another question on grades

[thatboy37]

i just finished doing my 7% grade and it takes roughly 233 inches from start to finish. my question is. is this to much of a incline in this distance that would have a major effect on my engines or would this put to much strain on my engines. also should i make the distance from start to top of incline a little farther. my consist would be a csx dash-9 pulling 15 gundersun twin stacks. would this grade be to much for this engine to pull these cars up the incline. help please any info/help would greatly be appreciated as i want go any farther with my laying track until i get a few opinions. thanks in advance.

[Anonymous]

 

 That sounds really steep but  .............................              

You could always sell all your current engines and replace them with Shays

 

Tim

[jimhaleyscomet]

Is it a straight shot?  Curves make it much more difficult. 

 I do not know how heavy your cars are nor how strong your engine is so I can not say what will happen.  I bet it would work but then most hobbyists stay below 2%.  Is there anyway to hook up a transformer and a few wires to test it.  You do not need a loop for the test.  If not, replicate the grade on a long 2x4 and test it.  

 I found in engineering the sooner you can model the final configuration the better.  

Jim  H 

[Frank53]

My math may be off, but a seven percent grade with a run of 233 inches equals a rise over the distance of 16.94 inches.

What is making you want to have that much rise in that distance?

At three percent you can rise about seven and a quarter inches.

[csxt30]

In my opinion, a 7% grade is way too much. It can be hard on your traction tires. If you're running in TMCC, you can add engines, double head or even triple. Still that's a really steep grade & could have problems later in case you wanted to run something else on that track. You can shorten the train up, of course.

Thanks, John   

[dwiemer]

Reggie, that does sound like an extreme grade.  Most seem to recommend keeping your grade at or below 4%.  Ultimately, it depends on a few things.  1-are you trying to stay somewhat in scale?  2-what type of load are you planning on pulling? (I know what you mentioned regarding the double stacks, but could you also be planning on any bigger trains?)  3-capability of your engine(s).  The only way to know for sure, is to run a test with the maximum load you plan on pulling.  A few things you should do to test this would be to load your consist behind your engine and see if it will enter and climb the grade.  You should also try starting the train (engine with consist) from a dead stop on the grade. 

From some of the pictures that you have shared with us, I suspect that you have motive power that will be able to handle this grade.  It is not just what a engine will be able to pull in a published report, it is also the tractive effort and its ability to overcome the grade while pulling such a load.  Good luck and please post the results.

Dennis

[jimhaleyscomet]

Just wanted to make sure you saw the discussion at

http://www.trains.com/trccs/forums/991878/ShowPost.aspx

 

Here is a picture of the setup I used for my test (a 20% grade is shown)

[thatboy37]

my fought guys the highest point is 7 inches off the table top. so it goes from 0 to 7" in 233" on a straight away. is that better i had it wrong in the first post sorry for saying it wrong. i hope this makes a little more since. a rise of 7 inches in 233 inches hope this clears things up, and maybe i can get better and more accurate responses.

[Roger Bielen]

Reggie, don't forget the transition from flat to grade.  Too sudden a change will cause problems, least of which could be uncoupling.

[jimhaleyscomet]

Reggie,

100*7/233 is about a 3% grade.  You should be o.k. but only a test will tell you for sure.  

Jim H 

[fifedog]

Reggie - my engines are required to loop around in 13 feet and rise 6". You'll be fine, but as recommended, make sure you have a smooth transition at the bottom of the grade.  Engines with speed control will chew up that grade with no problem.

[waltrapp]

"csx dash-9 pulling 15 gundersun twin stacks" - I can only speak from my own experiences but I'll share.  It sounds like some, certainly not all, of the advice above is based on traditional lore rather than first hand experience.

I think I posted this somewhere else about a short time ago so sorry about the repeat.

I have 25' long ramps that rise 7".  I run all MTH Railking engines all under DCS.  All have dual motors and traction tires.

4 of my 6 engines can easily pull 10 Railking boxcars up that hill.  2 of them spin their wheels about 1/2 way up pulling a mere 8 cars.  And these are boxcars, not the heavier gundersuns that you will be using.

One other bad thing happened last year that taught me a lesson.  It involves one of the 4 engines that I just mentioned that can pull the hill.  Last year after about 7 or 8 times up the ramp it would overheat and eventually quit running.  It turned out that I wasn't giving it enough 'power'.  I solved the issue by running with 18V instead of the 14V that I was using.

My point is that there are variables to consider and a global answer is not always available.  Personally I think 15 gundersons will prove heavy for a single engine, but who knows, maybe you dash 9 can handle it if it's MTH Premier, Atlas, or Lionel Scale. 

It would be nice to hear from someone that actually has your engine or a comparable one.  Alternately it would be just as good to hear from someone pulling heavy cars like yours.

- walt

 

[Frank53]

Reggie:

For your future reference, a quick rule of thumb - one eighth of an inch of rise over twelve inches of run roughly equals a 1% grade - there bing 96 eighth's in 12 inches. For every one eighth of rise you add, it adds 1% to your grade:

1/8" rise = 1%
1/4 rise = 2%
3/8" rise - 3%

etc