track radius

[curbur]

What is minimum track radius, HO scale, that will handle 50 ft. boxcar without derailing?

[Jerrys HO]

I had 18r and 22r at one time and my 50 ftr's ran fine. Looked kinda funny.
Since I have stepped up to 26r and 28r. still have some 22r on inside main but no more 18's.

Jerry

[Doneldon]

curbur-

It can be very tempting to use the smallest possible radius curves in an effort to pack the most track into the smallest space. Unfortunately, that often leads to quite a disappointment. While it is possible to run many locomotives and cars on 18", or even 15", radius curves, trains on such sharp turns don't look right. And there can be operational problems like the corners of cars bumping into one another, requiring that cars be coupled so far apart that they look even worse. Throw in derailments and changing tastes and the desire for larger equipment and the layout with tight curves becomes unsatisfying.

I urge you to consider using the widest curves you can fit into the space you have available, and in no case less than 18" radius. A better starting point, IMHO, would be 22". I can confidently promise you that you'll never regret going with wider curvatures but you may soon outgrow tighter ones.

Whatever you decide, welcome to the hobby and this board. I look forward to hearing about your progress.
                                                                                                                                                                       -- D

[jward]

I have 18r curves and I run 50 footers with no problems. I would resist the temptation to go less than 18r.

[curbur]

Thanks for the helpful information.

Curt

[Pacific Northern]

Thanks for the helpful information.

Curt

I agree, stay away from a 18" curve, just too sharp. It is usable, but looks terrible.

If you alternate 18" and 22" radius sections you will end up with a 20" radius curve. Use 4 pieces of 22" and then 3 piece of 18", you end up with a transition track. Add a 4" straight section and the ends will line up parallel to each other.

Better than an 18" curve but not as good as a 22" curve, but a compromise worth considering.

[Johnson Bar Jeff]

If you alternate 18" and 22" radius sections you will end up with a 20" radius curve. Use 4 pieces of 22" and then 3 piece of 18", you end up with a transition track. Add a 4" straight section and the ends will line up parallel to each other.

Better than an 18" curve but not as good as a 22" curve, but a compromise worth considering.

I must be having a mature moment because I'm not quite sure I'm following your suggested arrangement of the track sections.

Is it: 22-18-22-18-22-18-22?

Or: 22-22-18-18-18-22-22?

Or even: 22-22-22-22-18-18-18?

Thanks!

(I don't run 50-ft cars, and I've created transitions for small layouts using 18-R and 15-R curves by arranging the track as 18-15-15-15-15-18. Of course I agree that curbur shouldn't go that small a radius for 50-ft cars.)

[jward]

22 18 22 18 22 18 22 is the way I always did it.

[Johnson Bar Jeff]

22 18 22 18 22 18 22 is the way I always did it.

Doesn't alternating that way put slight kinks in the rail? 

[Doneldon]

J-J

Not exactly. It's more like a less severe change than when a curved
track is connected to a straight one. Trains should track just fine as
long as each track joint is straight and tight.
                                                                      -- D

[Joe Satnik]

Dear All,

A few of Armstrong's sectional track semi-circle recipes from a 1950's layout book:

22 h15 22 22 h15 22 22 h15 22  gives 20-1/4" radius.  (h = half curve)

22 h18 22 22 h18 22 22 h18 22  gives 21" radius.

Note: half 15"R not available in Bachmann HO E-Z Track. 

22 22 22 22 1"Straight 22 22 22 22 gives 22-1/2" radius on ends, 22"R in middle of semi-circle. 

18"R to 20-1/4"R to 22-1/2"R is set up for a 3 track concentric semi-circle with 2-1/4" center-line to center-line track spacing. 

The 21"R would fit with 3" spacing between an 18"R and a 24"R semi-circle.

Try them out on the free trial AnyRail.com track CAD program.  It's fun.   

Hope this helps.

Sincerely,

Joe Satnik   

[Johnson Bar Jeff]

J-J

Not exactly. It's more like a less severe change than when a curved
track is connected to a straight one. Trains should track just fine as
long as each track joint is straight and tight.
                                                                       -- J

Thanks, D. Interesting and useful to know!

A few of Armstrong's sectional track semi-circle recipes from a 1950's layout book:

Thanks, Joe. (I like your use of the word recipe.  )