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Jul. 5th, 2009 10:41 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
which_chickI had a nice 4th in Philly with the usual folks. There were mojitos and there was pico de gallo and it was good. I got up 6 am on Sunday and drove home to La's for brekkie (scrambled egg thingie folded over with veggies. French. Can't spell it.) and horses. Rode Callie over to Lynn's house to get Saffron. (La came along -- she led Saffron back with Irish Red, who needs the work). She was fine, no worries. I hadn't been on her in a while but she didn't do anything. Definitely no motor on that horse. When I got back, I weeded the onions in Hazel's garden and took the little (18") jumps up beside the corn field and set up the cross pieces in an X shape.
So, y'know, there are jump standards. The standards are about 18" tall. There are 8' cross pieces that are put on the standards in an X pattern. The cross pieces have some overhang, probably about 6" of the beam at the top, but the base of each cross piece sits at the foot of the opposing standard.
How tall is this jump? (People always say that math is useful for this shit. It isn't. The easiest way to measure how high the fucking jump is is to go the hell out above the corn field with a fucking tape measure and MEASURE the damn jump. However, traffic in Breezewood sucks and it's dark out and I'm kind of lazy.)
How would you solve the problem?
Well. Feel free to assume that the assembly is relatively close to symmetric because I'm ocd like that.
So, there's a short side 18" tall. There's a right triangle there, with a hypotenuse more-or-less eight feet long. Probably 7'6" is more realistic, because of the overhang thing. The other side can be found using the pytha -- fuck it all. This is not useful math. Make a PICTURE. Look at the PICTURE, Jessica. LOOK at the picture.
I drew some examples. That helped a lot. However, I'm tired and don't want to photograph my sketches for Internet Posterity, I'm going to summarize my findings for you instead of giving you the picture. You're getting the thousand words version instead of the picture. Mind, nobody is stopping you from making YOUR VERY OWN small sketches... You could if you wanted. I'm betting you don't want.
If the base of each cross-beam is placed at the foot of the opposing standard, the jump beams will ALWAYS cross halfway up the jump. Proving this involves Jommetry, which I didn't bother to do because I got A's in Jommetry and am now coasting on my hard-won skillz from 1985. The short form is this: You are making the diagonals of a rectangle with your cross beams. The diagonals of a rectangle are equal and bisect each other. Part of "bisect each other" is that they do so halfway up the height of the rectangle. Always. It's one of them things that you learn about rectangles in Jommetry. It's all rather elegant and pretty, really. (As I'm sure everyone reading this is aware, squares are a special case of rectangle and their diagonals not only bisect each other BUT ALSO they do so perpendicularly. Is that not nifty?) I had rather more fun remembering this than perhaps I should have had. :) (Read this nice piece about maths, please. Don't forget to come back when you're done... It's the sort of essay that totally understands the frustrating shortcomings that one runs into when one tries to use math-as-she-is-taught to solve actual real-life problems.)
So, then. the height of the jump is roughly half of 18" plus also a couple of inches for the cross-brace thickness. The cross-braces are landscape timbers. They're probably 3 1/2 or 4" wide. It doesn't really matter because the whole thing is sitting on unlevel ground. The jump standards are not exactly the same height because I am not an expert circular sawyer. Let's call it a foot high and be done with the maths. It doesn't really matter if the jump is a foot high or thirteen inches or nine inches. It's not a particularly big jump, here. A reasonably athletic person could step over this without much effort. So could my horse, to be perfectly honest.
Okay. So. A foot high, this little jump was. I trotted Goof up to the little jump and she was wiggly like a very wiggly thing. She tried to wobble left and right to get out of the jump. (I didn't permit it, mind, but it was offered repeatedly as an available option.) The thing with cross rail jumps is that they offer a visually inviting spot in the middle for jumping -- aim for the low part, see. They're a beginner-level jump for that reason. Nick overjumped. A lot. Beginner jumping horses jump VERY VERY big sometimes, like they're not sure they have a handle on the size of the jump and they kind of overdo. It's to be expected but it's still somewhat disconcerting. We landed and did some nice trotting circles and tried again. More wobbly, less overjump. Again. Again. I took her over the little jump about eight times, four per direction. The last one she was not particularly wobbly and didn't overjump too badly so I took her home and put her away. End on a good note, here. The goal is to teach this horse to address the jump, to go right for it, and not to be worried. I want a brave horse, not one that worries. In pursuit of that end, I'm doing very sedate, progressional work on her. She knows to aim for the appropriate part of the trot over poles these days and doesn't try to run out anymore, so I think she probably will get the hang of this, with more exposure.
So, y'know, there are jump standards. The standards are about 18" tall. There are 8' cross pieces that are put on the standards in an X pattern. The cross pieces have some overhang, probably about 6" of the beam at the top, but the base of each cross piece sits at the foot of the opposing standard.
How tall is this jump? (People always say that math is useful for this shit. It isn't. The easiest way to measure how high the fucking jump is is to go the hell out above the corn field with a fucking tape measure and MEASURE the damn jump. However, traffic in Breezewood sucks and it's dark out and I'm kind of lazy.)
How would you solve the problem?
Well. Feel free to assume that the assembly is relatively close to symmetric because I'm ocd like that.
So, there's a short side 18" tall. There's a right triangle there, with a hypotenuse more-or-less eight feet long. Probably 7'6" is more realistic, because of the overhang thing. The other side can be found using the pytha -- fuck it all. This is not useful math. Make a PICTURE. Look at the PICTURE, Jessica. LOOK at the picture.
I drew some examples. That helped a lot. However, I'm tired and don't want to photograph my sketches for Internet Posterity, I'm going to summarize my findings for you instead of giving you the picture. You're getting the thousand words version instead of the picture. Mind, nobody is stopping you from making YOUR VERY OWN small sketches... You could if you wanted. I'm betting you don't want.
If the base of each cross-beam is placed at the foot of the opposing standard, the jump beams will ALWAYS cross halfway up the jump. Proving this involves Jommetry, which I didn't bother to do because I got A's in Jommetry and am now coasting on my hard-won skillz from 1985. The short form is this: You are making the diagonals of a rectangle with your cross beams. The diagonals of a rectangle are equal and bisect each other. Part of "bisect each other" is that they do so halfway up the height of the rectangle. Always. It's one of them things that you learn about rectangles in Jommetry. It's all rather elegant and pretty, really. (As I'm sure everyone reading this is aware, squares are a special case of rectangle and their diagonals not only bisect each other BUT ALSO they do so perpendicularly. Is that not nifty?) I had rather more fun remembering this than perhaps I should have had. :) (Read this nice piece about maths, please. Don't forget to come back when you're done... It's the sort of essay that totally understands the frustrating shortcomings that one runs into when one tries to use math-as-she-is-taught to solve actual real-life problems.)
So, then. the height of the jump is roughly half of 18" plus also a couple of inches for the cross-brace thickness. The cross-braces are landscape timbers. They're probably 3 1/2 or 4" wide. It doesn't really matter because the whole thing is sitting on unlevel ground. The jump standards are not exactly the same height because I am not an expert circular sawyer. Let's call it a foot high and be done with the maths. It doesn't really matter if the jump is a foot high or thirteen inches or nine inches. It's not a particularly big jump, here. A reasonably athletic person could step over this without much effort. So could my horse, to be perfectly honest.
Okay. So. A foot high, this little jump was. I trotted Goof up to the little jump and she was wiggly like a very wiggly thing. She tried to wobble left and right to get out of the jump. (I didn't permit it, mind, but it was offered repeatedly as an available option.) The thing with cross rail jumps is that they offer a visually inviting spot in the middle for jumping -- aim for the low part, see. They're a beginner-level jump for that reason. Nick overjumped. A lot. Beginner jumping horses jump VERY VERY big sometimes, like they're not sure they have a handle on the size of the jump and they kind of overdo. It's to be expected but it's still somewhat disconcerting. We landed and did some nice trotting circles and tried again. More wobbly, less overjump. Again. Again. I took her over the little jump about eight times, four per direction. The last one she was not particularly wobbly and didn't overjump too badly so I took her home and put her away. End on a good note, here. The goal is to teach this horse to address the jump, to go right for it, and not to be worried. I want a brave horse, not one that worries. In pursuit of that end, I'm doing very sedate, progressional work on her. She knows to aim for the appropriate part of the trot over poles these days and doesn't try to run out anymore, so I think she probably will get the hang of this, with more exposure.
