Berkshire - minimum radius

[ebtbob]

What is the stated minimum radius for the Bachmann N scale Berkshires.

[ACY]

I would not try it on anything less than 11.25, however on one site it said the manufacturers suggested minimumradius was 19", not sure if that was an eerror though.

[sumfred]

mine runs fine on 9 3/4" ,although it does look horrible !!!!!!
Fred

[brokemoto]

Spookshow has stated that his will run on a nine and three quarter inch curve, but that is really pushing it.  He recommends an eleven and one quarter curve as a minimum.  It will look a bit silly on either one.  Thirteen to fifteen inch would likely be better, seventeen or better optimal.


Back in the HO days, the "experts" divided curves into three groups:  sharp, conventional and broad; radii were less than twenty four inch, twenty four to thirty inch and thirty inches, or better, respectively.   In N, this is approximately less than 13,05 inches, 13,05 to 16,32 inches and 16,32 inches, or better.

The guide for steam locomotives was:

Switchers up to 0-8-0, eight wheelers and moguls were allright for sharp curves
Consolidateds, mikados and pacifics were allright for conventional.
Decapods, Santa Fes, Berkshires, hudsons and articulateds required broad curves.  Some of the larger articulateds required curves even more broad than thirty inches in HO, 16,32 in N.

[Len]

To the prototype, just about any curve used in model railroading would be considered 'sharp'. The prototype measures curves in degrees of arc, and a 5 degree curve would be considered a fairly sharp mainline curve. That translates to an actual radius of 1,146.3', which would be an 86" radius curve in N-scale.

So I figure the old saw, "Bigger is better.", would apply. Go with the biggest curve you have space for. And keep your loco purchases in line with that size curve.

And just as an FYI, a prototype 45 degree arc (130.7'R) curve is the sharpest I've been able to track down. It was in a Jersey Central dock area track in New York. That equates to a 9.8" radius N-scale curve, which is pretty close to the 9.75" radius curves actually offered.

Len

[ACY]

Thanks for sharing that information Len. I know in my neck of the woods most mainline curves are in the vicinity of 1° give or take. So to be prototypical in n scale would require a 36 foot radius curve apparently, I don't even want to know what that is in some of the larger scales.
Edit: Made minor correction, somehow my post erroneously had 10 feet when I typed 36.

[Len]

I found a conversion chart of prototype curves to HO and N a while back and saved it. Lets see:

Prototype: 1 degree = 5,729.7' radius, HO: 790.3" radius, and N: 429.7" radius

Prototype: 2 degree = 2,864.9' radius, HO: 395.2" radius, and N: 214.9" radius

I don't think I've got the room for either one in HO or N.

Len

[gatrhumpy]

Mine runs fine on 9 3/4" radius curves.

[ACY]

Mine runs fine on 9 3/4" radius curves.

How much overhang is there though? I would think there would be quite a bit more overhang compared to even 11.25" radius.