mrazz wrote: I'm working on my first HO layout. Can anyone walk me through on how to draw in my curves? I'm trying to build easements and curves wider than 24 degrees, and I'm using no. 6 turnouts. My table is 8' by 12' with a small operating pit in the middle. The reason for the wide curves, I have 85' passenger cars to run. I'm having trouble understanding the whole concept of easments, locating the center of the curve and the steps to drawing a center line for my curves using a yard stick as a boom. Any information will be helpful. Thank you.
I'm working on my first HO layout. Can anyone walk me through on how to draw in my curves? I'm trying to build easements and curves wider than 24 degrees, and I'm using no. 6 turnouts. My table is 8' by 12' with a small operating pit in the middle. The reason for the wide curves, I have 85' passenger cars to run. I'm having trouble understanding the whole concept of easments, locating the center of the curve and the steps to drawing a center line for my curves using a yard stick as a boom. Any information will be helpful. Thank you.
...and...
Sorry that your question got such little attention since it's been Hi-jacked. That usually is not the case, and there are a lot of very helpful folks on this forum if you have further questions.
Here is a link to a page on the Model Railroader web site with Easment Templates:
Model Railroader Magazine - Model Railroading, Trains, Track Plans - Laying out an easement with Model Railroader templates Opens in a new window.
Even a small easement will provide some visual improvement by reducing the lurch even if it does not provide the full benefit one gets from a longer one.
If you are using cork and flex track, a "pretty good" easement will form itself from the spring in the materials if you provide enough slack in the track plan. I found that after all my careful drawing it ended up coming down to the offset of the curve, the length provided for easement, and the natural easement formed by the track. In the future, I will obsess less about getting that spiral easement drawn "just so".
Chris
Easement curves on a 4x8 in HO are difficult to fit in. Reason: an easement needs to be longer than the longest car to do any good for that car - the car that it's most needed for! Half of the easement length comes from what would otherwise be straight track, which there is precious little of on a 4x8. A 22in curve leading into an 18in radius curve does help a little, but is not a proper easement. The curved path of any numbered frog turnout (not an Atlas Snap Switch!) does have some easement built into it, so easements are not typically used on small layouts coming off the curved paths of turnouts.
Grade transitions are a subject with a lot of opinion but little science. The only rigorous approach to grade transitions that I know of is by Larry Blanchard here: http://cf.trip.net/~lard/model_rail/vcurves.htm. Note that if you use cookie cutter or spline roadbed construction, you automatically get sufficient vertical transistions - you just can't bend plywood or the splines too sharp in the vertical plane. The vertical circle segment Larry uses would likely be the most compact vertical transition, and cutting out a piece from cardboard as check on your work would work well. You shouldn't see any daylight under your cardboard template at the base of the grade. The convex curve at the top would be harder to check.
my thoughts, your choices
Fred W
5 cars and a RS-1 a credible coal train make. Leave the S and 1500 units at the yard unless you want to consist the two switchers to make a run.
Your RS-1 is appears to be your best power for the mine run in this situation. If you have it assigned to other service, then you need to schedule it twice in the workday to make it happen or buy a second RS-1. or similar.
Well, being a 4x8 thats going to have only a 2x8 extension for an elevated mine and a yard at ground level, the line going up the grade is going to be the branch run up to the mine. That said, the most I could probably see me using is 8 cars, and I plan on using my Atlas RS-1 and maybe an Atlas S-4 to run the mine branch (or using those to bring the empties up and use an SW1500 to switch the mine) thats going to bring loads down to the interchange track with the mainline, and then bring empties up to the mine (while mainline engines like my SD9 or maybe the RS-1 bring the loads out to the main interchange yard for destinations beyond the layout and bring the empties in).
think i'll be okay? I can only see bringing 8 cars up at the very max, probably more like 5 at a time
If you had a 2% grade going straight uphill it will just be X load against tractive effort of your engine at 2% grade. That 12 car train will go right up it without too much difficulty.
If you took that 2% grade and made a 180 degree curve out of it and ran the train upgrade... suddenly that engine thinks it is about... 2.4 to 3% in gradient. Suddenly the engine thinks it has more cars on the back and need to work harder.
One modeler on these forums once had a picture of his Bachmann 2-6-6-2 pulling 21 cars and caboose up a 2% winding S curve OUT of his yard. Most incredible.
Your 18 inch sectional curves combined with 3% grades will create 4% and/or possibly greater actual gradients and generate stringlining or other problems with your rolling stock. Heck I dont know if a train longer than one loop of 18" helix will even stay on the rails.
My heavyweights want me to get into the curve 16 or so inches before I actually get to that curve. And come out of the curve into the actual middle of the curve at the tight radius 16 inches past the tangent. I dont know how else to explain that in words.
Basically you create a curve that gets tighter in radius the closer you approach the REAL curve. That is a form of cheating and a way to ease your monstor 2-40-2 onto 8 inches radius before it has any idea what is happening.
Oh one other thing. S curves REQUIRES a straight section in the middle at LEAST TWICE the length of your biggest engine or rolling stock or you WILL have trouble.
Dont even think of changing curve direction on a grade of any kind without some kind of Vertical transitions.
Now that I have thrown a wrench into your thinking with the need to learn "Vertical Transitions" I'll shut up now.
alright, i'm finally starting to understand how to create easements. always understood teh concept, just never had any idea how to go about creating them.
I have a question though. How far away should you start the easement from the tangent track? I'm only making a 4x8 right now, and i'm going to be using 18-22 inch radii, but i'm still going to use easements. I've got a bunch of bachmann eztrack in 18 and 22 inch radii's that i was planning on using to draw out lines on the foam. Would starting the curve with a 22" radius before going to 18" radius work? I'm gonna be using flextrack; if i use say, an 18" radius at the end of the layout, and lay out a semi-circle, how far away from the end of the semi-circle should i begin the easement? As in, how far between the 2 ends of track (the end of the semi-circle and the end of the tangent track). Or, should I have them end at the same point, as if they were going to be connected, but then offset the tangent track some distance?
Also, one last question regarding curve radius: Does radius change as you go up an incline? I'm going to have a grade that is basically like a helix turned into an S-curve. I planned on using an 18" radius with that; will that cause any problems? I got the WS 3% incline set that I'm going to use for that. This brings up another issue: Entering and exiting a grade. Should you also have easements for that? I've always wondered about that. How do you have the track automatically just start the grade, or is there easements built in? I figured i would just shave off the top end section to make a smoother transition, but would i also have to use masking tape or duct tape or something to create a gradual build up of layers into the grade?
sorry for the threadjack, lol
Draw a half circle. (I use about 28 inches radius)
Draw straight track that are about 1 inch offset to the outside of that curve.
About 15 to 20 degrees of curvature before you arrive at the straight track, end the constant radius. Allow flex track to fall into a natural radius and reach the straight away.
With full length heavyweight cars, you look to use about 16 inches before you hit the curve and after you hit the curve.
You will find that your engines and trains dont JERK to one side as they leave the straights.
Try this site:
http://www.eldoradosoft.com/easements.htm
PS: to the forum.
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