Model of anchor and cathead (Blake's arrangement). Scale 1:12.

This model shows the arrangement, introduced in the early years of the 19th century, for carrying an anchor so that it could be readily released. The shackle end of the anchor was supported by a rope that passed over horns on the side of the projecting beam known as the 'cathead', while the arms of the anchor rested on a sloping shelf, known as the 'bill-board', on which it was retained by another rope. The ends of these ropes were secured by two levers, which were held in position by two hand-levers. When the hand-levers were pulled both ropes were released and the anchor descended without any constraint in running out beyond that offered by the mooring cable.