I have two layouts. One is 4x4 and the other is 3x5.5. Locomotives with 3 axles to the truck want to derail due to the tighter radiuses whereas locomotives with 2 axles per truck do just fine. I have one Kato PA&PB locomotive set that I would love to run if that is possible. I bought it before I realized about the 2 axle vs 3 axle per truck dilemma. Any ideas would be greatly appreciated. Jim
just as a guess, i would say that 9" radius is okay for two truck, but you need 11" radius or so for three truck, in most cases ...not all depending on the loco ... i work with HO so i just took half
Wider curves are the best curves. I heard you thinking, on model railroad layouts, of course. Not that this is about me but I tried doing the same thing you are doing and solved it by pushing my curves out. Now my stomach is bigger then ever and I haven't seen my feet in months. LOL What? What? What did I say?
Big long three axle locos need space. You could take a section of flex track and try different radiuses to establish just what the minimum radius would be.
I settled on 16" with easements for my 6 axle diesel units. Without the easements 17" would be my minimum. Anything less than 16" would also cause my 4-8-4 Daylight to climb the outer rail. Now I did have a layout with 12" curves but I knew its limits and stuck to 4 axle units. I sure miss that whimsical layout, but the 4% grades also limited train length. Wow, that was a long time ago.
Make sure your track work is impeccable. If you are using flex track make sure you don't curve it too much. I have a 3 x 5.5 layout like you with 9-3/4" and 11" curves and have no problems with 4-axle and 6-axle locos. With very few exceptions, all Kato diesels are designed to run on 9-3/4". From my experience Atlas 6 axles also work fine. If you are not sure about flex track, using sectional tracks will maintain the radius for you.
Having seen that layout I have to tell you I really liked what you did with it. I enjoyed the one time, I was allowed to operate a local and switch a number of industries. The bridge you built turned out great and was the key focus point of it, for me. The weather wasn't very kind as things heated up in Riverside, Ca. Didn't stop the fun.
I sure regrete removing the garage layout you saw. I thoroughly enjoyed having you and the gang visit and run some trains even in the almost 100 degree heat. It actually had the 16" curves. The layout with the 12" curves was only about 30"x54" and was running from about 1990 to 1996. I had a scratch built wooden trestle and was a bit whimsical. Even as small as it was the neighbors would enjoy our visits when I was in the garage running the layout. I am determined to get away from modular layouts and get back to free flowing trackwork. Good times.
You are so right1 It was the larger layout Steve and I saw. We enjoyed that time with you. He spoke of it often and with some obvious envy.
I agree with Mike, I have a 24" x 80" hollow core door layout with a 9.75" radius curve, and I do not have any problems running Atlas and Kato 6 axle locomotives. The largest steam locomotive I own is my Bachmann 2-8-4 NKP Berk and it even manages to make it around that 9.75" radius curve without any issues.
As noted above...most 6 axle locos and even long steamers will make it around tighter curves just fine. They may not look pretty doing it...but as I have stated many times...if the sight of locos and rolling stock hanging out to far when going around a turn bothers you...just dont look...JS
I too can run SD diesels on tight curves. I did have a problem with two areas when I built the layout but found that the flex track I had laid was out of gauge at joints on a curves in each case. No problems since fixing it.
