I'm a relatively new to sailing, but I've been a professional mountaineer and climbing guide for over 15 years. I'm a certified Rock Guide by the AMGA, and a member of Mountain Rescue Service here in North Conway NH. I've done lots of ascending/descending for both rescue work and big wall climbing.
Now, having tooted my own horn on that..I also should admit I've never climbed a mast. I just recently got a boat with a mast big enough to climb.
As such, I can't comment on what's the best way to climb as mast, but I will say that with systems such as these, it's always best to keep it simple. Keep the ropes, knots and bits of gear to a minimum. I've taught basic rope ascending to lots of people and always, always any added complication just ads to confusion and mistakes.
In reality, you need little equipment: a harness, a few locking carabiners, some webbing for foot loops and some 5 or 6 mill cord for prussic hitches.
The basics are difficult to describe. Here's a pretty good video that shows the basics: YouTube - Ascending Up a Rope
I'd skip the mechanical advantage systems. I'm not real clear how riggers are using it, but can't see how it would be any advantage for one person. Too much complication. It always sounds good in theory, but every turn of the rope though something ads drag, and the rope hangs up, doesn't flow like you think it should. In rescue work, we use systems with lots of redundancy, and often build in mechanical advantage because of the loads, but then we often have people to help tend all the devices the ropes go though. Picture this: you are hanging in a harness on the rope off the deck...no weight on your feet..easily slide up your ascender with foot loops attached..put your weight onto your feet and stand up using your leg muscles. Your torso goes up, with the rope freely traveling through an ascender near your chest you can just sit back and loose no height. With added pulleys, blocks and whatnot, the rope often gets hung up, and you don't have a free hand to work it loose..when you sit back down into your harness you end up back where you started from.
If you want to spend some money get some ascenders instead of the prussics although it's not really necessary. Ascenders are helpful in the climbing world when you need to climb hundreds of feet of rope at once, perhaps for many days in a row. To climb a 50 foot mast, you might save 10 minutes using ascenders instead of prussic hitches..it's up to you. No safety difference since the ascending tools aren't relied on to save your life.
The Big Gun Harness is nice, good that it has adjustable leg loops, but remember that a $40 Alpine Bod Harness will do the same thing. There's no difference in safety and you'd not likely notice any difference in comfort. In climbing difficult big walls like El Cap, it's not uncommon for the belayer to sit for 2 or 3 hours hanging in the harness, spend 20 minutes ascending the rope then hangs again for a couple hours over and over again. These guys notice subtle differences, and like nice harneses. When I'm guiding, I spend much of the day hanging in my harness and it's not as nice as the Big Gun!
Rope, static or dynamic? It won't make much difference. Static ropes tend to be stiffer so ascenders slide up them better where dynamic rope might fold above the ascender, but the actual difference won't matter in a 50 foot ascent. If you were climbing a 200 foot length of dynamic rope you end up going nowhere for the first 10 feet as you stretch the rope under your weight. Mechanical ascenders or prussic hitches won't damage either. The teeth on some mechanical ascenders look mean, but the don't damage rope under normal use.
Descender? You can use a Munter and a carabiner, but it puts a wicked twist into the rope below you. Not the end of the world but a pain nonetheless. I'd suggest a simple figure eight device.
How to tie off? Well, in climbing what we do is climb up a section of rope and then take a bight of rope just below where we are at (under the ascenders) and tie a figure-eight on a bight and clip it directly to your harness with a locking carabiner. Climb another short distance, then tie a new figure of eight on a bight and clip this to your harness with a different locking carabiner, then undo the first figure eight. The idea is you are never without being tied to your rope with the figure-eight on a bight, not even for a few seconds. You don't trust your life to the ascenders. How often you "back tie" depends how far you are willing to fall. Above a deck, you can't risk falling very far. With a static rope, you also can't risk falling very far.
You'll also need to know how to safely make the transition from ascending to descending. It helps to know how to back up your rappell:
See: Rock Climbing Tech Tips: Backing Up An Abseil
On the above page the setup you want is called "Friction Knot Below The Descending Device". It puts a prussic hitch where your hand is below the device. You can set the hitch to lock below the device so you can stop if you need to on the way down and go hands free. The hitch will also make it difficult for you to go to fast.
Ascending and descending a rope is not difficult, strenuous or dangerous if done right, but you'd be surprised how many little things can trip you up. Go slow, think about what you are doing and practice.
Originally Posted by backcreeksailor
After looking around at all the gadgets and gizmos that I could buy to get up my mast. I noticed that virtually ALL professional riggers that climb masts on a daily basis use a block & tackle setup with rock climbing gear. So that's what I decided to go with.
I'm putting together my rig now, but it's hard to actually ask real rock climbers about equipment selections, because the one's I've talked to don't seem to understand what you do and don't need for climbing a 40'-60' aluminum pole while moving around standing and running rigging without getting hung up.
Here's what I've got on order so far:
- 75mm Harken Carbo Ratchet Block w/ Becket for the top pulley
- 75mm Harken Carbo Single Block for the pulley that will be attached to my harness (I want a 3:1 lift setup)
- Black Diamond Big Gun Harness
So I need some advice on what else I need from any of you that use climbing gear to get up your mast solo.
- Since it's a 3:1 rig, I'm going with 200' of 7/16" line. But I'm not sure if I should get "Dynamic" (high stretch) line or "Static" (low stretch) line. The larger diameter static line is cheaper, but the lower diameter dynamic is what they recommend in applications where you might fall, (which is not in my plans). I'm figuring since the anchor point for the top block is going to be a low stretch halyard, then there's no point in using high stretch line. So low strech static line should be my choice, right?
- I'm assuming I need a symmetrical oval screw lock carabiner to attach the lower single block pulley to my harness. But what (if any) other carabiners do I need?
- Do I need a mechanical ascender?
- What should I used for a descender? Just a carabiner and a munter hitch seem to a be simple solution, but there are dozens of other types of belay plates, figure 8's, and mechanical devices for this purpose too?
Lastly and most importantly... What's the most simple and fool proof way to actually tie off while you're working? I'm looking for something that will hold me firmly and without question. But I also want something that's easy to "un"-tie and nearly impossible to jam or hang up when it's time to come back down.