When we look at rope systems in the tower industry, it is very common to see our safety lines connected to our dorsal harness ring. Many people believe that this is not only the safest but only connection point that can be made. But is it?
The dorsal connection point was originally added to industrial harnesses as a means of rescue. It was determined in confined spaces it was the easiest way to attach a worker for quick evacuation. In 1983, a study was conducted examining the stress put on the human body during falls connected to different points on the harness. One of the discoveries of this test was that the dorsal connection dissipated the impact force over the body more completely. It also had the effect of swinging the head forward. When connected to a sternal connection, the body was positioned back and the head also went back. It was determined that it was much more likely to have a serious neck injury during the fall if the sternal connection was used. For these reasons, we are allowed to fall further and generate greater forces on our dorsal harness connection.
But is this the only choice? Though the dorsal connection is considered the norm in the United States, most countries shy away from it. IRATA companies specifically advise their technicians not to use this connection for anything but rescue. In theory, a fall is safer from the dorsal connection. In the real world, our safety lanyards are rarely anchored directly above us. We anchor them to the tower and then move out to the gates. Any fall will generate a pendulum motion. Most likely our heads will indeed swing forward. But most likely they will swing into the tower structure, causing great bodily injury.
If the gate catches the lanyard and holds us away from the tower, we will be trapped hanging from our backs, making self-rescue nearly impossible. I devised a method of using two prusiks to pull the pressure off of my dorsal from the six-foot safety lanyard and put it on my sternum, and then climb up. It was slow, painful, and nothing I would expect anyone to do after sustaining a fall and possible injuries.
Using our six-foot safety lanyards, we have no choice. OSHA only will allow such lanyards to be attached to our dorsal connection point. But what about our rope backup devices? It is very routine to see these connected there as well, even though we have options.
A few weeks ago on our training tower, I climbed up using a Petzl dynamic cowstail which had 22kN carabiners with captive eyes on each side connected to my sternal connection point. Also connected was a lanyard made with dynamic climbing rope and two 22kN carabiners with captive eyes also attached to my sternal connection. Every part of my system was rated for a minimum or 22kN. Each lanyard was less than 24 inches in length. Everything fell completely with ANSI and OSHA requirements. I was connected 100% at all times. Like a crab-crawl with our sixes, I made my way up. I was immediately told by one of our foremen that what I was doing was illegal. He meant it jokingly, but honestly believed that I was in violation of OSHA and ANSI.
I think we forget that OSHA allows for a safety lanyard to be attached to our sternal connection if it keeps freefall to less than 2 feet. This is the principle that our ladder climbs work on. I would say we could also extend this to our backup devices we use on our safety lines when on ropes. Using the sternal connection gives our workers two key advantages: Shorter falls and the ability to self-rescue. It also keeps their safety line close to their body. This encourages people to use the two ropes as a system, with their backup above them, and not two separate systems working in opposition to each other, often with their backup trailing under them and to the side. Instead, it allows the backup device to drop straight down in the event of a fall, ensuring that it catches quicker.
I have yet to see a tower company use their ropes in this way. One of the ways SPRAT (Society of Professional Rope Access Technicians) list as how to tell the difference between a construction worker doing a controlled descent and a rope access technician is the attachment point of their backup device. I thought this was curious. There is no reason we should not take advantage of these systems as well.