Grade qestion?

[scubaterry]

I have an HO layout in my unfinished workshop. In my constant quest for more track I am thinking about putting in a second level. However before I do it I would like some feedback. I have approx 18 ft of wall to use and another 4 feet at the upper end for the actual industry spurs etc. I do not envision ever pulling more than four full cars up and four emptys down. I would like at least 12-14 inches of clearance at the upper end? Is this enough track length or am I dreaming. Thanks for your help.
TerryBLOCKED SCRIPTinsertsmilie('[:p]')

[SpaceMouse]

Unless I miscalculated. 12in/(18ftx12in)=5.555...% grade. My steamers have trouble with 3.5 and a couple cars.

[cacole]

That's a really steep grade, and you're likely to run into locomotive wheels slipping up such a steep incline, even without a long train behind them. On our local club HO-scale layout, we have inclines of 4 inches in 25 feet and have problems with steam locomotive wheel slippage when pulling 8-car passenger trains uphill.

[cuyama]

Actually, I think he said 18 ft + 4 ft ... so a total of 22ft. (But the end result is not much different).

That's 264". A 12" rise in 264" is a bit over 4.5%. If you need to go around curves (and it sounds like you will), the effective grade is increased, so your trains will probably act like they are on a 5-6% grade or more.

The other thing to consider is that you'll need a bit of the length at each end for vertical transition curves to ease the start and peak of the climb.

All in all, does not sound like a recipe for reliable operation.

When faced with such a situation, prototype railroads sometimes resorted to a switchback, which if it made sense for your prototype inspiration and era might be soemthing to consider.

Or you could decrease the distance between decks. Or instead of making them separate decks present them as tiers in the same scene.

Good luck.

Regards,

Byron
http://www.modelrail.us

[SpaceMouse]

QUOTE: Originally posted by cuyama

Actually, I think he said 18 ft + 4 ft ... so a total of 22ft. (But the end result is not much different).

I figured he'd want his industrial spurs to be flat.

[cuyama]

QUOTE: Originally posted by SpaceMouse

QUOTE: Originally posted by cuyama

Actually, I think he said 18 ft + 4 ft ... so a total of 22ft. (But the end result is not much different).

I figured he'd want his industrial spurs to be flat.

you're right, I didn't read it carefully enough the first time

[howmus]

scubaterry, I second (or fourth in this case) the advise already given. You would be far better off using a set of switchbacks or a helix to get the height needed for the second level. Even a very large steamer will lose a lot of pulling ability on a grade over 2%. My 2-6-6-2 can pull about 40 cars on the level but can only pull about 18 up a 2% grade. My 2-6-0 can pull 10 -12 cars on the level but only 4 or 5 up the 2% grade. When you get to 5% and above, I might get the engine up the grade with a small bobber type caboose.

[Anonymous]

5.5% is definately steep. A strong (and heavy) diesel could pull that load, but don't count on most off-the-shelf steamers doing it. It'll be groaning under the load for sure, especially if you're hauling loads of coal....

You MAY want to look at starting your incline as a mountain at one end of your layout as you make the turn to go up to the next level. By starting the climb as you approach the mountain, and then climbing around the mountain you can greatly add to your climbing room.

For instance, if you started the climb 4' from the mountain (curve) and climbed through the curve, you could add quite a bit. I'd definately keep the incline to 4% TOPS, nothing more. 3% is even better. Also, make sure that you ease into and out of the grades. For instance, 1% on the first foot, 2% on the second, 3% on the third, etc.

Running your grade like this, you'd see the following elevations:

Foot Evevation
1 1/16" 1% grade
2 5/16" 2% grade
3 11/16" 3% grade (keeping it through the curve, 24" radius curve)
4 through 11 stays at 3% grade and climbs 3/8" per foot.

The curve would take up 6' of track, and place you roughly 2 1/2 feet down the wall. At the end of the curve you'd be at 3 11/16", which would put you at about 3 1/2" ahead of the game. At that point you COULD increase the climb rate to 4%, which would be 15/32" per foot climb (just over 7/16" per foot) if you definately wanted to "go for it" on the climb. This would put the total climb up to 11" (7 3/8" + 3 11/16").

STILL not enough room between levels, as most people want 18 to 24" between levels. You need either more wall space, or a helix to climb betwen levels. Have you thought about that?

I'm currently building a new layout, and SOME of the climbs are at 3.5%, but they''re along mountainous terrain which I hope will tend to camoflauge the steepness of the climb.

Mark in Utah

[selector]

It isn't necessary with the wise advice given above, but juuuuuusst in case you are demuring, let me emphatically tell you that any grade above about 3.5% will not only look steep on your layout, but FEEL steep to your engines. Add a curve of any radius below about 40", and you compound the effect of the grade.

Could you live with a split level with just 7" between them? You would eventually appreciate how it looks once sceniked and running, but your pleasure in achieving trouble-free ops will be priceless. Trust us on this one.

[SpaceMouse]

I have two grades on my layout a 3.1% incline and a 3.7% decline. The engeins struggle to get up and struggle with the load pushing them down.

I tried to reverse the direction to make operations easier and couldn't do it. While my steamers could get 4 cars up the 3.1% hill, they could get only one up the 3.7%

[selector]

Q.E.D.

[Anonymous]

While we were in a learning phase wile planning our layout, I had 3 questions (that I've seen posted here too).... what's the minimum radius, what's the minimm clearance (for an over/under) and what's the maximum grade (all for n-scale).

I got (and saw) roughly 12,455 different answers. But one "old timer' I talked with at a show had some good advice.... 2" & 2%.

On our layout I had to use a little 3% grade to get what we wanted to do... and I do see a big difference in loco performance between the 2% section & the 3% section.

BTW, I have more gray hair than not, so it shouldn't have been too politically incorrect for me to refer to a knowledgable model train guy as an old timer ;)

[selector]

I am not familiar enough with 'n' to respond with any conviction, but I would say that the curvature radius depends on what you will run over/around them. If long, non-articulated steam, use the biggest you can get. In fact, you should do that ,no matter what ,for your main line. Smallest curve for 'n' on a main might be in the order of about 8 or 9", less (do they make them) for yard switchers.

As for clearances, 1/2" above the highest point on the tallest item running, or that WILL foreseeably run, on your road.

Grades, avoid going over 3.5% like your loco's lives (and motors) depended on it. The really experienced guys here will advise you to forget anything above 2.5%

Last bit of advice, do seriously think about what your layout might be wanted for in the next couple of years. Virtually everyone gets tired of what they have, and begins to think in terms of upgrading or 'improving' the layout (you will know what an 'improvement' will be by then because YOU will have determined its shortcomings). Try to accept and anticipate that you will add something that you aren't currently considering, and try to build in a 'fudge factor' of space, growth, or modification. Will you add a maintenance yard and a turntable? Can you anticipate adding in an industrial spur someplace? Do you have room for passing tracks and staging?

I hope you have a great deal of fun,however it goes. Good luck.

[scubaterry]

Well OK then, glad I asked before I went to the trouble of building. I kind of figured it was a no go but thought I would ask anyway. I certainly appreciate all of the responses. It is nice having all of this expertise at our disposal.
Cuyama: you mentioned a switchback? What is it and how does it work? TKs
Has anyone tried some sort of elevator system. I know it is not prototypical but I gave that up a long time ago. I am still in the learning phase. Maybe my final layout will be prototypical. Maybe pull the loco and a car on to a platform that could be raised up to the next level. Again thank you for all of your resonses and great info/advise.
Terry

[selector]

A switchback is simply a series of short runs of track across a slope that keep a low gradient. They go in a zig-zag up the side of a mountain, sort of like a donkey path.

The loco and cars will start at the bottom of the mountain slope and traverse the slope, climbing all the time, but on a sensible grade. At some point, the track flattens, runs into a turnout, and continues flat for a distance set by the company for the maximum lenght of train that is anticipated for that series of switchbacks. The train stops, reverses, and someone throws the switch so that the reversing train diverges and climbs up another traverse until it encounters the second turnout and flat run. This is repeated until the train gets to a pass or to a destination at elevation.

[Leon Silverman]

You didn't say how wide your layout would be. With either 18 or 22 feet of run length, you might consider putting a six foot wide mountain along this length that would hide a a double helix (two complete circles) inside with a five foot diameter (30" radius curves). This would give you a total run length of over 53 feet and result in a grade of 2.2%.

[Anonymous]

I am trying to design a layout with hills, bridges, etc. and thought it would be a good idea to make the main level about 1.5 inches above the layout board which would allow me to drop that much on one line and rise that much on another without too much of an incline. I haven't tried inclines out but I am surprised that members seem to recommend only 2% or 3% inclines.
I am relatively new at attempting a layout. I am nearly 70 and I've got my son's quite big electric train set that I bought him some years ago and I thought I'd like to set up and run by computer (I am a programmer).
Brian.

[selector]

Hi, Brian. Welcome to the forum. I am not a electronic wizard, but if you have not been reading here for very long, a gentleman by the name of Randy Rinker is very keen, both in the subject and in his graciousness at giving help. You and he might like to swap some details.

Oops. Posted this before I addressed your statement about the grades. I am curious about your being surprised at the recommendation. The physics for model trains is the same, in scale, for the real thing. Only specialized locomotives can manage grades above, say, 3%, and still make money for the road.

[cuyama]

QUOTE: Originally posted by scubaterry


Cuyama: you mentioned a switchback? What is it and how does it work? TKs
Has anyone tried some sort of elevator system. I know it is not prototypical but I gave that up a long time ago. I am still in the learning phase. Maybe my final layout will be prototypical. Maybe pull the loco and a car on to a platform that could be raised up to the next level.

Terry,

Others have posted the text description of a switchback. They were typically limited to logging lines and such after about the 1910s and 20s. (although there were some notable exceptions)

There's an example of a very short switchback section (that therefore, cannot gain much elevation) on my website at:
http://www.modelrail.us/gallery/id18.html

As to train elevators, they have been used with varying degrees of success. One of my clients just tore one out after three years of trying to make it work reliably (and he's a mechanical engineer) and we're redesigning his layout without the elevator. On the other (more positive) hand, one that apparently works very well was described by *** Roberts in Model Railroad Planning 2001.

Regards,

Byron
http://www.modelrail.us

[scubaterry]

I want to thank everyone for their responses. As always it was very informative. I guess I will at least for the time being stick with what I have got.
Terry