Working Aloft
Article credited to West Marine: By Tom Burden, Last updated: 2/08/2018
A bosun’s chair is the most popular way to climb your sailboat’s mast, if you need to change a bulb in your masthead light, retrieve a lost halyard or perform any one of a number of rig maintenance tasks. Bosun’s chairs are comfortable and you can sit in them for a long time, so they make working on the mast easy. The heavy lifting is done at cockpit level by a muscular “deck ape” grinding a winch.
To use a bosun’s chair, you need to follow some basic safety precautions. Inspect the chair, and look for wear or abrasion to the webbing, cut or worn threads and damage or fatigue to triangle attachment points. Don’t use a chair that is suspect in any way.
Make sure the chair is adjusted so you fit snugly and comfortably in it and are well secured so that a fall is impossible. The waist strap fits through the crotch strap. Tighten the Adjustable Back Support, which is critical for keeping you inside.
Attach your tools such as wrenches to one of the D-rings with a lanyard, so you won’t drop them, causing damage or injury. Instruct your crew working on the deck to never stand directly under the person who is aloft.
Never go up the rig of a sailboat when it’s hauled out of the water and supported on jack stands. The weight of a person, combined with the leverage of the long spar, could cause the boat’s supports to kick out with disastrous consequences.
Read and follow all instructions for use of the Bosun's chair from the manufacturer.
Do you always need two halyards?
Yes! You always use one of your halyards to hoist you up the rig, but you also need a backup halyard. Get assistance from two helpers down on deck. One person will operate the primary halyard; another will work the second, backup halyard.
Don’t rely on shackles or splices
Snap shackles are subject to stress corrosion and can fail under load or suddenly spring open. Overloading is not always apparent, especially with high-load stainless steel alloys such as Type 17-4. Instead of risking the use of a shackle or splice in a halyard, always tie bowlines. Locate them several inches up the halyard, since the line will tend to fatigue near the shackle, where it spends time making a highly loaded turn around the sheave at the masthead. If you have doubts about the condition of either or both of your halyards, replace the suspicious line for another halyard that’s new and strong.
Bounce testing the system
Before you go up, aggressively bounce-test your setup. Be careful to keep your weight centered over your feet, so if the system lets go, you won’t fall hard on your rear end. This shock loading will ensure your safety, and also take some of the stretch out of the halyards. The time to break any components, like halyards, bolts holding a winch, or the axle of a sheave at the masthead, is before you go aloft!
Making the halyards idiot proof
Just in case someone comes by and tries to remove your halyards from the winches, you should tie them. Tie both the primary and secondary halyard the same way. And do not walk away from the boat while the person is aloft.
This may seem like overkill, but what if your pair of deck assistants goes to the car for a tool or are below deck while you’re quietly lubricating some rod rigging at the masthead? If some clueless person should walk up to the boat and decide to remove the halyard from the winch, this method, used for both halyards, would hopefully prevent a catastrophe.
Gently and smoothly easing the person down
Lowering the climber down with abrupt and jerky motions is a common mistake by the winch operators. This is really tough on the person in the bosun’s chair. When they reach deck level, you’ll often see a wide-eyed expression of fright on their face. Instead, take one wrap off the winch and ease the person down smoothly and gently.
The last trick is to make sure that you go down far enough so you can get out of the chair. The winch operator should pay attention as the climber lands on their feet, and then ease the chair down so they can step out.
Bring gear and use a messenger line
Carry all of your tools and gear in the chair’s pockets, such as screwdrivers, wrenches, metal polish, a rag, rigging tape or electrical tape, Tef Gel and a brush. And attached a lightweight messenger line, so helpers can send up a tool. Or something can be lowered for disassembly and bulb replacement.
Bring your smartphone or camera to document the condition of rigging hardware.