Will scale minimum 072 large engines run on Gargraves 063 curves??

Some engines are rated conservatively and will take curves a bit tighter than advertised. Others require every bit of the rated curves, and will not tolerate even the slightest variation from that minimum.

The only way to be sure is to try the engines yourself or name the specific engines here and see what others have experienced with the same engine.

Remember too that opinions may vary depending on how carefully track is put down. An engine may take an accurate 63 inch curve easily, but derail on the slightest variation in the curve.

To keep a constant curve whatever the diameter without kinks, it is always best to swing an accurate arc with a pencil and string (or homemade compass) and be sure to follow that arc with your track.

Jim

Maybe some 4-8-4s might, but the bigger 2-10-4s and long articulated migh give you real trouble, especially with their over hang.

Also, not only can engines give you a problem in certain tight radius circumstances, but the longer passenger cars will cause trouble as well.  You might get a train of 21" cars around a 63" dia curve but they sure won't look very well.  Real railroads have restrictive areas where certain types of equipment are not permitted so, depending on your planned use for the track, you might just be Okay.  Also, if you have two normally acceptable curves, left and right, back to back, you certainly invite disaster.

Paul Fischer

It looks like theres plenty of room to flex track something in there. Why not bend yourself something between 63 and 72?

The longer the wheel base, the harder its going to be. A 4-12-2 is probably the most intolerant thing you could try. I think that would be an absolute no (even O72 is a crapshoot unless its laid well). Believe it or not, a big boy would probably do it, albeit with rediculous overhang. DD35s are rated to O54, and will run on it, so I wouldnt even worry about it. The DDA40s might be a stretch, but maybe. If you have kadees on long cars, forget it.

Just judging from the work in the photo, I'd say you can handle making the curve yourself. Just ease your way into and out of it and you should be fine. Make a jig to keep it even and just bend around it.

The vendors rate their min radius not on a simple curve; however, on complex turnouts. I have many engines that are rated for a higher radius that goes through a smaller one (Alco S2, 0-4-0, that are rated for 027 and go through 027 curves).  My GG1 is rated for O 72 and it goes through my 063 as examples. When I have questions regarding the ability of a potiential purchase, I have my LHS place it on my projected radius and see if it fits.  The other way is also true with some O42 engines not going through a complex set of turnouts one radius greater.

Here's another thought. Some manufacturers make the min curve statment based on the track THEY make. For example, Lionel doesn't make 63 so a minimum suggestion would be 72 because 54 is too tight. 63 might be just fine. Not all cases, but some.

I'm not sure that running at a slower speed would make much of a difference, as either all the wheels stay on the track of they don't.

If it were my layout, I would just buy half a circle of the O-63 or the flex, put it down with a couple of screws and see it the engines can navigate the curves.  Worse case is no they can't.  If that happens then you decide to either pull up the track or only run the smaller engines on it.

What's a half circle of gargraves run, $40 or so?

Jim

That's good advice.

If the track is desired for operating flexibility go ahead and build it anyway with the idea that any locos that can't take the curve will be restricted from it. I went that route on my HO railroad with some "substandard" curves on optional routing, and  discovered that nearly all of my equipment could handle it with little or no modification.

Of course wider curves are always preferred for better appearances with long equipment, but if sharper curves give you useful trackage for certain purposes ... go for it.

The Daylight may be a problem; it may not. Articulateds are articulated for just

that reason: curves and length. A 4-8-8-4, in essence, is two 4-8-0's, and can be

more forgiving than a 4-8-4. My Lionel USRA 2-6-6-2 says "O-54", as I recall;

but my friend's O-42 layout (he wanted a Mallet like mine) wouldn't have it. No go.

The Daylight may work; may not. Hope so - and the manufacturers do try to rate

conservatively, I would guess. 

Matt, nice layout! Thanks, I enjoyed the video.  I love the big boy (seems to be a cat favorite as well).