Here is a detailed set of photos made by a friend documenting the SRT portion of a climb on a white pine yesterday. The temperature was in the low 90's f. (in the woods). It was a little hotter at the top of the tree out in the sun but there was a slight breeze to compensate.
White Pine climb 7/16



The tree is 116 feet tall with a diameter of 35.5 inches a little higher than breast height, there is a large burl at breast height Paul Buck and I climbed using a combination of SRT and DdRT. The first TIP was at 79 ft., reached with a Big Shot on the first shot. I think a couple friends who came along to observe were impressed with the accuracy of the shot but may have been disappointed, perhaps they were expecting a half hour of artillery practice before finally getting the branch. I used my custom release and tensioning system in a new simplified configuration, pulleys removed. A footloop is used to stretch the sling further if needed. In this case the sling was extended 3/4's the length of the pole. I hit the 79' branch with a very narrow target window. I think using this type of adjustable release system allows the operator to calmly aim the slingshot without holding the tension of the sling at the same time. Big Shot rocks!

We climbed up and eventually I was able to stand in the crotch of a double leader with the extreme top pine needles approximately ten feet over my head. A nice view above the hardwood canopy and a very enjoyable climb. This is my personal best for height in a tree.
-moss

I notice you are not using a safety with those ascenders. There have been a couple of cases where they failed, and professionals are now using a short 10 mm line to tie a french prusic or some such above the top ascender. It secures the unit without slowing it down.

Originally posted by treemonster
I notice you are not using a safety with those ascenders. There have been a couple of cases where they failed, and professionals are now using a short 10 mm line to tie a french prusic or some such above the top ascender. It secures the unit without slowing it down.

I think there is a little confusion about when to use a back-up with ascenders. With my setup both ascenders are life support anchored on my saddle so if one fails, the other backs it up. If I add a prusik backup I would have two backups for a theoretical single life support anchor (in case of failure). I think it is highly unlikely for both ascenders to fail at the same time so I'm not adding the prusik.

A known scenario for an older version of the Petzl ascender to fail is when the climber goes off vertical. In that case clipping a biner in the holes at the top of the ascender prevents it from coming off the rope.

I'm not familiar enough with some of the other ascender configurations but if you were using say one upper ascender or a Croll ascender attached at the chest and a foot ascender than you would want to add a backup above your waist. It wouldn't be fun to hang from your foot if the top ascender failed.

Thanks for thinking of my safety, and let me know if you still think I'm missing something, 'cause I'd like to know if I am.
-moss