Freight containers

Claim 1

A DEMOUNTABLE CONTAINER ADAPTED TO BE MOUNTED UPON RAILWAY RUNNING GEAR FOR USE IN RAILWAY OPERATION AND ADAPTED TO BE MOUNTED UPON HIGHWAY RUNNING GEAR FOR USE IN HIGHWAY OPERATION; SAID CONTAINER COMPRISING AN ELONGATED SUBSTANTIALLY RECTANGULAR COMPOSITE BASE INCLUDING A BOUNDARY FRAME PROVIDED WITH A PAIR OF SIDE SILLS AND A PAIR OF END SILLS AND A FLOOR PANEL OF PREFABRICATED UNITARY RIGID SANDWICH STRUCTURE ARRANGED WITHIN SAID BOUNDARY FRAME, THE OPPOSITE SIDES OF SAID FLOOR PANEL BEING RESPECTIVELY SECURELY FASTENED TO SAID SIDE SILLS AND THE OPPOSITE ENDS OF SAID FLOOR PANEL BEING RESPECTIVELY SECURELY FASTENED TO SAID END SILLS, WHEREBY SAID FLOOR PANEL LENDS GREAT RIGIDITY TO SAID COMPOSITE BASE; SAID FLOOR PANEL COMPRISING AN OUTER WEATHER SHEET OF METAL, A FIRST SHEET OF PLYWOOD INTIMATELY ADHERED TO THE INNER SURFACE OF SAID WEATHER SHEET, A FIRST SLAB OF SYNTHETIC ORGANIC RESIN OF RIGID CELLULAR STRUCTURE INTIMATELY ADHERED TO THE INNER SURFACE OF SAID FIRST PLYWOOD SHEET, A SECOND SHEET OF PLYWOOD INTIMATELY ADHERED TO THE INNER SURFACE OF SAID FIRST SLAB, A SECOND SLAB OF SYNTHETIC ORGANIC RESIN OF RIGID CELLULAR STRUCTURE INTIMATELY ADHERED TO THE INNER SURFACE OF SAID SECOND PLYWOOD SHEET, A THIRD SHEET OF PLYWOOD INTIMATELY ADHERED TO THE INNER SURFACE OF SAID SECOND SLAB, AND AN INNER LINER SHEET OF METAL INTIMATELY ADHERED TO THE INNER SURFACE OF SAID THIRD PLYWOOD SHEET, SAID SECOND PLYWOOD SHEET OCCUPYING A SUBSTANTIALLY CENTRAL POSITION BETWEEN SAID FIRST AND SECOND PLYWOOD SHEETS IN SAID FLOOR PANEL.