Interesting idea, but you better verify the load rating on the single upper block. I'd be concerned about pulling the becket off the upper block where you're attaching the triple to the underside of it. The becket is generally intended as a tie-off point and would typically only see the load from one "throw" of the line. In the configuration you've drawn, the becket will see seven times that load.
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Checking the numbers, it seems that the limit may be on the sheave rather than the becket:
![[Linked Image]](http://www.apsltd.com/images/CATEGORY/medium/451.jpg)
Safe working load for H002, H004 and H076 is 227, 454 and 544 kgs respectively.
454 is 2 times 227 but 544 is not 3 times 227, so I guess the limit is on the sheave for the first two and on the structure for the third one. Probably too much guessing on my analysis, but 227 kg for the single block seems close enough to the 30 kg pull anyway. But on the other hand, not close enough to 1100 kg breaking load, so I would probably try it anyway... Plus, much of the pull tension is lost in friction, so effective loads are actually a lower.
