Abstract: An apparatus for positioning a person within a container tank for inspection, cleaning, or repair of such tank is described. The apparatus includes a pivoted parallelogram type support having a cage enclosure at one end and a counter balance weight at the other end, such support being pivotally attached to a hoist member for movement of the cage toward and away from the tank wall while maintaining such cage upright. The hoist raises and lowers the support and cage within the tank and through a restricted opening in the tank when the support is pivoted into a retracted position. Bearing means is provided around the hoist stem for guiding vertical movement and enabling manual rotation of the hoist member and cage. A valve actuated cylinder is employed to control the pivoting of the support by manual actuation of the valve from within the cage.

Abstract: An automatic high pressure spray cleaning apparatus and method for rapidly and efficiently removing material coated on the surface of an object are described. In accordance with the invention the axis of the cleaning liquid spray forms an acute angle with the object surface and such angle, as well as the distance along such axis between the spray nozzle and the object surface, are both maintained substantially constant over a given surface area. In addition, the pressure of the cleaning liquid at the surface of the object is also maintained substantially constant over such given area. The spray nozzles are automatically moved rotationally about a cleaning axis and longitudinally along such axis to scan over the object surface along a predetermined path while maintaining the spacing distance and angle substantially constant during rotation of the nozzles about the cleaning axis at a given longitudinal position on such axis, by motor operated drive means which may be controlled by an electronic computer.