Figuring Grades
Robert Herrick
Math has never been one of my skills so I pose a question. I am looking at a published track plan where 1/2'=1'. A grade rises 4% over 8 inches on the plan. Say it starts at 0 inches, what is the final elevation in inches?
Bob Herrick


Stephen Silver
My guess is 1/3 inch. If I recall a 4% rise is 1 inch every 25 inches. 8 inches is roughly 1/3 of 25. You can get closer I’m certain.
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On Sep 26, 2019, at 12:56 PM, Robert Herrick <rdherrick@...> wrote:


Robert Herrick
Thank you, Stephen.
Bob Herrick


Richard Johnson
A 4% grade is a 4% rise in 100 feet.
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Take the simple numbers, 4% of 100 is 4, be it feet or inches. You are looking at 8 inches so what is 4% of 8 inches; 8 X .04 = .32 of an inch. Close to 1/3 of an inch in height. You can do more math to make that a fraction or google a conversion which is 8/25ths of an inch. Regards all Rich Johnson www.RichardSJohnson.net "Those who enjoy freedom must endeavor to preserve it." "No free man shall ever be debarred the use of arms" Thomas Jefferson
From: HOn3@groups.io <HOn3@groups.io> on behalf of Robert Herrick <rdherrick@...>
Sent: Thursday, September 26, 2019 12:56:17 PM To: HOn3@groups.io <HOn3@groups.io> Subject: [HOn3] Figuring Grades Math has never been one of my skills so I pose a question. I am looking at a published track plan where 1/2'=1'. A grade rises 4% over 8 inches on the plan. Say it starts at 0 inches, what is the final elevation in inches?
Bob Herrick


Climax@...
A 4% ruse is 4 inches in 100, 2 inches in 50, 1 inch in 25 inches, half inch per foot would do it.
Original Message


Ric Case
Looking at the numbers I calculate the grade for the 16 ft to be just under 2 inch of rise!
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1/2 inch equals 12, 8 inch equals 16 ft of run or 192 total run. Figure around . 4 % in 8 ft is around 3.8 inch in rise, so 4 so 4% over 192 inch would be around 2 inches of rise! Ric Case EBT Modeler Hamilton Ohio 15133757694
On Sep 26, 2019, at 4:52 PM, Richard Johnson <killroy321@...> wrote:


ColoRyan
Grade = ( rise / run ) x 100
Where grade is a percent, rise is the elevation gain in inches, and run is the distance traveled in inches. You must use common units for rise and run (i.e. either feet or inches), don't mix! Example: ( 8 inch / ( 16 ft x 12 inch per foot) ) x 100 => ( 8 inch / 192 inch ) x 100 = 4.166%  Solving for run: run = rise / ( grade / 100 ) Example: 4 inch / ( 4% / 100 ) = 100 inch => 8.34 ft  Solving for rise: rise = run x ( grade / 100 ) Example: 100 inch x ( 4% / 100 ) = 4 inch


Darryl Huffman
A 4% grade rises 1 inch in every 25 inches.
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On Thursday, September 26, 2019, Robert Herrick <rdherrick@...> wrote: Math has never been one of my skills so I pose a question. I am looking at a published track plan where 1/2'=1'. A grade rises 4% over 8 inches on the plan. Say it starts at 0 inches, what is the final elevation in inches? 
Darryl Huffman You can find my Youtube Channel of Model Building Videos Here: You can follow my blog here:


John Cytron
I think you all have figured this incorrectly. Bob asked for the final elevation.
If the plan is ½” to the foot, then 8 inches on the plan is 16 actual feet. Think of each 1% grade as equal to 1/8th inch per foot in the real world. (⅛” = 1/96th of a foot or slightly more than 1%.) A 1% grade would rise 1/8th inch over 1 foot and 16 times that over 16 feet, or a rise of 16x1/8th which is 2 inches. Over 16 actual feet, the rise would be 16 times 1/8th or 2 inches. The calculations made by the earlier posters is correct to the scale of the drawing; that is, 0.32 inches. So what is 0.32 inches to 0.50 inches, the scale of the drawing?. It is 0.32/0.50 or about 0.64. 0.64 is almost ⅔ and what is 2/3rds of a foot? —8 inches. More precisely it is 0.64 times 12 inches per foot or 7.68 inches in the real world, that is, if the ½” to the foot plan were at full scale. I still like to figure 1/8th rise in 1 foot as equal to 1%. It makes for easy figuring. Anyway, why would you want a 4% grade as that is really rare even in narrow gauge (except for a few places like Baxter Pass on the Uintah RR and some others.Today's HOn3 locos could barely make that grade with 2 cars and a caboose. John


Mike Conder
Exactly, though 5/16" is probably close enough and easier to visualize Mike Conder
On Thu, Sep 26, 2019 at 2:52 PM Richard Johnson <killroy321@...> wrote:


Robert Herrick
John—it’s not that I want a 4% grade, it’s just what Robert Lah drew in the track plan published with his Chili Line article in the 4/94 MR to model Embudo to Barranca and I was stumped figuring what that would mean in actual inches. I’ve been intrigued by that plan since it was published, but it is way more than I want to tackle as a northof70 year old so I view it merely a point of departure.


Russ Norris
North of 70, hey? We're starting to get a lot of youngsters in the group now! Well, if you're gonna join the group, you'll need a nickname. Nobody gets in the door without a nickname. So start thinking, Bob. Better you pick it than some of the old geezers in this group. Present company included. 😁
On Fri, Sep 27, 2019 at 4:59 PM Robert Herrick <rdherrick@...> wrote:


Jeff Reynolds
I've been all through this, albeit with heavily cero bent brass locos and 30' cars @ 1.3 oz total weight. Lots of variable though. Grandt trucks take more motive power to take on the same grade as do Blackstone's. After some entertaining experimentation, the aforementioned numbers revealed 3% grade was the max for me. This also varied from engine to engine and was not dependant on weight or sprung or unsprung drivers. My 74 and 42 pull like crazy, at least as well as my good K27's and without suspension. Go figure.
jefe


claneon30
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kevin b
How about “Youngblood”? The Preacher well, I for one can't sign off on that as he is north of 70 and i'm 54. not that I wanna be called Youngblood, cause I don't. but, if nothing else comes up for him, I guess it'll be alright. Kevin.


Robert Herrick
Oh boy. I could mention a couple of monikers I was tagged with during my working years, but it might be more fun to see how creative you old geezers are.
Bob


Russ Norris
My bad, Bob. I belong to too many groups. You are currently in the HO3 group, which is much more sedate, where people exchange detailed info on modeling and refer to one another as "Bob" or "Russ". I was thinking I was talking to the NarrowGaugeChat group, a much smaller and more irreverent group that sometimes gets a bit silly but still understands the old saying that "model railroading is fun". If you believe that too you might want to introduce yourself to the chat group where, for sure, you will get your "handle" from us old geezers. Russ "Butch" Norris
On Fri, Sep 27, 2019, 9:35 PM Robert Herrick <rdherrick@...> wrote: Oh boy. I could mention a couple of monikers I was tagged with during my working years, but it might be more fun to see how creative you old geezers are.


Robert Herrick
Well, sir, I was a pot stirrer in my first career so don't get sedate on my account. Nothin' like a rowdy crowd to get the pot astirring.
Bob


Steve Hatch
8 feet is 96 inches which is close enough to be 100 inches.
So 1 inch in 100 is 1percent grade. 1 inch in 8feet is a 1 percent grade So 1/8 th inch per foot is 1 percent so 1/4 is 2 percent so 3/8 is 3 percent so 1/2 inch per foot is 4 percent. Close enough for a rule of thumb Stephen Hatch Railway Engineering


Dale Buxton
And yet beyond simple to calculate. Lol. D Buxton
On Wed, Oct 2, 2019 at 15:24 Steve Hatch <hatch@...> wrote: 8 feet is 96 inches which is close enough to be 100 inches.

