Throwing me a curve

Discussion in 'FAQs' started by Pitchwife, Feb 24, 2003.

  1. Pitchwife

    Pitchwife Dreamer

    Everything that I have read, both here and from other sources say that you shouldn't start an incline on a curve. With my current layout plan there is a place that I can't figure out any way to put a straight piece to start the incline without reducing the radius of the curve by a substantial amount. Right now it has a radius of 25 1/2" and is in a difficult location to access. Is there any way that I can do this safely?

    I guess my question is, which is the better route to go, a straight shot at a tighter curve or a gentle incline into a wider curve? :confused:

    If I can get away without the straight piece the design works better but if I gotta then I gotta.

  2. Clerk

    Clerk Active Member

    Clark. I have heard about that to but I did it anyway. If it works here is a picture.

    I have no trouble runing trains on them.

    Attached Files:

  3. Pitchwife

    Pitchwife Dreamer

    That's great news. I was hoping that it was possable. You have taken a load off of my mind. Thanks Clerk.

    Nice picture too. It always helps to have that visual input to back up the theory.

    As soon as I get something substansial going I'll post some photos myself. Right now I'm still prepping the room and finalizing the design. It might be a bit ambitious but I've been dreaming of it for so many years. Now is where the iron hits the tracks. :D

    Thanks again
  4. rockislandmike

    rockislandmike Active Member

    On an unrelated note, having a fridge with cold beer and/or coke right next to the layout is an excellent idea.
  5. Pitchwife

    Pitchwife Dreamer

    Also an excelent source of snow for those winter scenes. Just make sure you have adequate drainage. :D
  6. N Gauger

    N Gauger 1:20.3 Train Addict

    Dang - if that fringiner... regifer.. regefer.. ahhhh -- "Ice Box" wasn't there you could've extended that left leg about another 20 inches --------- ROFL !!!!

    Nice Layout!!!!!!!!!

    And yes you can start an incline with a Gentile Curve - If you can, is there any way you can Increase the radius???

    But 25.5 " will be ok - I definatly do NOT recommend (from experience) any radius smaller than that! :) :) :)

    So I guess my vote is for gentle grade and wider curve :)
  7. Pitchwife

    Pitchwife Dreamer

    The only way to increase the radius would be to knock out a wall. Only then I'd have to classify it as a Garden Railroad! :D
  8. N Gauger

    N Gauger 1:20.3 Train Addict

    ROFL -- Go for it!! I always wanted a garden Railway

    Anyway - Hope the answers helped :)
  9. Vic

    Vic Active Member

    Hmmm, that's a new one on me...practically every grade on my layout starts, climbs and ends on a curve. Was I supposed to know that wouldn't work??? :eek: :D :p....but it did:) :cool:
  10. N Gauger

    N Gauger 1:20.3 Train Addict

    No, just Tight Small radius curves - when you start pulling a lot of cars they have a tendency to derail around tight curves.

    Plus, this puts an extra strain on the engine(s) that are pulling them up the grade. It's easier to pull a straight line of cars.
  11. Clerk

    Clerk Active Member

    Guys. That happens to be a freezer. If it wasn't for that I could have extended another 2 feet and the other side is 11 feet long. I wished I had another place for the freezer but the wife says NO!!
  12. yellowlynn

    yellowlynn Member


    Waaaay back in the middle ages when I was first getting started in "real" model RRing, I had a layout that had several curving inclines. I didn't have a bit of trouble at all as far as that was concerned. I didn't like the grunt, grunt going up and the wheeee coming down so all my track is level now.. I do have a winding up, over and down under for my Shays. They could climb a tree if they could get a toehold

    All this boils down to is, I have had curving inclines in the past with not a single complaint.

  13. Pitchwife

    Pitchwife Dreamer

    Thanks everyone for the input. As usual you have come to the rescue! :) Your help is truely appreciated.
  14. RailRon

    RailRon Active Member

    Clerk, about that freezer:
    Couldn't you talk your wife into laying that box sidewise on the floor? Ok, now the door folds down when you open it. And yes, now the shelves would divide the interior into vertical compartments - but who cares? You still can put the same amount of stuff into that box! :D :D :D
    On the side wall of the freezer (which was now on top) there's room enough for a spacious engine terminal. How about that? :cool:

    Oh well, Clark - back to the theme of the thread:

    I never had problems with elevation changes in curves. But IMHO the most important thing is to have easements - horizontally and vertically. Obviously, abrupt changes in curvature or elevation call for instant disaster. :eek:

  15. rockislandmike

    rockislandmike Active Member

    Speaking of which, I really need to figure those things out (easements that is) before I tackle the rest of my layout. I'm a mathematical wizard, so I don't know why I get frustrated with the explanation in Armstrong's book.
  16. Pitchwife

    Pitchwife Dreamer

    I don't want to appear to be as much of a dummy as I am, :rolleyes: but can someone give me the lowdown on easements? I checked the MR website glossery but they didn't help much.
    I am presuming from the conversation that it means that you can't just go from a level to a grade at one point, but are there some standard rules, equasions, etc about them? :confused:
    Seems the more I learn, the more I realize I don't know. :D

  17. Vic

    Vic Active Member

    Hi Clark, About the easiest...pun intended...explanation I can give about easements is that it means to just start your grade in very small increments and with long distances so that you don't have a sudden and abrupt change from level to grade. There can be a lot of math associated with this but for modeling purposes its just not necessary. Just keep everything in smooth transition and it will work fine. My personal rule of thumb is that if it looks as if the level portion sorta "flows" into the grade then it will work just fine. In other words the more distance that you use to achieve the final height of the grade the more "easement" or transition you will have. My opinion...forget the math...its just not worth the trouble...the "eyeball method" works great!!!!

    Hope this makes sense:D :)
  18. RailRon

    RailRon Active Member

    You can do easements by calculating them. There are wonderful mathematic formulae around to compute them. :eek: :D

    But then again, you just use common sense and some eyeballing - and there you have your easements! :)

    BAD track geometry is, when your straight track directly changes to curved track with a given radius (say 30"). That's what you have when you use sectional track.

    But when you're laying flex track, let it simply 'flow' into the bend. Soft flextrack almost seeks its way itself. When it pleases the eye, then it's probably ok for operation.
    When you are laying (spiking down) track with individual ties, you should mark the track center beforehand. For that you can use a narrow piece of stripwood (say 3 ft) and fix it down with pins - a few pins in the straight section and a few in the part with the constant radius. Just like flex track, the wood seeks the easement curve itself. Follow the wood with a felt pen, glue down your ties - and voila! instant easement!

    For vertical easements: Never join two parts (e.g. plywood strips) at a point, where the grade changes. You'll probably end up with a sharp edge, going from level to inclined roadbed at a certain point. On the other hand, when the change of grade is 'pulled out' over one long strip of roadbed over 1-2 ft., it looks better and you'll have no operation problems.

    I know, there are many among us who really calculate these curves point for point. Of course this is the PERFECT solution. But I admit to be the lazy type, and so far for me the eyeballing technique worked out in a most satisfying way.

  19. Vic

    Vic Active Member

    Hi Clark, this is a crude drawing of what I was trying to say LOL:D

    Attached Files:

  20. 60103

    60103 Pooh Bah

    Easements for the mathematically inclined

    Model Railroader published a big article on easements several decades ago. The included a BIG foldout giving a lot of variations for selections of car types and gauges. They also marked the easements with common radii so that you could ease from one radius to another.
    I seem to remember that they were approximating the easement curve with a cubic spiral.
    When I worked it out for my N gauge at the time, I found that going from tangent to a sharpish curve, I had to place the tangent about half a gauge farther out than the pure radius, and use 2 passenger car lengths to ease, i.e. one each side of the start of the circular curve.
    I may be able to look it up if you're interested.

Share This Page