One steering gear power unit isolated on a coastal tanker
The 28,000 DWT oil tanker Nereid Star, built 2010, is alongside after discharging. During preparation for a coastal voyage through a narrow, 9-hour channel, the chief engineer reports that the port steering gear power unit has tripped several times in the past week. A cracked flange on the unit's high-pressure line is leaking hydraulic oil and the unit has been isolated. The starboard unit is running. A test in port, at 12 knots and light draft, gives 35° port to 35° starboard in 27 seconds. The SMS risk assessment, prepared by the company, states that 'one power unit is sufficient for harbour and coastal passage'. The planned maintenance record shows the automatic start test of the standby pump is 7 months overdue. The master says the vessel is 'still under control' and asks for the annual machinery survey to be completed so the ship can sail with the evening convoy. The next port has no repair yard, only a riding crew.
1. Does the steering gear arrangement meet SOLAS II-1/29? Explain your conclusion.
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No. SOLAS II-1/29 requires tankers to have two independent power units for the main steering gear, each capable of operating it, and arrangements that re-establish steering within 45 s after loss of one unit. With the port unit isolated, the ship has one power unit; if the starboard unit trips there is nothing to re-establish.
The 27 s test at 12 knots and light draft does not demonstrate the required 35° to 35° in 28 s at maximum ahead service speed and maximum service draught, so it is not evidence of compliance. The overdue automatic start test of the standby pump is part of the same system and adds doubt. I would not complete the machinery survey as satisfactory.
2. How do you deal with the company's SMS risk assessment and the master's request to complete the survey?
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An SMS risk assessment is a management tool; it cannot create an exemption from a convention requirement, and the company is not the flag administration. The statement that one unit is sufficient for harbour and coastal passage is therefore irrelevant to the compliance decision. The master's request is commercial pressure, not a technical argument.
I would require the leak to be repaired and both units, the automatic changeover and the bridge and engine-room alarms to be tested before departure. If repair at this port is impossible, the only acceptable movement would be a short tow or a voyage approved in writing by the flag administration with the defect controlled, not a normal coastal passage through a narrow channel.
3. What action do you take on the certificate and what do you report?
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I would withhold the annual machinery survey endorsement, issue a deficiency against the steering gear, and notify the flag administration or recognized organization and, where the port State has jurisdiction, the PSC authority. Steering gear failure is a classic detainable deficiency; the risk of a single unit failing in a narrow channel is not one the surveyor can accept on the master's assurance.
I would record the leak, the isolation, the test data and the company's risk assessment in the report, and I would not accept a condition of class that leaves one power unit isolated.