There are so many things to do at the tree house! It will fall down long before it will ever be completed.
On this particular day I attempted to replace the pulley we've used to bring equipment and timber up to the main house. The old one had shot bearings so couldn't function as a pulley anymore.
That crisp winter day will always be remembered - as just another day among the trees.
Tech note: The pulley consists of a flat strap, a quicklink (screwlink), a pulley block, Ø 10 mm dynamic climbing rope, and an industrial carabiner. This type of pulley is called a fixed pulley, it has a single block but no tackle.
The knots used are: Double Fisherman's Knot, two, since the rope was originally in two equally long parts (i.e., one knot to get a long enough rope, the other to make it one big loop). These knots also prevent the carabiner to reach the pulley block - which is good, but perhaps not optimal for the knots themselves.
The knot for the carabiner is an Alpine Butterfly.