Tuesday October 23, 2012
When climbing, always use the vertical fall arrest protection system made for 3/8 inch diameter solid core wire cable that automatically travels with climber. Safety cable kits normally contain the top and bottom brackets, safety cable and cable restraint brackets appropriate to the tower height. Body Harness and safety wire grab or clamp should be compatible. Widely accepted tower climbing guidelines state that any structure with a height greater than 3 meters requires a climber safety device.
A fall protection/arrest system consists of the following:
A harness with a dorsal (center of back between shoulder blades) D-Ring, and means of attachment that can limit the falling force to less than 1800lbs (e.g. a lanyard shockpack).
ANPC uses the DBI Sala -ExoFitNEX™TowerClimbers Harness – Back, Front & Side D Rings with Suspension D-Rings. Removable Seat Sling and Quick Connect Buckles. ANPC uses the Rohn 45G steel tower.
The human body can exert several thousand pounds during a fall arrest situation. In order to protect the climber most fall arrest lanyards utilize a dampener/shock pack to dissipate the fall force to less than 1800lbs. All fall protection/arrest lanyards should be double legged/(Y) and be used to maintain a 100% attachment to the tower at all times. They should NEVER exceed 2 meters in length.
Positioning devices are used in conjunction with fall arrest to create a working position while on the tower. These are static lanyards and devices that do no have shock packs. While in use, these devices should be positioned so that a climber can not move more than 1.5 meters vertically. As a rule of thumb, your primary connection to the tower should always be your fall protection, and then your positioning device.
A steel tower rung or weld could fail if a climber falls and the lanyard shock pack does not activate, or the climber is using a lanyard without a shock pack. Also, always position your lanyard hook overhead and around to another face (to your strong side) so that during a fall arrest situation, your shoulder will roll onto the tower first.
Third- Never rely on one point of attachment for positioning. On the tower, it is recommended that the climber choke at least 2 legs with a positioning lanyard, to create a solid point of attachment. Another recommended procedure is to use two large hooks, one on each side, to connect to two different points on the tower. My favorite attachment point of encircling at least two tower legs works very well and is known as the “gunslinger method” since a climber can attach and detach very quickly with this setup.
Working up top – Working on the very top of a steel tower can provide some challenging issues, one of which is positioning. If your harness has a seat, do yourself a favor and don’t try to use it while at the very top. While sitting in the saddle is comfortable, it does not provide enough upper body leverage to replace those obstruction lights. Instead use the side D rings so that your upper body and arms can be used freely above the tower. When attached to the top of this tower, a fall arrest anchorage point also becomes an issue. If your work could take some time, use a 1 meter long choker sling to create an attachment point by wrapping it around and choking all three legs independently. When used in conjunction with your 1 meter fall arrest lanyard, this setup will create a suitable anchorage point.