A delivery vehicle operates on a two-dimensional rail system with rails extending in a first direction and a second direction. The second direction is perpendicular to the first direction. The delivery vehicle includes a vehicle body; two sets of wheels connected to the vehicle body for engagement with the underlying rail system and for moving the delivery vehicle in the first and second directions; a container carrier for supporting a container from below, wherein the container carrier comprises a first conveyor; a conveyor drive shaft for driving the first conveyor; and at least one drive coupling. The at least one drive coupling includes a connection interface accessible from an outer side portion of the vehicle body. The drive coupling is rotatably connected to a motor drive shaft such that when the motor drive shaft is rotated the drive coupling and the connection interface are rotated.