DAVID FORTNEY I can only dream of 30" curves. I'm restricted to 24" and maybe a inch or two above that in places. It seems the larger layouts are the only thing talked about today.
I can only dream of 30" curves. I'm restricted to 24" and maybe a inch or two above that in places. It seems the larger layouts are the only thing talked about today.
Understood. On past posts about recommendations to layout designers with limited space, I've often suggested that any increase of radius can be helpeful, especially at low radii such as in the 18-22 inch range. If radius can be increased by only 2 inches, it could make a difference with some rolling stock operating reliably or not.
Mike mentioned: "I wouldn't take a 2" difference in min R too seriously. 4" is more significant."
But it would be serious if that 2 inch increase allowed a 6-axle loco to run vs. not run on a curve 2 inches less, or other rolling stock work vs. not work. Naturally increasing by greater amounts is going to yield even greater dividends, 4 inches or more. Yes, 2 inches won't make a hill of beans difference in appearance on those curves; operation may be a different matter.
Knowing that even 30" radii has been reported as iffy for some Walthers passenger cars, I bumped up my minimum to 32" to add a bit more margin - and that in one or two spots - I've increased the curves to a bit more than that in other places - 33, 35, 36 even 40 inches. I have a planned helix and plan to use 34" radius there.
To stick to a 32 inch minimum radius, I had sacrifices to make, including less capacity in my staging yard, narrower pinch points etc. Layout design is all about compromises, and sometimes borrowing from Peter to pay Paul. Givens and Druthers as JA called them.
Also just because somebody says that my min should be 30" does not mean I should follow that advice, 24" was my limit and that is it.
I haven't ready any messages telling anyone what they should and shouldn't do here. Obviously if space is limited, it's going to impose restrictions that may not be able to offer any lee-way. I've had a few occasionally tell me I should do this or that but sometimes they don't know jack.
Rio Grande. The Action Road - Focus 1977-1983
Okay, so we have come to see that, for curves, sharpness and broadness is a relative term. It's not really what the OP has posted about. He feels that it isn't obvious what makes Armstrong the 'dean', and I do see Byron's point that he may have been a little quick on the trigger, so quick that he shot himself in the toes.
Hopefully we have all done a good job of pointing out what makes Armstrong the figure in the hobby that so many of us claim he is/was.
riogrande5761borrowing from Peter to pay Paul. Givens and Druthers as JA called them.
One of my favorite groups from the 60's - Givens, Druthers, and Mary.
riogrande5761To stick to a 32 inch minimum radius, I had sacrifices to make, including less capacity in my staging yard, narrower pinch points etc.
You say that as if "32 inch minimum radius" is a line item on your "givens" list. Maybe a better approach would be to have a "Druther" of "Run a 1938 version of The Scenic Limited" so you can understand the tradeoff you are making. If you finish your list and only have this one train that requires a large radius, you can make a judgement call as to whether or not you want to limit the plan just to accommodate one train.
The point is that you should develop "Givens and Druthers" first in terms of scenic and operational goals, then develop your engineering standards to support them. Arbitrarily setting a minimum radius upfront is putting the cart before the horse.
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 riogrande5761 borrowing from Peter to pay Paul. Givens and Druthers as JA called them. One of my favorite groups from the 60's - Givens, Druthers, and Mary.
riogrande5761 borrowing from Peter to pay Paul. Givens and Druthers as JA called them.
riogrande5761 To stick to a 32 inch minimum radius, I had sacrifices to make, including less capacity in my staging yard, narrower pinch points etc. You say that as if "32 inch minimum radius" is a line item on your "givens" list. Maybe a better approach would be to have a "Druther" of "Run a 1938 version of The Scenic Limited" so you can understand the tradeoff you are making. If you finish your list and only have this one train that requires a large radius, you can make a judgement call as to whether or not you want to limit the plan just to accommodate one train. The point is that you should develop "Givens and Druthers" first in terms of scenic and operational goals, then develop your engineering standards to support them. Arbitrarily setting a minimum radius upfront is putting the cart before the horse.
Yes, a 32" minimum radius was a line item from the start as it was on my previous layout. Modeling focus is basically 1977-1983 and with it goes lot of long rolling stock. In addition to several passenger trains, I have a lot of 85 and 89 foot TOFC equipment, auto-racks and 86' foot auto-parts box cars. There are two spots where the radius is 32", and the rest are above that to one degree or another. The longer rolling stock may not look great on those 32" curves, as MRH points out in their article, but should operate reasonably well.
riogrande5761Mike mentioned: "I wouldn't take a 2" difference in min R too seriously. 4" is more significant." But it would be serious if that 2 inch increase allowed a 6-axle loco to run vs. not run on a curve 2 inches less, or other rolling stock work vs. not work.
But it would be serious if that 2 inch increase allowed a 6-axle loco to run vs. not run on a curve 2 inches less, or other rolling stock work vs. not work.
That is true. A 2" increment could make all the difference with that specific item.
But I would suggest the only way to determine that is to run said item of rolling stock on that particular curvature and see what happens. I absolutely would not count on the mfg's declaration that it is suitable for any particular curve unless there was more than the stated 2" difference in play.
We should consider that stated curvature is usually more of an approximation than it is an exact science. Assuming the stated min R, any item that is close to it may or may not run OK. People do want to take a mfg's stated min R as a given and seem to expect utterly reliable operation at that number, when in fact we should look at such numbers as the lowest possible min R and only able to be confirmed by operation on the specific piece of track with the specific item of rolling stock of interest.
Min R doesn't really mean everything with the same stated min R will run as well as the test article did, only that it's in the realm of possibility. That frustrates some, but it's much better to understand the meaning that can be drawn from min R in regards to your design parameter than to take it as an absolute number that can be relied on and applied universally.
EDIT: To further clarify, maybe we shouldn't rely on min R but instead rely on an op R. How do I refine op R? It's a number that the majority of your rolling stock can operate on safely clear of the issues that operating at the min R might create.
Going back to my comparison between the significance of 2" and 4" worth of difference, I'd suggest a good op R would be about 4" larger radius than the min R would be. That should be enough to take care of all the variables that are encountered by pushing everything to the limit at min R, yet still expecting the same performance on the sharper track as could be achieved at larger radii.
Mike Lehman
Urbana, IL