Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

For all you math people, grade cal in inches.

1741 views
7 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2006
  • From: west coast
  • 7,667 posts
Posted by rrebell on Wednesday, June 8, 2016 9:16 PM

Thank you, and yes it is a small space with transition happening in the space before. Only ore cars and such will be backed up on the dump. I have no math skills to speak of but not bad on investing so I needed to turn to you people. In building a model railroad, you just never seem to have enough room.

  • Member since
    January 2010
  • 2,616 posts
Posted by peahrens on Wednesday, June 8, 2016 5:35 PM

Don't forget that the transition from flat track to sloped track is extra length added, at less than the main sloped part.  That will either reduce what rise is achieved at the max height end (if the horizontal run is kept the same) or increase the total length needed past the flat track somewhat if the total height is to be achieved.   A third option, within the desired run of track, is to increase the main slope slightly to make up for the less than average transition slope.

Of course, if the track goes from flat to sloped but flat again at the top end, two transitions are included which doubles this effect. 

Paul

Modeling HO with a transition era UP bent

  • Member since
    July 2006
  • From: Sebring FL
  • 842 posts
Posted by floridaflyer on Wednesday, June 8, 2016 4:33 PM

OP needs to tell us two things, how high is the top edge of the coal ramp and what is the maximum distance from the top edge of the ramp to the point where he can start the incline, the longer the starting point is from the ramp the lower the %.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, June 8, 2016 3:32 PM

i'm also confused by the numbers

does it really matter what the grade is as a %?   don't you have a limited horizontal distance (the run) that has to climb some vertical distance (the rise or drop)?    don't you want to maximize the horizontal distance to minimize the grade?

greg - Philadelphia & Reading / Reading

  • Member since
    July 2006
  • From: Sebring FL
  • 842 posts
Posted by floridaflyer on Wednesday, June 8, 2016 3:29 PM

If indeed the run is 3 feet 3/4 inches the rise, (or drop) would be 1.98 inches. 

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Wednesday, June 8, 2016 3:02 PM

Is the run 3 and 3/4 inches, or is it 3 feet plus 3/4 inch? And what is a "drop" at 5.35%?

If you are saying your percent grade is 5.35 percent, this means that your track will slope down 5.35 inches for every 100 inches; 2.675 inches for every 50 inches; 1.338 inches for every 25 inches; and 0.054 inch for every inch.

So if your run is really 3.75 inch, you would multiply 3.75 inch by 0.054 inch/inch and end up with 0.203 inch.  This is about 13/64 inch.

  • Member since
    July 2006
  • From: Sebring FL
  • 842 posts
Posted by floridaflyer on Wednesday, June 8, 2016 2:55 PM

A 5.35% grade over 3.35 inches is about .2 of an inch rise(or drop if measuring from the high point). Are you sure you mean 3.75 inches?

  • Member since
    July 2006
  • From: west coast
  • 7,667 posts
For all you math people, grade cal in inches.
Posted by rrebell on Wednesday, June 8, 2016 2:38 PM

The specific probelm is if I have a run of 3 3/4" and a drop at 5.35%, how much is that. Reason is I am building the end of a coaling ramp and the sooner I start the grade, the lesser the grade will be 1/8" here and there adds up.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!