Often the need arises to join ropes together. This thread is focused on the tying of two ropes together the same size/type for life support.
The rock climbing, caving, adventure and rescue people know of the perils in tying the wrong knot when joining ropes for life support. There's also a lot of data and testing and I found a site where there's some great well explained results.
This site's PDF's toward the bottom are well worth a look. They are factual tests, and a range of knots used and ropes also including aged ropes to see strength loss. I have also loaded them here, view in order!
Bushwalkers Wilderness Rescue Squad - Research
When joining two same type of ropes together there's talk of using a figure 8 knot. However there's 2 ways of tying it, rethreaded or abnormal.
Here's pics of the two, AVOID THE ABNORMAL METHOD LIKE THE PLAGUE!