Chris is absoultely right, a climbing harness is by no means a legal nor safe substitute for a fall arrest harness. I won't get into fall arrest here again, it's been covered numerous times in the past, but I will say that a climbing harness does not meet OSHA
regs, and a fall in one
of those without a chest harness can snap
your back. Think about the physics, I don't need to describe it. Fall pro. is not a subject to be taken lightly. There are very strict OSHA
regualtions that DO apply to the entertainment industry, and only a preson well versed in the rules should be designing or applying fall arrest systems. And Chris is also right that it does need to be a FULL BODY HARNESS, furthermore, almost always requiring a dorsal (upper back) D-Ring for attachment to a lanyard
. And also, you CAN NOT tie yourself to just anything! The rule is, that every single component from the anchor to the harness has to be RATED for at least 5,000 lbs, and there has to be some form of effective shock
absorbtion included as well. A search of the forums should turn up quite a bit
of info on fall arrest systems (unless Dave has removed or blocked them) and as a closing statement I must stress that safety
isn't about compliance, it's about PEOPLE.
I think I better be clearer. First of all, I'm not recommending that anyone not follow all regulatory obligations. Second, I'm not making a recommendation that anyone buy anything.
was that for fifteen years or so, sit harnesses were the industry norm. Over the last 8-10 years, probably with the UK (HSE) leading the way, full body harnesses combined with fall arrest systems have become the regulatory norm. I, personally, do not see this as really being much of a postiive step in safety
. After all, the HSE did not argue that an inertial reel is more reliable than, two equalized 4' lengths of Spectra. And no one argues that fall factors are inherently low with current
fall arrest systems. The primary argument initially used by the HSE was that workers were finding proper anchoring with a sit harness too cumbersome and, consequently, were spending too much time unprotected.
Rather this is true or not, my feeling is that the big problem is proper training. IE, that even with the 'proper' kit too many people are getting hurt. For example, a proper full body harness should have *both* a sternal and dorsal point
for fall arrest. How these are used is critically important. The reason that sport climbers can fall many times a day on a sit harness without injury is that they are typically falling 5-15' on 50' or more of dynamic
climbing rope. Force at the waist tie in
is virtually always below 7 kilonewtons. In drop
tests with many fall arrest systems, forces at the lanyard
as high as 16 kN have been measured.
Since 12 kN is considered 'likely fatal' with the human body and since 16 kN is surprisingly close to the absolute ratings on several of the components in the systems, two things seem clear
(to me at least). First, there is very little margin for error for improper use with these systems. Second, a fall arrest system
is not, in of itself, a proper substitute for good, traditional work anchor practices.
A few other items in your post seem worth noting. First, the 'break in
half' or 'broken back' comment. It is important to understand that both a sit harness and a full body harness support your body in a fall in fundementally the same way. The reason that fall arrest systems are connected to the upper body is two fold. First, to accomondate the fall arrest systems themselves. If the system
, be it shock
absorbtion, inertial reel, or whatever, not deploy correctly the arrest becomes 'static', and quite likely fatal.
Second, as noted, the forces in these arrested falls are potentially very high, so while some people think of the full body 'supports' the upper body in reality, it aligns the forces much more perfectly on the lower body. This is important to understand because when you look at serious accidents involving these systems the second highest problem was improper force loading on the upper body (ribs into lungs, etc
.). The single highest problem was head and neck trauma associated with an unclear fall path.
The last thing worth noting is that weight ratings should be used with the utmost care in rigging in general and with falling in particular. Since we are potentially talking about a factor 2 fall of an adult male a static rating
of 5000 lbs is pretty much meaningless. The important thing is ratings involving dynamic
force and even then there are many factors to consider. For example, a locking carabiner
might have a load rating
of 22 or 24 kN - but only when properly loaded. Side loaded the rating
to less than 6 kN.
Also, it is potentially dangerous to tie in
to anything without some understanding of load multiplication (or what Joe Branam, my own original mentor in rigging, called the 'angle of the dangle').
So, please forgive the brief musings of a long timer. They were not suited for an inexperienced audiece. But DO think twice about using any fall related safety
equipment without comprehensive training.