I'm getting back in model railroading and things have changed since I last built a layout as a teenager. I have already tinkered with designs and does anyone know what turnout/switch size will best accommodate 22-24 inch turns, coming off both straight track and spurs? #4 is generally accepted for yards and siding, correct?
Any help is appreciated. CDC is next on my list to figure out.
if you go to the NMRA web site, you can read all about recommended curve radii and switch frogs. it pretty much depends on what kind of equipment you intend to operate. i would suggest you use the most generous curves and frog numbers you can get away with.
for instance, i have some industrial trackage that has a few number 4 and 5 switches in it and just like the prototype, i have had to restrict certain classes of large steam locomotives from using those tracks.
number 4 is probably a pretty good match for the 22 or 24 inch curves you mentioned.
Be happy in your work.
Charlie
A BIG FAT BACK!!!
Atlas now HAS turnouts directly relating to 22" curves. They might be of use to you:
Here:
Track curves:
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&ID=200420616
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=20014785
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=20014786
Switches here:
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=200822519
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=200822520
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=200822521
http://www.wholesaletrains.com/Detail.asp?Scale=HO&Item=150TRACK83&offset=25&ID=200822522
Another source, for example:
http://www.modeltrainstuff.com/544-Code-83-22-Manual-Left-Hand-Switch-p/atl-544.htm
CDC???? WHAT do you mean? DO you mean DCC? Smart move, When I got back intohte hobby 7 years ago, I stumbbled on DCC and haven't looked back yet! Here is a primer it should tell you all you need to know and more:
http://www.tonystrains.com/tonystips/dccprimer/index.htm
http://www.tonystrains.com/tonystips.htm
GOOD LUCK< HAVE FUN, its a HOBBY, not a government job!
-G .
Just my thoughts, ideas, opinions and experiences. Others may vary.
HO and N Scale.
After long and careful thought, they have convinced me. I have come to the conclusion that they are right. The aliens did it.
Turnouts,especially #4's are not all made the same. Atlas #4's are actually #4 1/2's. These will work with 22-24" curves. A true #4 (made to NMRA standards) is generally not a good choice particularly with steam engines. #5's will always work, but aren't available from every manufacturer. #6's will also work, but take up more space.
John Armstrong's book Track Planning for Realistic Operation addresses all these issues and many more. If you buy only 1 book on model railroading, this is the one. I highly recommend it.
Good luck
Paul
Rotor headI have already tinkered with designs and does anyone know what turnout/switch size will best accommodate 22-24 inch turns, coming off both straight track and spurs? #4 is generally accepted for yards and siding, correct?
I believe you realize that #4 turnouts are probably the smallest you would ever see on a model railroad, and as you suggest, are typically only suitable for freight cars and smaller switching engines.
i believe atlas snap-switches are equivalent to #4.5 turnouts and are designed to replace 18" sectional curve sections plus maybe an 1 1/2 straight section at the start of an 18" curve. galaxy posted links to atlas turnouts that similarly fit 22" curves.
The NMRA RP-12.3 Turnout Dimensions describes dimensions of statndard turnouts, and list the radii within a turnout, see (11). But this is only a short section within the turnout (#6 = 43").
greg - Philadelphia & Reading / Reading
back, rotor! When I built my layout with 22" curves, somewhere in my research pointed to #4's being equivelant, so that's what I've used. All my steam (plastic), up to a Genesis Challenger, go through them, though to some folks probably don't look right as they are sharper than prototypical. I don't know about brass loco's since I don't own any, though I've read they are built more prototypically in their tolerances, so they may not appreciate being run through #4's. What you intend to run may be the deciding factor. Hope that helps.
Duane
Snap-track turnouts don;t match any number, they are continuously curved to match 18" radius. They now also have 22" radius ones. Custom-Line #4's are really #4.5, so they are a good match for 22" radius curves but are not drop-in replacements. The table on the NMRA site or in Track Planning for Realistic Operation shows the two items of interest - RCR, or radius of the closure rail, which is the tightest curve on the turnout, and the Substitution Radius, which is the overall equivalent radius. Plan accordingly based on the equipment you intend to run. If unsure, test on sectional or flexible curve track to make sure you cna run your choice of equipment over the intended radius before actually fastening anything down.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi gentlemen,
the smallest radius in a turnout is 15" for a #4, 22" for a #4,5 (ATLAS #4) and 26" for a #5 turnout. The 15" radius is severely limiting the kind of equipment you will be able to use.
Rotor head #4 is generally accepted for yards and siding, correct?
As always it depends. Long modern freightcars and engines are in need of larger radii, especially when S-curves (crossovers) are involved. Since in yards a lot of pushing of rather long consists might be going on conservative planning is mandatory. Unless 80+ft long cars or passenger equipment is used #5 turnouts will do fine (with #6's in case of crossovers). For freight trains of the 50's, when 50 ft was the maximum length of most equipment the #4 and #5 combination might work just fine in yards
Paul.
I decided to use (on a 5' x 10' layout) #6 on mainline turnouts, #5 in yards. One issue is how locos will handle it, the other is how it looks. If you use curved turnouts, be aware the nominal (advertised) radii of Walthers Shinohara are not accurate, but if you allow for that (they are tighter than nominal) you'll be ok.
Also, consider easements from curves into connected turnouts.
Modeling HO with a transition era UP bent
peahrens I decided to use (on a 5' x 10' layout) #6 on mainline turnouts, #5 in yards. One issue is how locos will handle it, the other is how it looks. If you use curved turnouts, be aware the nominal (advertised) radii of Walthers Shinohara are not accurate, but if you allow for that (they are tighter than nominal) you'll be ok. Also, consider easements from curves into connected turnouts.
The larger radii are correct; the diverging, smaller radii are 2" less than advertised.
Dante
Numbered turnouts have no correlation to radius. They are simply two tangent (straight) tracks where one diverges at a given number. A number 4 turnout would diverge 1 foot for every 4 feet forward, and the speed restriction on it (by rule of thumb) would be 8 miles per hour.
A number 6 turnout would diverge 1 foot for every 6 feet of travel and would be rated at 12 mph.
A number 10 turnout would diverge 1 foot in 10 feet and be rated for 20 mph.
A number 20 turn out would diverge 1 foot in 20 feet and be rated at 40 mph and even that might be too fast.
A truly high-speed turn out, I am told, would require moving points at the points and at the frog. I have not seen this but I have been told that it has been done.
When you talk about radius you are strictly in model railroad land. Railroads do not think that way. But a Snap Track curve is simply an 18" Radius curve in one direction and a 9" section of straight track in the other. It makes for simple geometry for the users of snap tracks, but has little other use.
LION does use some snap switches on his layout because that is what he had on hand and was too cheap to go out and buy better ones. (especially since the interlocking that I was building required four of them.)
The LION does not think that any real railroad would use a snap track, but if one did...
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
hi gentlemen,
since the part of a turnout between the switchpoints (the moving part) and the frog usually is a curve you can't say radius has nothing to do with numbered turnouts.
That curving part is called the closure rail and it's radius is known. (look at my previous entry in this thread)
Out of the box #4 turnouts have a closure rail radius of 15", quite small. So larger engines and cars will have problems passing through them.
SmilePaul
Ah, yes, but. then a railroad does not measure curves in terms of radius, but more to the point, on a model layout, you could not draw a 24" radius circle and then expect to drop a numbered turnout on that radius like a snap switch would fit into an 18" radius circle.
Once beyond the frog (ribit ribit) you will usually find tangent track, or leastwise the rest of the Iron proper to the turn out would be a tangent of that new route.
ROAR
Paulus Jas Out of the box #4 turnouts have a closure rail radius of 15", quite small. So larger engines and cars will have problems passing through them.
Maybe some have that limitation. Actually, my out-of-the-box W/S Code 83 #4 turnouts have a 26" closure radius (checked with Ribbonrail gauges). The largest engines I have are 6-axle diesels and a 2-8-2 steamer, both of which negotiate these turnouts without a problem. Moral: check your own turnouts to be sure.
Hi Dante,
according to my information a 26" closure rail radius belongs to a #5 turnout (e.g. Track Planning For Realistic Operation 3'd ed page 78 and the appropriate NMRA sheet).
You are probably right, not every #4 turnout produced for the market will be exactly the same. Anyway this would add a new series of problems or possibilities for newbies and old hats alike.
BTW where stands W/S for? Walthers /Shinohara! The only producer of out of the box #5 turnouts.
I tried #5, 6, and 8 Walthers code 83 turnouts on a test board with my locos, 2-6-6-2 and diesel. No problems at all with the #6 and #8 turnouts. But the big steam engine did not like the #5 even though the radius is supposed to be 26". The front wheels pulled well out from center right when they reached the frog since there is no easement into the turnout curve, and derailed there. I couldn't really find anything wrong with the turnout using the NMRA test gauge but carefully "dressed" the points and frog anyway using files and a dremmel wheel, and it seems to work OK now.
I think the smaller the turnout, the more "touchy" (less forgiving) it is likely to be, especially for steam engines with the small leading and trailing wheels. Something to consider? Anyway, that experience led me to decide to stick with #6 and #8 turnouts on my new layout except on sidings that I do not expect to run a big steam engine through. Not that #5 wouldn't work, but I just expect more trouble with them. And would expect even more trouble with #4's.
Admit I am new to this again, but thought I'd throw out my test results for consideration.
Huntington Junction - Freelance based on the B&O and C&O in coal country before the merger... doing it my way. Now working on phase 3. - Walt
For photos and more: http://www.wkhobbies.com/model-railroad/
Not so, Peco has a #5 in code 83.
Paulus Jas Hi Dante, according to my information a 26" closure rail radius belongs to a #5 turnout (e.g. Track Planning For Realistic Operation 3'd ed page 78 and the appropriate NMRA sheet). You are probably right, not every #4 turnout produced for the market will be exactly the same. Anyway this would add a new series of problems or possibilities for newbies and old hats alike. BTW where stands W/S for? Walthers /Shinohara! The only producer of out of the box #5 turnouts. Paul
Paul,
I have many Walthers/Shinohara (W/S) turnouts of various sizes. Many are #4s, and I assure you that their closure rail radii are all 26".