Hello again. I’m still working on HO layout planning and have a couple of questions that are important to the main parts of the layout. I want to provide for the possibility of some articulated engines some day (e.g., Challenger and/or Big Boy) at least on one (outer) of 2 main lines. That being the case, I’m trying to keep one of the main lines with 30-32" radius.
Assuming the articulateds will run on these curves, will they look silly (even though they work)? If so, I can probably stretch the radius slightly at the more visible front of the layout. BTW, I presume the articulated locos would be the deciding criterion for radii, as opposed to related era passenger cars?? If I go to larger radii everywhere on the outer main line (say 36") I would probably have to plan a much less interesting overall layout plan.
I have a section with 3 straight & parallel main tracks where I’d like to put in 2 double crossovers, between the middle track and each outside track. I might use Shinohara turnouts, and I see they have a #6 double crossover. It would really help the use of space to use these, but I wonder if the long engines could negotiate these (though not absolutely necessary, but I’d want to know up front). More importantly, I’m confused by an article I read (link follows) on turnouts that suggests crossovers need a straight transition between the curved sections…which makes me wonder if the #6 Shinohara is too compact from an S curve standpoint. If so, I’d likely do 4 single crossovers with #8 or #10’s. But can I opt to install single crossovers with #8 or #10 turnouts with turnouts’ diverging tracks butted together, or does a straight “tangent” section need to be added (which increases the track center spacing). The article specifies a straight sections between the diverging curves of 5
Look silly to whom? I see people running that type of locomotive on much sharper curves and they don’t seem to mind how they look at all. I think you are the only one that can answer that question. layout a curve of that radius, put the loco on it, see what YOU think.
I don’t think so. Some of those Walther’s heavy weights really need some room to turn. The reason the locomotives are articulated is so they can go around tigher corners than they would if they were fixed frame. In fact in real life the UP takes the 3985 (Challenger class) to places they won’t take the 844 (4-8-4 class) because the 844 with its fixed 8 drivers will tear up track the 3985 that has only a fixed 6 drivers doesn’t bother.
Unless they are ridged brass models with no side play in the drivers then, No problem. The Genesis, BLI, and Proto articulates that I own do not have any issues going through #6 turnouts or crossovers. I have a frriend with Hobby town big boys and challengers. They do not seem to mind them. I presume the other brands will do just as well.
A double crossover HAS to have a straight section in it. That crossing is straight track.
Two single crossovers in sequence are much more prototypically common than double crossovers for cost and maintenance reasons. When looking at track plans, I almost unconsciously check for unnecessary double crossovers.
!) the larger the radius, the more realistic the scene looks. But layout space is always a consideration. My minimal radius for mainline is 38". But, that is because I am running N&W class A and class Y6b’s. I also, have the Powhattan Arrow for passenger running. The bigger curves help with running and looks. By the way, some of my locomotives are brass. This makes them more of a pain with respect to sharp curves. 2) crossovers do need to be on straight sections of track, there are some exceptions. I use #8 crossovers for the mainline because of the articulated locomotives. (they don’t like small turnouts or crossovers. 3) track centers have a lot to do with what type of locomotives and rolling stock you are running. The longer length of the equipment, the more “over hang” you will have. Therefore, the greater the track center spacing.
Crossovers assembled with ordinary commercial turnouts, which have the diverging route straight once past the point of the frog, automatically provide a straight section. Just measure from frog point to frog point to get its length.
Where problems occur is when modelers try to form a crossover with snap-track components, where the diverging route is a segment of a circle. Butting the diverging routes of two right-handed 18" radius snap-switches will give problems even if you never run anything but GP-7s and 40 foot AAR box cars.
The best thing you can do to improve the appearance and operation of any rolling stock on curves is to build those curves with spiral easements. Easements are NOT cosmetic - they reduce coupler offset and thus flange forces as the train transitions from tangent to curve or vice versa. Personally, I use them on hidden trackwork - where bulletproof operation is crucial.