Insulated floor construction and elements

Claim 1

IN A SHIP FOR THE TRANSPORTATION OF A MATERIAL WHICH NEEDS TO BE MAINTAINED AT A TEMPERATURE DIFFERING WIDELY FROM THE AMBIENT TEMPERATURE IN INDIVIDUAL CARGO TANKS LOCATED WITHIN THE HOLD SPACE OF THE SHIP, SAID SHIP HAVING A LARGE HOLD SPACE DEFINED BY SIDE WALLS AND A BOTTOM WALL FORMING A PART OF THE SHIP''S STRUCTURE, MEANS FOR INSULATING THE HOLD SPACE COMPRISING A PLURALITY OF SEPARATE PREFORMED INSULATION PANELS OF PREDETERMINED LENGTHWISE AND CROSSWISE DIMENSION LAID IN END-TO-END AND IN SIDE-BY-SIDE RELATION ON THE BOTTOM WALL OF THE SHIP''S HOLD AND ON WHICH THE TANKS REST, RAILS EXTENDING LENGTHWISE OF THE SHIP AND FIXED TO THE UPPER SURFACE OF THE BOTTOM WALL OF THE HOLD SPACE IN LATERALLY SPACED APART RELATION CORRESPONDING TO THE CROSSWISE DIMENSION OF THE INSULATION PANELS AND DIMENSIONED TO HAVE A HEIGHT CORRESPONDING TO A FRACTION OF THE THICKNESS OF THE PANELS, SAID PANELS HAVING RECESSES EXTENDING LENGTHWISE IN THE BOTTOM WALLS THEREOF DIMENSIONED TO RECEIVE THE RAILS IN CLOSELY FITTING RELATIONSHIP THEREIN TO PREVENT SIDEWISE DISPLACEMENT OF THE PANELS RELATIVE TO THE SHIP, AND OTHER MEANS SEPARATE AND APART FROM THE RAILS FOR HOLDING DOWN EACH OF THE PANELS ONTO THE FLOOR.