Amsteel Blue is a 12-strand high-molecular weight polyethelene cord from Samson. The 3/16-inch version that I tested has a rated tensile strength of 5600 lbs. Being so small, it makes a very tidy tether to connect harness to ascender, as shown in photo below.
Here's a closer view of a locked Brummel
With the tidiness comes a price: the rope is too short between the eyes to allow for regulation-length splice buries. Since the short buries could conceivably pull out, one normally throws in a locked Brummel at each eye to protect against this. To be more precise, it doesn't prevent the bury from pulling out, but it does guarantee that you still have an eye if the bury ever does pull out. How strong is the locked Brummel eye in 3/16-inch Amsteel Blue?
The test consisted in pulling to failure a locked Brummel eye with a long (5 or 6 inches) unburied tail. As long as the tail didn't unweave, the lock was secure and the Brummel could not pull apart. The tail got seriously scrunched from the forces involved but remained intact until 6 strands broke on one side at 2534 pounds. This is just over 45% of nominal rope strength, much better than any other locked Brummel I have tested in polyester or Vectran. This is also the only one that left such clear visible evidence for how the break took place.
Here's a closer view of a locked Brummel
With the tidiness comes a price: the rope is too short between the eyes to allow for regulation-length splice buries. Since the short buries could conceivably pull out, one normally throws in a locked Brummel at each eye to protect against this. To be more precise, it doesn't prevent the bury from pulling out, but it does guarantee that you still have an eye if the bury ever does pull out. How strong is the locked Brummel eye in 3/16-inch Amsteel Blue?
The test consisted in pulling to failure a locked Brummel eye with a long (5 or 6 inches) unburied tail. As long as the tail didn't unweave, the lock was secure and the Brummel could not pull apart. The tail got seriously scrunched from the forces involved but remained intact until 6 strands broke on one side at 2534 pounds. This is just over 45% of nominal rope strength, much better than any other locked Brummel I have tested in polyester or Vectran. This is also the only one that left such clear visible evidence for how the break took place.
