For these tests, the procedure for TCLL testing documented in the OCIMF (Oil Companies International Marine Forum) Guidelines was followed except that the rope was tested dry versus the recommended wet test. Dry was chosen as an acceptable method as long as all samples were subjected to the same conditions. Testing was performed at Samson’s Innovation and Training Center testing laboratory in Ferndale, Washington.
The test procedure called for each sample to be subjected to 4 levels of cycling based on the rope’s specified average break strength (ABS) — 50%, 60%, 70%, and 80% of ABS. The samples were subjected to 1,000 cycles to each of the first three loads (50%, 60%, 70%) and then, if they survived, 2,000 cycles at 80% of average break strength, totaling 5,000 cycles. The samples were then loaded to destruction, to measure the rope’s residual strength.
For ropes that survived this cycling, a calculation was performed to determine a theoretical TCLL value. This value is intended to represent the load-level at which the rope would fail upon completing 1,000 cycles (see appendix A for relevant calculation and test method info).