I’d like to create a derail-proof crossover on my layout – either direction between two main lines. I laid 4 Atlas “Snap” switches connecting with each other, but this creates a small S curve which causes occassional derailments (depending on the car length, coupler swing, wheel set and phase of the moon). I read somewhere that a better choice for crossovers would be #6 turnouts. Would this still create an “S”? I’m reluctant to put a staright between the turnouts since that pushes the mainlines farther apart in limited space.
Atlas “Snap” switches are actually less than a #4 switch, so derails would be possible at more than a crawl speed. I’d use a #6 personally, but a #5 would do if you don’t really have the space for a #6 or higher, a #4 would work in a pinch, and just remember to keep the speeds down to about 20-30 Scale MPH through them.
Also depends on what era and type of cars and loco’s will be going through the crossover, but a #6 would handle anthing modern.
Jack,
in the 2005 MR Trackplanning issue there is an entire section on dealing with and eliminating ‘S’ curves at crossovers, staging area entry and other such areas of the layout.
One point describes placing the crossover coming out of a curve, this eliminates the ‘S’ altogether, in this case I would imagine a #4 would be fine. Here’s a rather poorly drawn diagram.
notice how as the train crosses from in/out or out/in it continues on the same curve, no ‘S’.
Maybe this is a possibility for you, the book is well worth the $$ or at the least a look at in the LHS.
I’ve got a crossover leading out of my psgr depot and I run scale length trains (as to both train length and car length within the train) and most have diaphragms and are close coupled…all combining to make derailments an almost certainty. I avoid them by following both peices of advice above. I used Shinohara curvable #8s and placed them at the beginning of a left hand curve. The first switch is a left hand on the curve and it runs into a right hand switch that forms the beginning of the tangent. Problem solved for me, but I am fortunate in not having to deal w/ the space constraints that afflict most MRRs.
I’ve got a crossover leading out of my psgr depot and I run scale length trains (as to both train length and car length within the train) and most have diaphragms and are close coupled…all combining to make derailments an almost certainty. I avoid them by following both peices of advice above. I used Shinohara curvable #8s and placed them at the beginning of a left hand curve. The first switch is a left hand on the curve and it runs into a right hand switch that forms the beginning of the tangent. Problem solved for me, but I am fortunate in not having to deal w/ the space constraints that afflict most MRRs.
I may be missing something here, but what about crossovers ready made, like Peco and others? We installed crossovers on our club layout and we have no problems with them, even at speed. Don’t recall what brand they are, but I think Peco. Ken
The Atlas #6 crossovers will work fine. True turnouts have a straight section through the frog extending to the end of the turnout. You get a nice ‘straight’ section between the frogs of the 2 turnouts. I have used Atlas #6 code 100 turnouts in my staging yard and have had NO problems with trains running through of backing in theough a #6. Just use care laying the track!
My understanding of what Jim says is that beyond the frog of the #6’s the track is straight, therefor turnout-turnout will be OK as the diverging rails are straight not curved.
