In it I mentioned I just did a regular full bury with a lock stitch and sailmaker's whip. This splice doesn't reduce the rope's strength while the Brummel does because it's technically a knot. The number that jumps to mind is 37% derating but I'll have to see if I can find the reference again.
I wanted to revisit this statement because it was thrown out arbitrarily. The retained strength of a winch line in this case is going to the weakest link, which is very likely the way the working end eye is made to terminate in a thimble.
Rope is rated based on testing and the manufacturers have to put eyes in their test ropes to mount them on the machine and when they do it's usually a simple long bury with 12-strand. So by default whenever you use a long bury you *should* have 100% of the rope's rating.
Using a different splice will reduce from that and in this case Marco (
@rover67) is using a Brummel, which is not unusual in winch lines but not as many other places (like arborists, ships, etc.) in this specific application. The closest I've personally found is when loggers make whoopie slings they terminate one end with a Brummel and the other is a long bury for the adjustable exposed tail.
One example of how to tie is here at Sampson:
https://www.samsonrope.com/docs/def...c2_whoopie_sling_amsteel_amsteel-blue_web.pdf
In that document they use a Brummel for the fixed eye and say the sling itself can be used to 70% of the rope's rating.
I've read other documents testing whoopie slings that were on the order of 85% to 90% of the rope's rating. This chart comes from "Running Lines and End Connectors for Synthetic Rope to Reduce Logging Workloads" from research done at Oregon State by Dr. John Garland.
Exactly why all this is gets way off the point into even deeper esoterica but suffice to say I haven't been able to find information to my understanding that explains specifically how or, indeed, if a Brummel used in this way really does reduce capacity from the rope's rating.
However, a Brummel is technically a knot and those have an understood effect on rope strength.
So I assumed the worst based on Sampson's instruction of 70% (e.g. 30% reduction) and that any knot results in at best 80% of the original strength in my decision to use a long bury and have no question.
Also, the main point is that 37% has no relevance at all. Completely unsupported value that I probably misapply anyway.
I'm also not sure it's a freak-out-able thing anyway. But it does I think go to deciding whether to use 5/16", 3/8" or perhaps even 7/16" with a very built 80/100/200 for your winch line and how it's spliced.
