Bowline draws tighter as tension is placed on the standing part of the rope. The "Birmingham bowline" has two loops; the working part is passed twice around the standing part (the "rabbit" makes two trips out of the hole and around the tree). Other two-loop bowline knots include the Spanish bowline and the bowline on the bight; these can be tied in the middle of a rope without access to the ends. A triple bowline is used to make three loops. A Cossack knot is a bowline where the running end goes around the loop-start rather than the main part and
International Guild of Knot Tyers expressed a wish to be involved from the outset but due to distance were unable to attend the opening meeting. In 2001, archaeological historian Mike Loades attempted a reconstruction of a British Iron Age chariot. He called upon IGKT member Richard Hopkins for his knowledge and experience of how to use the binding and lashing materials available at that time - rawhide, hemp, and flax - and described his contribution to the project as "invaluable". This involves tying six basic knots - reef knot, sheet bend, sheepshank, clove hitch, round turn and two half-hitches and bowline - against the clock.