Vertically movable marine working platform structure having vertically movable groundable support frames

A vertically movable, offshore working platform structure is disclosed, which includes a working platform vertically movably mounted on parallel arranged support frames individually comprising a plurality of parallel disposed vertically elongate cords connected altogether to a support frame assemblage by horizontal members and diagonal members having their ends secured to the cords at panel point portions of the cords, and which also includes guides for the vertical movement thereof which individually have a length at least great enough to extend between two longitudinally adjacent panel point portions of respective cords. The guides of the working platform being of such a relatively great length as above, horizontal forces to be applied by the guide onto the support frame are centralized in their application mainly upon panel point portions to thereby realize that the horizontal forces being born in substantially even portions by respective cords through horizontal members and diagonal members, concentration of loads is avoided upon that portion of respective cords which lies between two longitudinally adjacent panel point portions.