Saturday, July 25, 2009

Rope Access: the safety factor

In my wild rock-climbing youth, I did what we called "speed rappelling". We'd put on a harness and pre-rig a descender, then run up to an edge, attach the rope to something as quickly as possible, and race to the bottom. A typical time frame would be five or ten minutes to check rope, harness up, rig the descender, and double-check; twenty seconds to tie on, drop rope, and clear the edge, or five seconds to clip on (depending on where we were); and about eight seconds for a hundred-foot drop. The goal was to tie on and get down, fast. The pre-rigging could take as much time as needed, but once you ran for the edge, it was all about speed.

Rope-access work is in extreme contrast to that. From the time I decide to head up, I've got over half an hour to collect and inspect gear and bag it for transport. Then, twenty minutes to harness up and get me and my gear to the top. Then, depending on where I need to work, I'll spend somewhere between twenty minutes and an hour doing the top-rigging to set and check my safety line, working line, and positioning line. The actual repair takes five or ten minutes at most. If I need to do another repair that's not near the first one, I'll probably need to redo the top rigging to reach a different area. When I'm done for the day, it's another half hour to strike my top rigging and get down, and another twenty minutes to check gear and put everything away.

The time difference here is the safety factor. Speed rappelling is fairly safe, really; you double-check your rigging before you start, and you make sure you have a solid anchor point before you start. The only danger moment comes from potentially screwing up your anchor rigging; there's a chance that, in a hurry, you could screw up you knotwork or anchor in a sloppy, unstable way, with dire consequences. Rope access work, on the other hand, is 100% safe. Everything is checked and double checked, and everything is redundant. You don't do anything risky, ever. Your gear is fail-proof, and your skill set is absolute. You're slow, and careful, and methodical, and there are no surprises. Nothing under your control will go wrong, and almost everything is under your control. I could take about a third of the time, and use about a third of the gear, and still be 99% safe. But that extra 1% is important. It's what separates daredevil kids from professionals.

Case in point: a few weeks ago I went up to patch a leak. It was overcast, but not expected to rain. But the weather changed its mind in the two hours it took me to get ready, get up, and get working. I noticed it was suddenly dark and looking like rain, so I hit top and started striking my gear. I had just finished packing the last of it when the rain started, and hard. This had danger potential; I was on top of a big glass-and-steel domed structure -- nearly frictionless when wet -- and I had already struck my safety line. If I were at the rock-climbing level of safety paranoia, this would be that 1% hazard zone. But, I'm at the rope-access level of safety paranoia. So I have ladder hooks. At the rock-climbing level of paranoia, I would just climb a ladder. At the rope-access level of paranoia, I use safety gear to climb and descend a ladder, and to get to the ladder from the top anchors. At no point was I ever unsecured. So even if I lost my footing on the wet glass dome or the steel ladder, I still wouldn't have taken a real fall. And even if I lost my footing, all my gear is attached to me; none of it is going to fall and land in the street. I made it down without incident, and never had to put my gear to the test. But incidents like this are the reason for all that extra weight and time and gear. Otherwise, that 1% will eventually catch up with you....

1 comment:

auntie 'm said...

That had to make for some maalox moments! I'm glad I wasn't watching you. It would have been nerve-wracking.