Abstract: A mast of simplified and standardized constructional design consists of a tubular section and ancillary components such as a masthead or boom support plates which are welded to the tubular section, the masthead being constituted by a casing and head-piece. The casing is provided with an incorporated anchoring member for the standing rigging, and with slots for receiving the axle-pins of sheaves and rollers. The casign head-piece has a central cheek for locking the sheave pins in position.

Abstract: The device comprises an element for rigidly fixing the articulated coupling device to a mast and a boom end-piece which are capable of pivotal displacement in perpendicular planes and each mounted on a common nut by means of a fork. Ribs and grooves formed respectively on the fork and in the nut remain in a position of interengagement after relative rotation through an angle of approximately 180.degree. with respect to a position of introduction of the fork into the nut.The invention is primarily applicable to the boom of a sailing boat which is pivotally coupled to a mast.