Abstract: A trailer assembly designed to transport rolls of rolled material, such as rolls of coiled steel. The assembly comprises a floor pan, one or more bunks, each of which comprises two opposed inclined members of a size and configuration to hold the roll off the floor pan, two laterally moveable side locks for each of the rolls, a lid enclosure which is hingedly moveable frontwardly or rearwardly between an open and a closed position, the lid when in the closed position forming a tight seal with the floor pan, and a stand for the lid when in the open position.