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.
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.
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.
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.
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.
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.
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.
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 too
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.
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 w
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.
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.
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.
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.
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 [:P]
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.
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.
