Patent ID: 7055441

Claim:
In combination with a railroad freight car body having a length, a deck having a selectively raisable end portion comprising a core of low density material and a skin of fiber reinforced plastics adhered to said core, said core having a length oriented along said length of said car body and said end portion having a concave bottom surface, wherein said end portion is movable between a raised position and a lowered position about a horizontal transverse pivot axis located at an inner end of said end portion, and said end portion further including a counterbalance apparatus comprising: (a) a compression spring supported by said car body; (b) a direction-changing force transfer device supported by said car body at a position above said end portion; (c) a first elongate tension-carrying member operatively connected with said end portion and said direction-changing force transfer device; and (d) a second elongate tension carrying member operatively connected with said compression spring and said direction-changing force transfer device so that tension in said first elongate tension carrying member causes tension in said second elongate tension carrying member and tends to compress said compression spring.