Converting surveyor gradients to real world gradients?

[cascaderailroad]

My Wopsononock RR, branchline is a 3 foot NG, (later on SG) real line out of Altoona Pa, up over the Appalachian Front Range. It has at its steepest a 4.75% grade, and has some radius as tight as 75m. It goes from 1000' elevation to 2710' elevation in 8 miles of trackage. It was one steep backwoods prototype RR, that had short coal & lumber freight trains, and a couple tourist passenger cars, hauled by Heislers and 2-6-0's, 4-6-0's, 4-4-0's.

 

[Davie_UCF]

Hi David -

I've been trying to wrap my head around gradients as well, so this thread has been really handy. Using the formula provided by Kennilworth above, the gradients shown in your screenshot translate into the following:

2.44 = 1 foot (or meter) rise in 41 foot (or meter) run [100/2.44 = 40.98]
1.97 = 1 in 51
1.57 = 1 in 64
1.17 = 1 in 85

Based on the numbers provided by stovepipe, most of the grades in your example fall into the extreme to "only if absolutely necessary" range.

Anyway, for my purposes (being in the US), I'll plan to limit myself to numbers less than 1.25 (1 in 80) as cascaderailroad suggests for my mainlines.

Thanks, everyone, for a very informative thread!

Ben

yeouch.
I'd gone crazy with gradients on my route mostly for the challenge and interest of driving it with the vehicle physics in cab mode.

I'm sure some can be reduced a bit if its just to go up a hill and go back down again.. but others eek

I understand it now which helps. The language of if its under a certain gradient it should only be if extremey neccessary is really useful.
I've been messing with Fraps so sat in the cab of one of my AI trains to watch the gradient while i was doing a cab ride video just out of curioustiy.. it was rather scary..
Might upload some videos to show off the rollercoaster world of mine.. and the route of course.

Edit, just to check i'm doing this right..
0.40 in trainz = 1 in 250?
100/0.40 = 250 ?

Thanks all.

 

[Kennilworth]

Hi Davie_UCF

Yes you've got it right. 0.4 = 1 in 250.

Regards

Brian

 

[farthegn]

Random

Just a little random info on the line that goes past my college:
The steepest grade along the line is right next to my coach's house and it's 4%!

Just 2 miles to the east are the Old Fort Loops, which have 3 straight miles of 3% grades, sometimes comming up to 3.5%.