A question on double slip switches - are they basically two switches combined into one piece?
The reason I ask this question is that it looks like a space that I’ve got two number #8s in (both right hand switches, one is part of a crossover to the main and the other is part of a yard ladder for A/D tracks), spaced closely together that the points are separated by only their factory spacing would seem to be a good candidate to replace with a single #8 double slip, giving my yard ladder the ability to start sooner, making the A/D body tracks longer.
I’ve played with this in XTrkCAD, and it seems to fit, but I’d like to know if anybody has done a similar thing - replace standard switches with a double slip.
Sure have, and I considered it a must-have on my layout. You are right, they are essentially a crossover with two diverging routes added allowing you to actually cross an intermediary track. Here is a photo of a Fast Tracks version, hand-laid, in my yard:
When I was building my current layout, the guys at the LHS suggested that instead of a crossover from Track A to Track B followed by a turnout into a yard or siding, that I use a turnout from Track A connected to a double slip to route trains to Track B or to the yard (siding). The reason was that the double slip would eliminate the S-curve caused by connecting a turnout to a crossover.
I would equate a double slip switch to a crossing with turnout capabilites.
On my two zone panels which will have to control double slip switches, they will be represented as the equivalent of two standard turnouts points facing points - because that is how they function. On the main panel they are simply X with a switch machine power stud in each leg. (The zone panels have rotary switches, thanks to the need to control and signal which panel has control of a given switch machine.)
On the ground, double slips are used to shorten yard throats, eliminate S curves and ease the travel of the wheels through the interlocking. OTOH, they are a high-maintenance item, so the prototype tends to minimize their use.
Note that I said minimize, not totally avoid. If the only way to cram passing capability onto a narrow mountain ledge between a tunnel and a bridge abutment is to route 100+ trains a day across a double slip switch in one direction or another, that’s what gets installed and used.
Chuck (Modeling Central Japan in September, 1964 - with double slip switches where necessary.
I would go for one. I’ve got one place on my layout where I could have used a double-slip if I’d thought of it. The geometry doesn’t demand it, and I’m not even sure I would use it all that much, but…these things are just so cool. I happen to like interesting stretches of trackwork, particularly turnout combinations that are unusual and eye-catching. Few things you can do with track compare with a double-slip in that regard.
Gimmickry, simply gimmickry. A double-slip switch is “just” two turnouts back-to-back, overlapping each other. Give me two single cross-overs over one double cross-over. Had a friend (civil engineer) help design a layout for me, and I spent MANY HOURS eliminating double-crossovers, double-slip switches, and three-way turnouts. The layout was to represent a RURAL environment for goodness sake. No need for gratuitous complexity. … And I wouldn’t think of operating a Big Boy on a backwoods logging railroad either.
I have been studying a track diagram for the old Dearborn Station in Chicago and there is a considerable use of double slip switches in the station area. Presumably, this was done to save space and eliminate S curves for the long passenger cars.
Double slip switches are also used extensively in freight yards for the same reasons. So, double slip switches may be ideal for OP’s needs. Gimmicky? No, more like practical.
On my 7 track stub ended yard, I use two double slip switches with below layout controls. This allows for closer spacing of tracks in limited areas. I have no trouble with them. Additional # 6 switches, allow access to any of the seven tracks, without the switcher having to leave the yard, and allows for longer double drill tracks Bob Hahn Click on photos to enlarge them. This pass-through 7 track yard has an old single motor double slip switch, and other switches within the yard, so that the main line is never tied up.
I use a double slip half way down my arrival departure track that connects to the main classification track. It acts as a split, so I can switch the classification tracks from either the yard lead or the arrival departure track. Convenient for swathing inbound trains without first having to move them to the classification yard, and building outbounds right on the departure tracks. At the same time I can have a local switching the storage tracks, or working industries that branch off of the yard lead.
I think Crandell’s picture of his hand-laid double slip demonstrates my point better than anything I could say. Beautiful workmanship, beautiful photography and a beautiful scene.
Heck, I think it was #4 on my list of “givens”, just after a roundhouse and (working) turntable. It was waaaay too important for the list of “druthers”.
Thanks for your compliment, Mr. B.
Okay, gotta take my blood pressure meds…where’d I put them…?
You should use double slip switches where it makes good sense to use them. It’s not likely that one would connect two industrial spurs to the same through track, but if there’s a legitimate requirement to keep the yard throat short/free of S curves under backup moves (or to keep from slamming your passengers from side to side…)[^]
Of course, when the pretty young lady looks at your hand-laid yard throat and says, “Hey! That’s cool…”[8D][tup] (Of course, the PYL in question is my grand-daughter…[:-^])
The praise is nice. Reducing the length of the throat by the length of a local freight - priceless![:D]
Man, I wish I could get the women in my life to appreciate trackwork. You are a lucky man.
I realized while reading Crandell’s last post that double-slips are a bit like roundhouses and turntables. They are way over-represented in the model world than in the real world. Many of us diesel users have them, even though they are kind of anachronistic by the late Transition Era. But, well, they’re just so cool…
