Section 143.595 - Vessels with one propulsor that move tank barges carrying oil or hazardous material in bulk(a) A towing vessel must have independent, duplicate vital auxiliaries. For the purpose of this section, vital auxiliaries are the equipment necessary to operate the propulsion engine, and include fuel pumps, lubricating oil pumps, and cooling water pumps. In the event of a failure or malfunction of any single vital auxiliary, the propulsion engine must continue to provide propulsion adequate to maintain control of the tow.(b) In the event of a failure, the corresponding independent duplicate vital auxiliary, described in paragraph (a) of this section, must be fully capable of assuming the operation of the failed unit.