OCC Forums

Best Practices in Mast Climbing


By DariaBlackwell - 23 Mar 2017


Past Commodore John Franklin has suggested developing a paper on best practices in mast climbing. I am opening this thread to gather expertise and advice from our members. I invite Alex Blackwell to tell about his experience with the Topclimber, a useful tool for single or short handed sailors that requires great care to use safely.
By Alex_Blackwell - 24 Mar 2017

Yes, the Topclimber is indeed a very useful piece of gear. It eliminates the need for someone on the winch to haul the working crew member up the stick. The Topclimber is basically a pair of cam cleats attached to a non-stretchy rope and then used to climb up this rope with minimal effort. Like other similar products it is derived from mountain climbing gear. More on our decision making and some initial lessons learned here:

However, as with all tools or equipment there are health and safety things one must take into consideration;
->Equipment must be thoroughly inspected before, during and after use
->Backup plans must be in place prior to use.

1. A misdesign in the equipment caused a failure which I fortunately saw while at the top of the mast and even more fortunately was able to rectify. Had I not done so, I would most certaily have fallen the 60+ feet to our deck.
2. Having a second harness with a second halyard tailed by a crew member would have averted the above mentioned almost disaster. This is something we now always deploy - lesson learned.
Here is a more detailed recounting of what happened:
By Dick - 24 Mar 2017

Hi all,
Generally, the following is for a crew of 2 or more, but a single hander can adopt the suggestions to fit.
First, it should be said that there are two forms of going up the mast: at a dock tied up and at sea (at anchor has the same safety concerns as at sea). I hate going aloft on the hard and believe it to be unwise at best. Safety issues overlap and what is safe tied up at a dock may not be offshore.
Proper equipment, well understood procedures, and good communication set the stage for safe work.
On Alchemy, we have a static line for back-up fall protection. On it runs an ATN Ascender (US company, http://www.atninc.com/atn-ascender-sailing-equipment.shtml) attached to my harness (there is climbing gear which performs the same function) which belays any fall within a couple of feet. I am not a fan of having a spare halyard attached to the climber and then having it belayed on deck every few feet. Too much to go wrong and the on-deck person may have too much to do if he/she is also tailing off a windlass or winch. It is rare, but if something happens to the on-deck person—a tool falling on the head—the climber might find it harder or impossible to get down. I like the climber’s safety to be as much as possible in the climber’s hands. (Please note, that any free fall of more than a couple of feet, belayed hard, is likely to injure and will generate serious, possible breaking, loads on rope and equipment.)
Bosun’s chairs may be fine for at-dock work (even there they have limitations for getting to the tippy top of the mast and also, one can fall out), but they are not for offshore work. A climbing harness is far far safer and, the attachment, being at one’s belly button, allows work at the truck of the mast. Harnesses are also impossible to fall out of and allow work positions (like at the spreader tips) that are difficult/impossible with chairs. This security makes them a must for offshore work to my mind. Climbing harnesses are quite uncomfortable for most any period of time (they are made to belay falls, not to work from). My harness is well padded and designed for mast work and its only drawback is that it is rather expensive, which, amortized over the now 20+ years I have used it, has been worth every penny (http://www.briontoss.com/catalog/aloftgear.html).
Lastly, for offshore work, a helmet is wise, even essential. Again, climbing gear is the best for this and Petzel makes good ones. The helmet goes a long way to prevent the one drawback of the ascender on a static line for a safety line; that is a blow to the head of the climber knocking him/her unconscious and unable to release the ascender to come down. Without a helmet, I would go aloft offshore only with my safety line controlled from deck.
Please also put lanyards on all tools likely to be used aloft.
Good communication needs to be figured out ahead of time. One couple thought radio headsets for his job was a marriage saver. We have occasionally used a handheld radio. Certainly, screaming back and forth has its limitations although it may amuse the marina.
We are fortunate enough to have a windlass that can take me up the mast easily. I understand that some electric winches can do the trick. Experience revealed that the right-angle drill chucked with a winch bit was too weak a couple of decades ago on a medium sized winch, but that might have changed now with higher voltage battery packs. Man or woman power is certainly possible, but on most of our boats (and winch sizes), this way makes for a lot of work. If one goes slow with a good winch handle, it is do-able, but may be too slow for offshore work as it leaves the climber vulnerable for just too long a time.
Manual methods are, I believe, best for single handers. With crew, other methods of gaining altitude usually seem better suited. The manual methods I have tried (ascenders and such) demanded of me a fair amount athletic skill and strength which I am sure would decrease with experience. Some put off work as going aloft was just too challenging. Most friends who have gone that direction have figured out easier ways (like putting steps on their masts). Please note also Alex’s comments on a mis-design which put him in danger’s way and John’s comment that Topclimber’s equipment needs great care to use safely. I am not a fan of any gear that needs great care to use safely when the down side is falling to the deck.
Please, come back with questions/thoughts/ comments.
My best, Dick Stevenson, s/v Alchemy
By bwallace - 26 Mar 2017

Hi fellow cruisers,
I might have something to offer on this mast climbing. I have been going up my mast for over 30 years, and early on developed a system so I would be able to ascend and descend the mast on my own.
Many systems allow you ascend, but you often need another person to lower you down.
Obviously it depends on your mast configuration, Mast head Rig, Fractional Rig, Deck Stepped or Keel Stepped Mast.
Darramy is fitted out for shorthanded Blue Water Cruising, although she isa standard production Beneteau sloop with a three spreader masthead discontinuous rig.
My experience is therefore related to my own boat, together with many others that I have been talked into going up to assist with a problem.
For Blue water cruising you probably have two halyards for foresails, two for mainsail. The Topping lift can be a spare halyard so that is one Main Halyard and Topping lift. We have a hydraulic vang so the topping lift becomes dedicated spare main halyard. We also have two spinnaker halyards so we have plenty of choice for above deck mast work. A keel stepped mast also gives a lot of flexibility to what the average cruiser can actually achieve whilst up the mast. As it provides additional security as to the mast staying up whilst working aloft with loose rigging!
The comments and information from both Alex and Dick, are excellent, but I have a few points to add.
I use climbing “shunts” which work similar to a clogger type of ascender, the advantage with a shunt is that you can lower yourself down as well, and it does not have the gripping bits that other ascenders used to have, which can chew your halyard up over time.
I know climbing equipment has improved over the years, and some of my comments may be out of date for technical climbers, but they still work well for me and are not expensive to purchase.
A halyard preferably Spectra or Dyneema is best, as there is little stretch. Attach the halyard at the base of the mast, and tension on a winch. Attach the shunts onto the halyard and use a long sling on the lower one, and a short one to fasten to your climbing harness. via a Caribena. The long one acts as a step, so you transfer your weight from your leg to the harness, and just climb up. You quickly learn which is your best leg for this. I am right footed, and find using the right leg is much easier and more comfortable to use for the ascending. Thick soled shoes also assist. (try standing on a ladder for half an hour barefoot, then put substantial foot wear on and see the difference. I use my walking shoes) Shunts are that simple, obviously you improve the technique with practice.
Now safety: If you are on your own, then a spare halyard is useful, which ever method you employ a lot of tangles can be avoided with quality rope and taking ones time. If I am on my own, I use a spare halyard preferably polyester for the stretch, my theory is that if you do fall, then a bit of give in the line will hopefully take a little of the snatch out of the line when you stop the rapid descent. As I am ascending when I get to the part of the mast that the safety line enters the mast (if it is a fair way up the mast fine, if not consider re routing your halyards so this line goes into the mast as high as possible) I then take as much slack out of the halyard so that I can tie a stopper knot in the safety halyard. The theory is that if you do fall, or the ascending halyard breaks (which is unlikely if you have a well kept vessel), you will be pulled up short of the deck. I know its a last resort, but I always carry a knife with me, and in theory you could then cut the safety and lower yourself onto the deck . Not forgetting you should end up somewhere in the region of other ropes being around. Mainly it should break the fall and do less bodily damage than hitting the deck..
Another way to ascend is using the Prusik Knot used by climbers for years. Helmets are essential when at sea, I don’t consider a climbing helmet necessary as they are designed to stop falling stones or rocks from damaging you. So the protection should be to stop you banging your head. I used to use my skiing helmet, but since the tropical heat destroyed the lining, I now use my cycle helmet. (Any protection is better than none).
I also avoid taking a bucket up, as they can often tip and you loose everything. Much better is a canvas bag. I made my own out of Sunbrella double lined the bottom and also sewed small pockets on the inside near the top to keep screws, split/clevis pins, and a roll of tape so you are not ferreting around in the bottom of the bag trying to find a tiny item. All larger tools have a loop on them to attach lanyard
A spare climbing sling is useful to take up so you can put it over the top of the mast to make an extra step up to get that extra height you may need sorting out the masthead light, or aerial etc
One disadvantage of using a halyard as a means for “shunting up” is that if the halyard is tight (which makes for rapid climbing) is that you cannot always get out to the ends of the spreaders. You can stretch and it can be a bit uncomfortable. Or for major work on one side of the rig, fasten the bottom of the halyard by the chain plate and tension. It works well. Decide which part of the mast you will be working on. Either use the fore halyards for anything forward of the mast, but also consider which side is your best side to work on. Working cross handed can be awkward and tiring, so forward planning is well worth while.
In 2013 I re rigged all the standing rigging on Darramy whilst in Fiji. We have a three spreader rig with discontinuous rigging, so what seemed to be a couple of weeks up the mast. I used the climbing technique described above, but Sue was on hand to send up stuff on yet another halyard and also worked the safety line. This included removing the lower spreaders for workshop attention. All unused halyards were then employed to steady the mast, but spare lines could also be used for this.
If you have a mate in the cockpit, then this is great, as they can lower you down comfortably, but again a few tips: how many times have you seen someone being lowered down the mast in a jerky fashion? A smooth decent makes life easier, does not put you off going up again if you have to. With the shunts method, you can just open them so they will come down the halyard with you whilst all your weight is taken on the safety line. Now the person in the cockpit should ensure that the tail of the safety is not tangled, leave two turns on the winch, open the jammer, and whilst keeping hold of the line step away from the winch and look up at the mast, ease the line hand over hand in a smooth manner, (being a distance from the winch gives you more control and you can watch the person coming down for a safe decent. Together with the ability to hold and stop in case the climber wants to check something on the way down.
I always make the ascent to the top of the mast first, then work my way down checking all fittings and pins and as I go. Remember to carefully check where the shrouds enter the swagged terminals, as this is often the first place to see potential failing rigging.
We have now purchased “Eric” a 28volt Milwaukee right angle drill from www.thecranker.com/ one charge can get me to the top of the mast three times, but also it has made all the winches into electric winches. I admit it age has made it harder to furl the genoa in a blow, and for getting that final reef out of the main it makes a great deal of difference. I think a spare battery will be ordered soon!
Final Tip, if you are not used to climbing, of are wary of heights. If you are cruising the oceans, at some time you will need to go up the mast. Get over that apprehension. Practice climbing the mast and get to feel confident. Practice may not make it perfect, but when that time comes for you to go up in an emergency that practice will have been well worth while., and don’t forget a small bottle of water especially in a warm climate. It can be thirsty work.
Hope this helps
s/v Darramy
By Dick - 26 Mar 2017

Hi Brian,
It has been a long time, 10+ years now me thinks, since together in the Azores.
I suspect John is going to be thwarted in his “best practices in mast climbing” wish. What is emerging are more like guidelines for safe ascent that skippers will massage to fit their vessel and circumstances. Yours is a bit of a hybrid as it incorporates single-hander ascent techniques with the occasional help of the crew.
A few comments:
The shunts look like interesting pieces of kit and may do the job better than the ATN ascender I mentioned, which, in fact, can be used to descend but perhaps less efficiently. If one’s ascender is only used as an emergency belay, I would not be concerned about how it stops you. Chewed up rope would be the last of your worries. Even ascending, this is done only a handful of times a season and, my take, is that little damage would occur.
I agree that it is important to have a plan B for descending.
With respect to helmets, I mention climbing as they are commonly obtainable and many serve the purpose as they also protect from falls where you might swing into the rock wall. The protection from the side is of primary importance to the sailor as it would be slamming against the mast in a seaway that is the concern. Some bicycle helmets cover this area but many just perch on top of the head and do not (same with some climbing helmets). If you have a bicycle on board you can have one helmet make do.
I would caution against using a Prusik knot, not because it is any way unsuitable for this purpose, but because it is an unfamiliar knot for most sailors. I would not want safety to depend on executing and depending upon un-familiar knots, as simple to use and easy to tie as it is.
Carrying a knife is wise as is the canvas (vs hard) bucket with multiple pockets. For bringing up additional equipment, I find a small line (of mast height length) attached to my harness is easier than a spare halyard: it is easier to tie smaller line onto the gear and is easier to handle. If at sea use a harness tether around the mast at all times to keep you from being jerked off the mast and end up swinging out of control.
Good to hear from the field that the higher voltage right angle drill will do the job now.
Most any method retain problematic elements, the most worrisome being an unconscious person up the mast, but there are ways to make this less likely, and awareness of the possibility and how terrible it would be, can generate the requisite care.
Best to Sue, Dick Stevenson, s/v Alchemy
By mervynwheatley - 1 Apr 2017

I returned from the last OSTAR singlehanded and direct to the UK. Half way across, I had the spinnaker up and a halyard parted. This did not matter as I always rig both halyards. However, the next day I decided to replace it. I kept the kite up as it was set shy and kept Tamarind nicely heeled.

My method is to secure a Jumar (ascendeur) to the harness and hang a long loop from another as a step. Although I am right handed (and footed!), I always use my left foot - no idea why: it just feels right. I don 't use a 'spare ' halyard because I 'm worried about it snagging on the way up and I reckon I 've got enough to worry about without belaying that all the time

It worked well and, although the Jumar is not designed for descending, it is interesting how quickly one can do so! Mervyn Wheatley
By Dick - 1 Apr 2017

Wow, I am very admiring. Thanks for the field report, always the best kind. Did you wear a helmet? What would you think of heaving-to for this operation, at least for a regular cruising boat, if not for yours?
Thanks, Dick Stevenson, s/v Alchemy
By mervynwheatley - 1 Apr 2017

I didn 't wear a helmet as I don 't have one on board and, frankly, I don 't think it would be much use if I fell! I think heaving to would be horrific. You want the boat heeled over and steady which means making way. My main concern was if the spi halyard/shackle/block failed in which case she would have come upright and that would have made life quite tricky. I was 70 then and it tightened me up a bit! Mervyn
By Dick - 1 Apr 2017

Hi Mervyn,
70 as well. My admiration grows.
Agree about the heaving-to being less stable than sailing with a relatively constant heel. I was just curious what you might say, as the question comes up at times. With regards to the helmet, it is not for a fall, it is for slamming against the mast if the mast swings a bit and you with it. I once saw a man up a mast at anchor and a power boat went by with a moderate wake and this guy swung wild for a couple of arcs in a way that was quite scary to watch. He felt very lucky to only have major bruises and, wearing no helmet, just a lump on his head rather than being knocked unconscious.
Thanks for your thoughts, Dick
By toothwright - 4 Apr 2017

Tragedy always concentrates the mind !
I have had some experience of mast work as our Gaff Ketch Kirsty required yearly mast varnishing! I have always used a multiple purchase tackle. A triple aloft on the main halyard, a double attached to Bosun 's chair. A large diameter rope is used to enable a good grip.
Needs confidence in the crew on deck to belay fall.
Drift of blocks means difficult to access truck.
Sufficient strength of climber - acts as a MOT for me as if I can 't manage to hoist myself I would not be confident going off shore !
Peter Flutter Tyrian
By bwallace - 4 Apr 2017

Hi Peter.

I used to use a 6 to one block system before I discovered the shunt system. IHave a look at the 28 volt Milwaukee right angle drill from www.thecranker.com/ It has made mast accent easy . That is provided you look after the crew, (ie no domestic disharmony before going up the mast)!
Enjoy your next accent.
Cheers Brian
By stevenkelvin83@aol.com - 14 Apr 2017

I use a mast ladder by Deffee Ltd, superb piece of kit which rolls up and is easily stored in a locker. The only inconvenience is that you have to take the mainsail slugs out of the track. It is then hauled up with the sheet and I use the spinnaker halyard for my harness. This means you are always tight to the mast and I also use a strop round the mast from my harness in-case I slip. Can be supplied in standard or bespoke lengths. In an emergency it can also be used as a drogue. I have no connection with Deffee ltd other than as a very satisfied customer.
Cheers, Steve.
By David.Tyler - 19 Apr 2017

I approach this from the point of view of a single handed sailor, and also agree with Peter 's comment: When the day comes that I can 't get to the masthead unaided, that will be the day that I give up cruising.
My kit and method goes something like this:
1. Climber 's harness. One with wide padded thigh loops is obviously more comfortable for a prolonged job of work.
2. A PETZL Grigri 2 attached to the harness with a screw-locking carabiner. The Grigri is a device that enables both ascent and descent. It has no teeth, but works by jamming the rope around a cam. There is a "dead man 's lever" that will only permit descent when pulled, and gives very good control of the rate of descent ( too fast, and too much heat is generated, damaging the rope).
3. I keep a length of 9mm static climbing rope especially for this task, as it works better than yacht braid in the Grigri. I either hoist it to the masthead on the main halyard, or pull it through a block at the masthead using a messenger. If the latter, I use a large shackle to butt up against the block, so that the stretch is limited to one mast 's length, not two.
4. A PETZL toothed ascender, with footloops attached. It is important to get the length right, depending on your height and reach. Two footloops are better than one, in a 'Y ' formation, so that the climber can put a foot on either side of the mast.
5. The ascender is above the Grigri, and (importantly), the upper part of the footloop runs through a second carabiner attached to the harness. This helps to direct the push of the feet more vertically, and thus more efficiently.
6. Also importantly, there is a short strop connecting the ascender with the harness. The toothed ascender is very aggressive in its action on the rope, which means that whatever else happens, a fall is impossible until it is removed from the rope.
7.The hard part of the ascent is to get off the foredeck and above the height of the stowed mainsail, then it gets easier. As soon as possible, a short length of rope is tied around the mast to limit the swing.
8. Once at the masthead, the ascender is left in place for safety and security whilst working.
9. When the time comes to descend, the ascender is taken off the rope, and then only one device is holding the climber, so this is the time for full concentration. The lever of the Grigri is used to descend under full control at slow speed.

I feel safer using this kit than being hoisted by someone else using a self-tailing winch. Going up is not so bad, but easing a heavily loaded line around the winch for the full height of the mast without mishandling it takes a little skill and concentration, and if they are not present, it 's my safety that is compromised.
By Dick - 20 Apr 2017

Hi David,
Sounds like a basically good plan and very nicely stated. A couple of comments and one caveat:
You choose going aloft with your kit, in part, because of concern, when up high, about being left to the mercy of errors on the deck crew’s part. This concern was addressed by the protocol that I described (and others did so as well) whereby the aloft crew has a safety line with ascender. When the deck crew is facilitating descent, all the aloft crew need do to belay the descent, is release the grip on the ascender on the safety line and he/she is belayed in place. In this manner, safety aloft, is always in the hands of the aloft crew. He/she must release the ascender to come down and, as they are spring loaded, any release of the grip stops the descent. The deck crew facilitates the descent but does not control it.
My caveat is your description of removing the ascender from the rope leaving you with only one device, as you put it, between you and a fall to the deck. Your admonition that this is the time for full concentration is very pertinent, but full concentration is a slippery item, especially when attending to tasks that not done regularly, and I would not want full concentration to be a component of safety. The method I described (as did others) always have 2 belays possible for errors of judgment or device/rope failure: the crew on deck with the halyard tail and the ascender in the aloft crew’s hand on a safety halyard. Even single handing, (no crew on deck handling the halyard) one does not need to remove an ascender from a safety line to descend. Slower, for sure, but safer.
Finally, there are a multitude of things that we cannot do (or do so well) as we get older and, for sure, getting up a mast on one’s own is one of them. Single-handing may also be in that category. And at what moment in one’s decline an anchor is swallowed is a very personal and complex decision. I would want you to consider (and other readers), that getting up a mast single handed (as you and apparently, Peter, suggest) may not necessarily mean the end of a sailing/cruising career. It is, of course, your decision, but, for me, too many good and safe and enjoyable years of cruising might be lost by so demanding a pre-requisite.
My best, Dick Stevenson, s/v Alchemy
By David.Tyler - 20 Apr 2017

Hi Dick,
Just to address the question of descent using the Grigri again: this is as foolproof and failsafe a device as I know, and this and a more "professional" version, the PETZL Rig, are widely used by tree surgeons, window cleaners and other roped-access workers, as well as by big wall climbers. It is used on its own, the professionals don 't see a need to back it up with another device. I only mention concentration because when one is descending, one has nothing else to concentrate on but descending safely, so one may as well give one 's whole mind to the job.
By neilm - 23 Apr 2017

We find the prussik very practical for a safety line. We set a spare halyard up tight. Attach a short prussik loop of a line about half to 2/3 diameter of halyard, and shackle the prussik loop to a safety harness.
If you do not know the prussik knot, YouTube will show you better than I can)
As I go up (on steps on Milvina, but works just as well when being hauled up) I push the prussik up from below. Coming down, pull the knot down with just a finger. Do NOT grip the knot, since you would have to let go in event of a fall, which would take excessive presence of mind.
This is simpler that having a halyard tailed by crew, and avoids anyone standing at the base of the mast, in the line of fire of dropped tools.
I usually go up in a bosun ' chair which attached to a halyard at my chest. This is completely separate from the above mentioned prussik to safety harness.
We added a webbing loop and a Wichard hook to the bosun 's chair so that I can loop it around the mast and stand on steps hands free. Even if you dislike steps, a pair at the right height to stand and work both hands at the masthead is worthwhile
By neilm - 23 Apr 2017

We find the prussik very practical for a safety line. We set a spare halyard up tight. Attach a short prussik loop of a line about half to 2/3 diameter of halyard, and shackle the prussik loop to a safety harness.
If you do not know the prussik knot, YouTube will show you better than I can)
As I go up (on steps on Milvina, but works just as well when being hauled up) I push the prussik up from below. Coming down, pull the knot down with just a finger. Do NOT grip the knot, since you would have to let go in event of a fall, which would take excessive presence of mind.
This is simpler that having a halyard tailed by crew, and avoids anyone standing at the base of the mast, in the line of fire of dropped tools.
I usually go up in a bosun ' chair which attached to a halyard at my chest. This is completely separate from the above mentioned prussik to safety harness.
We added a webbing loop and a Wichard hook to the bosun 's chair so that I can loop it around the mast and stand on steps hands free. Even if you dislike steps, a pair at the right height to stand and work both hands at the masthead is worthwhile
By bwallace - 23 Apr 2017

I like the idea to put a prussik knot on the spare halyard. That in combination with my shunts will be tried next time.
It also has the advantage of not needing complete domestic harmony if one has to ascend and decend!
Thanks for sharing that tip
s/v Darramy
By simoncurrin - 23 Apr 2017

Posted on behalf of Dick

Hi Neil,

Appreciate your thoughts and suggestions to having crew go aloft safely.

I am all for safety being in the hands of the aloft crew, which the prussic knot allows. It is a very tried and true knot, but generally not well known by sailors, primarily climbers, although climber’s techniques and equipment are slowly working their way into the sailing world. Where safety is concerned, I would suggest equipment that can belay a fall that is more in the “no-experience-necessary” category such as the mechanical ascenders I and others have mentioned.

If one want to use the prussic, I would suggest spending some time playing with it to get acquainted with its properties: how tight to make it? how quickly does it belay? Best ways to move it up or down? Drop onto the knot, how does the knot take up?, etc.

As for steps at masthead: this is a very practical solution to working at the truck if you are going up in a conventional chair where the halyard connection is chest height. As is the suggestion for a webbing loop.

If starting out or wishing to upgrade one’s equipment, I would suggest a harness. This allows for a halyard connection just above the waist giving access to the top of the mast. Steps could still be nice for stability, but in decades of use and removal/installation of all masthead equipment over the years, I have found steps un-necessary when using a harness. One can find reasonably priced harnesses on ebay or used at climbing equipment swaps or you can get ones more dedicated (and padded) for more money (mine was made by Brion Toss Rigging- amortized over decades of use it seems less expensive and is a positive joy to use). The above is an added benefit of a harness, but the choice of a harness can be driven solely by its increased safety over most (or all) chairs/seats in that they are impossible to fall or slip out of.

My best, Dick Stevenson, s/v Alchemy