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Tuesday, 07 January 2020


by Petrea McCarthy 

In part 1 we saw maintenance of the rig mostly involves checking for existing problems and preventing new ones. The options for maintenance aloft range from a basic inspection to removing each piece of rigging to check its condition and attachment point. If you feel the latter is necessary it’s probably better to pull the stick out and do a thorough check at ground level.


The first consideration in climbing the mast is deciding who goes up. Obviously, the lightest member of the crew will be easiest to hoist but there is no point sending anyone to check the rig unless they know what to look for. It is the skipper’s responsibility, so usually the skipper should be the one to go up there. As noted in the previous article, this is just guidance on how to complete regular maintenance of the rig and we would always suggest that if you have any concerns a professional rigger is employed to carry out a full rigging inspection. 

Your first time?

Climbing a mast can be daunting if you have never done it before. I disagree with the conventional wisdom not to look down. Once you have sorted out the safety aspects and your actual method, my advice is to climb up in small increments. Get used to the height as you go. Use your safety line at every stage so you cannot fall if things go wrong on deck.

Getting ready

Older painted masts are usually chalky so wear overalls or similar gear. Some people like the feel of climbing barefoot but shoes are far safer.

You’ll need to take the appropriate tools for your rig but I would suggest:

  • pliers or multigrips
  • flat blade screwdriver
  • Stanley knife – blade retracted
  • WD40 with a tube on the nozzle
  • Shifting spanners to fit any rigging screws you need to work on
  • rag and waterproof grease
  • any Allen or hex  keys needed to fit spreader end fittings
  • Duralac

To keep from spreading grease, Duralac and WD40 over myself and equipment I take a roll of toilet paper instead of a rag and stuff used squares into a separate pocket on the bosun’s chair.

Going up

Do it while the boat is afloat. Most boatyards ban climbing the mast of a boat on the hard and for good reason. A keel boat propped up ashore is defying gravity and your weight jerking around aloft can cause it to lose balance.

Attach two halyards to the chair using separate shackles or knots. Do not trust snapshackles for this job.

If possible, assign two people you trust to control the halyards and keep both taut. The halyard tailers must look up at the person in the chair, not down at what they are doing.

Use a safety line from the chair to the mast at all times. About a metre of 6mm or 8mm line tied tight round the mast can be slid up or down manually but won’t slide down if weight is thrown on it suddenly.

Keep clear below. Never allow anyone to stand beneath a person working up a mast.

Once the chair is ready to hoist, climb in and try it under your weight. I prefer to climb up and have the halyard tailers keep the halyards tight as I go. If they coordinate their tug on the halyard with your upward pull it can help enormously. Alternatively, you can just sit in the chair and have them winch you up if you’re unfit. Either way, take it easy and do not over exert yourself. This is no place to have a heart attack.

At each stop on the way up the mast keep your safety line attached and have your assistants tie off the halyards. While the climber is at the top of the mast, the assistants should flake down their halyards ready for the descent.


When the person up the mast is ready to come down the halyards must be untied without losing any tension. It is disconcerting to be dropped even a few inches when the halyards are released.

The primary halyard should take the weight while the other is kept slightly slack. The reason for this is friction.

As the climber descends, the halyard is eased out smoothly. It must be released under full control without binding on the winch. Two turns on the winch is the maximum needed, one is usually enough. Too many turns will cause the halyard to stick, resulting in a series of bounces for the person in the chair.

Doing the job

I check as I climb. It makes the climb easier and seems logical. What to look at depends on the layout of your mast but I’ll try to cover a ‘typical’ mast. You are looking for much the same things as you did at deck level. Corrosion of dissimilar metals, cracked fittings, seized sheaves, worn pins, stranded wire and bubbled paint.

Just above the gooseneck may be a group of sheave or exit boxes for halyards. Check fastening screws are tight but not seized; sheaves turn freely and not worn on one side. If you have mast climbing steps check their fastenings. Spinnaker pole tracks should be well secured and not bent or damaged. Sliders should run freely.

The attachment points for the lower shrouds will be just below the lower spreaders. Ideally, you will have someone loosen each shroud so you can check the clevis pin and tang for wear. Always ensure something else is holding the mast up when releasing any piece of rigging.

The bolt holding the tangs should be straight. Check the nuts are sitting flat and not tilted slightly towards the mast at their top. This would indicate a bent bolt, which needs to be replaced. If t-balls are fitted instead of tangs, check the t-ball for cracks and that the receiving plate is sitting snugly against the inner mast wall. Black marks around the rivets here indicate movement, which could be serious.

From this position check the base of the spreaders for cracks and signs of movement. Move out to the spreader end and remove the spreader boot or covering tape. The cap or upper shrouds should be held to the spreader ends in some way. This could be a wire seizing, or a clamp welded to the end of the spreader arm. Undo the clamp and check for corrosion where the wire meets the aluminium. Apply Duralac paste if necessary and reclamp the spreader end. Replace the boot or tape. If you have intermediate or diagonal shrouds terminating here, undo and check them as described in Part 1.

Often the lower spreaders are the site for a steaming or deck light. Glance at this but if it works leave it alone. If not, now is the time to take it apart and find out why.

Climbing further up there may be a second set of spreaders to be dealt with similarly to the first. Somewhere between the lower and upper spreaders, there may be a fitting for a spinnaker pole topping lift and a tang for an inner forestay or babystay. Check these and lubricate any exit box associated with them.

Mast head

At the top of the mast check the pins for forestay and backstay and the tangs and bolt for the cap shrouds. If you have a furler, check it is not wearing the wire of the forestay and its top cap, if any, is in place.

By moving the halyards over their sheaves you can see if the sheaves or their pins are worn. While the weight is off poke the sheaves upward with a screwdriver. Movement here indicates a worn sheave hole or pin. Check the sheave pins are straight. If they’re OK, lubricate with WD40. I say WD40 because it comes in an aerosol can. Light machine oil is better but much harder to apply in this situation. Up here may be all sorts of antennas and lights. I suggest you leave them alone unless there is a known problem.

Try reaching up to whatever you have there to find out if your bosun’s chair allows this. Many of them leave you short, so you need to cinch yourself up higher on the safety line.

Now you’ve completed the work, relax and have a good look around before readying for the descent. You will have briefed your deck crew to lower you slowly and steadily. If they are new to this remind them to look up and watch how you’re going. Once safely back on deck you can be satisfied you know the condition of your rig and any problems it may have.    

Even if you need to call in a rigger at this stage you will appreciate their work and understand what they do to charge you so much for their services.

How long does standing rigging last?

There are too many variables for a definite answer. In general: 304 grade 1x19 stainless steel is less prone to fatigue than 316, but more corrosion-prone. 

316 is better than 304 in low latitudes and is the wire of choice for the tropics. To find out which you have, check with a magnet. It won’t stick to 316.

Fatigue is a killer. Loose rigging fatigues faster than tight. Rigging exposed to constant movement like ferry washes in Sydney Harbour will fatigue quickly. Marginal sized wires will be more highly stressed than adequately sized ones. Having oversized standing rigging will add strength and cost, but not necessarily longevity.

Galvanised wire is cheaper and normally doesn’t last as long as stainless unless very well maintained, but shows when it needs replacement by rusting.Unstressed 316 rigging can last 20 years and more, but that is the exception. Expect a lifespan of around ten years maximum, but ensure you get a rigger’s opinion on older rigging to satisfy your insurer. After the mast falls down is not the time for this!

Choosing and using a Bosun’s chair

The chair should be strong and in good condition. Don’t assume it’s safe just because it is new. I’ve seen stitching fail on new, reputable brand chairs. Inspect and test the chair before trusting it. Even in my old faithful bosun’s chair I like to bounce a bit just above deck level before climbing any higher.

Leave the old plank-type bosun’s chair in the museum and use a conventional cloth chair with a solid seat. Soft-bottom wrap around designs are promoted as fitting snugly and this is certainly true. While they’re light and compact, for extended work aloft they’re uncomfortable and restrict circulation to the legs – and elsewhere if you’re a bloke.

Worse still are the adapted rock climber’s harnesses used by professional sailors on the pointy end of big racing yachts.

Select a chair that fits you, neither too small nor too roomy, with large, easily accessible tool pockets. Ensure the hoisting point is low enough to allow you to reach the masthead. My own chair has secondary lifting rings at hip height. To get right to the top of a mast I can cinch these together with a spare line and use it to hoist myself that last few inches.

Getting up there

I’ve mentioned the conventional way to climb a mast, but there are other options for the reluctant climber, or to help smaller crewmembers hoist a heavy person. On some boats it is possible to lead a halyard to the rope barrel on an electric anchor winch. If it’s powerful enough, up you go; no sweat.

Fit mast-climbing steps. You’ll still need a halyard and bosun’s chair so you can work hands-free, but for most people climbing steps is easier and feels more secure than dangling at the end of a halyard. Steps should be less than half a metre apart. It may seem easy at first to climb wider spaced steps, but unless you’re very tall or fit, it’s not.

On some boats a halyard can be led to a primary winch, which makes it easier to wind the climber up the mast if they can’t or won’t pull themselves up.

Be wary of clever gadgets. I once tried a special mast climbing device like a long rope ladder with PVC tube rungs. The idea was to hoist it aloft then climb it. It was terrifying because it could swing away from the mast.

My favourite is a 4:1 climbing tackle made from a double block and a double becket block, with a very long rope. I use 8mm braidline; 6mm is strong enough, but hard on the hands. The line should be five times the length of your mast, plus a bit - see below. The idea is to hoist the becket block to the masthead, preferably on two halyards. The lower end of the tackle attaches to the bosun’s chair. Sit in the chair, grasp the tail of the tackle, and hoist yourself!

Hint! After hoisting the tackle grab a winch handle and tension the halyards, otherwise they will stretch a little, allowing the top block to slip down from the masthead. You need maximum hoist to reach the very top of the mast.

It is even better if someone else does the hoisting and you assist by climbing. The extra length I mentioned allows the tail to lead to a winch, so the person tailing has some assistance. The beauty of this system is that you can use blocks already on board, like the mainsheet blocks.

Warning! If hoisting yourself, either tuck the loose tail into a bucket hanging on the bosun’s chair or be extremely careful where you allow it to fall. A tangle could prevent you from descending.

CAUTION - When replacing through-mast bolts take care not to dislodge the compression sleeve inside the mast.

It will be visible when you remove the nut and tang.

Happy climbing.

One last thing

Now you’ve gone to the trouble of checking your rig, make a note in your log book. Then do it all again next year.


Petrea McCarthy, editor of the Ideas Locker column in CH, is a former yacht rigger and long-term live-aboard cruising skipper. She operated her own yacht rigging business in Brisbane before going cruising full time, has been involved in both cruising and racing since 1967, participated in all major Australian ocean races, cruised the SW Pacific, Tasman Sea and circumnavigated Australia and Tasmania. Petrea now works as a freelance writer and lives in far north Queensland.

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