Heat-insulated railway box cars

Claim 1

A RAILWAY CAR CONSTRUCTION COMPRISING A PAIR OF LONGITUDINALLY EXTENDING AND LATERALLY SPACED-APART SIDE SILLS, A PAIR OF LATERALLY EXTENDING AND LONGITUDINALLY SPACED-APART END SILLS, THE ADJACENT ENDS OF SAID SIDE SILLS AND SAID END SILL BEING RIGIDLY SECURED TOGETHER TO FORM AN ELONGATED SUBSTANTIALLY RECTANGULAR FRAME HAVING A SUBSTANTIALLY HORIZONTAL TOP, A PAIR OF LATERALLY EXTENDING AND LONGITUDINALLY SPACAED-APART BODY BOLSTERS ARRANGED IN SAID FRAME ADJACENT TO THE OPPOSITE ENDS THEREOF AND DISPOSED IN SUPPORTING RELATION THEREWITH, THE OUTER ENDS OF SAID BODY BOLSTERS BEING RESPECTIVELY RIDIGLY SECURED TO THE ADJACENT ONES OF SAID SIDE SILLS, A ROW OF LATERALLY EXTENDING AND LONGITUDINALLY SPACED-APART CROSS BEARERS ARRANGED BETWEEN SAID BODY BOLSTERS, THE OUTER ENDS OF SAID CROSS BEARERS BEING RESPECTIVELY RIGIDLY SECURED TO THE ADJACENT ONE OF SAID SIDE SILLS, THE CENTRAL PORTIONS OF SAID BODY BOLSTERS AND THE CENTRAL PORTIONS OF SAID CROSS BEARERS HAVING LONGITUDINALLY ALIGNED OPENINGS THERETHROUGH THAT ARE ADAPTED TO RECEIVE THE ELONGATED LONGITUDINALLY EXTENDING FLOATING CENTER SILL, THE TOPS OF SAID CROSS BEARERS BEING ARRANGED SUBSTANTIALLY IN THE PLANE OF THE TOP OF SAID FRAME, AN ELONGATED SUBSTANTIALLY RECTANGULAR RIGID FLOOR PANEL ARRANGED MUTUALLY UPON THE TOP OF SAID FRAME AND THE TOPS OF SAID CROSS BEARERS, AND MEANS FOR SECURELY FASTENING SAID FLOOR PANEL IN PLACE UPON THE TOP OF SAID FRAME AND UPON THE TOPS OF SAID CROSS BEARERS, WHEREBY SAID FRAME AND SAID BODY BOLSTERS AND SAID CROSS BEARERS AND SAID FLOOR PANEL CONSTITUTE A UNITARY RIGID STRUCTURE.