Single Slip verses Double Slip Turnouts

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beiland

Well-Known Member
#1
Would anyone mind giving me their thoughts about using a single slip turnout rather than a double slip one,...positives vs negatives.??


I have in mind a place where I think the single slip would be advisable over a double, but before describing my particular situation I was looking to hear generalities about the two.
 

beiland

Well-Known Member
#2
Single or Double Slip Turnout





So here is my particular situation. I have two spur lines off of the mainlines feeding my peninsula area. It is desired that these 2 entering lines be able to select between either of 2 lines themselves. The most 'compact' manner to do such a thing is a slip switch.


A single slip switch accomplishes just what I want to do,...take the entering train and curve it around onto the same side, or cross it over to the other side. It does this in one single selection of the controller. It can remain on one single selection and do the same thing for trains entering from either track,...cross them over, or leave then curving around on the 'same track'.


Another nice feature of the single slip is that should the train stop, then get reversed while over this turnout, the train will NOT try to pick the opposite track and derail,,,as it might well do on a double slip switch. Is my thinking correct??


Since the double slip switch has 'another set of point rails' at its other end, that ARE NOT always set in the correct position, the train could well back up and try to chose a different route than it came in on. In other words it requires 2 control settings to get the dbl-slip to act in the manner I seek above, ….plus when I change the incoming route I have to make TWO selections to get it to operate like the single slip that I did not have to make any new selections.??








Overall view (sorry, still just a paste in for the peninsula plan as I have not finished final plan for it)









Enlarged peninsula (again, somewhat representative)









Slip switch location



Single or Double



The 2 tracks coming off the slip switch will be feeding the two container unloading/loading tracks located either side of that 'passenger station' in the original Tupper Lake plan.





The track on the left next to the aisle will be the 'escape track' for the locos that pulled the trains into the peninsula area to escape back to the freight yard area or the turntable,...a 22” radius one & a 24” radius one for bigger steamers.



Container crane (block of wood) straddling container tracks
 
#3
Would anyone mind giving me their thoughts about using a single slip turnout rather than a double slip one,...positives vs negatives.??

I have in mind a place where I think the single slip would be advisable over a double, but before describing my particular situation I was looking to hear generalities about the two.
The generality is that a double slip switch has all the functionality of a double crossover. Each incoming track can exit to each of the opposite tracks. It takes the place of 4 turnouts. With a single slip, only one of the incoming tracks can exit to both the other tracks. The other track can only cross through to the opposite exiting track, not to the opposing track. A single slip would be like two turnouts and a crossing.

Slip Switch Equivalent.jpg


So the answer to your question is, yes a double is twice as complicated, but it depends on what routing is needed.
From your scenario, it looks to me like trains from both tracks need to be able to choose either route in both directions. If that is a correct assessment, it dictates a double.
 
#4
I don't see why you want a single slip switch. It will really limit the operation. Slip switch at X with four routes into it: Main, Siding, Left wye leg, Right wye leg. (ignore the periods, they are there to space the letters out).

M...………..L
…….X...…..
S...………...R

A single slip will allow trains to go M-L, S-L, M-R, but not S-R or S-R, S-L, M-R but not M-L.
With a double slip all routes are available: M-L, M-R, S-L, S-R.
With a single slip switch, you have to give up either M-L or S-R.

I also still do not understand why you think reversing direction is an issue in a slip switch, you still have points on either side of the frog, You will have to check whether points on either side of the frog are lined correctly. You are going to operate in both directions over the switch, what difference does it make if you stop and reverse on the switch?
 
#5
I'll review your posting Dave, and come back with my justification if I can reaffirm it in my mind.

Meanwhile, have a look at my next posting, and perhaps that will help explain why I chose the now 'mysterious, simple turnout' I have in my possession,...what is it?
 
#6
A Case of Mistaken ID, ….Single Slip or What?



All of the slip-type turnouts I had in my possession were double slips by Peco and Roco. There was no doubts that these were dbl slips.



I had another slip turnout that I just assumed was a single slip as it had only one control motor. Now I am unsure if I identified it correctly?? Here is a photo of the two types together.




Then here is a photo of that mysterious turnout I first identified as a single slip. It is labeled an 'Atlas', made in Austria (likely by Roco), #4547. As I inspect it more closely it appears NOT to be a single-slip in our conventional thinking, but rather some 'automated crossover' ??










Here are a couple of other photos I found on the internet,...















Has anyone else experience with such a turnout? ...and how would you name it??
 
#7
I would suggest using the highest quality turnout you can find that will ensure trouble free operation over the coming years.

I have all Atlas Custom Line turnouts on my layout and for the most part have been trouble free, but if I was planning using a double or single slip turnout, my first choice wouldn't be an Atlas product, but the highest quality nickel silver product I could find.

You have an interesting track plan.

Greg
 
#8
A Case of Mistaken ID, ….Single Slip or What?
it correctly?? Here is a photo of the two types together.

Then here is a photo of that mysterious turnout I first identified as a single slip. It is labeled an 'Atlas', made in Austria (likely by Roco), #4547. As I inspect it more closely it appears NOT to be a single-slip in our conventional thinking, but rather some 'automated crossover' ??
Has anyone else experience with such a turnout? ...and how would you name it??
I would call it a double slip turnout. The translation from German calls it an "intersection switch".

"The Roco intersection switch is built as a crossover. The drive is switched on. The two outer metal heart pieces or not powered." The second paragraph says something about "See circuit diagram for switching the ?polarity?" Unfortunately I've not had German since high school 40 years ago. I can assume that in this case by "heart pieces" they mean what we call a "frog".
 
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#9
I have several Atlas "double-slip" (DSS) turnouts on my layout, (One is brass, the other is nickel-silver. Both function the same.) The neat thing about the Atlas DSS is that a train can't derail if the turnout is thrown "against" the approaching train! The worst thing that can happen is that the train will exit the turnout in the wrong route. The switch machine has control of all points simultaneously, whereas DSS made by other manufacturers, like Shinohara, have each pair of points controlled separately from each other. Thus, two switch machines or ground throws are required, and the points can be thrown against an oncoming train, resulting in a derailment! The diagram on the Rocco package shows a single switch machine, which might make it similar to the Atlas DSS in function. The turnout on the right in the photo showing two turnouts has two switch machines, and each machine appears to control one set of points at one end of the turnout, which might make it function like a Shinohara-type. Do I make myself clear...as mud?
 



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