I have read info on this forum regarding minimum radius that can be used with various sized steam engines, but what about a Helix? It would seem to me that these turns would be useless for a BigBoy or an Allegheny!!!
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The only problems encountered in a helix are grade and curve radius. If you have a small and steep helix (18" curves and a 5% grade) you won’t get ANY train up it. But if you have a helix built to decent parameters (30" radius and 1.5% grades) you should be able to get any train or engine combination up it successfully.
Thanks Ray, this is a big help, do you have any recommendations on helix mfgr?
Try www.trainstyles.com or call 262.241.9987 for a brochure or with questions.
Ray is right. I just finnished a 29" & 32" radii double tracked helix at 2%. Cab forwards, 2-8-8-2’s climb hauling long trains no problem. RMC had an interesting Article two months ago on helix building…
Is there any real life use of a helix or is it just a method to change levels in a confined area for a model? I am working on a plan for my first layout in 30 years and after getting my feet wet with a double oval I am thinking about a mountain switchback or a quarry with a narrow gauge line circling down the parimiter. The helix at the above mentioned website looked much to uniform to use for anything like that.
bukwrn,
There are a few real life helixs. As far as I am aware, the real ones are only one loop at most.
Model railroads use them a lot more that the real thing, but just like the real thing, they are designed to elevate track quickly in a short distance (as the crow flys). The most common model railroad use is for multi-deck layouts.
The first one that jumps to mind is the one turn helix at Tehachapi in southern CA. I think there is another one somewhere in CO. They are rare, but they do exist. I believe there are also several in Switzerland.
Amazing. http://tinyurl.com/3peqd I have always lived in the Midwest USA and the need for this never occoured to me. It is much more eligant then hidding an elevation change inside a “tunnel” as I have seen in many commercially designed layouts. Another idea for me to consider.
The Canadian Pacific Spiral Tunnels are a good case for real life railroading.
http://www.samlindsey.com/images/logging/Spiral_Tunnel_1.jpg
This is an excellent drawing of both tunnels showing how they do the job they were made for.
Gordon
Theres also Williams loop on the UP.The CP spiral tunnel is amazing .I havnt seen it in person.
Just gonna mention that CP spiral, too. Awesome engineering! I had a 36 inch minimum radius double tracked loop on an old layout, and streamliner looked perfect on it, and ran perfectly, too. About 2% grade there. You should have no trouble with a Big Boy steamer, I would guess, on a 30 inch minumum loop or helix. I don’t know your budget, but buying a helix can get pricey. You can have fun making one yourself. Lots of articles have been written about construction. Search the magazines and internet. Good luck. George
One famous Swiss set of helical tunnels is at Wassen on the Gotthard line.
There is a prominent church beside the line which the trains pass three times.
This URL shows a map of the layout, unfortunately in German.
http://home.arcor.de/d_h/k_wassen.htm
And this one shows the actual church on the right with the rail tracks visible if you search carefully.
http://www.exploitz.com/images/pprints/Wassen-and-Middle-Maienreuss-Bridge.jpg
BTW the trains on this line are often headed by two Re 6/6 electic locos of 10 000 HP each which somewhat outdoes a Big Boy.
Alex
I’ve got a 23.5" r helix with a 2.4% grade and run a Genesis Challenger up with no problems. A 12 car intermodel train (properly weighted) requires 1 road diesel to pull it up and with 2 diesels I can do over 20. It offers some interesting possibilities like using helpers if I want a longer train, but overall I’m happy with it. I’ve been testing for over two months on it.
Can’t answer the size of steamer question, but just saw a helix using 1/2 plywood subroad bed to support cork. The helix was elevated using all-thread rod on each side supporting about 1/8 in plates. Could have been steel or aluminum. Very adjustable, great clearance on either side, very stable.
The original question seems to already have been answered in the above entries. My train club, the Nazareth Area Society of Model Engineers in Stockertown PA has an HO scale, 4 track wide, five tier helix. When we built this, it was designed to be adjustable to allow for expansion, warpage, and any other shifts that might need to be corrected. The description of how to do it would be too long for here, but if you want details, you can email me at tadiehl@enter.net and I’ll try to answer any questions, and possibly take and post pictures if needed.
I would think the radius of the helix curves would be the deciding factor, just like on any other curved section of track. Of course, the rise of the thing would come into play here as well, but it seems the broader the radius, the less the rise. I would suggest you make the radius of your helix as generous as possible, probably even moreso than the radius used on the rest of your layout, to minimize the rise issue. ASSuming you have the room!
I have posted a couple detail shots of the helix construction methods. You can see them at:
http://www.enter.net/photoalbum/data/tadiehl/200055.jpg
http://www.enter.net/photoalbum/data/tadiehl/180613.jpg
http://www.enter.net/photoalbum/data/tadiehl/112026.jpg
Captions should show up ftom these links.