Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
Not sure where you are getting the numbers, but the Radius of Closure Rail for a #6 in HO is 43" - that's the TIGHTEST radius in the turnout. A 7.5 and 8 would be considerably larger. Even a #6 would not reduce your 30" radius curve.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The clue is that he called it a #7 1/2. I imagine he's talking about a Walthers curved turnout and the tighter leg is indeed listed as a 28" R.
One should bear in mind that the actual effect on rolling stock is porbably a little more severe than the stated radius on turnouts owing to the need to negotiate through the frog portion.
In any case, the safest bet would be to try the #7 1/2 curved turnout with the locomotive on the grade. Mock it up, then one would know for sure. Most likely it will work, but if you have a stretch of 28" radius, then that's the minimum radius. It doesn't matter how many feet of 30" radius you have on either side.
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There's probably a slightly greater tendancy to climb the outside rail if the wheels are turning vs just pushing the loco, but you should be ok. What brandh locos are these? Most of the common plastic and metal models of even the Big Boy are made to operate on as little as 18" radius, in some cases 22" is specified as the minimum. They don;t LOOK good going through such tight curves, but mechanically they handle it. Only in brass are you likely to find models made without the unprototypical articulation of the cheaper plastic models. On the read thing, the rear engine was fixed and the front engine pivoted from a point just ahead of the rear engine's cylinders. A brass model made as an exact replica will likely require even bigger than 30" radius curves to run reliable, a plastic or metal model from AHM/Rivarossi, BLI, Trix, or Athearn will pivot both engines more or less like a diesel loco and can usually handle very tight curves. Your bigger issue will likely be clearance if there is a second track outside of this one - the boiler overhang can intrude on an appoaching train or lineside details.
Capt. GrimekThanks Cuyama and Randy. Yes, I should have stated, it's a Walther's code 83 #7.5. If no one who's installed this combination (#7.5 coming off of a 30" R curve with those locos) I'll go ahead an mock it up. Would I be able to tell by merely pushing the loco through with my hand in both directions? I'm not wired up at all yet. Does it make any/much difference with articulateds if the drivers aren't turning under power just "sliding" through with my hand? - Thanks.
In some previous posts on this board, there was discussion about the fact that the inside radius of the Walthers curved turnouts is tighter than stated by Walthers. I have the following notes: "Don Z made measurements of each to determine the correct radii. They are: #6.5 is 24" outside and 16.5" {!!} inside {20" published by Walthers} #7 is 28" outside and 20.5" inside {24" W} #7.5 is 32" outside and 24" inside {28" W} #8 is 37" outside and 30" inside {32" W}"
And dante wrote: "I carefully checked the radii by drawing various curves and overlaying the turnouts and found the following: #6 (or 6.5; some labeling confusion): 24/18 #7: 28/22 #7.5: 32/26 #8: 36/30"
So there may not be total agreement as to the exact sharpness of the curves, but you can't go wrong assuming the worst case. And I would not feel very confident about learning anything by skidding the locomotive through the turnout... Setting up a temporarily-powered full simulation would seem to be worth the trouble, considering the eternal frustration of building it and then finding out it won't work.
"We didn't have time to do it right, but we found the time to do it over."
Best of luck - Gerhard
Capt. GrimekThanks Randy. These are Athearns. I've got 3" clearance between adjacent tracks on the paper template, but good reminder. I'll go see if this "new/additional" turn out changes that anywhere...as I wasn't originally planning on using this #7.5. I'm trying to use it to add another through track through the yard as well as doubling as a "terminal" track under the station. It was originally going to be used to get into some serial staging under the mainline which is elevated, but I'm now thinking that's not going to be worth the trouble later. (Hidden AND serial staging!)...Maybe not. Hey, while I've got you here, can you post the link to your own layout? I was enjoying and getting inspiration from yours before our old computer died..
Mine? It's in the signature under every message I post http://www.readingeastpenn.com
Hello "Capt. Grimek,"
The Athearn Big Boy and Challenger, afflicted as they are with what a friend of mine calls the "curse of Rivarossi," will have no trouble operating on a 28-inch radius curve. These models are built with both engines (each set of drivers and cylinders is an "engine") swiveling like diesel trucks, following the lead of the Rivarossi Big Boy and Y6b introduced in the 1960s.
In real articulated locomotives, the rear engine and the boiler/firebox are rigidly joined, and only the front engine can swing under the boiler. The front engine pivots on a pin between the rear cylinders.
The models' double articulation does allow them to negotiate train-set curves, and also reduces the boiler overhang on curves by a considerable degree. Nevertheless, many of us would prefer more realistic articulation, which among other things would allow realistic steam pipe connections to the rear cylinders. I know that's practical for HO models, because I used to have a brass D&RGW 2-8-8-2 that operated reliably on 22-inch radius curves.
So long,
Andy
Andy Sperandeo MODEL RAILROADER Magazine
Jim, not wired yet? Here's a tip that works for DC or DCC. Take a scrap piece of plywood (or one you can use as the base of your command station panel) drill some holes in it and mount yout command station and power supply on it with plastic tie-wraps. Add a pair if 3 foot wire leads and alligator clips on each. Now you have a test unit you can use anywhere on your layout or workbench. If DCC just plug in your hand-held throttle and you are good to go! For power feed you can use an extension cord and if desired a plugstrip also tie-wrapped to the board! John.
Well, my brain fart was thinking you meant a #7.5 STRAIGHT turnout, not curved ones, which of course do come with a 28" inner radius. I only posted the RCR and substitution radius for a #6 straight turnout because I had the numbers handy - and noted a 7.5 turnout would be even less of a curve. All failing to realize you were talking about the Walthers CURVED turnouts. All in all, it worked out in the end, so, what the heck.