Abstract: Standard engineering shapes or profile elements are united by screw clamps to form a releasable and adjustable boom arm or cantilever arrangement. By means of quadrangular clamp bodies, substantially vertical support arms carrying seating or reclining means for a person are mounted on a horizontal support arm and can be individually adjusted in relation thereto. The boom arm is mounted in a further screw clamp provided in the free end of a hydraulic cylinder and piston assembly and is therefore capable of being raised and lowered and swivelled about the lengthwise axis of the cylinder. A hand-grip capable of being pivoted away is provided for the safety of the occupant. Boom arms of this type are employed in bathing installations to safely transport patients and invalids into and out of bath or the like tubs. The releasable and adjustable design concept of the boom arm permits it to be dimensionally adjusted during its initial installation, so that preliminary dimensional surveys are superfluous.