Hi Bruce. I've been rehashing the elevator idea to see if I can solve the old "empties-in/loads-out" dilemma at the end of my proposed logging spur. There's a decent article in Model RR Planning 2001 that may be useful to us both... See if you can scrounge a copy from a friend or library. The only real downside will be that it has to accommodate a full train length and more. That may be difficult on my L-girder & joist benchwork; some more thinking needed here. I'd have the same problem with a helix: getting below the joists. That's why I elected to put my staging inside a mountain. Yep, it's hidden but I can reach everything from the sides except a couple of switch motors, and they are on the 'movit' list. (not difficult, since they use pianowire in a tube to operate the points)
About tightening the curvature of your helix... A couple of questions: what kind of trains will you be pulling? There's some real math to figuring out the effect of the curvature on pulling requirement to get up the hill. A curve adds to the effective grade. It escapes me now, but I've seen the calculation somewhere (NMRA site?) in the past couple of years. What's the Hudson's minimum radius, and max overhang on a curve? Long passenger cars have underhang on the inside of a curve. Some modern high-clearance cars need more headroom than the standard 3" of the NMRA guage. Try to have a good vertical easement onto & off the slope of the helix; too abrupt, and there'll be risk of uncoupling.
There's a neat idea in Model RR Planning 2008 with the loops of a helix alternating on the inside-and-outside of a backbone to provide more vertical separation between coils. This allowed the alternating loops to be visible in scenery, as opposed to there just being a big drum or box to stare at. Hmm....
As you may guess, I sort of enjoy the figuring-out of construction projects and the reward when the plans come together. My kind of fun!
Let us all know what you decide on. Have fun, always. George
Hi George, Thanks for all your help, BTW my name is Bruce, Mike is one of my dogs. Anyway it sounds like you really know what you're talking about. I do think a helix is my best solution, although I've given the elevator thing some thought, it sure would take up alot less room. I can't remember if I 've heard of a commercially available elevator or not. I guess I could research that. Anyway, yes my gauge is HO. I'm modeling NYC transition era, but most of my locos are switchers 0-6-0's, 0-8-0's and a SW1 diesel. I have one 2-8-0 and one BLI Hudson. I think I could get away with a fairly tight radius helix, as far as helix's go. What do you think?
Bruce
Hi, Mike. Oops! I made an assumption that you are working in HO, because of your 2' shelf depth. Hope that is correct. If you are in N scale, the helix will be nearly 1/2 the diameter of the HO I quoted. I see your point; the helix looks like the best solution for you. I don't see why it could not hang on the wall like the rest of the layout if you give it a decent frame and good solid brackets. I like the legless approach, but you'll likely need to put 1 or 2 in for extra stability. You mention your shelf is 54" from the floor. Is there any way to raise it a bit so the lower level will be easier to see? There's a million considerations to every little thing, but nothing is insurmountable.
There's been a lot of chatter in this forum about helixes, and the latest "Model RR Planning" mag has an article on one. It's worth a look.
Doing a bit of the math: very roughly, a 50" diam 1-track helix is about 157" length per coil..(It's actually less, since the track is set back from the edge of the coil) At 2.5% grade it only gives you about 3.75" height-change railhead-railhead That means there isn't a lot of room for thickness of material (subroadbed, track, support, etc). If you make the thing oval-shaped rather than round, the coil length will increase, as will the height between coils, and that can be a good thing. Is your layout going completely around the room.. even across the doorway? Or does it turn back on itself? Turning back means the helix should probably go by that door. You can make the entrance into the side of a hill to hide it. What you will run on it becomes important; a bigboy will need a bigger curve radius than a small loco. And, the curve itself may mean enough drag that a helper loco may be necessary if you want longer trains.
Like I said, a million things to consider... let me know what you think. I hope I don't dissuade you from trying a helix; there are a lot of them around. Back issues of MR have had some in them to give one ideas.
George
... an afterthought: a 'train elevator' might be an idea. I saw one in print recently. It looks a bit dicy to set up, but may be useful if losing floorspace is a problem. Now you got me thinking......
A helix with reasonable diameter of about 54" will gobble floorspace as previously mentioned. How about making a long grade parallel to 2 walls instead? You'd get about 6" of height change if the track went along 2 walls if you used 2.5% grade; even more if it went along 3 walls. Be wary of putting the trackwork inside a tunnel without access to clean up a derailment or fix something. Guess where the problems will occur! A removable viewblock isn't hard to make, and some of the grade can be serviced from above if you're nimble on a stepladder.
Have fun... George
You might want to keep in mind (if you haven't already) that a helix will take up anywhere from 12.25 to 23.36 square feet, depending on how tight the radius is. That's a BUNCH of floor space. and if your room is the same dimensions as the layout (like mine) it means you'll lose access to one of the corners...
If, OTOH, you have room outside the outer dimensions of the current layout, well then, go for it! There have been a lot of articles and threads about helixes, so there's lots of info out there.
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Gary M. Collins gmcrailgNOSPAM@gmail.com
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"Common Sense, Ain't!" -- G. M. Collins
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