Paneled roof sheet with integral carline

Claim 1

A RAILWAY CAR ROOF SHEET FORMED FROM A FLAT RECTANGULAR SHEET OF RIGID MATERIAL, ONE LONGITUDINAL MARGINAL EDGE BEING OFFSET UPWARDLY THE THICKNESS OF THE MATERIAL FOR OVERLAPPING AN ADJACENT SHEET, A PAIR OF SPACED STIFFENING PANELS PRESSED UPWARDLY IN THE MAIN BODY PORTION OF SAID SHEET, ONE OF THE ENDS OF EACH PANEL BEING ADJACENT OPPOSITE ENDS OF SAID SHEET, EACH PANEL EXTENDING TOWARD THE OTHER END OF THE SHEET, PASSING EACH OTHER, AND MERGING INTO THE SHEET ADJACENT THE OTHER END THEREOF, THE AREAS OF SAID PANELS ON EITHER SIDE OF THE TRANSVERSE CENTER OF THE SHEET BEING UNEQUAL, AN INTEGRAL CARLINE PRESSED UPWARDLY FROM SAID SHEET INWARDLY FROM THE OTHER LONGITUDINAL MARGINAL EDGE THEREOF, SAID CARLINE BEING SUBSTANTIALLY GREATER IN DEPTH THAN SAID PANELS, SAID OTHER LONGITUDINAL MARGINAL EDGE PROVIDING MEANS FOR UNDERLAPPING THE OFFSET MARGIN OF AN ADJACENT SHEET, A SHALLOW CORRUGATION PRESSED UPWARDLY FROM SAID SHEET BETWEEN THE CARLINE AND ADJACENT PANEL AND BEING OF LESS DEPTH THAN SAID PANELS, SAID CARLINE AND SAID SHALLOW CORRUGATION EXTENDING SUBSTANTIALLY FROM END TO END OF SAID SHEET.