Are helmets worth their weight.....in plastic?

29th Jun 2012

The BMC recently launched their campaign to encourage more people to wear helmets when climbing and inevitably the pros and cons of wearing helmets often gets discussed on our climbing courses.  What has always attracted me to climbing is the freedom it offers and the fact climbers are able to make their own choices and don’t have to conform to any rules.  No one is going to insist you wear a helmet (unless you are on one of our courses!) just like no one can make you use a rope.  Some years ago a well-known climber even exercised his right to free choice by climbing naked with a rope tied around a delicate body part – and although I was certainly glad not to be watching him from below it was great that he had the freedom to do it (bizarre as it may have been!).  So climbers can choose when and where to use a helmet.  That’s the way it should be.

But things change and our attitudes to things should keep pace with that.  The first commercially available helmet was called the Crompton Climber.  I once had the chance to try one of these on and it was a beast of a unit.  Really heavy and really uncomfortable were the key ways to describe it.  Things had moved on by the time I started climbing and the classic Joe Brown helmet was the lid of choice (not that there was loads of choice then!).  This was far better than the Crompton but still, by today’s standards, far from ideal.  I certainly remember, in my Joe Brown wearing days, sometimes looking at a route and thinking that I would take the chance and leave it at the bottom because it was so noticeable when I was wearing it (although I always wore it on winter climbs, longer mountain routes and if the route looked particularly loose).

Of course we are now spoilt for choice and some of the newer models are extremely comfortable – so choosing whether to wear a lid isn’t such a hard choice any more.  Personally, I have got to the point where I really notice not when I’m wearing a helmet…..I more notice when I haven’t got one on!  I was discussing this again with some clients a few days ago and it brought to mind a report I wrote for the BMC based on a helmet testing workshop I attended at Plas Y Brenin a few years ago.  If you are trying to decide when and where to use a helmet the information might be useful.

The workshop was a practical demonstration of helmet impact tests performed by Dr Mark Taylor of Leeds University.  Mark has become a world authority on helmets and he provided a fascinating insight into the current state of play in the helmet world.  Please note that the tests were completed with industry standard equipment but not under calibrated conditions so they should be used as a guide only. 

Mark started the workshop by outlining the studies that have been completed on head injuries and helmet use and it soon became clear that not many statistics are available.  A 1986 study by Read et al looked at 42 autopsies and head injuries were a major factor in 21 of them.  Read concluded that 25% of the deaths could have been prevented if helmets had been worn (although we didn’t explore how he came to that conclusion!).  Another study in Yosemite (1988) found that 9 out of 13 fatalities were due to head injury and Mark had also studied mountain rescue call out reports from the last 12 years (excluding Scotland).  These showed that 25% of injuries were head trauma and, of these, people wearing helmets were less likely to be fatally injured. 

The practical workshop session started with us visually inspecting a wide range of helmets and discussing their relative design features.  These ranged from the ‘Cromptom Climber’ (mentioned above) through to the latest models from many of the main manufacturers (and some lesser-known producers too).  Comparing some of these older models with something like a Petzl Meteor makes you realise just how reassuringly far helmet design has come in the last few decades 

Mark discussed the main helmet types and how they do their job in very different ways.  The Meteor style foam helmets (commonly known as lightweight helmets) absorb impact by distributing the force around the foam whilst allowing the foam at the impact site to distort.  Then there’s a hybrid style with a hard shell and foam shock absorbing liner like the Petzl Elios and finally the hard shell and strap cradle style helmets (commonly referred to as traditional helmets) where the impact force is mostly absorbed by the straps.  This creates an interesting situation where the lightweight models will absorb the force from a pointed object better than a blunt one – In this case it really is better to get hit on the head by a sharper object - just not too sharp!

Mark outlined the production methods used for the various helmet types and the drop test standards.  There are several tests performed on helmets including side impact tests, penetration tests and assessments to ensure helmets can resist being pulled forwards and backwards off the wearer’s head.  There was a limit to what we could perform in the corridor at PYB so our focus was to be a test that mimicked the drop test using a blunt weight.  The standard for this test is a 5kg weight dropped from 2 metres onto the helmet crown.  The EN (European Norm) standard requires the force transmitted to the head to be less than 10kn while the more stringent UIAA standard requires the transmitted force to be under 8kn.  Mark pointed out that no-one actually knew how much force was required to cause head injury because tests obviously haven’t been performed on people, but he suggested that it is very likely the transmitted force without a helmet would be well over 40kn. 
 
It should also be noted that these tests are normally carried out at a variety of temperatures (-20oc, 35oc and a test on a helmet that had been left in the sun for 400 hours) but our only option was room temperature.  We did discuss these temperatures and the whole group predicted that the low temperature test would give the highest reading due to the helmet getting more brittle.  In reality the helmet tested at 35oc tends to be weakest.  

The tests we completed on the day gave reassuring results with all the helmets passing both the EN and UIAA benchmarks.  Here is a brief summary of some of the results on the first drop test on some common helmets:

Petzl Meteor – 6.9kn
Petzl Elios – 7.9kn
Edelrid Ultralight – 4.4kn
Petzl Ecrin – 4.1kn
Carbon Dyneema – 6.5kn

However, we also went on to perform a second drop test on all the helmets and most models gave readings above the EN and UIAA benchmarks.  For example, the second drop on a Petzl Meteor recorded 10.5kn and the Petzl Elios was 11.5kn.

A few other issues were discussed in this session that might be of interest.  The perennial issue of whether it is safe to put stickers on helmets was raised and Mark pointed out that only stickers specifically authorised by manufacturers can really be deemed completely safe to use because no one can be sure how the adhesive will affect the shell material unless it has been tested.  On a similar point we discussed whether the effects of other chemicals have been tested and Mark said there had been a case of a helmet that had cracked after its owner had sprayed it with DEET based insect repellent a number of times.  Also, an outdoor centre that had regularly sprayed their helmets with anti nit spray had reported several cracks in the plastic.
 
It was a great session and seeing the helmets cope with such violent force was very reassuring but, of course, a lid will only protect you when it’s on.  So nowadays I wear a helmet for everything except low level bouldering.  We may have freedom of choice - but surely you’d be mad not to?!