Based on my new understanding, you should have no trouble even with a brass engine through that turnout. The closure radius of a #4 wye is well outside 35".
-Crandell
The majority of folks here think the #4 wye should work. I know that Proto advertizes the 2-8-8-2 to be able to negotiate #4 STANDARD t.o.s so I figured that loco would be ok.
It's good to hear that the Rivarossi B.B. had no problems. I guess...final trial and error will be the ultimate determiner...hopefully I'll have room to place a #5 on the layout IF I have problems. But won't know that for awhile yet. Seems like the odds are at least good that at slow speed things might be ok according to big steam users with #4 wyes..Thanks TA for your confirmation run.
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
Yup, maybe a hard concept to grasp but because the wye diverges in both directions, the frog is a no. 4 but the degree of replacement radius is the same as a no. 8 turnout. Check the Walthers line of track to see examples.
It will fit no problem. It's equivalent to two #8's lefthand + righthand back to back.
-D
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Tight!
I'm not going to say that it won't do it but I sure as the dickens wouldn't trust it on a regular basis.
According to NMRA RP-12.3 an HO-Scale #4 switch/turnout diverges from the tangent on a 43" radius off of the points; the (closure) rail radius, however, is only 15" and that is likely to give you headaches.
On the other hand an HO-Scale #5 switch/turnout diverges from the tangent on a 43" radius off of the points but the (closure) rail radius is 26" and that shouldn't give you troubles.
From the far, far reaches of the wild, wild west I am: rtpoteet
That'll make life much easier as I know the template/plan already fits and things are tight for going larger.
johncolleythe turnout indicates the frog only. What decides the radius is the distance from the points to the frog. If you laid a #8L on a #8R turnout you would see why the frog angle becomes a #4 (because both sides are diverging)
Crandell, thanks for the additional info as always.
John Colley, I've followed up with a regular email to you... So...if Mr. Colley and my buddy are correct about the equals a #8 standard turnout, the Big Boy should be ok? I can't think of any other variables (other than the radius of the approaching/leaving curves that might affect things...?
Affirmative! The "number" of the turnout indicates the frog only. What decides the radius is the distance from the points to the frog. If you laid a #8L on a #8R turnout you would see why the frog angle becomes a #4 (because both sides are diverging) and the frog axis would be right on the incoming tangents' centerline. I hope this clarifies. John
If it helps at all, Cap'n G., I have a Fast Tracks #6 double slip turnout in my yard, and I haven't found a single item that isn't perfectly happy negotiating its various widely divergent routes. If a #4 wye equates to a single #8 on each side, that is a nice long turnout, as Chuck suggests above, and pretty much everything, even most brass steamers, should have little or no trouble.
What i have seen is that it will work as long as you have a gradual radius (24" or better) off the turnout. I don't run steam, but a buddy of mine ran his UP challenger thru the wye on my layout and it negotiated the #4 wye turnout just fine. My radius is 30" off the turnout in both directions before connecting to a #4 right hand and at the other end a #4 left hand turnout to complete the wye (It's a big wye) .....chuck
I do not believe that a wye turnout # necessarily means that you can safely halve the actual diversion from the turnout's major axis (ie, straight ahead, linear to its single ingress axis). I think a #4 wye turnout will look like a regular #4 flipped over so that it is symmetrical on either side. In that respect, it should be no worse than a regular #4 through either route...and that means it won't be any better, either.
But I will continue to read in case I am mistaken. Couldn't hurt to learn su'thin'.
Edit- I think I just learnt su'thin'. I went to handlaidtrack.com and looked at a #4 wye template. It sure looks to me like one side of it is much more in keeping with a #7-8, visualizing the major axis as a normal through route. So, it seems as if you are right!
And that would make me........
I could see if I have room for a #5 but I doubt it and won't get to that upper level for another month or more.
The loco is supposed to negotiate 22" radius curves. (I'd be using Walther's Shinohar Code 83 HO).
Thanks. Dreaming, planning, cunning ;-)