Helmets: Modes of failure

[Christian_Chourot]

A large impact causes them to split (had this happen to a bike helmet once and was unconscious for a long time)

This got me wondering, have people got any stories and preferably pictures of their damaged/visibly undamaged (although obviously potentially unsafe) lids after a significant impact? I'm interested in what ways different helmets have failed in different circumstances and also, if anybody has had surprising damage occur after minor incidents that might hint at prior weakness.

It's just occured to me that I've used the term 'failure', although I'm hoping that the term 'success mode' is more appropriate! (by failure, I meant how the structure fails following impact.)

 

[nickwilliams]

Graham Proudlove did some work on this a long time ago IIRC (in the days when fibreglass was common). It would be interesting to see it updated. I'm sure the BMC Technical Committee has some interesting stuff as well.

If you are seriously interesting in picking this up, send me a PM.

Nick.

 

[mountainpenguin]

well a bit more detail.
The shell didn't suffer any faliure at all.
An initial inspection showed no proems however further flexing revealed that there was a split running about half way round the helmet!
There was no obvious dents on the outside.
I can remember if we took the shell off (this was more than 10 years ago)

 

[andymorgan]

With polystyrene bike helmets, the manufacturers typically recommend replacing them after any impact (at least the ones I have owned). I have wondered if the polystyrene Petzl helmets (SPELIOS/ELIOS) should also be replaced after any impact, including banging your head on the roof...

 

[Les W]

Isn't a caving helmet just somewhere to hang your light... 

Ducks and runs for cover

 

[graham]

Isn't a caving helmet just somewhere to hang your light... 

Ducks and runs for cover

Aye, you just tuck your candle into the band on your bowler.

 

[Brains]

I have discarded helmets because; one went all mouldy manky gooey inside; another because the fibreglass had been ground through; because the plastic cradle had failed; because the chinstrap rivet pulled through, and one because I had changed lighting set ups once to often and the holes joined up. One I broke in a rucksack by sitting on it edgeways... the current light support system is a CS protex that is fine for me, so far :-[

 

[Pete K]

Couldn't resist

In the real world of caving however, I have only personally killed one lid. That was trapped in a minibus hinged seat, effectivly squashing it side to side. It returned to its original shape but was obviously stressed as a series of white lines were visable in the plastic shell, other than that though, no obvious damage. It was the same type as the one in the picture above.

 

[graham]

My first caving hat was one of those papier mache ones.I dunno how robust it was but it was the most comfortable one I've ever had. I really wish I knew what happened to it 'cos I lost it a long, long time ago.

 

[Cave_Troll]

i have photographs of a climbing helmet, taken after its wearer fell on his head and knocked himself out.
http://www.flickr.com/photos/48651817@N00/3211662129

I also have a caving helmet (Caving supplies) that has a split going from the rim up into the main dome about 4 inches long

 

[Pitlamp]

Further to Nick Williams' comment, yes, Graham Proudlove did quite a lot of work on helmet issues. I think this was done in consultation with Phil Brown at Caving Supplies. If you are ever in the shop in Buxton Phil could probably tell you more. But I'm sure it was written up, somewhere in BCRA stuff probably (and almost certainly mentioned in Descent as well). I don't think he just worked on glass fibre helmets. In case it helps a literature search I think this work was probably done around the mid 1980s. Graham is the current Biological Recorder for BCRA so he's contactable via the BCRA website.

 

[SamT]

been thinking about replacing my ecirn roc recently for various reasons (too big, adjustment wheels are getting too 'sticky', smelly).

but one of the main reasons is the top is starting to look very very scratched and I reckon it will actually be really thin, it would be interesting to do some measurements with some calipers.

thinking of a Elios next, I have a very small head, and it seems to be quite a 'small' and neat helmet.

(nowhere to store my emergency bivvy bag though,  )  ducks and covers

 

[cap n chris]

I have an emergency bag stowed in my Elios - it's a bit snug, but possible.

 

[Katie]

If any one is planning on doing any testing on helmet strength after impacts I have two helmets I would be happy to donate.
1 is a petzl vertex that came detached from my head near the top of the bigger pitch in bar pot due to a mudded up catch.
The second is a ecrin roc that fell from the break through window of Titan to the event horizon (about 65m) - this wasn't mine but the guy who dropped it deceided he didn't want it back. Similar story i think - muddy catch not done up right. Neither shows much sign of external damage (but both duo's are a bit cracked and smashed but still vaguely work)

I have no personal experiences of the Elios helmets - but my little sister managed to break one that was only a few months old! It was a club helmet but hadn't had much use. She got her head a bit stuck in a rifty bit and so yanked her head free - this caused the helmet to crack!!!
I understand they got their money back after writing to Petzl but someone from EUSS on here might know better then me?
Katie

 

[Broken Chris]

My mate very kindly knocked some rocks down from the top of a 35m pitch while on an expo. Unfortunately I had no where to go so just had to wait for impact. One hit my helmet putting a nasty dent and crack in it, accompanied with a large blister on the inside. The rest of the impact was taken by my carbide light which was pretty mangled, but salvageable. Although probably not a very big rock, given the limestone we were in it would have been very sharp, which is how it probably managed to actually put a crack in it. Later investigation with a hammer to see how much strength was left in it was quite surprising - it took a hell of a blow to actually smash through the helmet totally.

 

[paul]

It's probably worth contacting the British Mountaineering Council for info as caving helmets are nearly always climbing helmets with lamps attached. I remember years ago an article in a climbing mag about a 20 year old Joe Brown glass fibre helmet passing all relevant tests (at the time) for a new helmet.

 

[matthewjc]

I remember years ago an article in a climbing mag about a 20 year old Joe Brown glass fibre helmet passing all relevant tests (at the time) for a new helmet.

With the great story about the 'development & testing' of the Joe Brown helmet done in the back of his workshop by wearing the helmet and being wallop'd over the head with a length of 2x2...

Matt

 

[Keith L]

I remember years ago an article in a climbing mag about a 20 year old Joe Brown glass fibre helmet passing all relevant tests (at the time) for a new helmet.

That's nice to hear, because I had one of those in my garage and that's what I'm using now I'm caving again 

 

[van the man]

Hi Bat Girl

Noticed this in your post,
(but both duo's are a bit cracked and smashed but still vaguely work)

Looking for some dead Duos to play with some more Crees.

Are they going spare?

Dont mind paying a bit and p+p of course

Michiel

 

[SamT]

Hi Bat Girl
Noticed this in your post,
(but both duo's are a bit cracked and smashed but still vaguely work)
Looking for some dead Duos to play with some more Crees.
Are they going spare?
Dont mind paying a bit and p+p of course
Michiel

tee hee hee - I think Batgirl's inbox is getting fuller by the minute