Here's the inside cover.

And one of the dozens of pages mentioning super-elevation

From this current NS industry track specification

There are dozens of other examples, old and new, easily found with a web search

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Posted by 7j43k on Saturday, January 14, 2017 7:23 PM

Arto
If I ever build another layout I would prefer to have 60" radius minimum for mainline.

 

 

Total endorsement from this location!!!!

Ed

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Posted by dknelson on Saturday, January 14, 2017 9:07 PM

Arto
  

FWIW, the term "superelevation" is not a railroad term. It's used in other transportation engineering applications such as roadways. 

Cuyama, I think our friend Arto mean it is not JUST a railroad term but is used in other fields.  It unquestionably is a term railroads (and railroad engineering texts) have used.

For my super elevated curves I used a flex track by Precision Scale Co. that comes with the super-elevation built in, via nubs on the bottom of the ties on the outside edge (heh - that is, outside if you lay the track correctly lol).  You need to trim the nubs where the super elevation begins and ends.

Dave Nelson

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Posted by richhotrain on Sunday, January 15, 2017 4:24 AM

7j43k
 
 
Arto
If I ever build another layout I would prefer to have 60" radius minimum for mainline. 

Total endorsement from this location!!!!

Ed 

I won't argue the point, but a 60" radius is going to require a 10' wide area to turn a train around at the end of the layout.  In my mind, a 48" radius would be more than enough. Ha, currently, my layout employs 32" radius curves.

Rich

Alton Junction

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Posted by richhotrain on Sunday, January 15, 2017 4:28 AM

Howard Zane

By the way, the visitor was not a jerk, he just did not know. Most likey 99.9% of visitors to my pike are quite complimentary and are excellent guests. I'm actually sort of honored when questions about techniques are asked. But I could write volumes about comments.....and some are quite humorous.

It seems to me that common courtesy dictates that a visitor can ask questions and make positive comments, but a visitor should never criticize or otherwise put down a modeler's efforts. Now, a visitor is free to think critically, but he should keep those thoughts to himself.

Rich

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Posted by jjdamnit on Sunday, January 15, 2017 11:46 AM

Hello all,

My pike is a 4'x8' table top in HO scale; basically an oval with sidings and an curved 3% rise to a coal unloading platform to a spiral trestle back to the main line.

I super elevate the ends of the oval and not the incline. I use sections of coffee stir sticks that are 3/64-inch (0.05-inch) thick along the outer edge of the curves.

The ballast fills in the gap from the roadbed to the ties. I do not use transition shims but rater let the ballast provide the requisite transition slope to 0º.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by Arto on Sunday, January 15, 2017 5:07 PM

richhotrain

 

 
7j43k
 
 
Arto
If I ever build another layout I would prefer to have 60" radius minimum for mainline. 

Total endorsement from this location!!!!

Ed 

 

 

I won't argue the point, but a 60" radius is going to require a 10' wide area to turn a train around at the end of the layout.  In my mind, a 48" radius would be more than enough. Ha, currently, my layout employs 32" radius curves.

 

Rich

 

Yes, but one must take into account what kind railroad & era is being (desired) modeled (as in it may never happen for me).

I like prototype. I like passenger trains and big locomotives. AT&SF and PRR (my first two Lionel as a kiddie).

I have an S-curve on my layout with radius of about 48" and passenger cars/large locomotives still don't look good enough for my taste. In fact, I'm not sure I would be satisfied with 60"R.

If I stay where I'm currently living there will be absolutely no 60"R min. mainline  ever. If I move to where we are thinking of, one of the criteria is space/proportions for a RR with larger radius curves. OTOH, may just buy a condo within walking distance to my favorite local club Stick out tongue

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Posted by ATLANTIC CENTRAL on Sunday, January 15, 2017 5:29 PM

The great Paul Mallery suggested that 48" radius in HO was the most desirable minimum radius for modeling any Class I system. It was from his recomendations that the current modular standard of 48" radius was developed.

In my more recent track planning and layout building efforts I have avoided space consuming turnback loops as much as possible prefering to place the viewers and operators inside of an "around the walls" continious plan, even if it involves peninsulas that go out into the space.

This approach conserves the space commonly used by loops, loops on peninsula ends have good access and make use of all the space for scenery, and most curves are viewed from the inside rather than the outside, were the sharpness of our model curves is less noticeable.

And even with all that I consider 36" to be the bare minimum and try to get as close to the 48" mark as possible, also using some even larger curves in "cosmentic" locations rather than straight track.

All curves less than 90 degrees are continous spiral easements back to back. Mainline curves are superelevated, all curves have easements.

Mainline turnouts are all #6 and #8, or larger......

And even with these track standards I avoid 80' passenger cars in favor of shorter versions and limit steam locos to those with a rigid wheelbase of about 20 scale feet.

The combination of curves 36" and larger, good easments, and passenger cars mostly in the 72' range creates a very good visual effect. All my passenger cars are close coupled with working/touching diaphragms.

Sheldon

    

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Posted by 7j43k on Sunday, January 15, 2017 6:04 PM

One nice thing about using a 48" minimum radius is that it pretty much matches the prototype.

The turning loop for WP passenger trains in Oakland was about 48".

A DD40AX with train had a min rad of 50".  Same for their U50C.

UP and NP Challengers were 40".

GN 2-8-8-0's and 2-8-8-2's were 49.5".

PRR T-1's were 49.5".

SD70MAC with train 38".

So, GENERALLY, 48" should handle most everything.  Barely.  Even if you have all the various pipes and stuff hanging down and/or connected.  And prototype spacing between bits and pieces.

Please note that word "minimum".  I've got a test track with 48" curves.  And, to tell the truth, a string of passenger cars really does look kind of awkward.  If I was lucky enough to have an airplane hanger for my layout, I'd certainly have my mainline curves wider, maybe 7-8 feet.   

But, going the other direction, with my 48", I don't HAVE TO buy those silly articulateds with diesel truck mounting.

 

Ed

 

 

 

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Posted by ATLANTIC CENTRAL on Sunday, January 15, 2017 6:32 PM

7j43k

One nice thing about using a 48" minimum radius is that it pretty much matches the prototype.

.........

But, going the other direction, with my 48", I don't HAVE TO buy those silly articulateds with diesel truck mounting.

 

Ed

 

Ed, the funny thing is, those articulated locos with the "diesel like" swivel, don't look like both engines are swiveling by the time you get up to 40" or 48" radius......

Because they swivel at the middle of each wheelbase, the lead truck and platform swing out way more than any movement in the rear, so on large curves they look pretty natural and apparent movement of the rear engine is not noticeable - unless you are really searching for it. 

They actually make large curves look larger.

On sharp curves, they do look rather funny.......

Sheldon

    

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Posted by 7j43k on Sunday, January 15, 2017 6:41 PM

Sheldon,

Yeah, I agree they generally look less-worse on wider curves.  But the other irritating thing is that they have also removed the steam supply pipes for the rear engine.

Ed

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Posted by ATLANTIC CENTRAL on Sunday, January 15, 2017 7:54 PM

7j43k

Sheldon,

Yeah, I agree they generally look less-worse on wider curves.  But the other irritating thing is that they have also removed the steam supply pipes for the rear engine.

Ed

 

Agreed, some are better than others in that regard. I must admit I have a small fleet of them, never could justify the cost of brass in my own mind - or I simply decided it was more fun to have more locos, so $1200 buys four rather than one.....

Actually if I dollar cost average my fleet of eleven plastic/diecast articulated locos, my average price is only $190 (picked up several at some super bargain prices), and they all run good and look good, for that I will accept a few compromises. Of course I have had some of them for more than a decade, and they are all DC without sound.

And thinking about the fact that I have eleven of them, I'm thinking eleven is enough......well, maybe one more, so the lone EM-1 can have mate......

Sheldon

    

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Posted by wojosa31 on Monday, January 16, 2017 12:24 PM

Superelevation, is an engineering term, used by railroad, and highway civil engineering people. The PRR CE 78 is also the only PRR document that referrs to a switch as a turnout. All the operating manuals (CT400 Book of Rules, for instance), refer to switches at switches. [As you can see, I'm an operating guy, not an engineering guy Smile]

Back to the topic, superelevation, is a two edged sword, both on the prototype and the model railroad. The higher the passenger train speed is , the higher the superelevation. On slow speed rail, that is 30MPH or less, there is little or no superelevation.

Model railroad application is actually similar. My current layout is an urban industrial railroad representing two parallel branches both maxing out at 15MPH. While my main line curves are 30" and 32" radius, there is no reason to superelevate these curves for switchers and road switchers, and '60s era freight cars running at 10 scale MPH. However, if you are modeling main line operation, then superelevation is a useful tool.

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Posted by E-L man tom on Monday, January 16, 2017 3:10 PM

jjdamnit

Hello all,

My pike is a 4'x8' table top in HO scale; basically an oval with sidings and an curved 3% rise to a coal unloading platform to a spiral trestle back to the main line.

I super elevate the ends of the oval and not the incline. I use sections of coffee stir sticks that are 3/64-inch (0.05-inch) thick along the outer edge of the curves.

The ballast fills in the gap from the roadbed to the ties. I do not use transition shims but rater let the ballast provide the requisite transition slope to 0º.

Hope this helps.

 

I use the same method of superelevation, except I use 0.040" thick strips of styrene. I place approx. 1" strips, spaced approx. 7-8" apart along the outside edge of the ties on my flex track. leaving about 10-12" of a 0" superelevation at the end of the curve for the easement transition. I've found that if you don't have this transition far enough from the end of the curve it will cause derailments on some, but not all pieces of equipment. That said, I don't glue these shims down so that I can adjust the placement of them after test running. Mine is a branch line, so superelevation of the curves is minimal. Needless to say, I don't use any type of adhesive to fasten my track to the roadbed, only track nails. 

Tom Modeling the free-lanced Toledo Erie Central switching layout.
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Posted by xdford on Monday, January 16, 2017 9:01 PM

I would just like to say thanks to both Howard and Tom as I have recently relaid the outer curves on my 4x8 with set track of compounding radii to replace the Peco flex that finally started to show its age.

Following your examples, I cut some strips of .030" and there is a marked difference in the appearance of the trains going around the curves before I paint the track sides and ballast the area! Some extensive testing is being done when I can venture down the shed as it is pretty hot here at the moment!

Cheers from Oz

Trevor

 

 

 

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Posted by Metro Red Line on Tuesday, January 17, 2017 1:04 AM

I've done the exact same thing on my layout, except I do N scale and use .020" styrene strips. I use a mix of .015" and .010" styrene strips, and thin strips of masking tape to do my transitions. 

 

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