what is considered a broad curve for HO? i have some 50 ft cars and 2 athearn gp 40s running on a 22 inch curve. looks unrealistic to me. im a big curve freak, but im used to n scale. im thinking at least 28 in radius. thanks…
In my mind, a broad HO curve would have a minimum of about 30 or 32" radius…but that’s just my opinion. No matter how much bigger you go, your equipment will look better on the bigger radius.
Don Z.
thanks don…im just trying to see if i can fit a nice curve through the walls of my around the walls shelf outfit. i already have n scale track running through there, but i cant shead myself of ho flashbacks! are you going to the temple, tx train show this weekend? im going sunday for sure…,…
JoeF posted this link before from the LDSIG
http://www.macrodyn.com/ldsig/wiki/index.php?title=Curve_radius_rule-of-thumb
Worked for me in HO and I run Gp 40’s w/ 50’ and 60’ cars
ratled
The Temple train show is cancelled due to Hurricane Ike evacuees living in the convention center. Save yourself some time and gas!
Don Z.
without this post, i would have driven 90+miles and then found out!!! i owe you one!!..thanks
yes sir!! that will work for me also. thank you for that info…
I have an HO around the room.
There is one section that is 4x8 three times around. It has 18" curves and snap switches. The subway has one 15" curve, but is has very short R-17 cars.
The rest of the layout has 30" curves and #6 switches.
If you’re going to a more generous curve you might want to consider a transition curve into your new larger curve(s). It will make the effect and performance of a given train even better. You might also consider super elevation of the new curve(s).
My minimum radius is 34", the maximum is 36", with slight transitions leading both in and out of the curves. Even at that, my 85’ passenger cars tend to look a little crowded at times, but my long-based steamers are VERY happy. [:P]
Tom [:)]
Don, you and the NMRA agree. They define ‘broad’ curve as 30" or better radius, 24" being considered the minimum for ordinary use. By that criterion, 22" radius is substandard.
If the viewpoint is inside the curve, a tight curve becomes more (visually) acceptable.
Proper spiral easements will make operations smoother on any curve down to the point where flanges crawl over the outside rail (or body-mounted couplers on long cars snatch shorter cars off the track sideways.)
Chuck (modeling Central Japan in September, 1964 - with easements)
The best senerio is a min radius that is 3 times the length of your longest piece of equipment. Anything smaller is asking for trouble, and anything larger is a bonus!
David B
I run 31 inch on the outside track and am contemplating a 34 incher. The Club railroad runs 36 inches with the Modular upwards of 40 inches, I think that has been cut back to 36, not sure.
I gave up alot of possibilities by using 31 inch track curves but I can run everything and not worry. (Not Brass, those are too expensive for me)
Curves in one way are like boats. If only my boat was two feet longer! Back when full length passenger cars hit the market in ehe 60’s MR repeatedly said 30" or bigger curves if they were to look right. My currently building railroad has 48" minimum and if I had the room it would be 60". Curves can never be too big a radius. In real life a 60" radius curve would be rated at 5 mph.
Remember this! Railroad surveyors had no place to tie a string for a radius! They measured the offset angle of a 100 foot chain in repeated steps. A 10 degree curve is pretty common in mountainous terrain and if on a grade would call for a speed reduction. It is helpful to remember that in HO a ten degree curve is 573 feet radius and that scales out to 88 inches! Way back in my plant engineering days I had occasion to get a local railroad’s specs for a spur I was planning into a warehouse. Their spec for minimum radius on an industrial spur was 12 1/2 degrees which is 459 feet and that scales to a fraction over 33 inches! Now do you see why many model railroads look toy like? And don’t forget to do the easements! jc5729 (the radius of a one degree curve) John Colley, Port Townsend, WA
After all the smoke and mirrors of what is the ideal curve size old reality sits in of available space.
Dreaming I would like 36" curves reaility I will settle for 18 or 22"-if I had the room for a HO layout.As it stands I am looking at 11" curves on my N Scale layout-yeah,I would perfer 24" curves-another pipe dream because of reality…
See how it works?
When I was first getting active in the hobby back in the early-to-mis-'60s one of my first acquisitions was a Kalmbach book titled “Practical Guide to Model Railroading”; this book gave specs for different scales–O; S; HO; TT–and for HO-Scale curves were defined as: Sharp–18"; Standard/Conventional–24"; Broad–30". In Kalmbach’s “101 Track Plans” they use the same standard adding a new spec for Extra Sharp–16.5".
I, of course, would advocate as others have that you use the largest curve you can fit into any location but if you want a layout with that minimum radius being a broad curve I would go with 30 inches.
On one of the clubs I belonged to there was one location where the mainline turned back about 200º on an 85" radius curve and trains looked absoulutely fantastic on it. Curves of that dimension are generally too large for home layouts although I once visited an HO-Scale layout on an NMRA tour that had several 60"+ radius curves. NTrak uses a 30" minimum which scales to 55 1/8" in HO-Scale.
I too am a
and the fact that an 18" radius curve in N-Scale–33 1/16" in HO-Scale-- is a broad curve was one of my primary motivations for converting from HO-Scale two and a half decades ago. I’m not sure exactly what your viewing angle is but using the NMRA 1:3 standard for freight cars your 50’:22" ratio is not out of line and you might just find that a view closer to trackside instead of one from a helicopter would improve the realism of your observations.
I’ve about Mainline 47’‘, branch 23’‘, industrial 19’’ at some spots.
With 23’’ some of the engines have problems, my friends bring with them at friday night.
Wolfgang**Mainline 47’',**Mainline 47’‘, branch 23’‘, industrial 19’’ branch 23’‘, industrial 19’’
fluff, you are correct, a 28" curve in HO is very generous…for most of us. If you are running passenger cars of quality longer than 75 scale feet, they won’t look all that generous. They’ll run fine if the tracks are well-laid, but those cars will look tightly wound on 28" curves. Imagine what long heavyweights look like on the stated minimums of 24"!
As a result, all of us have to fiddle with our druthers and plans until we can shoehorn into our available space something that we can live with. If we’re unlucky and self-limiting at the same time, we may have to fore-go operating some of our prized possessions on what results from all those compromises. But in the final analysis, the single greatest determinants of what constitutes a useful curve on any one layout is what we intend to run on the layout and what space we have to do it.
-Crandell
So an 85’ passenger car with couplers is a foot long(with mustard and pickled cabbage(pc gone mad!) please)and my curves need to be three feet which firmly places my track at the very edge of my space. There goes another rule for me to break! Good thing the NMRA police department doesn’t have a SWAT team.[:-,]