Field repair roof panel for a railway car

DETAILED DESCRIPTION The invention relates to a replacement roof panel for repairing damaged railway box car roofs in the field.
The repair panel is formed from a generally rectangular piece of sheet material having lateral end portions shaped to form slots for receiving the margins of the existing roof sheets.
The lateral end portions are folded to provide a first or bottom flange of double thickness and a second or top flange.
In the installed position the lateral end portions rigidify the roof structure and the double thickness bottom flange acts as a back-up which prevents weld burn-through during welding of the top flange.
When a portion of the roof is damaged it is cut away leaving a generally rectangular opening defined by the longitudinally extending side plates and laterally extending margins of the existing roof sheets.
The repair panel is installed by shoving the bottom flange under the edge of the existing roof sheet such that the edge is in the slot.
The repair panel is then pulled back and the bottom flange of the other end is positioned under the opposite edge of the existing roof sheet.
Thus the edges of the existing roof sheet are positioned in the slots formed by the top and bottom flanges of the repair sheet.
Once it is in position, the field repair roof sheet is welded to the existing roof sheet and to the side plates of the car.