6 Axle Locos & 18" Curves

[ricktrains4824]

If you like ultra modern units, get the new run of Bachmann GEVO’s with sound, they run just fine so long as you swap the rear couplers to long shank. My Athearn Genesis SD70Ace also runs on 18" radii curves no issues.

My Intermountain GEVO took some additional tweaking, but now also runs well.

Atlas 8-40C (&CW) units (at least the old run) also work well with 18" curves.

Older runs of Bachmann Spectrum SD45’s, 8-40C (&CW) series, and the Athearn BB SD40-2’s, and GE Dash 9 and AC44 series units also work well on 18" curves, and can readily be found on the bay, and at train shows. (As do certain runs of the Athearn RTR AC44 series units, but I would test these first, as some seem to snag on details, and others didn’t. Maybe it’s a certain run had something different?)

And, yes, I have a few 18" radii curves on my layout.

While I would love a bigger layout, that is currently not a option. So, I learn to make do with available space. This includes swapping to long shank couplers, and not running extremely long overhang cars. (80’ or longer.)

Yes, I have successfully made all of these units operate on 18" smoothly, but my 18" is smooth, no kinks or humps.

I also have a bashed Athearn drive SD70 (with a rail power shell) that will negotiate the 18" curves, but dislikes the #4 turnouts on my yard lead. (Occasionally will pick it, other times does just fine.) I was also given a set of Proto E8 units by a friend, and they will run on 18" curves, but will not take anything under a #6 turnout for anything!

So, you can run 6 axle diesel units on 18" radii. You just might need to swap out couplers, or tweak in other ways to make them work.

[kbaker329]

I started a post on this years ago. I received some good information and some helpful ideas. I also heard a lot of opinions on 6 axles not belonging on 18” curves.

In my experience, there is no quick fix. I found that there was adequate lateral movement in Athearn, Proto2000 and Atlas units. It came down to track work. Track that worked fine with 4 axle units needed tweaks. I had elevation changes combined with curves that caused two axles to lift the third right over the top of the rail. I had flex track joints that looked square and perfect but needed file work and more. It took a lot of tweaking and caused a lot of frustration. I just looked for repeat areas and started working on them. There are still units that I can’t use and I’m debating on whether I want to keep my current layout or rebuild with larger curves

Perfect track, square joints and zero elevation changes are the only way. It’s not impossible but it will take a lot of trial and error. You will have to decide whether the effort is worth it or not!

[riogrande5761]

Posted by YoHo1975 on Friday, June 08, 2018 11:25 PM

I’ve been in this hobby for the better part of 33 years. And for 33 years it’s been an axiom that 18" radius and 6 axle locos don’t mix. Even 22" is getting at the hairy edge in some cases. It sounds like some in this thread have had success with certain models and careful track arrangement. I would note what works, what doesn’t and approach any purchase with a mindset that 18"+6axle is never recommended

Pretty much this as a rule. ^

Disappointed for sure that for the design, engineering and quality of modern HO diesel locomotives that they generally won’t accomodate 18" radius track. Final words on the phone by the Walthers rep to myself and LHS manager “we strive to have all of our (HO) products run on 18” track". Well, so much for that.

Here is the thing, some engines would require too many compromises in fidelity to “trick” them to operate on very sharp curves, such as 18" radius. The prototypes they are copying would never operate in real live on much larger curve equvelents. There are some engines which simply do not lend themselves to sharp curves so don’t throw the manufacturers under the bus because, despite their best intentions, it ain’t very easy to do.

My suggestion you have a choice; either rebuild the layout with larger curves, even sliightly larger - 22 inch curves will still fit on a 4x8 - or just forget large six-axle engines for the most part.

A mans got to know his limitations.