An exhaust hood connectable with an unloading carriage during juxtaposition thereof with a coking chamber and designed to overlie a quenching wagon alongside that carriage has walls converging upward to a roof having two ducts rising from its front and rear ends, these ducts merging into a substantially centrally positioned vertical flue with an inserted dust filter and a downward extension forming a normally closed bunker for the reception of solids dislodged from the filter by periodic vibration thereof. A bypass is formed by a branch of the flue which can be linked during unloading with a pipe atop the juxtaposed carriage having an intake end above the region of the coking-chamber door to pick up waste gases escaping there. The hood may be supported by an ancillary guide track and an overhanging shelf on the side of the quenching wagon opposite the carriage track; alternatively, it is guided at one end on lateral rails of the quenching wagon and at its other end by an outrigger riding the track of that wagon, possibly in front of an engine towing same.