Am a newbie; but just wanted to 'shout out' a genuine "Thanks!" to all of the guys who responded to my recent inquiry regarding HO curve radii. I received some excellent tips; many tips confirmed and validated some of my own preliminary drawing plans. Thanks a bunch. This Forum sounds like a neat place/neighborhood family to go to in the future. BTW:
Please post some recommended grade ratios. For example, I realize that you need about 4inches height for one track to go over/above a lower track. How steep, or , what would be an approximately realistic grade-ratio? Should I lay my track at a 1inch elevation per 2, or 3, or 4 feet of linear length: or what? Thanks... Your tips are really appreciated.
Georgia Flash
Hi!
Assuming you are modeling standard track gauge, mainline railroading (as opposed to narrow gauge and/or logging or mining), you really should keep the grades no steeper than 2 or 2 1/2 percent. What that means, is that for every 100 inches (round to 8 ft) the track will rise 2 or 2 1/2 inches. Any more than that will severely tax your locos and the number of cars they can pull up grade - and will give a more toylike impression. Note that the prototype mainline RRs hate grades with a passion and do all they can to minimize/eliminate them, and I believe the max grade is about 2 1/2 percent (mainline RR).
Also, when you build your grade, make sure its relatively constant all through the length of the grade. To do this, figure out the projected track rise for a short distance - like 1 foot or 20 inches - and work with that throughout the grade. In example, a 2 percent grade would be about 2 inches in 8 feet, or 1 inch in 4 feet, or 1/4 inch in one foot.........
ENJOY,
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
To add to the post above, you will want a transition curve at the bottom and at the top of your grade. By that I mean easing into the grade from horizontal/level with a gradual curve until you are rising at the rate that will accomplish your clearance height at the top and at the same time giving you room for the corresponding transition curve back to level. Typically, but not for longer steamers, your vertical curve should run about 6-8" for every 1% of grade, but the greatest single determinant will always be each engine as it tries to climb into and up the grade.
Woodland Scenics sells foam riser blocks that are pre-cut with certain grades. For instance, if you wanted a 2 percent grade, you would buy the 2 percent package. I used them for part of the layout I am working on. I do not remember the cost, but I thought it was a bit pricey for what it offered. It is definitely pretty easy to use, but you are limited to that grade, unless you want to start shaving the foam (messy).
I think in the future, I might just use strips of hardboard (masonite) in either 1/8" or 1/4" to create the slope, and just put scraps of foam under it to support it every xx inches. I am using flex track and securing it with latex caulk, so I am not concerned with using tacks for the track. My thought is that the hardboard will help ease the transition into and out of the slope. Plus, if I wanted a 1.9 percent slope, that is an option. Unlike the foam, where you are set to what package you bought.