Abstract: A rail-mounted transport device for ultra-heavy loads, in particular for changing steel mill converters includes a vehicle which accepts the load independently and is guided on tracks to a delivery station via a turning station where the transport direction is changed, in particular by 90°. The vehicle frame has an annular component for accepting the load, at least three turning wheels provided at the periphery of the annular component, and transport wheels arranged on the vehicle frame, wherein the transport wheels and/or the turning wheels are adjustable in height by means of adjusting elements. The adjusting elements are connected to actuators which can be brought into a position above the vehicle frame in which the transport wheels are raised from the rails during turning. Motors drive the turning wheels to rotate the vehicle frame from the previous transport direction into the desired transport direction.