Minimum radius for 2-6-6-2 or 2-8-8-2 articulated loco

[Frankv]

We have 22" radius ez track. Will that work with articulated locos? My grandchild has a plastic model of a Big Boy. He wants a working one. I have very low sales resistance with this child, so it is likely he will get one. What radius would you suggest for him to be happy while running it? Thank you.

[Nigel]

I would suggest you go with the Bachmann Spectrum 2-6-6-2 - one with sound if it is in your budget.  It is a much smaller articulated than a Big Boy, and will not have problems with 22" radius curves.

Athearn and Trix have HO models of the UP Big Boy that are rated to go around 22" (or smaller curves), but they look pretty bad doing so, and have a tendency to hit anything close to the tracks.

[ABC]

If you want a big boy (4-8-8-4) or challenger 4-6-6-4, I would recommend a minimum radius of 30 inches. The Bachmann 2-6-6-2 will negotiate tighter curves much better than most big boys or challengers, I would recommend for best results a minimum radius of 24" to be safe. Pretty much use the largest radius that you can fit on your layout, but 22" radius is the absolute minimum for most larger steam engines, and many brass models requires curves in excess of 30" radius.

[Pacific Northern]

The Bachmann 2-6-6-2 is easily run on 22" radius curves, it is also quite capable of running on 18" radius curves as well, due to its design there is little overhang. I have two of these and they are marvelous running steam locomotives.

An excerpt from a review

" Each six-drivered engine is essentially a cast-metal truck with a vertical gearbox. A universal shaft at the top connects it to the flywheel mounted on the motor shaft. Both engines swivel and rock slightly under the boiler to ensure that all of the drivers contact the rails for maximum tractive effort. This "double truck" design allows the model to negotiate an 18"- radius curve and reduces its front-end overhang on sharp curves."

[Frankv]

Thanks guys for the helpful comments. Believe I will concentrate on the 2-6-6-2. I've checked the Internet for 2-6-6-2 for sale, but I think I need to start a new thread to get help on that.