HERE ARE A FEW PHOTOS OF THE
VALLEY GIANT #9
SpringLoadedCammingDevice
AFTER UNDERGOING ACTUAL PULL TESTING
STRUCTURAL FAILURE OCCURED AT A LOAD OF 5000+ lbs (22+ kN)
This Valley Giant #9 SLCD was pull tested to failure to determine its maximum strength under controlled conditions. The SLCD was placed in a rigid steel plate box with parallel (vertical) sides. The box was 8.5 inches (216mm) across, close to the maximum range of the #9 SLCD. The cam's sling was passed over a 1" (25mm) diameter bolt in the loading frame. A quasi-static (slowing increasing) load was applied to the SLCD until it failed.
RESULTS:
At 4740 lbs (21.1 kN), the Spectra sling failed where it passed over the 3/16" (4.8mm) diameter SLCD cable. It was a new, commercially purchased 5/8" (15.9mm) sewn sling, rated at 22 kN. The SLCD itself exhibited almost no effects of loading to this level. One cam of the SLCD showed very slight bending, 0.035 inch (0.89mm) out of plane.
After reslinging the SLCD with a doubled 5mm kevlar rope sling, a second pull test of the SLCD was performed. At 5010 lbs. (22.3 kN), the SLCD pulled out of the frame. Three of the four cams exhibited severe bending deformation; the fourth was essentially undeformed. The axle bolt exhibited slight bending deformation, about 0.025 inch in 5 inches (0.65mm in 127mm). The cable exhibited a sharp bend where the sling had loaded it. No other damage to the SLCD was evident.
VALLEY GIANT #9 STRENGTH RATING: 12kN
Each Valley Giant #9 SLCD from the batch was subsequently proof loaded to 2700 lbs. (12 kN). This is the rated strength. The actual laboratory breaking strength of all units can be expected to be in excess of 4500 lbs. (20 kN).
Actual field conditions, such as soft rock, wet or icy surfaces, flared or offset placements, unusual loadings, etc. can significantly lower the holding power of any SLCD. Never trust your life to just one piece of protection.