I designed these systems many years ago so that they could be used either independently or in union with the Sack-drag system in Blog-1. As usual, all the equipment required is "alpine standard", though its use as depicted may be considered by some to be unorthodox.
As I have explained in many previous blogs, much of my overall soloing rope technique is based on "rope loop" systems. These are just simple variations on a retrievable protective system that I use on narrow, exposed ridgelines in poor conditions. Being essentially a very lazy solo climber, I try to develop very simple, multi-purpose rope work that requires as little thought and effort to execute and retrieve as possible.
This system gives a good 25 - 30 metres (depending on rope length) to effect a crevasse crossing. The self-belay and arrester devices are a personal choice - I use either a reversed shunt on a dynamic rope sling, lark's-footed to my harness, or a dynamic sling "classic Prusik" around a doubled rope.
Once the crossing has been safely made, the knot in the rope bag is undone and the rope is retrieved by a slow steady pull on the side connected to the sack. The inertia of the sack's weight easily dislodges and retrieves the entire anchor system. You then simply continue to steadily pull until the equipment arrives at your feet, and the remaining rope's end is pulled through the vacated anchor point.
One of the other options of an anchor uses multiple "Abalakovs" on hard, "dry glacier" ice. Note:The first option can also work on a hard ice bollard without a hip-belt addition.
I always liked the idea of a simple "ice core" drill on the end of an alpine axe instead of the usual spike. It's a very simple modification which would do both jobs and enable one to bore out good-diameter Abalakovs in hard dry-glacier ice. I suppose someone will think of it one day, and incorporate it into an axe-handle. Even the longest ice-screws are not really up to the task as Abalakov anchor-drills.