I purchased the Woodlands 2% riser set and have been trying to figure out a way to have a 2% grade in the space that I have. Using the risers it is about 6" too long. I can only get to a height of 2 1/8" from the top of the foam to the top of the riser. I don't think that is enough clearance for the track that runs underneath. I was wondering if there were any tricks that I could do - like remove sections so that the rise is a bit steeper in places, etc or should I abandon the 2% and go with a 3%?
If you're running steam-transition era equipment that should be no problem. If you're running more modern equipment, have trial runs to see if there is enough clearance.
3% can be done. However, if there is any way you can stay closer to 2%, you'll be much happier. Keep experimenting and see if 2% can be made workable. Boxcab E50
General concensus here from what I've seen is that you should try to keep your grades to 2% or less, or accept that your consists will be a lot shorter. I've had an issue similar to yours in terms of gaining height and allowing sufficient clearance. In the end I've accepted a compromise. One of my reversing sections runs into a lower level that I use for staging as well as some through running, one entry into the reversing section is too low for autoracks and intermodal equipment, but the other gives me sufficient clearance so I've decided to live with it. Even saying that I certainly have 2.5% grade in some areas and this definitely affects the pulling power of some locos. I'm hoping Bullfrog Snot will go some way to improving the situation (and that I never forget about the height clearance problem and send something expensive the wrong way out of the reversing loop)
You should be OK at 2-1/8". Roadbed is about 1/8" thick, and track about 1/8" or 3/16" high. So you've got about 1-7/8" or 1-13/16" of clearance. That's 25' or 24'-2" on the prototype. With modern equipment that might not be enough, so I would do what Bob suggests, and test your equipment.
That won't be enough for modern double stacks and maybe not for auto racks with. Better test it out assuming that is the kind of gear you're planning on running. If not runninig the double stacks you're probably OK.
The lower the grade, the better. Due to a construction mistake, one of my grades went from 2.5% to about 3%, around a 24" radius curve. A modern four loco consist will easily pull 100 cars up that grade, except the couplers don't hold. And going down is actually worse, as the weight of the train will cause the pancake effect. For practical running, I'm limited to 50 car by that grade, although I can pull 65 or even 70 to show off. On my straight 2.5% climbs of about 20' I've never really found a limit, as more than 65 cars means the tail of the train is on a curve as the locos head into the next curve. I've done 100 cars, but had to couple the train past that 3% grade. Going down is the real problem. A 100-car train will pancake on my layout on 2.5% grades. Just my observations on my layout.
You can always shim the riser a little bit. This will give you a grade slightly over 2% but not anywhere near 3%. I assume from the height involved that you won't be running trains much longer than 10' at the most. If that's the case you can probably get away with 3%. We run 12' trains up grades like that at the club, but you need four or five locos. Not that I recommend it... 2 -1/8" is probably enough for doublestacks and autoracks, but only just barely. When you subtract space for roadbed and track it needs to still be more than 1 3/4". Any bridge you have obviously can't hang down more than than the same thickness. Some modern models (e.g. Walthers doublstacks) may need to be lowered because they are manufactured way out of scale.
Hello. There is my example: Now I have a 2.5% at one place of my layout. One Wahlters-RS2 (sufficiently light loco) can stably pull about 6 or less middle freight cars. I use 2 X RS 2 for dependability of pickup and 12 cars in train. I have not so large layout. The length of my station ways is equal 1m10cm (43') Earlier i tried to use 3% grade. - I had a lot of headpain. 5 car long ICE3 modern train with traction tires had a problem to get it! Now all ok with 2.5%! ---- Thanks, Vadim.
Pancake effect? I thought I've had every type of derailment in the world, but apparently not -- I've never seen a pancake effect. What happens, exactly? The term suggests something collapsing dimensionally (and catastrophically) into a compressed stack. It sounds horrible. Any pics?
I like to point those thinking about steep grades to this post by rtroop last year: How to Calculate Tractive Effort. His post explains exactly why we want to keep grades to a minimum and curves to a maximum.
How much clearance you need will, of course, depend on what type of bridge you use. As long as you use a bridge that does not extend below the track much more than about 1/8", then 2 1/8" should be plenty. 2" is enough clearance for a double stack and Unitrack roadbed(and this is with the more out-of-scale Walthers double stack).
Is there any way that you can cut into the foam on the lower track to gain more clearance? Perhaps cut a long shallow ditch with a slight grade. Or delete the cork or road bed in that section? Or is that the begining of your up and over and it cant go down any more?
Yes, I have pics. It will take me a while to find them. Ah, here it is: It's a bad scan taken in the early 1990s, but it's the best I have.
D-Rio has... ...the answer. Lower the grade on the ground track. It's an old "trick" to gain height. Lower the track below the bridge. They use the same trick to un-stick tarctor trailers that get stuck under bridges by letting air out of their tires- it's the way Dudley Moore made a carrer in film- by heightening and it's a clever way to say you did it. Just a thought that some one else had. Plus I read it in MR some years ago. Mark
The implementation on this one is an illusion. If you start at A, and circle up to B, where B crosses over A, the travel distance between A and B is always the same. Therefore any change in clearance, no matter if you raise B or lower A, the grade is still going to increase. The only way to gain clearance and keep the grade is to lengthen the distance traveled between A and B.
i figured the pancake effect was when it pancaked the floor. i have the book "track planing for realistic operation" in their it says clearance anyplace from just over 1 1/2 - 2 being normal. again this is just out of the book but maybe of some help in making your decision. oh forget thats from top of rail to bottom of overpass.
I had 3% risers and found them too steep for my small steamers. 2% worked out much better for me. I only had 2" rise from railhead to railhead. All my track had cork roadbed but where my tracks crossed I used only 1/8" doorskin for the roadbed in place of cork on the upper track, and on the lower track I had no cork for about a foot, so I gained 1/8" clearance.
