Tide, inadequate mooring, open scuttles in galley and toilet, a switched-off engine and a crew who were busy transferring bunkers from a barge to the tanker Atlantic Muse, resulted in the pusher tug Mariner 1 capsizing while still moored to the barge.
A report by Marinha Do Brazil, the Brazilian Maritime Authority, concludes that the mooring arrangements with “the tugboat berthed at the barge with hawsers of spring and bowlines, without a hawser athwart” meant that an ebbing tide of up to 4 knots opened the gap between the tug’s bow and the barge, forcing the tug to heel over, submerged the portholes of the gallery and toilet with subsequent flooding.
The tug’s engine had been switched off while bunkers was being transferred and the vessel was unmanned because its crew were working on the bunkering operation so no steps could be made in time to manoeuvre the tug to reduce the heeling.
The tug was successfully refloated later with fairly minor damage.
Among the recommendations in the report:
“1.- During this type of operation of Port Support, the correct and complete water tightness of the freeboard deck of the craft should be guaranteed;
2.- The classification of the craft should be reviewed, in accordance with data obtained from the stability study;
3 – Evaluate the inclusion of the obligation to install two means of starting the bilge pump of this type of craft; ex. automatic and manual;
4 – In the establishing of the Safety Crew Card, it should be assured the manning necessary and adequate, of the tugboat during the tasks of transference of fuel, making possible the rapid and correct interference in the operative conditions in special/specific cases of operation.
5 – Re-evaluate the qualification of Master of craft of Port Support, considering the item 0104 lines b) and c) and the item 0106, of the NORMAM-02/DPC;
6 – Re-evaluate Categories and Limitations included in Annex 2-A of NORMAM-13DPC,
General Schedule of Certifications, for this type of craft; and
7 – It is not recommendable that the function of Supervisor of the task of transference of fuel, be performed by a crewmember of the tugboat, and can be someone not of maritime or waterways personnel, in order to assure the minimum periods of rests, that is six hours continuous.
The full report can be downloaded here