OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700:

I hate ladders like these, seen the two by's pull off after a
short while especially if your shouldering a load going up or
down. The rungs should be in notches.

This is a good point.

We have so many ladders, most of which are roped end-to-end to the trees
for height, that we just made them as simply as we could.

You can see that we have cargo netting, to allow us to cross from tree to
tree once we climb up the ladders:
https://c4.staticflickr.com/4/3865/1...e8c93589_c.jpg

But, we also usually wear safety harnesses and ascenders whenever we work
more than 15 or 20 feet up (which is almost always since it's a steep
slope so what is 15 feet up at the uphill end of the cables is something
like 50 or 70 feet up at the downhill end.