Model or a Mastery Sheer. Model of a mast crane, a mast lifting, on base plank. The legs lean forward and are retained by two crowds and four stains of bolders confirmed. The foot in which the crowds are adjustable in three positions. Behind the bollards are two capstan and two beting. There is a major predict between the paws of the mast crane. Two hoists, one for the top and one for the lower part of the mast: the rope is attached to the top of the mast crane and is hence through the double block that is attached to the mast and a three-disc block at the top of the mast crane, Then to a block to the beting, back to the three-disc block at the top and down again. There are two blocks at the top of the mast. Sports for climbing are arranged at the back of the paws of the crane.