After seeing this quote in another thread and knowing it not to be correct...
riogrande5761every modest home layout in MR magazine since the early 1980's had 30 inch minimum curves, I've always considered anything much less than is getting into the sharp range
I decided to do a little homework to see what the MR Trackplan Database could tell me about this.
I collected the specified minimum radius on layouts from the 100-300 square feet category (this sounds "modest" to me). I left out narrow gauge layouts, layouts where minimum was not specified, and one 400_ sq.ft. layout that was in the wrong group. Where a mainline and any other radius was specified, I used the mainline number. I ended up with 82 layouts.
Of the 82,
60 had a minimum radius less than 30"
22 had a minimum radius of 30" or more
The median radius was 24"
I think it's interesting that this still matches up with John Armstrong's numbers of 18, 24 and 30 for sharp, conventional and broad.
I knew going in that every layout wasn't 30" or greater, but I was a little surprised to see that it was only 27%.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
I would think the radius of curves is determined not only by the room size, but also what you are running. And by what time period your railroad is set in.
SouthPenn I would think the radius of curves is determined not only by the room size, but also what you are running. And by what time period your railroad is set in.
When I forget to post messages like a lawyer and use absolutes like "every", I frequently get burned. Chalk another one up - it will help me to choose my words more carefully next time. And of course, undefined words like "modest" can have ways of developing a life of their own. Modest is to one person maybe different to the next.
I think that it's still worth noting that it has really stood out to me after reading many articles that 30-inches minimum radius came up over and over as the dominant standard. That said, I didn't base my comments on a track plan data base but by the many articles I read since the 1980's in MR magazine, and it stood out to me that 30" was the standard minimum I saw repeated over and over in sizable layouts. And frankly I"m too lazy to go do an exhaustive study of what magazines I still have left - I'm going to enjoy my free time doing other things thank you. Probably tweaking the parameters of a survey, I'd guess the average minimum may very well increase - cause my memory isn't that bad.
Smaller minimums seem to remain popular, probably due to space limitations but also probably because of old fashion standards seem to linger including that old 4x8 straight jacket. I still argue strongly that you aren't doing yourself any favors. It's always ALWAYS a good idea to try to increase your curve minimums as much as you can manage to make your trains look better and operate better.
It reminds me of a tech forum of I've been a member of for years, people come in and ask for advice on flat screen TV's and how big they should get. A similar sort of advice exists there too, whatever TV size you think will be big enough, go a least one size bigger because you ultimately will wish you did after the fact. Same goes for model trains. If you think 22-inch curves will do, sure, you might be able to get your trains to stay on the tracks reliably, but how will they look? Will you wish you chose larger. But as the old saying goes, YMMV. I am never satisfied with sharper curves and even 32-inch I've chosen look quite sharp under 89' flat cars or autoracks.
I feel that since John Armstrongs day when sharper curves were more the norm, things have changed and since then it's becoming more and more popular, at least among the progressive modelers, to up the radii of what they find satisfying touse. I still argue that the better terminology would be:
18" curves - very sharp24" curves - sharp30" curves - conventional40" and above - broad (an arbitrary number based on nothing in particular.
Well, maybe I've been reading too many progressive type of articles and forums, such as MRH where there was a study done on what curve radii and what is necessary to make model trains look good on those curves. They came up with a series of formulars on car length vs. curve radii and I found it very though provoking! No we can't always have those ginormous radii that make our models look more prototypical, but it definitely drives home a major point, bigger where possible is better.
Rio Grande. The Action Road - Focus 1977-1983
carl425I collected the specified minimum radius on layouts from the 100-300 square feet category (this sounds "modest" to me). I left out narrow gauge layouts, layouts where minimum was not specified, and one 400_ sq.ft. layout that was in the wrong group...I knew going in that every layout wasn't 30" or greater, but I was a little surprised to see that it was only 27%.
I suspect Jim's working definition of modest size is actually at the top end of your range of modest. Point being, where there's space, people prefer to go wide. if you reran the data as min R vs SF and included layouts up through 500 to 600 SF, the relationship he was pointing out tends to hold up. Obviously, some caution about absolute statements is recommended , but aside from semantics the point remains that people generally don't build big layouts with small min R unless they're doing traction. Even in narrowgauge, larger than 24" is preferred if you have the space for it...and we're obviously talking HO here, as O and N would be at opposite ends of this spectrum
Mike Lehman
Urbana, IL
riogrande5761When I forget to post messages like a lawyer and use absolutes like "every",
Your posts don't need to look like they were writen by a lawyer, but they don't need to look like they were writen by a radius snob either.
riogrande5761That said, I didn't base my comments on a track plan data base but by the many articles I read since the 1980's in MR magazine
The Track Plan Database comes from the articles in the magazine. Every plan lists the issue that it appeared in.
Also the minimum is listed, but that doesn't necessarily mean that all or even most of the curves on the layout are that tight. I am at 200 sq ft and my minimum is 24" so right in the center of the pack. But, most of the curves are more like 30" or greater and I have easements into the few sharper ones. My EM-1 may not look good on the tighter curves but most of the time it looks fine and I have no derailment issues anywhere regardless of what is running.
Personally I didn't want to give up desired features just to keep all of the curves broad. Now if I was working on a 400+ sq ft layout that would probably change things. I bet many of those here would say the same.
Huntington Junction - Freelance based on the B&O and C&O in coal country before the merger... doing it my way. Now working on phase 3. - Walt
For photos and more: http://www.wkhobbies.com/model-railroad/
mlehmanif you reran the data as min R vs SF and included layouts up through 500 to 600 SF
I assumed Jim's definition of "modest" to mean about the size of his own layout which as I recall is 18 X 10 - 180 sq ft. My definition is "spare room" sized, which fits what I thought Jim was suggesting. 600 square feet is 20 x 30 - not a modest layout.
carl425 riogrande5761 That said, I didn't base my comments on a track plan data base but by the many articles I read since the 1980's in MR magazine The Track Plan Database comes from the articles in the magazine. Every plan lists the issue that it appeared in.
riogrande5761 That said, I didn't base my comments on a track plan data base but by the many articles I read since the 1980's in MR magazine
Ah, so that includes back to the 1930's or way back when the magazine started. Hmm... so why don't you break that data base up into time slices and see if the minimum radius average increase over time. That would be interesting to see; you see I was only basing my memories and thoughts on articles I've read since the early 1980's or so. It's very possible as model railroaders got more progressive and had garage or modest basement, my guess is you'll find the average minimums may be higher. It would be interesting to see.
Oh, and my idea of modest is something, lets put a rough number on it, thats bigger than 200 square feet, just to throw out a number. My smallish basement room for my smallish sized layout is 10x18' - I settled on 32" minimum.
riogrande5761Ah, so that includes back to the 1930's
Nope. It only includes back to the point where the magazine was produced digitally. I'm not sure of the exact date that started, but it was way after the 80's.
riogrande5761why don't you break that data base up into
Yep, that would be interesting, but our friends at MR use the term "database" rather casually. "Folder" would be a more accurate description.
Crunching that data sounds like a great article idea for the statistically inclined among us...that's not me
mlehman Crunching that data sounds like a great article idea for the statistically inclined among us...that's not me
Are you sure? Aren't we all secretly afraid to learn that ours is smaller than average?
riogrande5761They came up with a series of formulars on car length vs. curve radii and I found it very though provoking!
That data was actually first posted on the Layout Design SIG's site and is a useful curve radius rule-of-thumb.
One of the things that has changed since the original publication of Armstrong's Track Planning for Realistic Operation is that real-life freight equipment and locomotives have grown in length (such as auto carriers). The rule-of-thumb helps estimate curve radius based on equipment length.
Having said all that, minimum radius is always a matter of trade-offs between the minimum needed for good operation, what looks good to the layout owner's eye, and what will allow a layout that meets the owner's concept and vision to fit in the room.
I recently completed a fairly large multi-deck custom HO plan for a client that is based in the modern era. Although he would have liked broader curves for appearance’ sake, we maxed out at 32” minimum on the visible layout and 30” in hidden areas. Horizontal easements will help with appearance and operation. We just couldn’t fit anything broader in the space without compromising on his desires for a long mainline run, etc.
John Armstrong once told a room of layout owners and designers that the only thing worse than a minimum radius that was too small was one that was too large. While he was speaking slightly tongue-in-cheek, I’ve certainly seen cases myself where folks sacrificed too much (IMHO) for a broader minimum radius than they absolutely needed.
Byron
Layout Design GalleryLayout Design Special Interest Group
cuyama riogrande5761 They came up with a series of formulars on car length vs. curve radii and I found it very thought provoking! That data was actually first posted on the Layout Design SIG's site and is a useful curve radius rule-of-thumb. One of the things that has changed since the original publication of Armstrong's Track Planning for Realistic Operation is that real-life freight equipment and locomotives have grown in length (such as auto carriers). The rule-of-thumb helps estimate curve radius based on equipment length.
riogrande5761 They came up with a series of formulars on car length vs. curve radii and I found it very thought provoking!
To be fair, 89' foot flat cars and autoracks were being used in the 1960's, and private passenger operations were still going too (85' long) so it seems that John Armstrongs book, which I reverently keep and reference, would have been written at a time when those should have been included for consideration in track planning. Certainly passenger cars, which is why John argued for at least 24 inch curves in a world where many home hobbyists were still thinking 18 and 22-inch curves. Granted, other than scale length passenger cars, long HO train cars such as autoracks and TOFC flat cars were pretty rare in those days. We really didn't start getting lots of 89' freight cars in HO until the Walthers and Schaffer Rails auto racks hit the market, and soon after Accurail 89' flat cars.
Yep yep on easements - I use them too on my 32" curves etc. And yes, of the more recent built large layouts, 30 and 32 inch curves still often end up being the minimums - which certainly should work well for smooth operations as long as some fincky stiff wheeled brass isn't introduced. I had a set of Kumata CIL/OL/HCB brass California Zephyr passenger cars and depending on the car, some would not handle a 32 inch curve, but would do a abit bigger and negotiate it. That last layout I had with those cars I designed with a 33-inch minimum, and was praying I could be ok running them. It was torn down and I sold off the brass CZ cars in favor of the BLI cars, which I now have.
I always loved Johns sense of humor. His answer to the broad curve was to include one or two scenic curves with a very broad radius, that you could enjoy long cars on and have them look nice - then everything else was a reasonable minimum that would allow you to run all your equipment smoothly and reliably, which most historically seem to put in the 28 to 32 inch range as a minimum.
John's, point of course, regarding settling for too large a radius is well taken as you need to be able to work with a space and get a track design into it that allows for maximum use and operationability etc. I find that it's not usually a problem it this forum that people are using too big a radius; if anything the universal problem is the opposite, they are trying to shoe-horn trains around as tight a curve as they can manage - usually in the 18 and 22 inch variety, which sure, nock yourselves out.
Very often, people who have room for a layout that can take 18 & 22 inch curves, can sometimes manage to add a little more width to get curves up a little more and open up their ability to operate some longer cars well - even 24 or 26 inch minimums are a major improvement IMO. Think out of the bun, er out of the taco shell, er out of the 4x8 straight jacket! Be free my minions! =P
riogrande5761everything else was a reasonable minimum that would allow you to run all your equipment smoothly and reliably, which most historically seem to put in the 28 to 32 inch range as a minimum.
Did you read the part of Byron's post about choice and trade-off's?
You need to get over this idea that your preferences need to be everybody else's standards. I for one don't give a damn about auto racks or passenger cars. From the track plan data it looks like MOST others with room sized layouts like you and I have don't care about them either. And these are not average layouts we are talking about. They are layouts good enough to be featured in MR magazine.
I am willing to limit my rolling stock inventory rather than having to settle for a boring donut of a layout. It is a choice for us all to make for ourselves.
Carl, why the negative vibes here? I like 1970's and 1980's rolling stock which includes some long rolling stock. I also think there is merit to pushing the boundaries - it seems like your taking things kind of personally here - sorry if you think my donut layout is boring. Merry Christmas I guess.
Retired statistician speaking. IMHO, compiling statistics on minimum radii on X layouts published in MR over Y years is simply wasted motion. Each of those layout owners had a set of givens and druthers different from all others. Comparing them isn't comparing apples to oranges, it's trying to find meaningful data in fruit salad.
I have a fixed, finite layout space. I have also tested all of my rolling stock for minimum radius capability, individually and coupled into reasonable trains. The result was incorporated into my planning, which calls for minimum 610mm (24 inch) mainline curves. I could just as easily have devised plans with 30, 42, 48, 56.5 or 72 inch minimums, which would have wasted space and made it impossible to include the prototype features I wanted.
I also have a short line with 350mm (14"minus) radius curves, which runs short (or very flexible) cars and locomotives to match. Only one thing forced that on me - I WANTED it that way!
Note that I do not run humongulocos, TTX flats or 89 foot hi-cubes. My curves suit my prototype rolling stock. The fact that Sheldon's curves are wider is totally irrelevant to me. He has his standards, I have mine. Presumably you have yours. If not, develop them based on rational considerations, not on a meaningless statistical average.
Chuck (Lone wolf modeling Central Japan in September, 1964)
riogrande5761Carl, why the negative vibes here?
Sorry, I did not mean to insult your layout. I was referring to the boring donut I would have had to build if I had insisted on a 30" minimum radius.
My point is simply that no specific number makes a good or bad radius. It is only good or bad when you take into account the other choices that Byron pointed out.
Merry Christmas to you too. Maybe Santa will bring you one of those WW2 German rail guns to run on your big curves. I'll be looking for a bobber caboose.
Come down to Richmond some time and I'll show you what I'm doing and explain how and why I got there.
The Maryland and Pennsylvania was noted for sharp curves including one that was 20 degrees which is equal to 39 inches in HO. And 54 inches in S scale which I am using.
I am building the first phase of my layout in a 12x31 foot space. Testing has demonstrated that short cars and engines typical of the early 1950's Ma&Pa will run quite nicely on 24" radius curves. But I have been able to increase that to 27 inches (just in case a future acquistion requires a little extra) and still have a central peninsula. I can't run 80 ft passenger cars, but then the Ma&Pa couldn't either. My longest car will be a 56' open platform passenger car.
In my case the sharp curves are in keeping with my prototype.
Enjoy
Paul
Hi Chuck,
tomikawaTTRetired statistician speaking. IMHO, compiling statistics on minimum radii on X layouts published in MR over Y years is simply wasted motion. Each of those layout owners had a set of givens and druthers different from all others. Comparing them isn't comparing apples to oranges, it's trying to find meaningful data in fruit salad.
The intent was never to present any meaningful statistical analysis, just to point out that minimum radius is a choice arrived at by careful consideration of an individual set of givens and druthers and the choice made by most individuals that built publication worthy, spare room sized layouts, was a number less than 30.
I know it's not the Diner, but how about a round of Christmas cheer for everyone!?!
Carl,
Sound slike you have your preferences, too. If min R isn't one, something else often is. There's value in everyone's opinion here, I'm pretty sure.
tomikawaTTRetired statistician speaking. IMHO, compiling statistics on minimum radii on X layouts published in MR over Y years is simply wasted motion. Each of those layout owners had a set of givens and druthers different from all others. Comparing them isn't comparing apples to oranges, it's trying to find meaningful data in fruit salad...My curves suit my prototype rolling stock. The fact that Sheldon's curves are wider is totally irrelevant to me. He has his standards, I have mine. Presumably you have yours. If not, develop them based on rational considerations, not on a meaningless statistical average
Well, BTDT, Chuck.
Sure wish I'd had the option of making the "too wide" mistake.
But I don't think it's a meaningless as you think. A while back, there was a discussion somewhere here on the other side of min R coin, which is the considerable increase in SF of the average US family home. Obviously, everyone doesn't live in an average home or can use it all for the layout...kids, wives, pets all have to share also.
All joking aside, knowing what the average min R is could help folks who've never built a layout and, ahem, feel somewhat inadequate in terms of the space they have available get more comfortable with the space they do have. Sometimes, being happy in life is about adjusting expectations.
Such data, while not really able to give conclusive guidance on what any single individual should do, at least provides the perspective for them to consider as guidance in what reasonable curve min R they should consider.
I'm a big fan of not reading too much into your data, but I think such an exercise would also show the influence of changing life styles, house designs, and prototype changes on layout design. YMMV
I would postulate that curve radius has been influenced by many things. Like the most popular era to model is the 1950s, it's shorter rolling stock. The largest snap track radius is 24" to fit nicely on a 4'x8' sheet of plywood. The 4'x8' sheet of plywood layouts. (didn't everyone have one?) The decade the layout was built: the plethora of couplers that were available and non interchangeable or compatible; couplers attached to the trucks; large steam engines that had flanges on all drive wheels or not; and the overall quality of the available equipment.
There are too many variables to consider.
Remember too that the mind is good at remembering that which we can relate too. Remembering seeing a curve radius that is at or about what you use is perfectly normal. Forgetting those layouts with curve radii that is different from what you use is normal too. The human mind is built to work that way. I can recall many of the layouts featured in MR in the recent past that involved steam, especially in the north-eastern US. Is what I model. Ask me to remember a diesel layout set in the west? Not happening without seeing the article again.
Mike
Water Level RouteRemember too that the mind is good at remembering that which we can relate too. Remembering seeing a curve radius that is at or about what you use is perfectly normal.
An interesting observation. Kind of a variation on a theory I heard the other day on the popularity of the cable news networks. "People seek out news coverage that affirms them, not coverage that informs them".
carl425 Water Level Route Remember too that the mind is good at remembering that which we can relate too. Remembering seeing a curve radius that is at or about what you use is perfectly normal. An interesting observation. Kind of a variation on a theory I heard the other day on the popularity of the cable news networks. "People seek out news coverage that affirms them, not coverage that informs them".
Water Level Route Remember too that the mind is good at remembering that which we can relate too. Remembering seeing a curve radius that is at or about what you use is perfectly normal.
It's called confirmation bias. (Wow, I did remember something from those classes!) You must be referring to the Fox News vs. CNN debate. I hear about that one frequently at work.
Water Level Route carl425 Water Level Route Remember too that the mind is good at remembering that which we can relate too. Remembering seeing a curve radius that is at or about what you use is perfectly normal. An interesting observation. Kind of a variation on a theory I heard the other day on the popularity of the cable news networks. "People seek out news coverage that affirms them, not coverage that informs them". It's called confirmation bias. (Wow, I did remember something from those classes!) You must be referring to the Fox News vs. CNN debate. I hear about that one frequently at work.
Let's just let this particular side-issue die here, shall we?
--Steven Otte, Model Railroader senior associate editorsotte@kalmbach.com
SouthPennThe largest snap track radius is 24" to fit nicely on a 4'x8' sheet of plywood.
24" radius won't fit on a 4X8, since radius is measured to the center of the curve in scale model railroading and you also need a bit of room for safety at the edge of the benchwork.
4X8 sheets of plywood are the reason most sectional track makers offer a 22" radius in HO. Coincidentally, this makes the monolithic 4X8 not the ideal choice for modeling in HO, but that's another story.
carl425 After seeing this quote in another thread and knowing it not to be correct... riogrande5761 every modest home layout in MR magazine since the early 1980's had 30 inch minimum curves, I've always considered anything much less than is getting into the sharp range I decided to do a little homework to see what the MR Trackplan Database could tell me about this. I collected the specified minimum radius on layouts from the 100-300 square feet category (this sounds "modest" to me). I left out narrow gauge layouts, layouts where minimum was not specified, and one 400_ sq.ft. layout that was in the wrong group. Where a mainline and any other radius was specified, I used the mainline number. I ended up with 82 layouts. Of the 82, 60 had a minimum radius less than 30" 22 had a minimum radius of 30" or more The median radius was 24" I think it's interesting that this still matches up with John Armstrong's numbers of 18, 24 and 30 for sharp, conventional and broad. I knew going in that every layout wasn't 30" or greater, but I was a little surprised to see that it was only 27%.
riogrande5761 every modest home layout in MR magazine since the early 1980's had 30 inch minimum curves, I've always considered anything much less than is getting into the sharp range
Thanks for crunching the numbers. My 13x7' layout has a 28" max radius which can easily handle the SD45 loco.
In this case, the type of equipment dictated the curve. The opposite was true when I had a four-axle loco. I like having a broader curve becasue I can run many more consits and had room for an additional two siding tracks. Most important of all was the grudging War Dept. approval.
Everytime one of these discussions comes up, sooner or later it begins to seem like a "you're not a real model railroader if ..." with the sum total of those "ifs" being a relatively large layout (larger than the typical spare room in most tract homes). This included a discussion on how the average home size is larger. To be honest, I'm not sure that's completely correct (in that it, like Microsoft support, may be true, but also useless). For several reasons. The size of upper end homes has bloomed greatly which will take the average up, but the size of the typical home may not have followed suit. Also, I've noticed a trend today to count the basement, and sometimes the garage, to get an apparent square footage larger than the same house would have measured 20 years ago.
Many/most homes do not have basements. And of those that don't few even have dedicated spare rooms for a layout. I'd love to have a spare room. Maybe once both kids are grown and on their own. Right now I have a shelf along two walls; a total of 26 square feet. Not even as much space as the proverbial sheet of plywood. It has one curve of about 19 inches. While I'd love 30 inch radius, it's just not going to happen.
My point of this is a lot, maybe most, model railroaders have to deal with the constraints thrown at them. Especially new and potential modelers. I would not have become a model railroader if things had been like this 40 years ago. While there was too much nit picking over quality of workmanship, there wasn't the nitpicking over you're layout is too small. The workmanship question has pretty much gone away because so few scratchbuild anymore; everything is RTR. But the size question has not.
jim