Bob,
Some of what I have to say has already been said by others or is information you already have but here goes anyway.
As the attached photo shows, I have been up the mast on a 26 foot Nonsuch. I do not consider myself an expert. One of the local riggers has also been up the mast and he did exceed the 200 pound mark.
I have a bosun’s chair and go up on the winch or with a 4:1 tackle. I weigh less then 200 pounds although by the time clothes, tools and chair are added I would be close to 200. My brother, Rob, who kindly ground the winch for me in an early climb, swears I weigh over 300 lbs. I now have a Winchrite electric winch handle and it will haul me up the mast. Much better then doing it manually. I must warn you that when someone steps off or on to a 26 footer, the top of the mast moves. If it is a big person you get big movement. If you look down at that point you will see dock, boat, water, boat, dock, water and so on. I have been up to the top of the boom hangers on a 30 with a carbon fibre mast. It was much more stable.
Thor and Peter are both right. Work on the mast when it is down if at all possible. If those fail and you don’t have a mast tower handy then take a number of precautions when you go up. I now belong to a sailing club that has a mast tower. I am sure the tower is safer but I find working from the chair easier for most tasks except working right at the top of the mast. When I am in the chair I have trouble getting high enough to work on the masthead instruments.
Wear a fall protection harness that is in top notch shape and is properly snugged up. Do not use the halyard shackles. Tie your own bowlines. Make sure the attachment point is high enough that you can’t invert. I tie one halyard to the chair with a long tail and then tie the tail to the fall protection harness. The second halyard ties to the harness at my back between the shoulder blades.
When I go up the mast, like you, I also use a friction loop around the mast. If things go wrong it will hold me to the mast and slow the descent. It should allow me to grab the mast and stop the descent. Again make sure it is attached high enough that you can’t invert on the way down.
If you use a bosun’s chair it should have safety straps so you can’t slide out of it.
You should have a second halyard. The cheek block on the side of the mast is not designed for big loads bust it is better then nothing for running a back up halyard. The screws appear to be 1/4" stainless. There are 4 of them. I believe but do not have full confirmation that the sheer strength on this four screws exceed 300 pounds by a considerable margin. Maybe one of the engineers in the group can answer that question.
In the photo I attached, there is no second halyard. I now have a messenger line through the cheek block so I can run a second halyard when I need to. The messenger line is a light weight nylon and is stretchy enough that it does not interfere with the movement of the boom.
Absolutely, carefully check your halyards to ensure they are in top notch condition before you put your life in the hands of those fibres.
Remember you can’t really check the mast head sheaves if you are hanging on the halyard and the mast on a Nonsuch should be taken down periodically so they can be fully inspected. Before you decide to make the climb, be absolutely certain that you can’t move that date for pulling the mast forward to the present and that the work you are planning can’t wait until the mast comes down.
Practical Sailor conducted a test on mast climbing systems some years ago. They had a warning about the ATN system. At least on the older style system if it was not correctly installed the bolts holding the grabbers together could back out as you climbed. You might like to check that article out if you have not already read it.
Mark Powers
La Reina 26C
Vancouver, B.C.
