Minimum Radius curves - a follow-up

[bob39520]

Last November, before I had a loco or a layout, I asked the "Bach Man' about small layouts. Got some great advise and built my first layout ( 30" x 96") w/ 13 1/2" radius curves. I run a 0-6-0t w/dcc and sound and a 0-6-0 goat switcher both by Mantua. That worked so well that I figured that if 6 wheels were O.K., 8 wheels would be better. I ordered a 4-4-0 modern American/DCC by Spectrum. This only works if you take off the front 4 pilot wheels but the loco looks ridiculous going around curves. In all fairness, a gentleman named 'Sid'  wrote that loco's with pilot trucks would not work on a small layout like mine but I was too new and did not know what "pilot Trucks" were and didn't ask. (Didn't want to sound stupid). I have the 4-4-0 sitting on a shelf to remind me not to try that trick again. Hope this helps some of you new guys with your projects.

Just a thought, would a small 'Shay' take a 13 1/2 radius curve?

[jward]

a 13 1/2" radius curve? in HO? i wouldn't recommend going below 18" in HO. anything below that belongs on an N scale layout. no wonder you were having problems with that 4-4-0......

[lmackattack]

I have seen the 3 truck shay make it around 14" radius so a 2 truck might make it around 13"?

Search You tube and you will see a 3 truck running on 14"

Trent

[Chris350]

You might be pushing it with a three truck shay.  A two might work.  A Spectrum Climax would most likely work fine, but  hey are very hard to come by.  Perhaps a Riverossi Hiesler would be a candidate.  13"  is really tight.

[bob39520]

a 13 1/2" radius curve? in HO? i wouldn't recommend going below 18" in HO. anything below that belongs on an N scale layout. no wonder you were having problems with that 4-4-0......

Actually, I thought I was doing pretty good at 13 1/2". I got most of my ideas for my layout from an article in the April 2008 issue of Model Railroader. Tom Millers' (no relation) Meramec Valley RR runs with 12" minimum radius curves.
Tom has been at it for 25 years, me - only actually running since March 2009.
Although I would love to have the room to run 18" radius,but then I would be in On30.

[jward]

in HO, those 12" curves are not suitable for serious operation unless you are running streetcars. i am familiar with the article in model railroader, it was a beautiful layout, but not much operational possibility there.

in N scale, those 13 1/2 radius curves are about the equvalent to a 22-24" curve in Ho, and they work very well. when i was in N scale, i built a layout with 14" minimum curves, after having problems with the 9 3/4" radius curves that come in the train sets.

if i may ask, what are you modelling with those 13" radius curves?

[Nigel]

Hi Bob;

Contrary to some of the posts here, 13½" radius is fine in HO for serious operation, but there are limitations.

Most 0-4-0, 0-6-0, 2-6-0 and some 2-8-0 models will work okay.  You may have to lengthen the tender draw bar on some.  As you found out, avoid the 4-x-x models.  They have problems with lead truck to cylinder clearances.

The Mantua 2-8-2 is rated for 14" radius, and if your track is perfect, it may do 13½".

For cars, stick with 40' or less scale length.

#1 thing - enjoy this wonderful hobby.

[simkon]

I don't think he said you couldn't run a 0-4-0, 0-6-0, or 2-6-0, I think he was just saying that it wouldn't look the best, because it wouldn't be prototypical to run anything more than a streetcar or trolley on that small of radius curves. But typically 4 lead trucks can be a problem as has been stated on several occasions. In real life, 2-6-0 didn't run on the scale equivalent of a 13" radius curve, but a street car or trolley did on occasion.

[renniks]

Prototypical?
Suggest nothing under 48"(not 18)for HO. Had an N scale folded dogbone layout with some 9 & 3/4" curves and ran anything including Mallets with no trouble.

Bob,
It's your RR and you use what you need to fit your space. Just pick suitable stock and ENJOY.

Eric UK

[jward]

i was referring to operating reliability, which i define as the ability to have relatively trouble free running both forward AND reverse. i am sure that, by using smal locomotives and 40' cars, you could get reasonably reliable forward running. but experience on my own and others layouts have shown me that even on an industrial setting, 15" curves were pushing the limits of reliability when backing, and this was with small switcher type diesels and 40' or less hopper and ore cars.

for reliable forward operation you'd want to have truck mounted couplers, which do not take kindly to backup moves. when backing, the couplers cock to the side. body mounted, the resulting sideways pressure is dissapated through the car's underframe and bolster. what pressure is transmitted through the trucks tends to force both wheelsets against the same rail. with truck mounted couplers, the sideways pressure tendsd to force the trucks to skew, and the two wheelsets are pressed against the opposite rails. a truck riding skewed in this manner will force the wheels off the track at any imperfection in the track, or sudden lurch of the locomotive.

in n scale for many years almost everything had truck mounted couplers. in the past 20 or so years, locomotives, and some cars, have body mounted couplers. the mixture of truck and body mounted couplers is what causes problems on those 9 3/4 radius curves. i eventually converted most of my n scale cars to body mount couplers, and for the first time had trouble free operation in my yards.

[bob39520]

if i may ask, what are you modelling with those 13" radius curves?

I'm not sure if I am answering your question but here goes:
At one end is the 'Old Coal Mine', at the other is the 'Coldwater Coal Co.'
Between them I have a Coaling Station, Sand Station,Storage Tank Kit,4 Trestle Bridges,a Concrete Bridge,Warren Bridge,3 Signal Towers,4 Water Tanks, and a removable mountain and tunnel w/a water tower on top. Also a Centennial Mills Inc. Kit and a bunch off small stuff. Built the stuff myself just to see if I could do it. I spend my time moving coal cars around and listening to my little 0-6-0t go chug,chug,chug. My wife gets a kick out  of it.

FYI-just bought (not delivered yet) a Bachmann Spectrum On30 DCC 2-8-0 Consolidation. No use for it yet, but someday....?

[Michigan Railfan]

Your layout sounds pretty neat, Bob. But, I think what jward meant was, what railroad are you modelling, if any, or just any roadname?

[jward]

no, he pretty much answered my question. he's running a small tank engine and probably mostly 2 bay hoppers, well under 40 feet in length.
given that, he may be able to pull this off. i'd still advise widening the radius to 15" though. he's definitely pushing the limits.

please post some photos, it sounds alot like some of the places i've been in real life......

[pdlethbridge]

There are no limits to how anyone can have fun

[bob39520]

please post some photos, it sounds alot like some of the places i've been in real life......

I will do that when the Grandchildren come to visit (Thanksgiving maybe) as they know how to do that stuff.  Thanks to all for your input and advise.