So, checking a visor mask at a tourney is no more than a visual check then.
We don't even punch test the mask area beneath the visor in front of the mouth? Well. That seems... counterintuitive.
Not if I'm doing the check... can't put the probe on the lexan, but I DO always punch the mesh....in the case of a lexan, I hit both sides above and below the lexan...which is in front of the mouth.
Many years ago at a local event in LA there was a mask failure with a Negrenii (sp?) Non FIE mask the mask passed punch test, I did the test, and the failure was with in an inch of one of the areas I checked. No obvious rust or dents. Blade went thru intact and caused a small cut below the bottom lip. Fortunately the fencer had his mouth closed.
Must've been from that bad back of mesh Negrini got.....I failed 8 of those same masks in one season...most, if not all of them, at scholastic events (which is why one HS coach will not buy Negrini masks anymore)
Yup, Negrini really screwed the pooch on that batch of masks. I wouldn't strain my spaghetti with them, fearing I'll lose too much pasta slipping through and going down the drain.
TWas this an FIE mask? What, if any, safety check was done prior to allowing it to be used?
It was indeed an FIE mask. (FIE clothing/masks is standard in competitions here and since this is the European Championships nothing less would be accepted.)
If it matters, the mask was an Uhlmann one. If you go back and read the original article, the author has been given the permission to post a photo of said mask. Please note the copyright!
The mask check was mostlikely a standard one; ie. bend, visual mesh control, check bib and the "band" overlapping the mesh/textile joint. I have NEVER seen a puncture test on any competition I've ever been to in Europe, so I would guess that was not done. Also, who knows how the mask was stored and handled prior to this.
Being from the frozen wasteland AKA Canada, I would imagine that a visor could be greatly weakened by severe cold (ie. while lugging your fencing back and forth to practice and competitions.) Blades get crispy, too.
FOR THE LOVE OF GOD WON'T YOU BUY MY TACTICAL WHEEL!!!????
That's a bit of a concern....Uhlmann was only recently approved for the lexans (within the last year and a half, I think)...although I don't know if the rules require the lexan ITSELF to be manufactured by the mask maker the way they do for traditional FIE gear.
If so, it might be limited to Uhlmann....if not, it could potentially affect other masks with shields made in the same lot.
That's a bit of a concern....Uhlmann was only recently approved for the lexans (within the last year and a half, I think)...although I don't know if the rules require the lexan ITSELF to be manufactured by the mask maker the way they do for traditional FIE gear.
If so, it might be limited to Uhlmann....if not, it could potentially affect other masks with shields made in the same lot.
Or it could just be completely random...
I'm certain this incident will heavily inspected. I also hope the report will be made public, as a lot of people have interest and concern in this. From a regular fencer's (ie. me) view though I'm just so very happy it didn't run out uglier than it...
Lexan masks have been in use only a short time and already we have a potentially life threatning injury. Maybe fencers should be able to choose if they want to use lexan. Does anyone know why lexan was chosen over stainless steel mesh?
If one looks in more detail at the picture shown on the Swedish Fencing Federation website, one can see 4 especially interesting details:
1. There is no whiteing of the remaining Lexan. In a previous thread, I told about when a former collague had stress tested Lexan windows with sladge hammers and axes. He reported that the Lexan went white at the impact area when it was hit sufficiently hard, long before it broke.
2. There is no sag in the remaining Lexan. My former collague reported that the Lexan windows that they tested sagged before it was finally penetrated, in the visor seen in the picture the remaining Lexan appears to retain its pre-failure shape.
3. There are at least three hairline cracks extending from the hole upwards in the direction of right side of the visor pane.
4. There is a crack extending straight downwards from the hole, in the direction of the middle of the lower edge of the visor pane. This crack has two interesting features: its edges are separated from each other, and it extends past the lip of the metal frame holder.
My take on this:
The fact that the failure looks qualitatively different from the failure described by my former colleague indicates to me that those two Lexan parts are different not only in dimensions. If the fencing visor would have had exactly the same material properties as the Lexan window, then the visor should have failed with some whitening and appreciable sag. It did not, and I therefore strongly suspect that it is not solely a case of the Lexan visor being to thin. However, SEMI representatives will no doubt check this, just to be able to rule it out.
That said, my engineerīs gut feeling is that there two especially interesting reasons for the qualitative difference in failure.
1. The two Lexan parts (visor vs. window) might be made from materials with differing specifications, and thus material properties. If you look in a catalog for polymer materials, you will notice that every material is sold in several different grades, with corresponding material properties listed.
2. The visor has been compromised by some chemical/thermal attack.
I predict that SEMI will have a talk to Uhlmann about the first issue, and check out unused visors with a variety of combinations involving acetone, dropped cigarette lighters, and other stuff that concievably are found in armoury rooms.
The lower crack (observation #4 above) is the most intriguing to me. Assuming that it is not a camera artifact, why is the crack separated? The other cracks are not, so it appears that the visor pane is fixed in at least several points around its circumference, holding those other cracks in their closed position. One possible explanation for this could be that the lower crack extends to a screw hole in the visor pane. The symmetrical position of the crack would seem to support this hypothesis. Once a crack has propagated to the screw hole, then stresses in the visor (either due to impact, or created earlier) would have more leverage to open the crack.
It would be quite interesting to see the visor pane dismounted from the mask shell. Does the lower crack extend from the impact hole to a screw hole, as I assume? Is there a crack extending from the screw hole to the lower edge of the visor pane? If that were the case, one would have a prime suspect for the failure initiation point, since I find it hard to assume that such a crack could be created after the crack from failure hole to screw hole, given the energy available. Such a crack creation would necessitate a tear-out failure, and anyway the blade has probably gone through the failure hole by then, thereby not exerting any large forces on the visor pane any more.
Another intruguing question is - given the assumption that there is a crack extending from the failure hole to a screw hole - whether that crack started at the failure hole and propagated downwards, or the other way around. A micrograph of the crack surfaces would reveal this, provided that they have not been fiddled around with. If the crack propagated downwards, then the problem is probably at the impact point (or very close), either due to excessive impact force, or to locally compromised material properties. If the crack propagated upwards, then the problem is probably with the screw hole.
I sure hope that they find the missing piece(s) so that it/they can be inspected.
Here is hoping for a speedy recovery.
Peter Gustafsson
MSc. in Mechanical Engineering, job experience in wear and failure analysis
Peter, by rule there shouldn't be any screw holes in the visor pane. That was a design flaw in the first generation of visors that was subsequently removed.
-B
"Oh but you can't expect to wield supreme executive power just because some watery tart threw a sword at you!"
Were those masks recalled or disallowed, or was the rule only applied to future generations of masks? If the former, was the rule change recent enough that this one could have been made before the change?
Were those masks recalled or disallowed, or was the rule only applied to future generations of masks? If the former, was the rule change recent enough that this one could have been made before the change?
The former design, which was really early in the visor era, was decertified. There were also changes in the maximum dimensions of the visor back around then.
The screws one sees in the visor brackets only go through the bracket, not through the visor itself.
-B
"Oh but you can't expect to wield supreme executive power just because some watery tart threw a sword at you!"
Does anyone know why lexan was chosen over stainless steel mesh?
In hopes of appealing to television executives, who had complained about the inability to see fencers' faces through traditional masks.
A decade or so ago the IOC began looking into dropping events from the Olympics. Television broadcast rights are a major source of revenue for the IOC so the ability of a sport to appeal to television executives was a significant factor in their deliberations. The FIE Executive Committee responded by pushed through a number of changes in hopes of increasing fencing's appeal to those television executives (in some cases ignoring negative recommendations from their own subcommittees).
The foiltip had enough energy to blast through protective lexan.
You can infer what kind of damage it might have done to induce "profuse bleeding" from the corner of a mouth. I don't think the foil tip needed any help from the plastic shards.
I would think that it was more likely an epee! I mean come one, a foil making that kind of penetration? I've held a piece of cardboard and had the best foilist on my team lunge at it and it bent before penetrating
I would think that it was more likely an epee! I mean come one, a foil making that kind of penetration? I've held a piece of cardboard and had the best foilist on my team lunge at it and it bent before penetrating
Perhaps you should have a very athletic fencer with poor technique lunge at the cardboard. Good technique encourages the blade to bend properly.
The lower crack (observation #4 above) is the most intriguing to me. Assuming that it is not a camera artifact, why is the crack separated? The other cracks are not, so it appears that the visor pane is fixed in at least several points around its circumference, holding those other cracks in their closed position. One possible explanation for this could be that the lower crack extends to a screw hole in the visor pane. The symmetrical position of the crack would seem to support this hypothesis. Once a crack has propagated to the screw hole, then stresses in the visor (either due to impact, or created earlier) would have more leverage to open the crack.
After seeing the picture, I too, found that portion most intriguing. I can't help but wonder as well if that is indeed the best clue.
Beer, it's whats for dinner! ~ a young snowboarding Canadian The meek don't want it! ~ sticker on a rock band's guitar
Damn....that's a scary pic! Looks like it just shattered...anyvwhitening would indicate fatigue in the material, wouldn't it?
Another reason to suspect this basic design....the lexan plates are relatively flat....the full mesh masks must have angle on the front of less than 130 degrees so an oncoming blade gets deflected....looks like ALL of the blade force hit the mask here.
I hesitate to read too much into a single picture (especially since I'm more used to working with steel than plastic), but it looks like the initial failure might have occurred somewhere near the top of the hole, where edges appear most jagged. A flap of plastic then folded inward along a more or less straight line until it snapped off, creating the long, relatively smooth edge running across the lower left hand edge. The dents in the metal frame which the ancient one pointed out may have been caused by the plastic flexing underneath the metal frame before it broke off.
Originally Posted by foibles
