New Safety Box - Proposed Design

Discussion about ways to make the sport safer and discussion of past injuries so we can learn how to avoid them in the future.
Divalent
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Re: New Safety Box - Proposed Design

Unread postby Divalent » Sat Feb 20, 2010 2:29 am

KirkB wrote:I'm not yet convinced that the inserts need to be soft ...
but this will be side pieces that won't see big forces, just glancing blows. If it doesn't need to be hard, why make it hard? (It does need to be smooth, (and durable) hence my suggestion it be laminated with a stiff but thin veneer of a teflon sheet).

KirkB wrote:I'm more concerned about rounding the top edges of the box ... but I'll leave that discussion for now. ...
Divalent wrote: If made from a rubberized material, there might be additional features you could incorporate. For example, you could make a version that incorporates some of the features of the maxsafe box pad. ...

Not sure what you mean. Is this with the basic shape that I show plan, side, and end view of above ... or something different?

If you look at the maxsafe pad, it extends padding along the sides and *DOWN* into the box along the whole length, except right at the back, where there is no padding so that it won't interfere with poles. Essentially you are proposing a box that is narrower at the stopboard end, which has the effect of making the sides of the box down at that end unnecessarily wider than they (now) need to be. Since you are in effect moving the bottom corners of the box inward 5.5 cm, then padding that extends 5.5 cm in from the existing sides shouldn't hinder any pole planted in your new design. So why not incorporate that into the design, by having your retro fit material contain the padding the would cover this area. Make the side wall angle a bit steeper so that, instead of meeting the sides of the existing box exactly at the upper side edge, it "overflows" the top edges and continues off to the side a bit. And do this all the along the sides. Let me see if I can do some ASCII art:

.................;;;;;;;; <- this is rubber material from retrofit that "overflows" side edge
................***,-------------- <- this is the top surface of existing box and surrounding ground
..............****/
............*****/ <- this is the side wall of existing box (with *** = rubber retrofit)
..........******/
______******/

think of ** and ;;; as the rubber material in your retrofit, and / and ,------- as forming the existing wall and edge (dots are just space fillers because the forum posting routine strips out leading spaces)

BTW, now a vaulter has a 11 cm wide target to hit to get a clean straight plant into the back of the box (15 cm, less 4cm of pole plug). Your design will narrow that 1 cm or less (4 cm less 4 cm = 0?). I'm not sure how accurate and repeatable plants can be, but it seems to me that a good vaulter would, with existing boxes, rarely if ever experience rapid repositioning of the tip by the sides of the box. Whereas with your design, it likely to be most of the time. Would that be a concern safety wise? (be careful with your initial tests to see what sort of effect it will have.)

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KirkB
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Re: New Safety Box - Proposed Design

Unread postby KirkB » Sat Feb 20, 2010 4:31 am

Divy, I like your innovative thinking, and I'm happy to collaborate with you on this. There's a bit of a misunderstanding here ... only becuz I have yet to post my revised design. It's no secret ... I'm going to be fully disclosing the entire design ... but I just haven't done the drawings yet ... and there's minor changes to the cardboard prototype that I want to make before I take more pics. Once I get this work done, it will become more evident how this all fits together. In the meantime, I'll try to answer your Qs, and I think you're fairly close to our ideas in some areas. This problem is excacerbated due to me just wanting to spend as much time in the next week and a half enjoying the once-in-a-lifetime Olympics in my home town ... so I've put the project on hold for a couple weeks. Stay tuned til after the Olympics are over.

How about that Canadian skeleton pilot eh? The crazy beer-drinking, fast-talking auctioneer Gold Medalist ... Jon Montgomery! Canada's answer to Shaun White! Go Canada go! :yes: :yes:

Divalent wrote: ... If it doesn't need to be hard, why make it hard?

The latest design retains the same measurements ON THE BOTTOM PANE as the drawings above ... but has side panes at a 15 degree angle until you get to within 24 cm (or so) of the backstop ... and then the angle is 37 degrees ... 7 degrees more than a standard box. As a result, the "hole that you might fall into" is reduced in size ... at ground level ... by a significant amount. It's hard to explain without the new drawings, but you can imagine that if there was no padding whatsoever above the plywood frame ... and you landed feet-first onto where a standard boxes side edges would be ... then it would be just like landing on the ground next to the box ... in other words, the FLAT area around the box encroaches INTO the box. This is safer. But on top of that (literally) ... you round the corners of the plywood, and you add a thickness of dense rubber, and you add dense foam on top of that ... you have additional padding. So that's why the BASE inserts can be hard ... becuz everything above them is SOFT.

Divalent wrote: It does need to be smooth, (and durable) hence my suggestion it be laminated with a stiff but thin veneer of a teflon sheet.

Your idea of a thin teflon sheet covering the inside panes of the inserts is good ... I think ... I'm not experienced with teflon ... other than knowing that it's a non-stick surface used in pots and pans ... so I'm glad to draw on whatever experience you have with appropriate carbon/plastic composites.

Divalent wrote:
KirkB wrote:I'm more concerned about rounding the top edges of the box ... but I'll leave that discussion for now. ...
Divalent wrote: If made from a rubberized material, there might be additional features you could incorporate. For example, you could make a version that incorporates some of the features of the maxsafe box pad. ...

Not sure what you mean. Is this with the basic shape that I show plan, side, and end view of above ... or something different?

If you look at the maxsafe pad, it extends padding along the sides and *DOWN* into the box along the whole length, except right at the back, where there is no padding so that it won't interfere with poles. Essentially you are proposing a box that is narrower at the stopboard end, which has the effect of making the sides of the box down at that end unnecessarily wider than they (now) need to be. Since you are in effect moving the bottom corners of the box inward 5.5 cm, then padding that extends 5.5 cm in from the existing sides shouldn't hinder any pole planted in your new design. So why not incorporate that into the design, by having your retro fit material contain the padding the would cover this area. Make the side wall angle a bit steeper so that, instead of meeting the sides of the existing box exactly at the upper side edge, it "overflows" the top edges and continues off to the side a bit. And do this all the along the sides.

OK, I gotcha now. You're very close to what we have in mind. But your dimensions are off a bit ... and we know that we can substitute the wood for rubber, but we won't be doing that for the first WOODEN prototype. For the first RUBBER/FOAM prototype, then yes ... exactly.

Re the dimensions, you can't save 5.5 cm on each side of center. At the backstop, the side panes on my NEW design encroach the box by 2.5 cm on each side. You could retain the 120 degree angle (30 degrees off vertical) instead of 127 degrees to encroach a bit more ... but I kinda like having a little bigger angle there ... even tho there's some debate as to whether that improves safeguarding from pole kick-back or not. I'd like that extra 7 degrees to eliminate all doubt ... for the craziest of HS vaulters that aren't properly supervised or coached (a safety factor needs to cover the worst case ... like designing buildings to survive earthquakes). If you were to encroach 5.5 cm on each side (instead of 2.5), then you wouldn't be allowing any room for the pole to bend ... unless I've totally misunderstood you on this point. You have to allow at least the 120 degrees of a standard box ... no less.

Divalent wrote: BTW, now a vaulter has a 11 cm wide target to hit to get a clean straight plant into the back of the box (15 cm, less 4cm of pole plug). Your design will narrow that 1 cm or less (4 cm less 4 cm = 0?). I'm not sure how accurate and repeatable plants can be, but it seems to me that a good vaulter would, with existing boxes, rarely if ever experience rapid repositioning of the tip by the sides of the box. Whereas with your design, it's likely to be most of the time. Would that be a concern safety wise? (be careful with your initial tests to see what sort of effect it will have.)

My thinking is somewhat the reverse of yours on this ... altho I'm open to considering all opinions and opposing views. My thinking is biased by how I vaulted ... aiming towards the left corner of the box (I'm a lefty). I never once concerned myself about the pole butt glancing off the left side pane and ricocheting ... inadvertently ... into the right-hand corner. In my entire career, I think this happened just once. So whether the path to the stopboard is "straight on" or guided by the side panes makes little or no difference in my way of thinking.

IMO, the speed of the pole tip in the forwards direction far outweighs any rattling back and forth an a sideways direction. Same goes for ricocheting off the bottom pane of the box and bouncing up and over the stopboard ... it hardly ever happens, becuz the forwards speed of the pole tip draws it to the stopboard before it gets a chance to bounce up. If I was to worry about one of these and not the other, then I'd worry more about too fast of a pole drop causing the tip to bounce off the bottom pane. In reality, this rarely happens ... not enough to worry about it.

The ADVANTAGE of the narrow chute to the stopboard is that if you're off a bit ... like by 7.5 cm on either side of center, for example ... then you're GUARANTEED of planting EXACTLY in the center of the stopboard ... without even aiming. In fact ... to be ridiculous about this ... since the front of the box is 60 cm ... you could plant the pole 30 cm off center and STILL plant perfectly centered on the stopboard ... provided of course ... that you pole has fallen to ground level as the pole butt hits 30 cm off center.

Keep in mind that this is a training device. If you take the wildest, most inexperienced vaulter in the group, the question is whether the inserts would help or hinder his plant. Will he LIKE his pole to be centered for him ... or will he prefer to aim for the center of the stopboard himself? :confused:

I'm open to counter-arguments to this way of thinking.

Quite frankly, I think the width at the bottom of the stopboard (15 cm) ... perhaps designed about 100 years ago ... was not set at 15 cm for any particular reason other than to give the vaulter a bigger target to shoot for. I honestly don't think safety was a concern back then ... there was no such thing as stalling out and landing in the box from 4.00m+.

Kirk
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Divalent
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Re: New Safety Box - Proposed Design

Unread postby Divalent » Sat Feb 20, 2010 4:06 pm

Kirk,

I admit my responses have to some extent just taken your general aim of reshaping the box to make it safer, and the concept of a retrofit to an existing box to accomplish this (a brilliant idea in and of itself from the point of view of getting any useful devise implimented across the country) and tried to explore the possibilites even if they didn't stay exactly true to your original intentions.

Imagine if the plan was to just narrow the box by bringing each side in ~5 cm all along their length. The result would be a backstop with a width as you propose, but otherwise dimensions (angles, clearances, gaps, etc) that are consistent with today's boxes with respect to how a pole would interact with the box once it was planted and the vaulter is on his way up. What I mean by that is this: if indeed a pole planted in (say) the left corner and which bends off to the left has plenty of room to do its thing without being interfered with by the rest of the box, then with this proposed narrowing it will function the same as existing boxes in this respect. Thus, I don't see anything gained by making the angles more accomodating, since the additional clearances are not needed. And so why not fill that space (some of which you essentially propose to be just air, as a consequence of changing the angles) with padding instead? (I can't imaging any shape of the box that would be safer if there was air rather than padding filling some volume, as long as that padding would never interfere with the pole.)

Additionally, going back to the maxsafety pad, the concept there is to bring the collar in to cover the top edges on the sides by overflowing some padding down from the top of the sides, except where such padding would interfere with the pole bending close to the backstop. SInce your concept is to narrow the channel, and to do so by adding material along the sides, why not add to the safety by 1) making this filler material out of a yielding material (e.g., a springy rubber) and 2) have it overflow out and up to cover the top of the sides (e.g., the same surfaces that the max safety collar is covering from the other direction).

However, the thing that will change by just bringing the sides in a fixed amount all along the box is the width of the box throat that the pole is moving down, and here I have no experience to predict what will happen (just my imagination, as a scientist who understands physics etc but not the practicalities of the pole-planting situation). You say you always aim for the left corner; does this mean that your pole often interacts with the left side wall of the box, or is it just coming in along the base and heading that way? (I think it would make a difference.)

Regarding the angle of the base of the side walls with respect to the runway axis, your original design contemplated increasing that angle by keeping the "opening" at the runway end the same while narrowing the backstop width. On the one hand, if you instead keep this the same, then the "padding overflow" can cover the side corners out near the runway just as well. But on the other hand, as one who has never vaulted, I don't know whether 1) the throat angle, and 2) the fact that just about every pole plant is now going to glance at least once off the sides of the box, will make a significant (and dangerous?) change in how the pole interacts with the box. I just don't know. So I will leave it to you guys with experience to assess that. I only raise them as things you might want to be cognizant of when you are testing it out. It might be useful to make some high speed videos of what the pole does as it goes into the box (maybe choose a vaulter like you that always aims for a corner, since they are more likely to be hitting the sides) and compare with the behavior when using a narrower box. (60 frames per sec probably won't suffice, as a 10 m/sec speed would be about 16 cm (~6 inches) per frame; not good enough to get detail on the amount of banging around that might be going on).

Anyway, just some thoughts/comments to feed the idea mill.

BTW, the "teflon" sheet could probably really be any flexible but durable plastic about 1-2 mm in thickness and with a slick surface. Just something that wouldn't tend to "bite" or resist the motion of a pole plug as it struck with a glancing blow, and which would protect the underlying padding material from wear and tear.


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