I am planning my fist garden railway and want to know how i calcualte grade. 4% grade means what? is that 4" of rise over 100" of length. thanks for the help
Yes, that’s right. Try to limit yourself to a 2-3% grade. I round off the 100 inches to 8 feet then all you need is an 8 foot 2x4, a level and a tape measure to figure out your grade.
- Brian
CCRAIL
A few “general rules of thumb”.
Grades: Try your best to keep the grades below 4% (try harder for 2%). Higher grades mean fewer cars being able to be pulled by any given engine. Higher grades also cause more wear and tear on engines and drive trains, leading to stripped gears.
Curves: Keep your Curves as large as possible 8-10 ft diameter when possible. Tighter curves also limit pulling power, (actually the cars will begin to tip over into the curve is the train is too long. 8 ft. curves will allow you to run most everything out there on the market, with maximum train length. 4~6 ft curves will limit what equipment you will be able to run.
Tunnels: Keep them straight and no longer than you can reach from each end. If you do make them longer, ensure you install access portals.
Rails: Longer rails (5, 8, or 10 ft) make for fewer joints, which makes for better operations. In other words, fewer “picked joints” causing derailments.
Now that I have recited the general rules, as we all know every rule is designed to be broken. You need to know the consequences before violating the rules. I have broken them all.
Grades: I have a “ramp section” for trolley service to the top of my waterfall. Due to constraints as to how much real estate was available and the height I needed to climb I have a 38 foot long section with a 14%~16% grade. I did this knowing I would be replacing gears/street cars a lot more often than should be normal. The only things running on this section are “expendable” streetcars.
Curves: All my mainline curves are 8 ft. Selected locations have a curvature of 6 ft and one location with a 4-ft radius, at the beginning of the streetcar line to the top of the waterfall. Being aware of these limitations, I can still have fun operation.
Tunnels: Mine makes a 90-degree curve, but is s
You’re right, 4" rise in 100" of travel is a 4% grade.
The formula is R/L=% … R=rise, L=length of travel, %=percent of the grade .
So, in your case, 4"rise/100"of length=.04 (.04x100=4%).
Walt
One more thing Keep your track level side to side. twisted track will cause derailments.
dave
I second that motion! A little bit of side to side sway looks realistic for an old dilapidated branch line. If you want the sway then try to stay around 1/32 ~ 1/16 inch difference in rail level. Depending upon your car length and weight anything more than that can cause cars to tip at speed and on curves.
and then… 1/8 inch per foot equels 1% so if you only have a 2 foot level and have the need for 3% grade use a scrape of 1X4 ( 3/4" ) at one end of the level with the other end on the same serface to get your desired grade.
Dave
P.s. I’m Currently using 3/8" spacer in 3ft for 1% grade…
Ttrigg passed along some excellent advice. I have one thing to add: Grades on curves: If you can avoid grades on curves completely, your railroad will be more reliable. If you must have grades on curves, restrict them to about half the prevailing grade.
steamdonkey:
Most execelent comment, must add that one to the standard “guidelines” listing.
This is my first time building a GR and it is a small start. The layout is about 40 foot total mainline with a switch yard but I am worried about hurting the gears on my engine as I have a section that is about 40 inches long and 3 1/2 inches rise meaning about 8% grade. I run a USA trains GP38-2 with about 5 smaller cars so it goes just fine and I am hoping it wont do to much damage. Any advise on the damage I might be doing to the engine would be great.
Thanks
That’s a pretty steep climb and the USAT 2 axle diesel trucks are notorious for splitting the gear hub on the drive axles under a heavy load. Many fix it by wrapping the split hub with thread soaked with CA or replacement gears are readily available.
-Brian
Where would be the cheapest place to get a replacement and it should not be too bad as it only pulls two boxcars, two little flatcars, and a small tanker right now. I am looking at landscaping it too about a 3% grade.
Thanks
Regrading sounds like a good idea. The GP38 should be able to handle ~8 cars on a 3% grade.
Order replacement gears directly from Charlie Ro. Contact customer service (best by phone) for ordering info - http://www.charlesro.com/contact_us.htm
-Brian
I traced my last major derailment to a lack of side-to-side level at a curve. Does anyone have advice for rehabilitating uneven sectional trackwork? I am guessing that there are strains in the trackwork due to actual layout not matching what the sectional track was meant to do. I’ll plug away at it and report on progress.
Steamdonkey - it would probably help if you described the problems with your trackwork in more detail. What did you mean by “rehabilitating”? The advice given above in this thread is spot on. The method(s) of “rehabilitation” may very depending on how your track is laid. If it is simply laid in ballast on the ground, then that is the easiest to “rehab” by simply taking a bucket of ballast (crusher fines) around with a small scoop and small (3" to 4") paint brush. Also take a nice small level and a long (3 or 4 ft) level.
Use the short level across the rails for side-to-side measure, and use the long level along the rail length to check for humps or dips. Fix everything by pouring on additional ballast, gently lifting the track and and working in gently with the brush. If you have a hump, try gently working the track (use a little pressure and gently side-to-side motion) down into the ballast first, or if that isn’t enough. then remove excess ballast until everything is level. Keep measuring across the rails with the short level to avoid creating more problems as you perform your repairs.
Also, it has not been mentioned above that we should avoid short transitions from level track to graded track and vice versa. Make the transition at the bottom and top of every grade as long/gradual as possible. That will help avoid de-coupling and derailment problems.
Al
Excellent advice, gbbari. I nearly added the ‘grade transition tip’ in my message but deciided a short and focussed message is better. What I’ve done so far is to tear out a too-long 1*6" bridge and changed the landscape so a two-foot bridge suffices. I do indeed lay my sectional track on crusher-fine ballast and then top-up for a more realistic (i wish) look. I use the supplied aristo/usatrains rail joiners with extra screws. i am just about ready to buy a fistful of rail clamps for the ‘problem’ joints where the rails don’t line up nicely. Part two after replacing the bridge is playing with ballast to level things as best I can. The thing is, I have a feeling the track does not simply lie flat on it’s base – there are some other factors kicking in like torque between track sections, which cause rail to lift and bend.
I apologize for partially hijacking ccrail’s thread since this really has nothing to do with calculating grades, so I will take this discussion of rehabilitating problem trackwork to a new thread.
AL