Expendable grain car door

Claim 1

FOR USE WITH A BOX CAR HAVING AN INNER SIDE WALL PROVIDED WITH A DOOR OPENING DEFINED BY A PAIR OF UPRIGHT POSTS AND A FLOOR: AN EXPENDABLE BARRICADE REMOVABLY MOUNTED ACROSS THE DOOR OPENING ON THE INTERIOR OF THE CAR, SAID BARRICADE INCLUDING A FIRST BREAKABLE MEMBER ADJACENT THE FLOOR OF THE CAR AND EXTENDING ACROSS THE DOOR OPENING, A SHEET OF BREAKABLE MATERIAL ALSO EXTENDING ACROSS THE DOOR OPENING AND HAVING SIDE, BOTTOM AND TOP EDGES, THE BOTTOM PORTION BEING POSITIONED INWARDLY OF THE FIRST BREAKABLE MEMBER, A SECOND BREAKABLE MEMBER EXTENDING ACROSS SAID DOOR OPENING IN POSITION TO REGISTER WITH THE TOP OF THE SHEET, MEANS FOR FASTENING THE VERTICAL EDGES OF THE SHEET DIRECTLY TO THE INNER WALL OF THE CAR INWARDLY BEYOND THE DOOR POSTS, AND A RELATIVELY RIGID, UPRIGHT REINFORCING MEMBER DIRECTLY CONNECTED TO SAID SHEET AND HAVING ITS UPPER END POSITIONED IN REGISTRATION AND SUPPORTING ENGAGEMENT WITH THE INNER FACE OF SAID SECOND BREAKABLE MEMBER.