A shaft-mounted rotatable furnace vessel or converter is provided with bearing housings journaling its shafts that are adapted to be raised and lowered on jack mounts or stands of a pair of spaced-apart stationary support piers. A driven trunnion shaft of the vessel or converter is provided with a conventional separable part type of coupling connecting it to a motor drive mechanism. Each jack mount or stand has a wedge-shaped or inclined slide part carried by a guide member for endwise guided movement, as effected by a reciprocating type of fluid motor operatively connected to one end of the slide part. Each bearing housing has a slide or wedge-shaped portion cooperating with an associated slide part and adapted to be raised and lowered by endwise movement of the slide part. An end retainer having a pair of spaced-apart portions projects upwardly from the jack mount adjacent an end thereof on which the motor is positioned and through which the motor is adapted to operatively extend in its connection to the slide part. This end retainer has an abutment portion to abut one end of an associated bearing housing; it cooperates with an opposite end retainer that is removably secured on the jack mount to abut an adjacent end of the associated bearing housing. The upwardly projecting end retainers positively or securely retain or mount an associated bearing housing with respect to the slide part. The end retainers also function to limit the maximum endwise movement of the slide part in either direction. The inclined or wedge-shaped slide portion of each bearing housing is complementary with the slide part to raise and lower the associated housing when the slide part is reciprocated by the fluid motor. The structure enables a converter vessel or furnace to be raised with respect to its piers or stands, in order that a transport car may be wheeled into position between the piers and stands and into a cooperating position under the vessel, that the support or weight of the vessel may be transferred from the stands to the car, and that the vessel with its bearing housings may be transported or moved from an operating station to a repair or maintenance station and, if desired, from the latter station to a hold station, and then returned to an operating station. The car has means for moving it into an aligned position with respect to the bottom of a converter vessel at any of the stations and for endwise moving the vessel after the second-mentioned end retainer of each of the pair of bearing housings has been removed.