My only question would be...

My only question would be... where will the helix fit? It looks like the pennisula in the middle is the only likely place - and it doesn't look wide enough.

N would just fit..

You could fit one in N scale I think.. 36" penninsula would leave room for a 16" helix, reasonabl broad for N.

N-scale helixes require a lot of loops. It can really take a while for a train to reach the top. I know one guy in my area that has a monster helix on his N scale layout and it takes a while for the trains to pop out. It works for him because the layout is big enough to absorb it but your mileage may vary.

i thought you were using pre-fab benchwork. Won't that be problematic for doing Helix benchwork and doing multi levels?

Chris

My N-Scale helix fits in a

My N-Scale helix fits in a 3'x3' space, is about a 2-2.2% grade with 6.5 turns, rising 2" every turn.  I need to time a train one day going up to see how long it takes, heh.

How many cars?

Shaun, how many cars can a single locomotive haul up that helix?

I am planning to build a small 16" R 2 turn helix to provide some cosmetic distance between two points and also provide a little extra clearance for a staging area. I want to make sure the prototype's ruling grade elsewhere on the layout is where trains stall, not my helix!

Chris

So far I've only run my

So far I've only run my autoracks, about 6 of them, with 2 engines.  I'm not running really long trains due to the size of the layout.  I need to get my BNSF 12 car-hopper unit train and a double stack and make some runs up the helix to see how those do. 

I figure everything will probably need at least 2 engines, maybe 3.

Yes, test your helix

You want to test your helix and see how the pulling capacity of your locos on the helix compare to the pulling capacity of your locos on any grade that's on your visible layout.

Ideally, the performance will be about the same - you don't want the steepest grade on your layout to be in the helix.

A helix can be deceptive because having the entire train on a curve adds extra drag above and beyond the helix grade itself.

For HO, the Layout Design SIG has determined the extra drag is + 28/R, where R is the radius of your helix.

For example, if you have a 30" radius helix in HO, you need to add + 28/30 or plus 0.93% to the helix grade to get its drag equivalent to a grade on straight track.

If the HO helix just mentioned used a 2.2% grade on that 30" radius curve, then the grade drag equivalent would be 3.13%. This means your locos in the helix will only pull what they could pull on straight track with a 3.13% grade.

I'm not sure what the formula might be for other scales, but you could start with adjusting the formula by the scale ratio to HO. In other words, N is about 54% of HO, so you might try + 15/R as the extra drag factor.

A helix does not have to be

A helix does not have to be round it could also be an oval the extra track(strait sections)will make the grade less steep and cut down the drag factor of the curve.....of course this takes up some realestate. Just a theory and some thing to think about.

Not just a theory. The extra

Not just a theory. The extra drag happens only for those wheels/axels that are on a curve where the inner and outer wheels need to rotate at different rates. If you make a helix where two half circles are connected by tangent tracks only the portion of the train actually on the curves will be generating the extra drag.

Cheers,

Charlie

My only question would be...

You are correct that if I go with a helix it would have to be at the end of the center peninsula. Howvere since this is N Scale a 36 inche width should allow me to use a 17" radius curve quite comfortably. The problem is that I am not 100% sold on using a helix to gain the height needed to get to the upper level or down from it. I am tryimg to avoid and unreasonable grade % especially since I anticipate the avergae train length to be 15 cars plus locomotive and caboose.

Irv

N would just fit..

I am not 100% sold on a helix primarily because of the leangth of time trains could be out of sight.

I am using Woodland Scenics benchwork but I am not above putting some wood in there for strength and stability. As it is I am thinking of beefing up some sections with custom benchwork using L-girders and joists. So it wpn't be a problem or not much or one for the purpose I intend.

I've tried to use the Woodland Scenics stuff because you can build pretty quickly primarily because it is light and doesn't require any power tools for cutting and assembly. I also do not own or have access to anything other than a drill and hand held jig saw so I couldn't handle anything that would need to cut with a table saw. Ad to that that my woodworking skills leave alot to be desired.

Irv

Ruling grades

I don't necessaily have to use a helix, or at least not a very big one since I should have about 23 feet of space (less the distance towns and yards would occupy) to raise the track level from the car float location along the lower right wall. Now I have done any work to see what kind of a grade that would give me but I would think it should give me a reasonable height and at least make any necessary helix a much smaller one.

The only fly in the ointment so to speak is I do not know at this time how much space the yards or modeled towns will take at this point. I do know that my car float operations and the necessary yards will occupy at least 4 linear feet out of the 9' 7" along the right wall.

Irv

wood working skills are learned

I am not a good carpenter or speller for that matter but the more you work with wood the better you get. It does pay to have the right tools and learn how to use them properly. Bare minimum a circular saw, Jigsaw, hammer, and a set of various clamps and a good drill. Table saw nice but not  nesecery but is nice to have.

A few things I have heard form others about helixs is that if train is too long that it does what is called stringlineing where one side of train cars are pulled in ward as if it were a drawstring had been pulled. It can be fixed by superelevating the track slightly to prevent derails from stringlineing.

There is a couple of helix forumla cruncher programs out there that are worth looking at.

Wood working skills are learned

I never took wood shop in high school. What I did learn about woodworking was from my father although I never did a lot of it. One of the things I can't do is saw a straight line and that's why I need to have or get access to a table saw.

I need to make some carfloats out of wood planks and I don't dare cut them with my jigsaw as they'll come out less than straight and won't look convincing.

I also need to make some shelves for the Woodland Scenics stands I am using. These hselves will be used to hold drawer systems as well as books, magazines and other stuff that I want to store under the layout.

As for a helix, I want to see if I can find a way to use the parts of the layout along the top and left walls and the central peninsula to gain some height so that I can either elimnate the helix or at least make it as small as possible.

As for train length, that still has to be determined but I am thing of 15 cars plus the locomotive. The 15 car length comes from the fact that my car floats should carry that many 50 foot cars.

Irv

Feldman I could not cut a

Feldman I could not cut a straight line either till I used a saw that had a lazer sight on it if you can keep the light on the mark it works pretty good but I can see where a table saw would help as well.

You could make the whole layout a "helix" or more of a coiled snake by starting a bit lower than 3' from the floor and gradualy have the right of way climb up hill around the walls this would probably be great for a point to point layout.

Helix with roadbed track

Ryan over at the Model Railcast made a helix using bachman EZ-track. He just snapped it together in a spiral and used threaded rods and thin metal supports. Its an interesting idea. They make a 19" ez-track that would be just right for N. Its only a teeny bit big for your space there.

I would not go running out and spending money to try it.. but I will be following his progress. I just thought of it because it does duck the need to do woodworking. I just wonder hoe well the joints between the track pieces will hold up under constant use.

Chris

May jigsaw doesn't have a

May jigsaw doesn't have a lazer sight. I don't cut anything that I haven't drawn a line to follow on but my hand may not be steady enough to keep the jigsaw on it.

As for your helix idea, It may be a good one but it doesn't fit my needs.

Irv

Jigsaw

My jigsaw cuts look like a troop of drunken monkeys took turns trying to sign their names with the saw.

Seriously, you aren't making period replica furniture. Its model railroad benchwork.. close is usually good enough.

One of the things I like about true L-girder construction vs butt joint construction is no precision is required. Wait until I post the next set of pictures for my spray booth construction where I try to cut circles out to mount the fan..

That being said.. I always draw a line too.. that way I know how bad I missed.

Chris

Close may be good enough for benchwork...

Close may be good enough for benchwork, but it isn't good enough for car floats which I need to be convincing. A table saw there is an absolute requirement. One of my friends has a table saw so I guess I will have to ask him to cut the wood for them.

Irv

how about having a partial double-deck

If the double-deck is only along the top and right walls, you won't need a helix to connect the decks.  Sufficient altitude can be gained using space along the left and bottom walls and peninsula.  Some 45 years ago I accomplished the same on a 5x10 HO donut layout.  In my former space and your present space, this is more effective if one is modeling a mountain railroad to justify the long visible climb.

No Helix to climb 15-18 inches in N Scale

I am not modelling a mountain railroad. That said a can honestly say that the actual tracks in real life did climb from the car float aprons in Bay Ridge in Brooklyn, NY to the Bronx, NY via a series of bridges and viaducts over various waterways. So I don't think it would be questionable in having such a rise. The only question in my mind is how realistic it would be to have part of the layout rise that much and still have the lower level depict certain other scenes including three interchange yards. That might preclude any solution that doesn't include some sort of helix.

Irv

stringlining

I've read that the stringlining issue is more due to the radius of the curve.  The LDSIG suggests that stringlining is more likely to happen on curves of 3x radius.  i.e. 3 times the length of your typical car length.  So based on their recommendations in HO scale for a 6" car you'd almost be assured of stringlining at 18" radius.  I'm not sure that superelevating would help and might even worsen the stringlining effect.  4-5x seems to be vastly preferred with 5x+ allowing virtually no issues with coupling on curves as well.  In any event, you're going to want a larger radius on your helix.  As Joe said, this is not the place to have your ruling grade and if you combine that with your minimum radius you're just begging for trouble.

-

S

LDSIG recommendations

Thanks for your advice. Maybe I should spend some time with LDSIG. I haven't done this yet. I've been busy worrying about making car floats and aprons.

Irv

It's definitely true that the

It's definitely true that the chances of stringlining go up as the radius goes down. But that's only part of the story. Other things contributing to stringlining are:

• track quality - are there any burrs or bumps at rail joints for a flange to ride up on or places where the track rocks from side to side causing our unequalized (rigid) trucks to lift a wheel/flange out of solid contact with a rail?
• smooth operation - if your trains jerk when they run each jerk increase the chances of something coming off the tracks
• tension - the longer a train you're  pulling through a curve and the steeper the grade going through that curve the greater the forces acting on the train become. Tension will attempt to get the cars to take the shortest path between the pulling power (locos) and the anchor (the rest of the train) which is not to follow the curve in the track.
• pulling power - if you anchor the caboose somewhere and keep adding power to the head end eventually either a coupler will fail or some of the train is going to get pulled off a curve. Refering to the previous item, if your train stalls on a curve with a grade with a single engine up front (but without stringlining) then doubling the length of the train won't cause a stringline (on that curve anyway). But adding another loco will double the tension on the train (especially at the head end) and increase the chances of a stringline.

Hope this was helpful.

Cheers,

Charlie

Issue 1 of the magazine covers this in depth ...

The new curve radius guidelines article in issue 1 of MRH covers the LD SIG's curve radius guidelines in depth.

These guidelines work for any scale and they have revolutionized how I look at layout planning. The insight they contain helps you know exactly what to do regarding the curves you're using in your design: coupler issues, tracking issues, stringlining, etc.

Once I understood the idea behind these curve radius guidelines the light bulbs came on big time.

Watch for this article in issue 1 ...