[Before Matt gets going, a word from John.]
We sailors tend to be a close-minded lot, often thinking that all the good knowledge resides with fellow sailors, the more experienced the better.
But that's often not true. For example, we almost all used sidedeck jacklines, and many of us used high-modulus materials for jacklines and tethers, before some rock climbers and engineers pointed out with irrefutable logic how ill-advised both those methods were—you can learn about that in this Online Book.
Given that, I'm excited that Matt is coming at this subject grounded in his industrial fall-protection training, coupled with his deep understanding of the forces at work from his professional engineering training.
Despite having climbed masts for some 50 years, I learned a lot from reading what follows.
If you have a sailboat large enough to cruise on, you'll probably have to go up the mast at some point. This can be one of the riskier parts of cruising, particularly since many (probably most) of us don't have the proper training, or the proper equipment, to do it safely.
And guessing, or relying on internet forum advice, can be dangerous—it only takes one error to cause a disaster we'll regret for the rest of our life, whether that's measured in minutes or decades.
Much of the risk comes from the rare, non-routine nature of the task. Unlike a cell tower technician or a mountain climber, who work at heights all the time and are (usually) well trained and practised, cruising sailors might only go up the mast once or twice a year. It's easy to forget some of the details and special safety precautions if you haven't needed them for ten months.
We should, then, give some careful thought to how we're going to do this.
What follows is a description of how I do it, on my boat.
My approach is copied more or less verbatim from industrial fall-protection training, which I took back in my commercial construction days.
This is not necessarily the best way for you to do it, on your boat, but we can at least get an idea of the risks that must be considered and the industry-standard precautions to take against them.
I must emphasize that working at heights is not something to take lightly! I can tell you how I do it, but you are responsible for your own safety, and for obtaining any professional training that seems appropriate.