I had the opportunity to “witness” the ATN Top Climber mast climbing system the other day. One of my boat neighbors used his to go to his masthead to install a wind instrument. I stood on the pier and watched.
First, you can read about the system on their website here: http://www.atninc.com/atn-mastclimber-sailing-equipment.shtml
The system works by attaching yourself, via ascenders, to a halyard that is fixed in a static position. The halyard is simply a standing line pulled taut with your winch, upon which you climb with the ascenders. You sit in the harness, which has a hard seat incorporated into it, and put your feet into the “stirrups.”
The seat is attached to one ascender, and the foot-loops are attached to a second ascender. While seated with your weight resting on the upper ascender, you pull your feet-ascender up about 18 inches and clamp it onto the line. Then you stand up, adjust your seat-ascender up 18 inches, and sit down to raise your feet-ascender again. Repeat until you reach your destination.
Basically, it works – with caveats. I watched my neighbor achieve the mast-head this way, BUT… it is not easy. And, the higher your mast, the more difficult it is. Why? Because you are pushing yourself straight up for 30 or 40+ feet, and it’s exhausting. Also, you tie off the bitter end of the halyard – typically to the toe rail, or a convenient cleat, and the climb is at the angle created by the slant of the line. You are dangling under the line as you climb. You climb around shrouds, spreaders, and any other fittings or lines that are in the way (this is true with any mast climbing system). Finally, when you get to the top, you can only see above the mast-head if your halyard goes to the mast-head. If for some reason it terminates somewhere below the masthead, you will not be able to see over the top or do much effective work. Remember, you have about 24 inches of webbing between the feet-ascenders, and your foot-loops that you stand up in. If you can only clip the ascender to within several feet of the mast-head, you will have lost that many feet of height, plus the 24 inches (or so) between your feet and the ascenders. You think, why won’t that be high enough? Imagine this: you are sitting in the harness near the top of the mast, and in order to see over the mast-head you have to raise your feet-ascender up to where your hips or waist is(are) because at some point your seat-ascender and feet-ascender are going to meet because you’ve run out of halyard. Then you have to stand up from a full squat position while you are leaning backward from the mast.
I’m here to tell you, it’s a difficult proposition. My very athletic neighbor had a difficult time with it. By the time he was in range, he was pretty tired. Is it impossible? Not at all. Again, it depends on how your halyard runs. I suspect that if it goes right over the mast head, it is easier because you can slide the feet-ascender closer to the top, and you can more easily rest in the seat just below the top. If the halyard exits the mast through a slot, there is another problem: the line is so close to the mast that the ascender can’t fit in the space it needs, so you have to clip it lower down.
Conclusion: It’s not as easy as the adverts indicate. It does work… but you should take your time on the ascent. Carry water with you. Rest periodically on the way up. Make sure your halyard will enable you to go all the way to the top. Most importantly, use a safety line with the necessary helper(s) on deck. Actually, you can’t have too many helpers looking after the safety factors. Check your halyards. Check your cleats for securing the halyard. Check your seat attachments and ascenders for grip. Hang from the Top Climber just above the deck before you ascend to check the security of the ascender’s grip on the line. Check your safety harness, and hang from it also before you go up. Make sure you tie all your lines to your harness – don’t trust the shackles you use to attach the sails – this is your life we’re talking about. Even the best gear can be used unsafely, so think through the ascent and don’t get in a hurry. Think through the decent as well. Do it right, or postpone your ascent until you can get the right safety equipment and helpers. Review the process with your helpers and make sure everyone knows their role.