Good article. I have been fortunate to have had a job were being suspended high above the ground was part of the job requirments. The highest I have been is 65m(200+ft). I have taken what I learned in that proffession, to the boat. This is how I do "it".
Firstly, I believe you can go too overboard
with all this. Keep the system simple. The more complicated, the more chance of a mistake being made. I don't have lots of differing safety harnesses and gear
for different applications. Proper harnesses are rated and should be tested regularly to ensure they are safe and legal
As Gords article suggests, DO NOT ever EVER, use a snap shackle. They may "lock" within it's catch point, but it is far to easy to apply pressure to the release pin and unlock it.
I use a Bosuns chair. A properly built chair is safe. The chair is not going to fail. What you do have to consider however, what if you loose balance or maybe even for some strange reason, unconciouseness. Will the chair hold you, or could you flip out. So I wear my normal safety harness, NOT as a fall harness, but as a means of holding me into the chair, should something happen.
I use a second short tether harness to attach myself to the mast
once I have reached the top. This is becuase it is a two person excersise for us. Dawn hauls me up using the anchor
capstan as the winch. The halyard runs through the brake, around the halyard winch, and to the capstan. So if in some circumstance she lets go, the halyard is captive. When she lets me down, she comes back to the halyard winch and controls the decent from there. But just in case she gets a little confused (maybe I need to trust here more, but it is that "look" in her at eye when she has compleate control of my life
) the tether is there as a back up.
All tools need to be tetherd. Not only is a falling tool dangerouse to my wife below, but it makes a terrible mess of a deck
from that height. And worse, if we are in the Marina, I have a very expensive boat beside me. I was very lucky with that one day. I just drove a bolt out of the mast head
. It flew out and landed in the water
right were the M$$ boat normally sat. It was out that day. It would have probably gone clean through his very expensive front glass windscreens.
For safety, inspect your chair and harness thoroughly before every use. Apart from that, it is safe and can be very fun. I love it and I regularly take teenagers out on the boat, were I give them a chance to go up the mast. They love it.