Abstract: The device comprises a horizontal shaft (1) which is connected to a coupling head (2) at the lower front angles of the container (3), through conventional pins (4). The axis or shaft remains anchored through a traction cable or chain (8), and is driven by way of telescopic hydraulic cylinders (9) situated along the rocking body or in the cradle of the trailer. The traction cable or chain passes over various return-pulleys and remains anchored at its extremities to respective fixing points of the chassis. The axis or shaft (1) has fixed extremities, a central movable portion and a pair of intermediate rollers (13) bearing on the rolling tracks (21) of the cradle or rocking chassis (10). There are also provided small wheels (18) which are situated on the other side of the rolling tracks. The container (3) bears posteriorly on a table of rollers (25) and optionally on a pair of side rows of rollers which are displaceable vertically through the action of hydraulic cylinders.