ATLANTIC CENTRALBut if no one has a discussion...
You mean like your first post in this thread?
ATLANTIC CENTRALBigger is better......... My choices, 36" minimum mainline, 48" prefered.
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.
carl425 BigDaddy More than 2 weeks since the thread started and the OP is no where to be found. Not even a "thank you I'll check those books out." This is a drive by thread. Maybe he decided based on the reply's that he didn't have room for a layout and gave up on the idea. I've seen would-be modelers scared off by the radius snobs before.
BigDaddy More than 2 weeks since the thread started and the OP is no where to be found. Not even a "thank you I'll check those books out." This is a drive by thread.
Maybe he decided based on the reply's that he didn't have room for a layout and gave up on the idea. I've seen would-be modelers scared off by the radius snobs before.
Possibly so. And, as someone who sold trains for years, I have seen people build layouts with 18" radius and then get frustrated because their 85' passenger cars will not stay on the track.
When told why they simply gave up and left the hobby.
Using smaller curves is fine, as long as you understand and accept the restrictions you are putting on yourself and the layout.
But if no one has a discussion.....and no one suggests why larger curves might be better.........
Sheldon
BigDaddyMore than 2 weeks since the thread started and the OP is no where to be found. Not even a "thank you I'll check those books out." This is a drive by thread.
More than 2 weeks since the thread started and the OP is no where to be found. Not even a "thank you I'll check those books out." This is a drive by thread.
Henry
COB Potomac & Northern
Shenandoah Valley
I really don't run passenger equipment, but am more freight oriented.
Even current production brass models run the gamut from steamers that are compact and specifically designed to operate on 24" radius to those that must have ahem, larger, radii (36" and up). It depends upon what the owner of the layout wants to run. Many brass 2-8-2 and smaller locomotives will negotiate "conventional" radii, depending upon how one chooses to define "conventional".
Do they look better on 30" or 36"? Sure.
Some of us cannot have all the curves that big--easements are your friend, use them.
John
cuyama I'm glad that my many of my layout design clients aren't as hung up on some folks on this thread seem to be on specific values for curve radius -- they wouldn’t be building and enjoying their layouts today. The selected minimum radius must serve the layout concept and fit the room. Many folks successfully build a model railroad without an expansive basement at their disposal. Easements help a lot. The Layout Design SIG’s curve radius rules-of-thumb, which were the basis for the MRH article, are an excellent place to start when making those trade-offs.
I'm glad that my many of my layout design clients aren't as hung up on some folks on this thread seem to be on specific values for curve radius -- they wouldn’t be building and enjoying their layouts today. The selected minimum radius must serve the layout concept and fit the room. Many folks successfully build a model railroad without an expansive basement at their disposal. Easements help a lot.
The Layout Design SIG’s curve radius rules-of-thumb, which were the basis for the MRH article, are an excellent place to start when making those trade-offs.
The only thing I am hung up on is close coupled passenger cars with working/touching diaphragms.
Layout Design GalleryLayout Design Special Interest Group
Armstrong covered that well too, with his "coefficient of lurch" (nothing to do with the Addams Family) where he demonstrated that a tighter radius curve with proper easements results in smoother operation than a larger curve without them.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
carl425 DrW In the prototype, curves below a radius of 870 ft are very rare; that would amount to 10 ft in HO. They have the unfair advantage of not having to turn before hitting a wall.
DrW In the prototype, curves below a radius of 870 ft are very rare; that would amount to 10 ft in HO.
They have the unfair advantage of not having to turn before hitting a wall.
The question is not having to turn before you hit the wall, the question is how close do you get to the wall before you start turning.......
Seriously, if one wants to run modern equipment, or if one wants to run passenger cars, something above 30" radius, and preferably above 36" radius, should be considered the minimum for the mainline. And they should be minimums, with any curves that can be larger, being larger for the visual effect.
All curves should have sprial easements, changes in direction less than 45 degrees parabolic curves (two easements back to back, no fixed radius), just like the prototype.
Just my views....
DrWIn the prototype, curves below a radius of 870 ft are very rare; that would amount to 10 ft in HO.
It is interesting to note that curve radius is probably the one item where the selective compression between model railroads and the prototype is most pronounced. In the prototype, curves below a radius of 870 ft are very rare; that would amount to 10 ft in HO. Taking it to the extreme, the standard curve radius on new high-speed tracks is 4000 m for 300 km/h (186 mph), and up to 7000 m for higher speeds. 4000 m equals around 13,000 ft; in HO, this would give you about 150 ft (feet, not inches).
rrinkerThere's a guy posting in the LDSIG and Layout Construction groups on Yahoo who seems to think he needs 48" radius minimum for N SCALE which is just insane -
And awsome looking if he can get away with it! =p
Pushing the limits is great but in the end I want to have a workable raillroad and I only have so much space. If I had a hanger to build in? Sure I'd go 60" minimum radius and no turnouts smaller than a #10. I haven't seen a model made yet that REQUIRES those sort of dimensions (in HO). Sure it would look nice, but can I build a practical layout in my basement if I used 60" radius curves? If all I wanted was a giant version of your basic oval, I could do it. --Randy
Hence why John Armstrong always did a "givens and druthers". Context is the key here; no air craft hanger? It's common sense that model railroading is all about compromises, although some might be able to kick up the radius a couple of inches without a major change to a track plan.
Rio Grande. The Action Road - Focus 1977-1983
A big part of that change in radius classification is the trend to bigger equipment by the prototype. In the 50's even the real railroads didn't have 89 foot articulated auto racks. The trends didn;t follow exactly liek today, but in the 50's there were a lot more people modeling the 1920's and earlier, which had even SMALLER equipment than the then-contemporary 50's railroads. Modern stuff is just HUGE. An RS3 looks small next to an SD70ACE or AC4400CW. Just like a 1910 Consolidation looks small next to a late steam era 4-8-4's.
Since I model the 50's with predominantly 40' box cars (and shorter hoppers), 30" radius curves will be just fine - that's the 5x car length figure. There's a guy posting in the LDSIG and Layout Construction groups on Yahoo who seems to think he needs 48" radius minimum for N SCALE which is just insane - although the style of his postings makes it hard to understand what he's trying to say. Pushing the limits is great but in the end I want to have a workable raillroad and I only have so much space. If I had a hanger to build in? Sure I'd go 60" minimum radius and no turnouts smaller than a #10. I haven't seen a model made yet that REQUIRES those sort of dimensions (in HO). Sure it would look nice, but can I build a practical layout in my basement if I used 60" radius curves? If all I wanted was a giant version of your basic oval, I could do it.
My observations were correct for me and not meant to contradict any "databases"; I gravitated to articles I found the most inspirational to me personally (e.g. Eric Broomans Utah Belt, David Barrows CM&SF), and many other articles of that caliber) and noticed remarkably consistant pattern of 30 inch minimum radius listed in the layout information tables. It bespoke that quite a few trend setters in the hobby appeared to also be setting some standards in minimums, at least in that class of layout.
Personally I think there are some major advantages to pushing the boundaries if layout design and making curve radii a priority as much as possible. Joe's article mentioned above gives "legs" to it.
Using transition curves you can get away with a tighter radius.
riogrande5761I have noticed the majority of moderate sized layouts in MR magazine articles have minimum radius curves of 30". Noting that trend, it might be appropriate to update the terms:
Yeah, maybe if your observations were correct. This is like the situation we have today with cable news - people seek out the news that agrees with their point of view. If you look at the track plan database and do the math like I did, you'll find the median minimum radius for modest layouts is 24".
I do agree that the work done by the Layout Design SIG that Byron mentioned earlier and was the source for the MRH article you quoted is the best advice available today.
IRONROOSTERJohn Armstrong was oriented towards the folks who had smaller spaces and the attendant tradeoffs between things like curve radii and railroad like operations. The first edition of Track Planning for Realistic Operations included several examples of how to modify some of the published plans of the day to improve their operating capabilities. Sure 36" or 48" minimums are nice.
I bought John Armstrongs book back in the 1980's and it has been a major help in my designing and building 3 layouts so far. But keep in mind, not only was John Armstong dealing with smaller spaces and "givens and druthers", he was also a product of times when standards were simply oriented around sharper curves.
For example, in his book he refers to 3 major classes of curves by the folloing terms (from memory):
18" Radius - Sharp24" Radius - Conventional30" Radius - Broad
Just my observations but since the mid-late 1980's and after, I have noticed the majority of moderate sized layouts in MR magazine articles have minimum radius curves of 30". Noting that trend, it might be appropriate to update the terms:
18" Radius - very sharp24" Radius - moderately sharp30" Radius - conventional42" Radius - broad
Of course many modelers still have to contend with limited space and use old style sectional track curves such as 18" and 22" radius, but it does limit the rolling stock being run and beyond that, appearances of rolling stock can be impacted as well. There is a great article written by Joe Fugate on that subject in the January 2009 MRH issue.
http://model-railroad-hobbyist.com/mrh2009-01/curve_insights
Some rules of thumb are discussed in the article which point out that the curve ratio is a factor of the length of rolling stock. By way of example, a 40 ft box car, which is 43 scale feet over the coupelrs (5.9 inches). If you multiply that by 2, you get 11.8 inches - so basically a 12 inch curve will allow a 40' box car to track, but just barely. If you go to 3x the length, you get an 18 inch curve for reliable tracking. Those 40' box cars would look less toylike when viewed from the outside of a 24 inch radius curve. See the list below - measure the length of your rolling stock and do the match to see where it falls.
2.0 x Some equipment may track reliably, but 2x is generally considered pushing it.
2.5 x Most equipment will track reliably if everything is of similar length.
3.0 x All equipment should track reliably; coupler performance adequate if altered to allow 50% car width swing.
3.5 x Equipment will look less toy-like when viewed from inside the curve.
4.0 x Equipment will look less toy-like when viewed from outside the curve.
5.0 x Most reliable coupling on curves with body-mounted couplers and near-scale draft gear boxes.
Paul Mallory was oriented towards club layouts (and very large home layouts). John Armstrong was oriented towards the folks who had smaller spaces and the attendant tradeoffs between things like curve radii and railroad like operations.
The first edition of Track Planning for Realistic Operations included several examples of how to modify some of the published plans of the day to improve their operating capabilities.
Sure 36" or 48" minimums are nice. But the reality for most of us is that those minimums are either impossible or leave us with a loop of track and little else.
Many of us would do well with talgo trucks and deep flanges. That's how Lionel O27 trains get around a 13" radius curve.
Paul
carl425 ATLANTIC CENTRAL Paul Mallery, another great from back in the day, had a little different take on radius than Armstrong in his Trackwork Handbook I'm sure you don't mean to imply that Armstrong was a proponent of tight radius curves. This is not the case. He was about understanding your options, how one choice impacts others, and finding the best compromise that would allow you to satisfy as many of your desires as possible while dealing with the reality of available space. OTOH, like we have in all evdeavors where human males participate, there are those in this hobby who are always looking for the opportunity to say "mine is bigger than yours". ...and BTW, I do not mean to identify any specific individual as a member of this group.
ATLANTIC CENTRAL Paul Mallery, another great from back in the day, had a little different take on radius than Armstrong in his Trackwork Handbook
I'm sure you don't mean to imply that Armstrong was a proponent of tight radius curves. This is not the case. He was about understanding your options, how one choice impacts others, and finding the best compromise that would allow you to satisfy as many of your desires as possible while dealing with the reality of available space.
OTOH, like we have in all evdeavors where human males participate, there are those in this hobby who are always looking for the opportunity to say "mine is bigger than yours". ...and BTW, I do not mean to identify any specific individual as a member of this group.
No, it is not a criticism of Amrstrong, just pointing out that other leaders in the hobby had somewhat different opinions.
And even 50 years ago or longer, a fair number of people did understand that better operation and better appearance was acheived with larger curves.
And, it plays along with a concept I support, there is a difference between a large layout and a complex one. A layout may occupy a somewhat larger space to allow larger curves, longer yard and sidings, etc, without being anymore "trackwork intense" than a layout others would have in a smaller space.
BMMECNYC Here is a good starting point. http://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-11.pdf
Here is a good starting point.
http://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-11.pdf
We could debate this till the cow's come home. BMMECNYC's advice is sound and rather than the starting point should be the end point. Recommended Practice 11 very clearly indicates appropriate rolling stock for what ever radius you have. Seems simple enough that once you know what your limiting radius is, you know what type of railroad you can model. If there's a disconnect between what you have and what you want your choices are to either change scales or find a larger space.
Ray
ATLANTIC CENTRALPaul Mallery, another great from back in the day, had a little different take on radius than Armstrong in his Trackwork Handbook
Well, the OP hasn't chimed in since his first post on Feb. 27. Hopefully, he's read some of this, and decided accordingly.
Mike.
My You Tube
BMMECNYC Creative Layout Design, by John Armstrong covers this whole curve radius thing well. As does Track Planning for Realistic Operation, also by John Armstrong. The latter is in print. The former I stumbled upon on consignment in my LHS. Paid original cover price. Even had the original sales slip still in it. I should find mine and put it in there for posterity.
Creative Layout Design, by John Armstrong covers this whole curve radius thing well. As does Track Planning for Realistic Operation, also by John Armstrong. The latter is in print. The former I stumbled upon on consignment in my LHS. Paid original cover price. Even had the original sales slip still in it. I should find mine and put it in there for posterity.
Paul Mallery, another great from back in the day, had a little different take on radius than Armstrong in his Trackwork Handbook.
He lobbied for much broader curves for HO trying to represent Class I mainlines, with 48" being the desired goal for mainlines.
A target I am getting close to with my current layout rebuild, with 36" as my minimum mainline.
40' cars or less and 44ton/0-6-0s/HH660s and Alco S1s. 18" for pier tracks, other sidings between 18-22. Largest planned radius at the moment is somewhere around 55" in one or two places. Layout plan is being professionally critiqued.
BMMECNYC Fair enough. I use 18" radius for spurs.
Fair enough. I use 18" radius for spurs.
Ah. I see you are going with prototype curves!
A Baldwin 660HP diesel switcher could do 16.5" with train (presumably 40' box). And 6.9" by itself, FWIW.
A UP SW10 could do 14.5". That's probably without train.
A BNSF GP15 is 16.5 singly. And 23.5 with a second unit coupled.
Ed
BMMECNYCFair enough. I use 18" radius for spurs.
Good point. Many model railroaders make the mistake of seting a min radius for the main line and using it everywhere. On spurs and in industrial areas the prototype may have curves that modeled in scale would make many model railroaders cringe.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
jjdamnit Hello all, Lone Wolf and Santa Fe Here is a list I made up of minimum radius for different type of equipment. Toys = 18” Most scale models = 22” Scale models with accurately detailed fames and coupler pockets = 24” Steam Locomotives = varies up to 30" or more. The quote that 18-inch radii is for toys! Seems to be nay saying to me. Hope this helps.
Hello all,
Lone Wolf and Santa Fe Here is a list I made up of minimum radius for different type of equipment. Toys = 18” Most scale models = 22” Scale models with accurately detailed fames and coupler pockets = 24” Steam Locomotives = varies up to 30" or more.
The quote that 18-inch radii is for toys! Seems to be nay saying to me.
Hope this helps.
18" radius was the HO standard for years. Many fine HO layouts have been built with 18" radius. Still bigger is usually better, especially with the newer locomotives and cars which often do not have the design compromizes that were accepted in "the old days".
Lone Wolf and Santa FeHere is a list I made up of minimum radius for different type of equipment. Toys = 18” Most scale models = 22” Scale models with accurately detailed fames and coupler pockets = 24” Steam Locomotives = varies up to 30" or more.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"