Grade system

[Anonymous]

I don't get it.. maybe an expierienced railroad worker can explain this to me... hint hint Expierienced

like Ed.. he'll know

If you look at page 46.. of TRAINS juse 2003,
there are thigns i don't understand; the Grade system.

2.5, 2.3.. i see a 3... 2.4, 1.9

what on earth does that mean.. Because i know we use a totalyy differnet system up here

but i would like an explination from anyone who understands it..

im utterly clueless

THX.
Detour Kev.

[JoeKoh]

Hi kev
to try to answer your question grade is how much elevation you have in a mile of track.its like being on a see saw.I am at ground level you are at the top.how much force would it require to push me up to you.that is your percent. the higher the percentage 2.3 3.4 etc the more helpers you will need to get the train up the hill and down the hill with dynamic braking.imagine a train at saulda with a 5.1% grade wow. hope this helps out
stay safe
joe

[mudchicken]

Simply stated, that number is the distance (in feet) that the train moves vertically (up or down) as it moves 100 feet along the track. Old friend gravity can make life miserable on an undulating 1% grade just as much as a steady 3% grade. It's a lot better to have your train all bunched together (or stretched apart) than it is to have both things happening repeatedly a speed in a short period of time.

-mudchicken

[edblysard]

Thanks Kev for putting me on the spot, my math sucks, but here goes.
Grade percent is the expresseion of the change in elevation versus distance travled.
If you changed elevation by 10 feet while you travled forward or backward 1000 feet, the the percent of grade is .01%. (10 feet divided by 1000 feet) equals .010, or one tenth. Expressed as a decimal it would be .010, as a fraction it would be 10%
There are two types of a mile, a statute mile,(5280 feet or 1.61 kilometers) and a natuical mile (6076 feet, or 1.852 kilometers)
A statute mile is what you see on marked on a road map, as if the world were flat and you drew a line from point a to point b. A natuical mile takes into consideration and includes the curve of the earth. If you took straight pins, and stuck them into a globe at two points, then carried the lines of the pins up high enough that you could lay a ruler flat on them, and measured the distance in a level line between the two pins, you would get one figure,(statute miles) but if you were to bend your ruler on the surface of the globe, and follow the curve between the two pins, you would find the distance greater between the same two points.(natucial miles)
Statute miles are straight line, or sight miles, nautical miles are actual miles travled following the earths curve.
The grade percents you are reading about are based on change in elevation versus distance travled in nautical miles, or the change in height versus miles travled. So a 2.5% grade means you travled 6076 feet, and changed elevation by moving up or down by 151.9 feet, or 2.5%
Heres the forumula.
Take the change in elevation expressed in feet,(how high up or down you moved) divided by the distance travled in feet(how far forward or back you went) to get grade percent. Kilometers works too, you have to use it for both numbers.
So you take 151.9 feet, divide by 6076 and get .025, or 2.5% grade.

A..............................B
(statute mile following straight line)
*
* *
* *
* *
* *
* *
A * *B
(natuical mile following the curve of the earth)
Greater distance travled, but still between the same two points.
Hope this helps.
Stay Frosty,
Ed

[Mookie]

or count the telephone poles, pi r square it and divide by 2....

Mook

[edblysard]

That works too!
Ed

[CShaveRR]

Good explanation, Ed, fair math, but lousy interpretation!

Your ".010" is not a tenth, it's 1/100, or a one percent grade.

You had it straightened out by the bottom part; your 2.5 percent grade seems correct.

Not really a flame, just an illumination...
Carl

[Anonymous]

Thank you Joe, Carl, Ed, Jenny, Mudchicken...

thank you.. i undertsnad it now

i feel like i shoulda known it beofre too..

Cheers and thanks,
Detour Kev

[wabash1]

kev here is the way we do it down south 3 engines on line as we go down we tighten up the dynamic until we hit #8 and its just screaming. then if we cant control the speed we grab air. if we go past 15lbs of air in full dynamic we consider this a heavey train on a steep grade, this is the simple way

[Mookie]

ok - I am lost as usual. I read in a past Train magazine about a grade being about 1 foot for so many miles. Does anyone remember that one?

I need to have someone go at this from a "something I can relate to" rather than a math problem - remember - I am a visual person - so I will go home and build a grade in the backyard!

Jen

[CShaveRR]

Kind of hard to do, because the whole thing is about numbers. But I'll try here (I'm working this out as I go along.

Being a Nebraskan, you probably live in a city with streets based on a grid ststem, say eight blocks to a mile. That's 660 feet to a block. Say you're at the low end of a block, and from your second-story window you can look evenly into the first floor of the house at the other end of the block, 660 feet away. That's about a 12-foot rise in 660 feet. Or, one foot higher for every 55 feet traveled, which is slightly less than a two percent grade.

It's still numbers, but I hope I've given you a credible and tangible answer.

I know the Nebraska stereotype--do they even allow grades that steeep east of North Platte?

Carl

[Mookie]

Carl - Lincoln is flat until it is icy and then it is nothing but hills. But Omaha is a nightmare! I didn't realize what a steep hill I live on until I tried to go down the sidewalk one really icy morning - didn't do that again!

I frankly don't know how the people in Omaha manage in winter - like I said, we don't get the snow like northern NE and the rain - in Kansas/MO but we get the in-between - sleet and ice!

I do remember an engineer saying when you go south out of Lincoln, there used to be a 1.5% grade and it was steep - I was amazed, didn't sound steep to me! I think he said they finally graded it down and did some work out there and got it lowered. If anyone knows about the area around Roca, please let me know.

Thanx Carl - I will put that in my memory bank!

Jen

[wabash1]

Jenny

As a engineer i am supposed to know this. but when you run the same territory you know what to exspect. hence my answer. like they said it is a drop of a foot in so many feet on the terrain. I wont try and get into the formula i think ed did a fine job. and other people here. the key is unless you have a track profile to know what the decent is you wont be able to guestamate the grade.

[Mookie]

Wabash - everytime we vist, you open up new questions. Track Profile? I can guess from the name, but where does it come from and just an overview of what it contains.

Thanx

Jen

[Jackflash]

Jen j's right without a track profile you are
just guessing at the grade, maybe everyone on
the railroad knows, or no one cares (the most likely). a profile is a paper with a drawing of
the road showing, one view shows curves and their
degrees, another view will show hills (without the
curves) milepost will be shown, rivers, bridges,
signals too, I've seen them in book form, most
of the time though they are similar to a map,
they fold up from a large long piece of paper to
a small package that you could put in your pocket
usually they are used by people learning to run
on a territory. jackflash

[Mookie]

ok - now I am back on track (groan). But I can see where this would be a valuable tool for the newbies.

Thanx

Jen

[mudchicken]

(1) Track Charts & Grade Profiles get used for plenty of other things. Spent 15+ years of my RR career drawing the things on and off. Always amazed me what was mis-interpreted (sp?) by folks using the things....(especially by operating types trying to match speed tapes against them...which goes hand-in-hand with the thread about locomotive wheel diameters).

(2) Jenny - If you are like most folks around Omaha with a relatively new house and yard, you have about 50 feet out the back door to the 6 ft. cedar fence. If the yard was flat (ha,ha - somewhere west of Lincoln), then it would be a 12% grade from the back door threshold out over the top of the fence. With considerable effort, a locomotive without any cars might climb halfway up the fence in that 50 feet,

[Mookie]

Mudchicken: That is a steep grade! That is a great visual, too.

Thanx

Jen

[Jackflash]

Most of the operating types I know never look at
the things, its just a fact thats known that it
takes X number of engines to pull a certain hill,
but dont know the grade, and if the grade was
known, it wouldnt change anything, sounds like the
operating types you speak of are officials trying
to catch someone doing something wrong, when they
couldnt do it right themselfs. jackflash

[wabash1]

hey jackflash

have you ever seen a official do anything right? and i aint talking the first time i am talking the 8th or 9th time. some never get it right. but us people who do it day in and out who are repimanded still move frieght and make profits for the robber barons. ( did i get it right missouri)

[edblysard]

Hey, the officials on my road can golf, and pretty darn well. All they need is for someone to keep explaining it to them, and find the ball, point them towards the green, point out which hole they need to shoot for, and nudge it in when no one is looking. What more would you expect from some one who wears cuffed slacks and workboots with tassels?
Stay Frosty,
Ed

[Jackflash]

j and Ed, sounds like its the same all over,
jackflash