A few days ago I shared the exciting news that Mountain Assurance is preparing to launch a short online course entitled ‘Mountain CRM’. This short course in Crew Resource Management and human factors in avalanche terrain will be a mix of written material, short lectures and audio interviews.
What is CRM?
But the obvious question is: what is CRM? Like any good three letter acronym it can mean different things to different people. In the context of human factors we are talking about ‘Crew Resource Management’, a term first used in aviation.
CRM training courses were introduced to mitigate the affects of heuristics and other human factors, but have since grown to encompass many ‘non technical skills’.
As mentioned in my previous blog post ‘The Human Factor in mountaineering and snow sports – Going beyond FACETS‘. I believe that non technical skills for skiers and mountaineers include: situational awareness, decision-making, teamwork and communication, leadership and task management and the application of these skills in the winter environment.
For leaders, instructors and mountain guides working in the winter mountains, CRM behaviours and non technical skills can be used alongside existing decision making frameworks such as ‘Be Avalanche Aware’ (BAA).
The winter mountains may not be your work place, but some of the behaviours and non technical skills will almost certainly be relevant to lots of recreational user groups in the mountains.
An introduction to ‘Crew Resource Management’ and ‘Human Factors’ in Avalanche Terrain
A generic definition of CRM might be the training of the cognitive and social skills needed to support technical training in order to optimise safe and efficient operations.
Work (or recreation) in avalanche terrain requires exactly that. The use of cognitive and social skills to better cope with uncertainty. We are not pre-hospital doctors or pilots but our observations and decisions are made in dynamic mountain environments with the potential for signifiant consequences.
Although we are arguably working in a low tech environment, in contrast to a modern flight deck, CRM has a place in any environment which relies on humans in the system.
Mountain CRM is an opportunity to “train your brain for avalanche terrain”.
What you will learn…
✔️ Enhance your awareness of human factors and human fallibility
✔️ Develop the knowledge, skills and attitudes to mitigate errors and manage risk
✔️ How to prevent and manage group errors
✔️ To use CRM knowledge as an outdoor professional, to balance making a living with safety
✔️ Integrate CRM knowledge, skills and attributes to shift the culture of the outdoor professional sector and help prevent incidents in avalanche terrain
Sign up via the link here for further news and information on the go live of Mountain CRM straight to your inbox: https://share.hsforms.com/1I35IP6_HROOhL4mfTMuh9A3pgcj
Human Factors – “it’s all about the Human Factor, init [sic]”
For many winter sports enthusiasts the acronym of FACETS will need little introduction, especially for those who have undertaken any avalanche training. Interest in Human Factors among winter sports enthusiasts, has rocketed in recent years. It is an in vogue subject.
Here lies the problem, in our search for answers we are applying concepts from other sectors with little understanding of Human Factors (HF) as a scientific discipline. We have an early awareness of Human Factors, but the application of HF is far from understood in a snow sports context.
What are Human Factors (HF)?
Human factors and ergonomics (commonly referred to as human factors) is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. The goal of human factors is to reduce human error, increase productivity, and enhance safety and comfort with a specific focus on the interaction between the human and the thing of interest. Source: An Introduction to Human Factors Engineering. Wickens, Gordon, Liu, 1997.
HF is clearly a broad area with its basis in various areas. Stephen Shorrock summarises it well as ‘Human Factors’ emerged from many disciplines, with none dominating completely. Human Performance is related primarily to psychology, physiology, and sports science, with psychology dominating industrial applications. Source: Human Factors and Human Performance is there a difference?
Human Factors (HF) in Avalanche
So what about Human Factors in avalanche terrain, snow sports and mountaineering? Historically our understanding has been framed by heuristics and the work of Ian McCammon in the early 2000’s. McCammon researched avalanche incidents and identified six human factors that were significant factors in avalanche incidents.
Ian McCammon proposed the main human factors (effectively heuristics) that may influence decisions as: Familiarity, Acceptance, Consistency, Experts, Tracks/Scarcity and Social Facilitation. These factors form the acronym FACETS. For more details on this from Avalanche Canada.
Heuristics are simply short cuts to decision making which allow us to make decisions quickly and efficiently. Very simply they are “rules of thumb”. Frequently these work in our favour, but sometimes result in error. Also referred to as cognitive bias, there are many at work.
More recently the Cognitive Bias codex proposed 180+ cognitive biases. The reality is that the situation is more complicated than the six general influences listed in FACETS.
Heuristic Traps in Recreational Avalanche Accidents: Evidence and Implications – FACETS
Ian McCammons original paper can be found here at: Heuristic Traps in Recreational Avalanche Accidents: Evidence and Implications. I would recommend reading the full paper as a seminal work on the subject of Human Factors / Heuristics. For those who want a two minute summary this video runs through FACETS in two minutes:
Quite rightly this seminal work has seen the widespread adoption of the FACETS acronym worldwide, from avalanche training courses to introductory winter skills. But it remains a broad brush stroke approach to a much bigger and nuanced subject, the reality is it’s complicated!
The bulk of this blog post was written after a conversation with Karl Klassen of Avalanche Canada at the Snow and Avalanche Foundation of Scotland (SAFOS) conference in autumn 2019. Why? Because we both speculated that despite an increased awareness of FACETS that there hadn’t been a significant change in behaviour in the field. I should point out that’s an opinion, but we should perhaps ask what’s going on?
Roll forward to autumn 2020 and I have just digested this paper from Jerry Johnson et al : Rethinking the heuristic traps paradigm in avalanche education: Past, present and future.
I would recommend reading it, and then reading it again!
Jerry Johnson: Rethinking the heuristic traps paradigm
In rethinking heuristic traps, Johnson reviews McCammons work which has been widely adopted over more than 15 years.
He points out that the initial research was conducted into avalanche incidents alone, and while that may identify the root cause of incidents fails to take account of the wins. As such incidents (or accidents) might not be the best window into decision making on the ground.
This builds on Laura Maguire’s lecture Maguire, L. (2020). Cognition in the wild: Supporting avalanche professionals through cognitive systems engineering . Canadian Avalanche Association Spring Conference which is available below.
In short, taking a systems approach to the “nerd fight”, you can view this video here at https://youtu.be/M3HR_Uuvqf4
Changing the narrative around Human Factors
Human Factors is a broad term and at a practical level we should be talking about the application of non technical skills by mountaineers and skiers.
I think that non technical skills for skiers and mountaineers include: situational awareness, decision-making, teamwork and communication, leadership and task management and the application of these skills in the winter environment. Understanding decision making is likely only by adopting a systems approach to our “wicked learning environment”.
As a Mountain Guide and instructor I am focussed on the practical application of these skills on the mountain, I am no psychologist. Even if people understand and recognize human factors, indications are this knowledge does not effectively change behaviour in the field. If there is any chance of affecting these behaviours it is through a consistent and solid planning process that, hopefully, produces a trip plan that keeps people out of situations where human factors might have a negative influence! [Avalanche Canada].
Johnson is arguably on point with the final section of his abstract: We end with a discussion, and a call to action to the avalanche research community, of how we could move towards resolution of these weaknesses and add value to prior work on human factor research. Our aim is not to disparage the seminal, paradigm shifting work by McCammon, but rather draw attention to how it has been operationalized and how the industry needs to move beyond this paradigm to see further gains in our understanding of avalanche fatalities.
To climb Mont Blanc remains one of the great accessible challenges in the Chamonix Mont Blanc Massif for climbers and alpinists. Standing on the highest summit (4810m) around and looking across the Italian plains, along the alpine arc and below to the smaller chains of Les Aravis and Chablais is a seminal experience.
But we are faced with a mountain under pressure from visitors and continually degrading conditions due to climate change. Year after year Mont Blanc is becoming a riskier proposition.
In recent years, I have climbed (and guided) Mont Blanc on a handful of occasions choosing to make attempts early and late in the season to avoid the heat waves, and crowds of the high season. More recently, at the high of the season I have decided to avoid it altogether.
We all have to decide the level of risk we are prepared to tolerate, and this approach has always seemed logical for some guides in an attempt to reduce the cumulative risk of making multiple ascents.
The reality is that limits in hut space and availability due to crowding puts significant pressure on guides and independent climbers to attempt the mountain on schedules that wouldn’t be their first choice. The result is an incremental mission creep towards narrower margins of safety, and judgements on the ground taken on smaller and smaller criteria.
The Inconvenient Truth
A new project initiated and led by the Petzl Foundation, arguably places my own previous strategy in doubt. These independently led projects have centred around the Goûter Couloir some times simply referred to as “The Death Couloir”. No sensationalism is required here though, with this intimidating location and its immediate surroundings being responsible for an average of 3.7 fatalities per year and countless injuries.
Regardless of your experience to climb Mont Blanc by the normal route (voie normal), you will need to pass the couloir, either in ascent, descent or both.
The Petzl Foundation asked the simple but logic question: How can we reduce accidents in the Goûter Couloir?
Presenting such a significant objective danger due to rock fall, the Petzl Foundation postulate that the Goûter Couloir tarnishes the image of mountaineering. That assertion is certainly an inconvenient truth, but one that would be worthwhile stepping back and scrutinising away from the commercial pressures of the tourism industry and individuals livelihoods.
The full links to the reports, are available below and worth reading in full.
Petzl Foundation Reports – Mont Blanc
The latest reports make some stark observations:
“Despite its limitations (see Conclusion), this study provides valuable information for those planning to ascend Mont Blanc:
– The number of rock destabilisation events recorded over the course of the study is an indicator of extreme gravitational activity.
– In 2019, a rock destabilisation event was recorded every 37 minutes on average and every 24 minutes on average during a peak of activity between 7 pm and 8 pm.
– The highest frequency of rock destabilisation events was recorded between 6pm and 8 pm. It increased an average of three hours after temperatures became positive at the top of the couloir.
– Rock destabilisation events grew more frequent and larger in size when the couloir became exposed to the sun.
– The time of day when rock destabilisation was least frequent was between 9 am and 10 am.
– The couloir was as dangerous at 3 pm as it was at 10 pm.
– Rock destabilisation was more frequent at the beginning of the season, partly as a result of snowmelt. However, these events were relatively small in size, but still hazardous for mountaineers.
– The frequency of rock destabilisation events was lower in the second half of the summer season, but the longest events (“boulder showers”) and those involving the highest volumes of material also occurred during this period.
– The liquid water present in rock fractures seems to be the primary factor governing the risk of rock destabilisation. The more liquid water is present in the cracks in the rock (melt water/precipitation), the greater the frequency of rock destabilisation events. Mountaineers need to be particularly cautious during periods of snowmelt or after rain/storms.
– The presence of snow in the couloir is not necessarily a guarantee of safety, since snowmelt promotes rock destabilisation.
– A cold period marked by frequent freeze-thaw cycles is conducive to the occurrence of rock destabilisation. Only a cold period without thawing (which is rare in the summer) can reduce the frequency of destabilisation events.”
Climbing Mont Blanc
The conclusions from this report adds evidence to the widely held view that crossing early in the day before the couloir is fully in the sun, is in relative terms “safer”.
This includes ascent and descent, so hut reservations that facilitate these timings are essential. Starting early from the Tete Rousse Hut, and staying at the Goûter Hut in descent is one option. There are inevitably financial barriers to this, and the issues of securing bookings of huts that are in significant demand.
Finally if starting from the Tete Rousse Hut, some guides choose to start at first light. So at least they can see the conditions in the couloir and will get visual confirmation of any rock fall activity. Choosing to cross in the dark, although common, degrades you ability to make observations.
There are alternatives, and with fifty major 4000 metre peaks in the alps there is a whole collection of challenging objectives on these classic peaks alone. Although any alpine route will be subject to objective dangers and can never be risk free, there are plenty of summits that can be climbed without the same exposure to rock fall on Mont Blanc.
[Originally published in July 2016 this post describes and ascent of Les Droites, Chris Bedford’s last 4000m summit in the Alps].
In mid July, unsettled weather cleared through the alps leaving fresh snow and colder conditions behind. It was an ideal opportunity to grab an ascent of Les Droites with Chris Bedford.
Chris had been waiting for an opportunity to try Les Droites again after an attempt a couple of years ago. To leave it at that would be a gross understatement, as Chris had climbed all of the other major 4000m summits in the Alps, many with his wife Liz. Just one remained – Les Droites.
A quick text exchange followed: “Do you want to do Les Droites? I think it could be good.” The immediate reply of “Yes, deffo!” sealing our plan for the next couple of days.
With this single objective in mind we made the approach to the Refuge Courvercle and had an early night in preparation for our start at midnight. Here lies the difficultly in timing an ascent of Les Droites. It’s imperative to leave early to ensure that the south facing slopes are still sufficiently frozen in descent. Why not go earlier you ask? Well start too early and the glacial approach and initial slopes won’t have sufficiently refrozen from the heat of the day.
Acutely aware of this delicate balance we started out from the hut shortly after midnight to find that the glacier was only moderately consolidated. We traversed carefully through the crevasses trying to pick out the line which we had observed the night before. Making good progress the starting couloir was in sight, only to remain on the horizon as we slowed to a crawl in knee deep unfrozen snow on the glacier.
The likelihood of a successful ascent was rapidly slipping away with the minutes, and I wasn’t looking forward to explaining to Chris that our attempt might be over. Neil Johnson, had experienced tricky conditions accessing the Jardin Ridge the day before and had urged us to simply “keep the faith’.
Keep the faith we did, and the glacier was soon behind us, albeit with some wallowing in deep snow. The approach couloir was good neve however, allowing fast upwards progress onto the broken mixed ground below the East Summit. There was much scope for variation here and we moved together following our nose through the small mixed steps and ‘corde-tendue’ climbing towards the summit.
We moved together up the final steep snow slopes before pulling onto the crest at the top, Chris leading us up onto the top of his final 4000er.
Thanks Chris for a fantastic experience being a very small part of a long term project.
Both Chris and Liz have now ticked all the major 4000m peaks of the Alps, and although I may stand corrected, may be the first husband and wife to do so?..
In December 2014 there was much discussion within the UK instructional and guiding community following the Fatal Accident Inquiry Determination into the tragic death of Graham Paterson on the Isle of Skye.
Sheriff Principal Derek CW Pyle made the following recommendations under the Fatal Accidents and Sudden Deaths Inquiry (Scotland) Act 1976:
1. Consideration should be given by Scottish Government and relevant stakeholders to discovering a means, whether statutory or otherwise, to ensure that mountain guides in Scotland are properly qualified and equipped to provide a commercial guiding service for adults.
2. The relevant authorities should inform the public of the importance for amateur climbers and hill walkers of at least two members of any party being fully equipped to deal with the possibility of an accident occurring to the leading member of the party.
The full determination can be viewed here at: https://www.scotcourts.gov.uk/search-judgments/judgment?id=ba0fbba6-8980-69d2-b500-ff0000d74aa7 (note the terms “mountain guide” is used generically in the document, rather than representing the qualification).
Personally I have no desire to dwell on the events of this tragic case particularly within a small mountaineering community. As ever it is important that we apply the lessons learnt from these incident’s to ensure our own safety as well as that of our clients.
Immediately after the determination (which in itself is less that specific), there was much discussion about the second recommendation and whether parties should be equipped with a multitude of technical devices to summon help. As usual views were polarised, mine included, as the recommendations for satellite phones, EPIRB’s, Spot Locator devices etc were championed on social media networks and in personal communication.
As usual ‘technology’ and tangible advances in equipment were pushed to the front of the discussion rather than considering the ethos of what Mountaineering Instructors and Mountain Guides are trying to achieve.
Firstly, we should and in many cases do, foster self reliance within groups regardless of whether we operate at 1:1 or on a much larger ratio. This simply means ensuring that members of the party are adequately equipped for the venture, have some situational awareness as to their location and the plan for the day, combined with a brief to summon help if required. All of these issues are well engrained in the Mountain Training UK Awards at all levels, for those who have chosen to undertake them.
Secondly, the choice of communication to summon help should be carefully considered on a needs based assessment. To do so those working in the mountains and amateur mountaineers should understand how to summon help and the timescales with which that resource can be sought. Finally, it’s worth considering whether one way communication e.g. Flares, EPIRB, Spot Locator or two way communication is more useful e.g. VHF Radio, mobile phone or satellite phone.
In discussing the panacea of “tech” many have failed to acknowledge the the first recommendation of statutory regulation.
The recommendation of statutory (or other) regulation of mountain guiding activities in Scotland is a radical departure from the current status quo in the UK as a whole. Currently, activity leadership in the hills and mountains of the UK is unregulated with the exception of those under 18.
Within the European Union the UK is one of the few countries which chooses not to regulate these activities. However, arguably we are in a way very good at self regulation within the industry, with a proven pathway to demonstrating competence as defined by the Health and Safety Executive (HSE).
The HSE acknowledge four ways to demonstrate competence: to hold a qualification, to hold an equivalent qualification (e.g from within the EU), to have received training by a suitable advisor (i.e. in house/organisation) or have significant experience. As such many people do the obvious thing and use the Mountain Training UK Awards as an obvious way to demonstrate competence by proxy.
The challenges with this complicated system is that it sadly isn’t very transparent for a client hiring somebody to take them into the mountains. While it should be encouraged that people ask questions when entering into a service agreement, the whole point of the instructional and guiding community is that individuals shouldn’t necessarily need to take the full responsibility of the enterprise?
Sadly, Mr Paterson didn’t hold a substantive Mountain Training UK qualification but had started the process registering for the Summer Mountain Leader Award. It should be noted however, that there was no legal requirement for him to do so.
As for statutory regulation, Sheriff Principal Derek Pyle made the stark observation that mountain guides should be properly qualified and equipped to provide services to adults. Critically, Mountain Training UK also issued a Briefing Note for its Providers and Association members regarding this Fatal Accident Inquiry – Skye.
This makes interesting reading and makes particular reference to the terms ‘Guide’, ‘Instructor’ and ‘Leader’ all of which relate to very specific qualifications. These titles are not legally protected and are frequently abused or simply ignored due to lack or understanding or apathy.
As instructors and guides perhaps we can be more transparent about how we use those terms, and those associated with them. e.g. Aspirant MIA, Aspirant MIC. Particularly, when they do not represent a position within the MTUK framework. Note: The names MIA and MIC have now been replaced by the MCI and WMCI respectively.
That’s one small thing that we can do as individuals to make our industry more transparent. If we can’t regulate ourselves effectively then somebody will probably do it for us.
[James Edwards 1976-2016 – Originally posted on 11th November 2016 these personal memories of James Edwards have been republished here].
It was during the summer that I learnt of the death of James Edwards following a fall hillwalking on Ruadh Stac Mor. He was in the remote area of Fisherfield to set up a radio link for ‘The Great Wilderness Challenge’ with Dundonnell MRT.
Dundonnell MRT were not only faced with a rescue in one of the remotest parts of the UK in bad weather, but also of one of their own team members. Despite being in a situation that no rescue team would choose, the rescue was conducted expediently and with the upmost professionalism. Sadly, James tragically died in hospital a few days later.
For those that know James, it was immediately apparent that this was also one of the UK’s best exploratory winter climbing areas, and one in which he was one of the leading protagonists when it came to climbing new routes.
Simon Richardson recently posted an excellent obituary for James over on Scottishwinter.com, which goes a huge way to record James’ contribution to Scottish winter climbing. It was in Scotland that he was most at home and in the remote Northern Highlands in particular. But he was also an experienced alpinist having climbed in the Alps and in New Zealand.
I first met James’ as a student at the University of Sheffield where we both shared lectures in Environmental Geology and Environmental Geoscience. There he shared a house with Gareth Hobson and Sam Barron, making perhaps one of the most motivated climbing households in the area. It wasn’t until James’ moved to Edinburgh that we climbed together with any frequency, both in Scotland in winter and in Chamonix.
James’ passion for exploration, whether it was new crags that he hadn’t visited or the opportunity to climb new routes, was infectious. There are parts of Scotland that I haven’t returned to, and if its remote, I will have almost certainly been there with James.
Our first new routes together were on Coire an Laoigh in the Grey Corries were we also repeated many others including a direct start to the classic ‘Centre Point’ VI,6.
Climbing with James was never a simple mechanical process, it was always an experience, during which we shared many laughs along the way. My memories are numerous, such as taking a 20m ground fall in the Cairngorms and James having to help me into Glenmore Lodge to attend the interviews for the ‘Night Watch’. Walking into Beinn a’ Bhuird, taking some big falls while attempting a new line, and returning from a car bivouac at Invercauld Bridge to try again the next day. He didn’t mind a walk.
James energy was incredible, another memorable experience was climbing Minus One Gully, Indicator Wall and Tower Ridge on Ben Nevis in a day while staying in Onich. He didn’t mind an early start either.
Thinking I would get a steady second day, we decided to do the Long Reach on Etive Slabs. It was great to feel the warm sun on your back and climb in rock shoes, until the sun when down and we were wearing just t-shirts. Not to mention the fact that I had to be back in work in Buxton the following morning.
One of the last times we climbed together was on the Fiddlers Nose (sic) on Sgurr and Fhidleir. The weather deteriorated quickly and we had to bail in some exceptionally high winds. This short bit of video (Facebook post) was taken just before we bailed – rubbish weather, high winds and another route we had to retreat from. James was loving it, in his element as always…
Driving back towards his home near Inverness, James’ spotted a deer that had been hit by a car. Ever resourceful and thinking of feeding his family for a month, James jumped out insisting that we could get the beast into his Berlingo. All I will say on this matter is that lifting a deer into a vehicle is desperate!
It was this rich fun loving life experience that made James one of Scotland’s much loved members of the winter climbing community. Not only that but a much loved teacher in his community near Inverness. My thoughts are with James wife Tanya and their sons Finlay and Reuben. James will be sadly missed.
On the 21st of May the Scottish Government issued a road map outlining a phased reduction in coronavirus restrictions.
Phase 1 indicates that exercise and recreational activity may be possible close to home, with minimal travel still advised. While it may be possible to achieve small trips close to home for those lucky enough to live in the mountains, for many travel will remain restricted.
We hope to be able start guiding activities again in Phase 3, which we anticipate to be by late July at the earliest. Until then we do need to be patient, and we will be reviewing our risk assessments in line with advice from the British Mountain Guides (BMG) and Mountaineering Scotland.
In the meantime please feel free to get in touch regarding rock climbing and mountaineering in the summer. We look forward to seeing you soon.
Update 13 June: Currently, we anticipate that this will be from the 15th July onwards. Our first priority will be to reschedule bookings from earlier in the season where we can. In addition we also welcome enquires for climbing and mountaineering activities in Scotland, please feel free to get in touch.
Update 3 July: The Scottish Government has confirmed the relaxation of the travel restrictions for outdoor recreation from the 3 July during Phase 2. The full guidelines can be found in the Phase 2 update 3rd July 2020: Guidance for hill walking and climbing during covid-19 from Mountaineering Scotland.
Mountain Assurance Ltd has also signed up to ‘We’re Good To Go’ a national initiative to demonstrate that we are compliant with the latest government guidance regarding Covid-19. Most importantly, we want to reassure you that we have been working behind the scenes, so that we can head to the mountains responsibly when the time comes. More details about the procedures we have put in place can be found on our Covid-19 page.
Earlier this winter my ‘Built to Send‘ X0 arrived in the post ready for some Scottish winter climbing action. Having admired these British made rucksacks for some time I was eager to put the X0 though it’s paces.
Rarely do you see a product these days that stands out in a crowded market place, even less so when they appear to champion the attributes of ruthless simplicity and durability. Well, BTS have done exactly that, bringing a modern and fresh style to the durability of niche products like Pete O’Donovan’s – POD Sacs of old. Combine such an ethos with space age materials and you have a winning combination.
These packs are simple and subtle, with a myriad of options for load carrying. They come supplied with an “alpine customisation pack” which allows you to add ice axe retainers and a shock cord panel to your specification. Same with the compression straps which are removable.
Most importantly for me the X0 is a comfortable carry and plenty big enough for Scottish winter and alpine climbing, although some might prefer the slightly bigger X1. With a large open top (think haul bag style) these sacs pack like the “TARDIS”, swallowing plenty of kit in a storm, when all you can think about is bailing to the car. The X-Fold, Built to Send’s version of a roll top, works well with the stiff fabric.
Fabric brings me neatly onto durability, and BTS have confidently declared these sacs as “bombproof”. Well, the jury is out slightly given the premature finish to my winter season due to the COVID-19 lockdown, but I have no reason to doubt it! These sacs are at home when making contact with the punishing Cairngorm granite and excel when it comes to negotiating the odd chimney. Having bottled carrying the X0 on the narrow “slanting crack” of ‘Postern’ on Shelter Stone Crag recently I can also say that these sacs are easily hauled by the convenient load bearing grab handle on the back.
Currently retailing at £229.00 the BTS X0 won’t be for everybody, but these excellent sacs should definitely be on the radar of mountaineering instructors, mountain guides and professional users. Not to mention those who like a Scottish winter chimney or two. For those who are destructive with their kit, these sacs will pay their way many times over.