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HO Helix, space needed?

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Posted by hon30critter on Friday, August 28, 2020 7:34 PM

Wdodge0912
Well I think at most I want to run would be 12 cars on a train with my one 4 axle diesel. Im fine with 6. Im not going super detailed or super realistic, just want to do something where I can run some trains and have some kind of industry that gives me something to do for operations when I want to do that.

Hi Wdodge0912,

If that's what you want then go for it!!! Hopefully you will be happy with the design, but if not you can always start over.

I think the real point is to start building something. I got myself into a classic 'procrastination by re-examination' (or however that phrase goes), and I wasted several years planning and then re-planning my 'perfect' layout. I have been in the hobby for about 18 years. I finally started to build a layout this year which doesn't resemble the layout I spent years designing in any way, shape or form!

Cheers!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by Wdodge0912 on Friday, August 28, 2020 6:58 PM

Well I think at most I want to run would be 12 cars on a train with my one 4 axle diesel. Im fine with 6. Im not going super detailed or super realistic, just want to do something where I can run some trains and have some kind of industry that gives me something to do for operations when I want to do that. If I can squeeze in a bigger table I will, but if I cant I still want something. I figured l the split of a Helix would be a good way to divide the scenes so it feels like 2 different areas. I figured if I had 2 4x6 layouts that I can hook a helix in between or something to make the footprint less. 

 

I still might just have a 4x8 come down from the ceiling, or possibly ifnI can find one cheap enough, set up a 5x9 ping pong table that I can fold up but still have some distance for some buildings I'd attach to the table. 

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Posted by ROBERT PETRICK on Monday, August 24, 2020 2:31 PM

riogrande5761

. . .but the video demonstrates it IS possible to build a small radius helix and it can function for a suprising variety of trains and rolling stock, including long steam engines and 85' passenger cars. 

I agree.

One question that always (and I mean always) pops up on this forum is, "What is the smallest tightest steepest helix that can be used?"

I think this video and its producers answer that question in extremis.

Just my opinion, of course.

Robert

LINK to SNSR Blog


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Posted by riogrande5761 on Monday, August 24, 2020 1:42 PM

Doughless
Watched the video.  Seemed like a pretty fair test.  Kept adding cars and power.  The 46 car long train stalled and stringlined, but the 3 diesel 34 car train went upgrade with no problems. It looks to me like the helix structure, the subroadbed, is thinner than even the roadbed.  I assume that's what helps provide height clearance and limits the grade.

The helix is constructed of gator board which explains the thickness.  They offer components (to order) to allow hobbyists to build a helix any where from 18" radius up to 36 inch radius.  So you don't have go with the 22 inch helix, but the video demonstrates it IS possible to build a small radius helix and it can function for a suprising variety of trains and rolling stock, including long steam engines and 85' passenger cars. 

And as noted 3 six axle engines was able to pull a 34 car train up the helix with out issues.  From tests, you had to exceed around 40 cars before stringlining started to occur.  But helixes can but built in larger diameters which should handle auto racks and double stacks etc.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by Doughless on Monday, August 24, 2020 1:20 PM

riogrande5761

 

 
cuyama
 
riogrande5761
This guy has proven you can actually get away with a lot on a 22 inch helix:

 

 

Watched the video.  Seemed like a pretty fair test.  Kept adding cars and power.  The 46 car long train stalled and stringlined, but the 3 diesel 34 car train went upgrade with no problems.

It looks to me like the helix structure, the subroadbed, is thinner than even the roadbed.  I assume that's what helps provide height clearance and limits the grade.

- Douglas

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Posted by riogrande5761 on Monday, August 24, 2020 7:49 AM

rrinker

 Pretty sure he said 60 and 70 foot passenger cars, clearances prohibited modern autoracks and double stacks. Or maybe those really low slung passenger cars were 80' types.

Here is a description of the passenger train:

- Athearn Genesis HO SD70ACe

- 85' Amfleet Coaches x 5

So those are 85' passenger cars.  But of course this example is 22 inch radius and 3 turns so there are some limitations such as the modern autoracks and double stack.

 

I have a hard time believeing it's only 2.2% grade, that's only 3" total clearance between levels, subtrack out the track height and thickness (what little there is) of the roadbed.

The grade, according to the PDF for the 22" helix is 2.58%.  The material is gatorboard so the decks are fairly thin as opposed to other thicker deck helixes.

I also have to assume the turnoiut at the bottom leading in to the helix is a #5 or better, as my BLI T1 4-8-4 will NOT negotiate an Atlas Custom Line #4 (which is really a 4 1/2) by itself, the internal radius of the turnout is too tight for the 8 drivers, The Bachmann EM1 I can see, smaller drivers, so the 8 wheel rigid wheelbase of each engine is smaller than my T1, but the BLI C&O T1 with 10 drivers.....

The video is about the 22 inch 3 level helix and what is possible.  The turnouts are not at issue here.

IMO, he squarely refutes skeptics with what can be done with a 22 inch level helix and that is the point.  Seeing is believing.  He does show where the limitations are so you know what can and can't be done.  This is for the benefit of the original poster.

 

 

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by hon30critter on Friday, August 21, 2020 10:12 PM

FWIW, here is the NMRA Helix Calculator. It is in the middle column half way down:

http://michiana-nmra.org/resources.html

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by SpaceMouse on Friday, August 21, 2020 9:31 PM

I think I might take a different tack here. If the conflict is with stuff, build your layout to get rid of the stuff. Make a shelf layout 4.5 feet off the ground against the wall and hide all your stored stuff below--out of sight, etc. Then just design your layout as a single level.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

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Posted by selector on Friday, August 21, 2020 5:08 PM

My helix, built 8 years ago, was about 6' in diameter, had a 2% grade, twinned radii at 33 and 36", and only 4" of separation between ramps.  There's no way in aitch ee double hockey sticks a 22" radius is going to pass HO scale items, on top of Code 100/83, through 2.2% gradient ramps.

Let's let logic do the talking...AKA mathematics:  

a. 22" radius means a 'loop' distance, closed once, of just over 138" of circumference for the loop (Pi X D);

b. 138" of distance with 2.2% grade comes to 3" of net rise;

c. Next level has roadbed thickness, plus tracks, and then HO trains of some description, and it has to fit in 3"....??!?!

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Posted by rrinker on Friday, August 21, 2020 2:01 PM

 Pretty sure he said 60 and 70 foot passenger cars, clearances prohibited modern autoracks and double stacks. Or maybe those really low slung passenger cars were 80' types. 

 I have a hard time believeing it's only 2.2% grade, that's only 3" total clearance between levels, subtrack out the track height and thickness (what little there is) of the roadbed.

 I also have to assume the turnoiut at the bottom leading in to the helix is a #5 or better, as my BLI T1 4-8-4 will NOT negotiate an Atlas Custom Line #4 (which is really a 4 1/2) by itself, the internal radius of the turnout is too tight for the 8 drivers, The Bachmann EM1 I can see, smaller drivers, so the 8 wheel rigid wheelbase of each engine is smaller than my T1, but the BLI C&O T1 with 10 drivers..... 

 There are a lot of cuts, but then they do show the stringlining when the trains got too long and the weight of the cars at teh tail end pulled the middle over. So who knows. Still, to do this on a 4x8 layout - you end up with 2 sections, each 4x4, for track, plus a 4x4 area for the helix. Net layout space: 4x8. So it serves no purpose, you gain nothing except the extended run time hidden in the helix.

 If you had 200 sq ft, and took out 16 of it for a helix, you's have 184 sq ft on the lower deck and 184 sq ft on the upper deck - a net gain of 168 sq ft of layout. That would make sense. Unless there is room for the helix outside of the layout space, wher using some extra 16 sq ft of space to gain an additional 4x8 area for the layout. But if that extra 4x4 area is available, the you could have a 4x12 layout with no helix, or 2x 4x8 plus a 4x4 helix. 48 sq ft of layout without a helix, or 64 sq ft on two levels with a helix.

                                 --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by riogrande5761 on Friday, August 21, 2020 1:24 PM

cuyama
 
riogrande5761
This guy has proven you can actually get away with a lot on a 22 inch helix:

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by cuyama on Friday, August 21, 2020 10:33 AM

riogrande5761
This guy has proven you can actually get away with a lot on a 22 inch helix:

I didn't watch the whole video, but I saw only single engines going up and down. Maybe there's a portion with a train, too, but that's where the challenges have arisen for many.

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Posted by riogrande5761 on Friday, August 21, 2020 10:27 AM

This guy has proven you can actually get away with a lot on a 22 inch helix:

https://www.youtube.com/watch?v=4N2Uqi--2xc

 

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by cuyama on Friday, August 21, 2020 10:19 AM

An HO 22" radius multi-turn helix has proven too tight to be practical in a number of cases. It is not just the steep effective grade from the friction of the curves, but also the tendency for cars to stringline -- that is, to derail across the center of the helix. Some of the commercial helix kits are mislabeled as to their nominal grade and are actually steeper. Note also that with clearance allowed for outside supports, even a 22" radius helix will probably be a little wider than 48”.

With short trains of short cars, it might be made to work, but more than a few modelers have abandoned even 24” radius multi-turn helixes and found alternatives. In the space that you have, one might consider unconnected decks: more railroad in the same floor space, but not a continuous run. While out-of-the-ordinary, this concept works well.

One must also consider the supports needed for an upper deck in a free-standing movable layout. Not impossible, but a lot to engineer and build.

Finally, if one builds a 4X8 (for example) lower deck and the helix takes up about half of the area, there seems to be not that much advantage in scenicked layout area over building a single deck.

Byron

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Posted by rrebell on Friday, August 21, 2020 9:42 AM

You can do what you want with 18" radius curves with a helix of less than 40" and 3% grades, gaining aprox 3" per loop. Now depending on the space there may be a better solution. Seen people run a single line to a water heater and loop that and head back on a single line etc.

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Posted by rrinker on Friday, August 21, 2020 8:35 AM

 And a 22" radius helix would need nearly 3% grade to clear each loop with enough space for even a thin roadbed material. That's just the actual grade. Compensating for the curves would make it even worse. Short trains of short cars only, in such a thing. And it needs to be pretty bulletproof, as stopping and starting a train on a steep grade at 22" radius is just asking for it to stringline into the center of the helix.

                                                --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by ndbprr on Friday, August 21, 2020 8:23 AM

A helix with 22" radius curves will take the full 48" space to make a full turn in both directions and a lot of your available space.  Have you considered using a switch back to gain the height. Used by real railroads the train goes uphill to dead end

The switch behind the train is alligned for the next segment which it backs up and then repeats in a forward direction. The lower level can have loops on each end for continuous running and swiching could be done on the upper level

 

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Posted by rrinker on Friday, August 21, 2020 8:05 AM

 You're not going to get a workable helix AND layout in a 4x8 in HO. Or N. The problem is, the sharper the curves, the steeper the grade has to be in the helix to get clearance, and the sharper the curves, the steeper the effective grade already is. As a bare minimum, you can figure at least a 5x5 foot area for a helix, and that's putting the track really close to the edge with 28" radius. 

 I'm going all the way around my room, quite a bit of space, so the 'wasted' space of the helix relative to the area gained by the whole second deck makes sense. Having a helix that uses close to 100% of the space that would be added by the second deck, instead of just using the helix space as part of the layout, doesn't make a whole lot of sense.

                                             --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Wdodge0912 on Friday, August 21, 2020 6:05 AM

Gotcha. Im not at all sure how to calculate all that extra stuff. Wow it be possible to extend the helix section along the back. So each end is a 22" radius curve going up, and the 6ft between maintains that grade? Let's say a 3% grade, idk? I'm not looking to run many cars, maybe 6 max between the levels. I can always have the sw1500 hook up to the RS1 as well, or maybe get another sw1500 and run both of those together to do just the incline, idk 

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Posted by RR_Mel on Friday, August 21, 2020 5:31 AM

My HO layout is a bit larger and in our garage on casters so I can move it around.  I have a twice around mainline with a 60” diameter helix.



There is no way that a helix won’t take up a lot of space.  My way over weight Cab Forwards with over 5 oz of drawbar are just barely able to pull 20 cars up the 30” radius 3½% helix without wheel slip.  I needed 3½% to gain 9” in the helix.  A pair of E7s weighing almost two pounds each can handle an 11 car over weight passenger consist without any wheel slip.

The tighter the helix the more pulling resistance.  A single stock locomotive will barely pull 5 cars up my 30” radius helix.
 

Mel



 
My Model Railroad  
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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HO Helix, space needed?
Posted by Wdodge0912 on Friday, August 21, 2020 4:18 AM

So im still planning different ideas since the space I have for trains hasn't cleared up yet (need to get more storage andlve.some other stuff to the basement still, sadly it isn't a full basement or none of this would be an issue)

 

I had an idea I tossed around after seeing an ad on social media for pre-built helices, both HO and N. Since I'm in HO, kind of gave me an idea. Right now I'm stuck at 4ft width, and 8ft length. I might be able to squeeze in another 2 ft length. The idea was if I could do that, do a double decker layout with a helix in between. Could model 2 different areas, and have a all the industries and interchanges I'd want. I wasmt sure how big a helix would be, how much room it would take up but the idea would be to have a 4x6 layout that loops  on one side, amd uses the helit to go to the other level, where that would also be another loop on the end. I'd imagine it would be like having a 4x12 in a 4x10 space, with a divider in between the 2 sections (just a helix in this case)

 

Since I'm not going super detailed, amd the layout would roll to the center of my garage (the single 4x8 was going to drop down, but I doubt I'd ever get my garage cleaned out enough to park in) i figured just a thin 1/8" divider would separate the helix from the 2 scenery areas. 

 

I am planning on smaller cars and locomotives. Longest locomotive I am planning to run regularly is an RS1. I also have a SW1500 I'd run. I'm sticking with my DC stuff, since it's all good and have plenty of the same transformers that all work amd are a good brand, so I figured Id have the Helix on a switch for the transition. 

 

I have thought about also looping each level around the helix, so that I could leave one train running around and do work with the other loco on the other level.

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