Lastspikemike I intended to point out that the track centre spacing for Peco #6 is the same as for the #7. I conclude that the angle of the diverging route to the main route is the same in both cases. Without actually being there and putting down the turnouts in the available locations (or paper templates as some do) it is not possible to decide which will work better, if at all. I also understand that I may not see the ultimate objective. But then I'm not trying to solve the issue. I'm offering possible solutions I have used in similar spots. I'm also exploring the situation presented because I have a shelf layout under construction. I have a 9' yard/ station. My longest train will be longer than that. I'm cheating by moving the yard lead around the approach bend (and using mainline track as part of the yard lead but that's a whole 'nother rats nest). Two Peco #7 to makevthe main line crossover and then connecting the yard lead to the main with a third Peco #6 LH on the far side of the crossover so as to both maximize the dedicated part of the yard lead and the mainline passing/runaround siding I need for my long passenger train. The constraint is the grade commencement point on the main which is defined by the elevated crossing point further around the shelf. For 2% I need 16' so minimum of 8' if I split the grade into up and down which is the only way it fits. Therefore, I appreciate the explanations. I am not seeing exactly why there's a difference between using the #6 to initiate the yard siding as part of the transition straight and installing a #7 as part of the easement into the curve, initiating the siding a little further down the S bend, closer to the position of the viewer in the photo. The subsequent S bend created in the siding by the turnout should not be different enough for that to be a factor. The planned siding creates two successive S bends in the siding no matter which turnout you use. At least as I understand the plan. You have then three S bends to deal with. By moving the turnout into the curve you provide a longer transition straight for the main line S bend and by using a #7 you also create a longer transition straight for the siding entry. I don't, at the moment, see how that changes the third S bend in the siding. In fact, depending on exactly where the #7 fits into the main line curve the third S bend in the siding may well be eased. Looking at the photo again I note two possible changes to make it easier. I see an opportunity to fit the #7 at the far end of the transition straight. That moves the entry to the S bend in the siding to the beginning of the transition straights in both the siding and main line. The other aspect I notice is the pencilled line for the siding track Maintains the track separation closer to the planned turnout location than is perhaps feasible. Moving the turnout further back to the end of the LH curve (oriented from the perspective of a train entering the siding) and using a #6 or #8 LH instead of a RH to create the siding might work better, preserving the desired track spacing.
I intended to point out that the track centre spacing for Peco #6 is the same as for the #7. I conclude that the angle of the diverging route to the main route is the same in both cases. Without actually being there and putting down the turnouts in the available locations (or paper templates as some do) it is not possible to decide which will work better, if at all.
I also understand that I may not see the ultimate objective. But then I'm not trying to solve the issue. I'm offering possible solutions I have used in similar spots. I'm also exploring the situation presented because I have a shelf layout under construction. I have a 9' yard/ station. My longest train will be longer than that. I'm cheating by moving the yard lead around the approach bend (and using mainline track as part of the yard lead but that's a whole 'nother rats nest). Two Peco #7 to makevthe main line crossover and then connecting the yard lead to the main with a third Peco #6 LH on the far side of the crossover so as to both maximize the dedicated part of the yard lead and the mainline passing/runaround siding I need for my long passenger train. The constraint is the grade commencement point on the main which is defined by the elevated crossing point further around the shelf. For 2% I need 16' so minimum of 8' if I split the grade into up and down which is the only way it fits.
Therefore, I appreciate the explanations. I am not seeing exactly why there's a difference between using the #6 to initiate the yard siding as part of the transition straight and installing a #7 as part of the easement into the curve, initiating the siding a little further down the S bend, closer to the position of the viewer in the photo. The subsequent S bend created in the siding by the turnout should not be different enough for that to be a factor.
The planned siding creates two successive S bends in the siding no matter which turnout you use. At least as I understand the plan. You have then three S bends to deal with. By moving the turnout into the curve you provide a longer transition straight for the main line S bend and by using a #7 you also create a longer transition straight for the siding entry. I don't, at the moment, see how that changes the third S bend in the siding. In fact, depending on exactly where the #7 fits into the main line curve the third S bend in the siding may well be eased.
Looking at the photo again I note two possible changes to make it easier. I see an opportunity to fit the #7 at the far end of the transition straight. That moves the entry to the S bend in the siding to the beginning of the transition straights in both the siding and main line.
The other aspect I notice is the pencilled line for the siding track Maintains the track separation closer to the planned turnout location than is perhaps feasible. Moving the turnout further back to the end of the LH curve (oriented from the perspective of a train entering the siding) and using a #6 or #8 LH instead of a RH to create the siding might work better, preserving the desired track spacing.
Mike, my experince supports much of your theories. In my use of curved Peco turnoouts, I have found that a regular #6 turnout accomplishes the same thing with not much adjustment of the surrounding track.
In Jim's situation, I don't think he wants to adjust the surrounding track at all, keeping the curves precisely as he has them. The curved turnout simply doesn't fit as well because of whatever differences there are. As indicated before, I don't think that he can reduce the 60 inch radius to a 36 inch outer radius quick enough before he goes off the edge of the peninsula. The embedded 60 inch easement within the 12 inch long turnout needs to be shorter. If it were only 2 inches, say, he could spirally decrease from a 60 inch easment to a 36 outer radius and still stay on the benchwork.
He has to keep the frog close enough to the end of the peninsula in order for the inside route to clear the post, and keep the curves as smooth as possible.
But maybe he could fiddle with it a bit more and it would work like you say.
Because of similar (but not exactly the same) spacing and angles of the #6 straight and #7 curved turnouts, I don't find many uses for a #7 curved Peco turnout. In my experience, its because of the excessively broad 60 inch radius of the outer curve. There are many more uses for the Walthers product, and probably the Atlas.
Having said that, my switching district has found where the curved turnout is the perfect track.
A regular #8 is in the passing siding to start a spur. I immediately connected a curved turnout onto the diverging track, backwards pointing, so the broad radius acts as a curve into a spur and the other track heads back to another spur. The whole thing is a swithcback. The curved #7 turnout works better than a straight #6 turnout there just because of the unique confines of space in that particular spot.
If Peco would've made that outer radius about 46 inches, I would have more uses for it, but, it would also lengthen the entire piece of track.
- Douglas
As you can see in the yard picture, it took a second turnout's diverging route on the 60" radius side, plus straight track on the 36" radius side of the Peco to get the two tracks to come close to one another.
Unless you were already in the curve, you wouldn't want to put a broader radius than 36" on the inner leg of the Peco, otherwise you have a reverse easement - a sharper curve leading to a broader curve. Not to mention changing the curve directly off the diverging side of the turnout is an invitation to get a kink.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hmmm, I guess I didn't explain it very well. Even though the centers of the track are two inches apart on the turnout, continuing a 60 inch curve around a peninsula and continuing a 36 inch curve as well is going to cause those curves to continually separate farther apart as you lay track.
Even if you close the 60 and widen the 36 as you lay track, its going to take either a long distance or some very unnatural and unelegant adjustments in the two curves to get them to do what Jim wants them to do.
Both have their advantages and disadvantages.
Atlas curved code 83 is 22" inner and 30" outer.
Rio Grande. The Action Road - Focus 1977-1983
Lastspikemike Will this reply post? Odd, I got the 403 error repeatedly so edited my post rather than post in sequence. Having trouble understanding the suggested problem with radii when using a #7 Peco given I've used a lot of them and find them handy for compression.
Will this reply post?
Odd, I got the 403 error repeatedly so edited my post rather than post in sequence.
Having trouble understanding the suggested problem with radii when using a #7 Peco given I've used a lot of them and find them handy for compression.
As Jim said, the disparity in the 60/36 radii makes it difficult to start a curved passing siding like RIO is trying to do, and keep the track centers an attractive 2.5 to 3 inches apart. For that particular space, the two tracks will be too far apart as he builds smooth curves off of the disperate radii.
A Walthers curved turnout with closer radii would keep the curves closer together, but the trade off is that you get an awfully long turnout with (sometimes) unstable point rails since they are so long too.
LastspikemikeHaving trouble understanding the suggested problem with radii when using a #7 Peco given I've used a lot of them and find them handy for compression.
It's all about the geometry of the area in question. I don't have any pictures to demonstrate the why handy. The Peco #7 have a much bigger difference between inner and outer radius (36"/60") which I assume was made to allow them to be more compact but giving them a disadvantage in certain circumstances. The Walthers/Shinohara #8 has a nominal 32" inner/36"outer radius and due to that configuratoin they are much longer.
Each of the above may work in some places and not others. I've used them both and know this from experience. In the photo posted earlier, both turnouts can be seen. In the forground is a Peco code 83 #7 LH curved, and in the distance inside track there is a code 100 Shinohara #8 curved.
riogrande5761 I haven't run trains on the #6 so was not aware of the lurch factor being a problem.
I wouldn't want to consider it a problem. I simply noticed that my longer locos went through a #6 Peco differently than what I saw with Atlas #6s. I figured out the points diverted at a sharper angle. If you don't have the comparison of the Atlas #6 in your face constantly then you probably won't think anything of it.
I agree. The wide disparity between inner and outer tends to limit how/where you can use Peco curved turnouts and why I couldn't use it in this location. I did find another location where the #7 Peco worked well:
And speaking of Walthers #8 curved, I have a Walthers left hand curved #8 (nominal 32" inner and 36" outer), but it's geometry didn't work either. One of the reasons I don't want to use them here is the inside radius is closer to 30 inches, say say even 28 inches, which is smaller than my mainline minimum radius.
I also prefer Peco #8 on the mainline, but here it seemed a #6 could work and still have plenty broad curve - I haven't run trains on the #6 so was not aware of the lurch factor being a problem. Peco #6 or #8 both fit, but the #8 leaves a considerably shorter length from the curve to the points and 89' rolling stock is planned to be run.
riogrande5761 I've got a Peco #7 curved turnout and test fitted in in the area of interest - it didn't fit well at all. The stright #6 or #8 are a better fit geometrically.
I've got a Peco #7 curved turnout and test fitted in in the area of interest - it didn't fit well at all. The stright #6 or #8 are a better fit geometrically.
Its difficult to use the Peco curved turnout because there is a wide disparity between the inner and outer radii that would not work well in that area you're working with. As you found out.
OTOH, a WALTHERS number 8 curved turnout would have the outer 36 and inner 32 (or is it 30?) and is better suited for starting two parallel sweeping curves.
I am a bit farther along in laying track than you. What I noticed about the Peco #6s is that, in order to achieve their compactness whereby they shorten the distance from the points to the frog, the points diverge away from the stock rails at a more severe angle than the Atlas #6....which is a longer turnout from points to frog.
It doesn't hurt performance, but my longer locos and cars tended to "lerch" sideway off of the stock rail rather unelegantly. (You can see that angle in your pic that has it perfectly angled toward the camera).
So that's why I suggest a #8 turnout since you will want to have the free-ist flowing train movement merging into that section. Two big broad sweeping S curves that should not be impacted by a sideways lerch in the middle of it.
It is a matter of taste of course. You may not notice it (until some jerk on the internet had to point it out), but the longer Atlas #6s allow longer locos and cars to move away from the stock rail at a more gentle angle.
Since I stick with Peco, I use #8s exclusively on the main and use #6's for spurs, where their compactness comes more into play.
A #6 or #8 will fit there. Either can be positioned so the diverging rou flows into the inner siding track. ( no danger w regard to the support pole.) The biggest difference is a longer straight section before the back end of the turnout.
Just from the angle of the pic, I think a #8 would look better there. The way the turnout is positioned, it looks like you will need a bit of straight track coming off the turnout before you can start the curve as to not hit the post. Trains will not flow as smoothly into that long curve, IMO.
A #8 would start with a shallower diverging angle and you could start a curve immediately to remain more parallel with the outer track. It would flow more elegantly, IMO, without so much of a straight section between the diverging leg of the turnout and the curve. You might be able to clip an inch off of the tangent leg to shorten the overall lenght of the turnout and avoid the S curve issue you're concerned about. Also the #8 would make for a very gradual S curve.
Just an observation from the angle of the pic.
And if you're scrounging for #6s, that would be another you could use elsewhere.
A #6 should be fine there, since the tightest part of a #6 is still a less sharp curve that either the one leading in to the turnout or either one leading out of it. If the current tangent it 27", even putting in the turnout should result in a tangent that's still more than a car length, even for 86' TTX cars. With slightly over a car length tangent between curves, the S curve is pretty much a non-issue.
rrinker I cheated - the preview "look inside" on Amazon for Track Planning for Realistic Operation is the page with Armstrong's chart Big Smile Neither of my copies is available at hand. Yes, a #6 into a 30" or so radius curve should be a bit of an easement. I'm using #8s for my mainline crossovers, including the crossover to the first AD track in my yard, after that - #6, maybe some #5 in the city trackage where space is tight. City branch service would be by a switcher, and all smaller cars anyway. --Randy
I was thinking of using a #8 at the first bifurcation into my yard as well, and the rest #6 for the yard.
I scored another code 83 #6 Electrofrog (which are getting rare) which is good because I ended up stealing one from the bunch I am going to use in the mainyard to use going into one of my sidings.
Here is the spot I am referring to. There is an S curve here with about 27 inches of straight tangent between them. The trick is I want to have a turnout to go from the 36" radius curve (to the right in the photo) to split into a 33 and 35 5/8th radius curve to the left.
As #8 turnout would fit but the straight tangent section would be shorter than I would like, especially if operating several Tangent 86' boxcars through it. However, the #6 would still do the job and provide a somewhat easemented curve into the siding while allowing more tangent to the S curve.
I cheated - the preview "look inside" on Amazon for Track Planning for Realistic Operation is the page with Armstrong's chart Neither of my copies is available at hand.
Yes, a #6 into a 30" or so radius curve should be a bit of an easement.
I'm using #8s for my mainline crossovers, including the crossover to the first AD track in my yard, after that - #6, maybe some #5 in the city trackage where space is tight. City branch service would be by a switcher, and all smaller cars anyway.
Thanks Randy - substitution radius perhaps was what I was curious about. Assuming Peco's #5 and #6 (I only have #6 so far) are matching NMRA standards, they would match what is listed in John Armstrongs book, which I have at home somewhere.
My plans are to use a #6 right hand into a siding. Since it has a larger radius than the siding curve of 33" radius, it should somewhat hopefully act as an easement of sorts.
Regarding #8 turnouts, I am planning to use them in some locations where single track enters a siding, and the geometery will be similar to a cross-over, and also a cross-over as well.
Thanks for having that info handy.
Subsititution radius is the closest equivalent for a proper numbers turnout. THere's chart in the NMRA standards somewhere, also in Track Planning for Realistic Operation. #5 is listed at 44", #6 at 56" . That's for HO.
The sharpest curve in the turnout is the closure rail radius, which is tighter. A #5 is listed at 25" radius, a #6 is 43" radius. Which is why, other than crossovers where an S curve is generated, #8s are just space wasters - unless you have minumum radius curves over 40".
In case you are curious, the #8 Closure Rail Radius is 67" and the substitution radius is 110". A #4 is 15" and 29"
A bunch of answers that don't answer the question is par for the course.
I don't mind as long as someone can offer the approximate radius the curved part of the Peco #6 code 83 turnouts is (you know, as if you could drop that part into a curve - what is that radius equivelent. Probably fairly broad for a #6. Just wondering if someone knew off the top of their head.
Could you be more specific. I'm forecasting a bunch of answers to occur that may not answer the question.
The Peco 83 has straight track beyond the frog, and of course, the point rails are straight as well...just angled to act like a curve.
The only actually curved rails are the rails from the point rails to the frog. The curved rails would be the main constraint for equipment performance. By my rough eyeball overlaying flex track onto a #6, it looks about 36 inch radius. Of course, the #5 turnout would have sharper curved rails. I don't have any #5s to overlay.
If you're looking for track plan design question , where the entire turnout, angled points and straight sections too, could somewhat replace a curve; I do not have that info.
The Peco 100 has a design more suitable for determining a radius to compare it to a curve.
Just wanted to make a distinction about what you're actually asking for so the folks who have better information can help.
Does anyone happen to have handy the curve equivelents of the code 83 Peco turnouts, such as the #5 and especially #6?