Is a 1% helix practical?

Hi all, I've been experimenting with some of the premade foam inclines and have found that even at the shallowest grade available (2%), most of my steam locos aren't able to pull more than a couple of cars up the grade.

I don't have the straight line space available for a 1% grade, but a helix could be an option. My question is, is a 1% helix viable, and/or will a curved 1% grade end up with similar performance to a straight 2% grade?

The layout I'm building will have 2 or 3 levels, getting trains from level to level would be a nice bonus but not a deal breaker if it won't work with my rolling stock - I can simply keep the levels separate.

Thanks for any insight.

 

A traditional 1% grade helix will eat lots of real estate. There may be other options but they may require challenging (varying geometry) build engineering.

 

Correct, a 1% grade allowing for some extra room, lets say 2" between track levels, would require a 200" run. Which would translate into a 31.8" radius curve. If you have the room, I'd say that's very doable.

 

What radius do you have to work with? Curvature plus grade eats up tractive effort so the wider the radius the better. Adding some weight can better pulling power and then there is the tried a true solution which is to add a cheater boxcar or box cars behind the loco which would be something like a Kato 105 mechanism with weight in the car. And of course there is double heading locomotives.

 

I don't know how fanatically prototypical you wish to be but you could look at using electric helpers engines through the Helix ala GN through cascade tunnel. You could just run catenary to the tunnel entrances to get the illusion. Would make some operational fun cutting on / off the electric helpers.

 

Thank you all, my layout is only 36" deep so a 31" radius is not going to work sadly.

I'm intrigued by the idea of helper locomotives, I'd hoped to automate most of the running with JMRI and that sounds like quite a fun challenge.

My best puller so far is my Kato Mikado, it's managed 8-9 40' boxcars up a 2% grade. Is that about what you'd expect, or should a longer train be possible without helpers? My 0-6-0s can only manage one car up the same grade.

Also fascinated by the elevator idea. I'm assuming that lifts an entire section of track - train and all up to a higher level?

Thanks so much for the insights.

 

A helix doesn't have to be round. You could build it as an oval using smaller radius curves.

Do you have the optional set of drivers with traction tires (P/N 11-604) installed on the Kato Mikado?

 

These results are throwing me a bit. It's been a while since I calculated it but, if I recall correctly, I have about a 2.7% grade in my helix with about a 21" min radius and I pull pretty long trains up it. Granted, I typically run 3-4 (diesel) locos in a consist...now on DCC.

 

Have you tried adding weight to the locomotives? Traction tires? Bullfrog snot? All three will increase an engines pulling power. Also, curves put more strain on an engine. A helix is just a uphill curve. Keep your curves flat and your straights uphill will also help.

 

Hi Tehachapifan, If you have a 21" radius and you're helix has a 2.7% grade, then if my calculations are correct, each loop is approx. 131.95 inches and the separation between loops is approx. 3.5 inches, does this sound correct?

To figure a grade you take the rise / run giving you the grade in a percent.
Example 1" rise / 100" of run = 0.01 or 1%. If you double the numbers, 2" rise / 200" of run = 0.01 still a 1% grade.

 

That's about right. It was originally built for HO scale and later converted to N, accounting for the separation between loops.

 

You will certainly need to take the radius of the helix into account when calculating the effective grade. Years ago, John Allen and John Armstrong did some experimenting with this and derived formulas for grades on a curve. My Grade Calculators utilize their formulas:
http://railroadboy.com/grade/

- Jeff

 

My last layout included a 40" diameter helix, and I assure you it, and a two level layout will NEVER BE DONE AGAIN! I had problems ranging from simply the time it took to transverse this length of track, to frequent derailments from a poor choice of mounting, using the old uncured rubber roadbed ostensibly to absorb shifting wood, and the use of Atlas code 70 flex, cheap never pays.

Two levels is another particular embodiment of hell.

 

I on the other hand love helix's and the running room it gives me. No more "Flat Lander" layouts with short trains running around in circles. Oh, don't get me wrong my first layouts were just that and I had lot's of fun with them. Overtime I lost interest in them and started finding ways to loop my track up and over (Tehachapi Loop & Williams Loop - inspired). There's nothing like watching trains snake through the canyons, up and over high mountain summits and back down again (Cajon Pass - inspired).

On my layout I have multiple helix's at approximately a 2.2% grade. Wide radius curves (N-scale) 24" to 30". A 2.5" clearance from top of rail to the bottom of the upper supports.

The Key for gradients: A 1/8" rise per linear foot = a 1% grade. A 1/4"rise per linear foot = 2% grade.

The Trick is: Using a one foot bubble level, metal ruler with a 1/4" riser attached to the bottom foot side, on one end. Should the bubble sit in the middle, it reads level and you have a 2% grade

If you are still with me.

My Secret is: Track work, track work, track work. Installation of your track. Nothing worse then running trains and they de-rail repeatedly at a poor joints in the track. If you look closely you can see where I overlapped my joints. Most of the time there is a 2 to 3 inch overlap. Just look for the rail joiners. Works amazingly well. We can get into this later.

I use Atlas code 80 flex track, Kato Unitrack #6 switches and Peco Large radius switches. It should be obvious

Someone out there is thinking I want to see this dream layout. Well, cough sputter, clearing my throat. This isn't a pretty picture and I'd never sell you on the idea of building your own...with it. However, it does illustrate what can be done when you set your mind to it. It is a multiple helix layout. Not a traditional helix by any means. I wanted certain sections of it to be viewable where you could see the trains running in and through it. I used ovals as suggested earlier.

I need other pictures, now buried on a C.D. in some unmarked packing box. So you can see how it all works.

Those who've seen it in person had nothing but compliments for it. "Mesmerizing" was what I heard most often. "Smooth riding and trains just glide over it," thanks to my closest friends. Of course I've had a few newbies come through who were overwhelmed by it ,"I don't want that!" I assured them they didn't need to build such a colossus, but look at all the fun... they'd be missing out on.

No it isn't a four track main for the Pennsylvania Railroad. Although, you'd certainly think so. It is a, "Folded Over Pretzel-ed Dog Bone" Steve would describe it to visitors and friends. Someone else said of it, "It's a glorified Run Around." Okay, they got me.

You can see a two track main which basically allows trains to run to the top on one track and back down on the other. Looks like a two track main. The "Meets" are amazing.

The center two tracks, is a coal district. It simulates the illusion of full loads out and empty loads in. Only to run around the "Dog Bone," and repeat the same illusion. A unique concept.

In the upper right hand corner is the Mini-City portion of the layout. Looks like it's sitting on the helix. It isn't. It's laying flat on my table saw. The helix is actually laying on it's side and I rotated the picture for a better presentation.

In the left hand corner you can see a yard ladder for the hidden staging yard. Here, I could store 40 car freight trains. All waiting crew call to head out onto the Pike and make the trip.

The layout supports three Reverse Loops and one Wye. Why! I'm no pansy when it comes to building my railroads and I like a challenge. Great when it works.

I refuse to use tight radius curves. The minimum radius is 15". I will use it only for industrial spurs and yard tracks. I do have a 7.5" radius curve for a trolley line. It doesn't work well or look good and nothing stays on the track. Can you guess what plans I have for it? Your right. Wider curves are the best curves.

I owe you this explanation. The picture of the layout was taken after it arrived here in Nampa, Idaho. You can see cat hair and spider webs on it. I needed mouser's to keep the mice at bay. Never mind, I had a soft spot for the two female felines that got the job. They took over my cat shed. Having problems with vision I backed off on operations, routine maintenance and you can see the results for yourself.

Good news! Eyes have undergone surgery and vision is amazing. I have plans for restoring the H&P RR and getting it back up and running. I'm on the shorts and this may take the rest of my existence to get it back-up and running. KILLZ paint is on order and I will paint the layout to get rid of some of those oop's cat's make.

So why stop now?

 

I got to thinking. John A., has a video of my helix that shows it shortly after I finished building it. It was during the Holiday Season and it's named the Christmas Rush or Fast Mail. Featuring both my Santa Fe and Union Pacific Mail Trains. Video Courtesy of John Acosta.

Of course once the scenery gets in place there will be a tunnel portal and you wont' get to see the internal workings of the helix unless you duck under the layout.



Can you tell I'm stuck on having a helix? AND multiple levels of train action.
Hey, don't be calling it a spaghetti bowl. Nope! It's a Folded Over Pretzeled Dog Bone. Grin!

Don't let the fear of the unknown stop you. Diagram, measure and do it some more. Kick this pig and get it up and running. Once you catch on to How-To, you'll be addicted and there will be no stopping you.

Don't forget to lay track as you go. You don't want to be installing track after the sub-roadbed is in.

You don't necessarily need anything commercially made. However, if it makes it simpler for you such as a teaching tool, then do it.

Go for it.

 

There is so much to talk about when it comes to helix's or helixi.

A 1% grade would be ideal but not always practical. I have some 1% sections usually at the start or end of a grade. A transition thing.

What about pulling 40 car trains up my steepest 2.2% grades? The rule of thumb here and it isn't always true or 100% fool proof. "For every ten cars one locomotive will pull them." Simple math, I need four diesels in a lash-up to make the pull. Noting it pretty much holds true for my layout. Keeping in mind I run with Analog DC and most of my locomotives have their original weight. DCC powered locomotives are considerably lighter and pulling ability may be in question or less then.

We could get into a discussion about traction, weight of the locomotives and so on. I'm not the expert on such and would defer you to more prominent members of the club. Other then to say pulling power, Traction tires, BullFrogSnott all have their application. And I'm not a fan of Traction Tires.

In another discussion on going here on TB we are talking about properly weighted cars with trucks and wheel-sets with minimized friction. In order to pull these grades my train cars need to be as free rolling as is possible. I accomplish this two ways. I prefer Delrin wheels and truck frames. I only approve of a few metal trucks and wheel-sets. Picky, picky, picky S.O.Rr. (Son of a Railroader). You thought I was going to say something else...didn't you?

I've also become a member of the "Slinky" model railroad associates. I don't want my trains bouncing forward and backward, on a downhill run, like a "Slinky". A Yo-Yo would be an apt description. Slack is one thing and you can expect that. But the problem isn't so much the knuckle couplers as it is a train car with with dirty bearings, creating friction and sticking from time to time. Like putting the hand-breaks on.


I was talking about train meets on my mainline. Would you like to see one? Waiting! Just one of you? That's enough! Any excuse I can use to show it off.

Video courtesy of John Acosta.

I obviously have to much time on my hands.

 

I designed my layout back in 1983 and it's still running. Overall size is 8' by 5.6". Entire bottom level is staging yard. NO HELIX. There are effectively three levels; the eight-track staging yard is the entire bottom level, and then the one-way entrance and exit tracks work uphill around the entire layout at around 2%, emerge first on the middle level and continue climbing at 2-2.5% to the top. With that I have 25-30 car trains with 3-4 units on the front, which is admittedly pushing it. It's proven practical. As Rick says, you simply can't put enough effort into trackwork. But it's also meant that I take tractive effort very seriously, no wimpy locomotives need apply, EVERY coupler has to be RDA adapted, wheels have to be well maintained, and you take train handling very seriously. Bad train handling will stringline an uphill train, and a sudden stop on a downhill train is equally catastrophic.

Because of the tractive issues I had with a Life-Like Berkshire, I invented the powered express reefer kit, still sell it. It will do 25 cars on the flat by itself, 8x8 pickup and drive with two traction tires. Forget the Kato 11-105, no guts, no glory.

As most of you know, this has led to a lot of research on tractive effort, current trends on light locomotives due to DCC and sound cutouts, slippery wheel syndrome, etc.... all driven by this one layout design feature. I certainly wouldn't go any steeper than 2.5% for any reason at all if you want more than a 10-car consist.

I think the definition now of what I built way back when is a 'Nolix", it works like a helix but didn't eat the entire layout. And I'm only getting into and out of staging, not trying to pull off two separate scenic levels. There's only 4" between the highest and lowest point.
http://www.randgust.com/atsfplan.htm
It's not unlike the MR Canadian Canyons concept this month, just a different way of getting down there.
My design goal was to be able to take any train out of staging and run it as both an eastbound and a westbound, so there's a hidden reversing loop in the middle, it works pretty well and is semi-automated with position lights and polarity checks. The entire staging yard is simplified with one-direction entrance, lit switch indicators, position lights, and automatic 'dead zones' at the end to absolutely stop a train cold instead of overrunning its storage spot. You have to release a train by holding down a pushbutton until it is clear of the dead zone. Simple. All trailing point switches are free floating as there's only one direction in the staging yard so you can't possibly derail on an incorrect switch. You also can't even run in reverse without holding an 'emergency reverse' button down that bypasses directional diodes. Every trick I could throw at it.

 

Wonderful info and insight all, thanks ever so much.

 

You are more then welcome.
I can only hope the things that others as well as myself have presented here will answer some of your questions.
Nothing like a multiple level layout. They are entertaining layouts and that's exactly what I call them.

Kind of off subject. You may have noted in the videos that a lot of my heavy weight passenger cars have missing wheel-sets. These operated on 11" radius curves and with all the wheels in place they had a tendency to bind and/or drift up and out of the rails. Derailing the train. Same story when operating on the 9 3/4" early curves. Some train cars and locomotives should never run on tight radius curves. They hardly look pretty or you could say right. So, I removed the middle set as a temporary fix. It worked, just not something I liked very well. The railroad got orders to widen those curves. Accomplished. You might want to know, the shop has been notified to requisition proper wheel-sets and reinstall them.

Let us know how your layout progresses. Pictures and videos are always welcomed.