Section 143.590 - Propulsor redundancy on vessels that move tank barges carrying oil or hazardous material in bulk(a) A towing vessel must be provided with at least two independent propulsors unless the requirements of § 143.595 are met.(b) There must be independent controls for each propulsor at each operating station.(c) In the event of a failure of a single propulsor, the remaining propulsor(s) must have sufficient power to maneuver the vessel to a safe location.