UTM and Hull Thickness Gauging for Ships Calling at Salalah

Inspection services for ships at Salalah

Each service has its own page with the method, the class requirements and what the report contains.

Where Gauging Is Done at Salalah

Gauging at Salalah is done afloat. On the container terminal, the team works on deck and in accessible tanks while cranes are working, keeping clear of lashing and cargo areas and following the terminal's safety rules. Areas under hatch covers or behind stowed boxes are left for a later call or for docking, so the scope has to be realistic about what a working container ship exposes. Short calls reward preparation: tanks to be gauged should be emptied, ventilated and tested before arrival, so the team does not lose the call waiting for access. At the general cargo terminal, bulk carriers and multipurpose ships give longer access to holds, decks and tanks.

The anchorage is where feeders and other ships waiting for berths can be gauged at more length, reached by launch through the agent, but sea conditions during the khareef often rule it out. For drydocking, ships from Salalah generally head for Asyad Drydock at Duqm or yards elsewhere in the region. Gauging in Salalah before such a docking gives the yard a measured view of hull structure and tanks, and the team can follow the ship to Duqm for the in-dock part if the owner wants continuity.

• Container terminal berths — upper deck, hatch coaming, side tank and scrubber piping gauging on mainline container ships during the box exchange
• Container terminal, feeder calls — ballast tank, hatch cover and deck gauging on regional feeders, which often allow longer access than mainline ships
• General cargo terminal — hold, tank top and hatch cover gauging on bulk carriers loading minerals, done before loading begins
• Salalah anchorage — condition and pre-purchase gauging on ships waiting for a berth, outside the monsoon season
• Asyad Drydock, Duqm — in-dock gauging for ships that dock up the coast after a Salalah call; see our Duqm page

Regulation and Market Context at Salalah

Oman's port state control is carried out under the Riyadh MoU. The Arabian Sea is not an emission control area, so ships here comply with the 0.50% global sulphur limit, either by burning compliant fuel or by running scrubbers, which are common on the large container ships that call at transshipment hubs. Scrubber wash water is acidic, and on container ships the discharge line often runs through a ballast or void space near the engine room before reaching the shell, so a leak there is both a structural and a pollution problem. Because container ships fall outside the ESP, the gauging extent at renewal is set by IACS UR Z7 and the ship's class rules, and it grows with each renewal survey.

Container ships on Salalah services are operated by the mainline carriers but frequently owned by charter owners and run by third-party ship managers, who carry the risk of hull condition between charters. Condition recorded at redelivery, and found again at the next charterer's on-hire inspection, affects charter negotiations, so on-hire and off-hire gauging has a clear purpose here. Routing between Asia, the Red Sea and Europe has shifted in recent years, changing which services call at Salalah, so we plan around the call schedule the owner actually has rather than a typical rotation.

Wherever a ship is outside a sulphur emission control area, the global 0.50% sulphur cap applies, and many of the ships calling at Salalah meet it with an exhaust gas cleaning system rather than compliant fuel. Scrubber wash-water piping, the overboard discharge and the hull penetration around it corrode quickly in service, especially on open-loop systems, and are worth adding to the gauging scope.

How a thickness measurement job runs at Salalah

Most of the work on a Salalah job happens before the team boards: scope, plan and access are settled first, so the time on board goes on measurement.

Salalah International Airport serves the city, and our team usually reaches it through Muscat on one of the domestic connections; the port at Raysut is a short drive from the city. The ship's agent arranges ISPS passes for the container and general cargo terminals and launches for anchorage work. Indian technicians need an Omani visa for business travel, which we apply for once the call is confirmed. Container schedules shift, so we keep travel bookings flexible and stay in contact with the agent as the ship's arrival time moves, which is the main risk to a short ultrasonic thickness measurement in Salalah.

• Send the vessel name or IMO number, ship type, class society, the survey due (annual, intermediate, renewal survey number, CAP or owner's condition survey), the port and dates, and the scope you expect.
• We confirm the scope against the class rules for that survey, prepare the thickness measurement plan with frame and section references, and say whether the measurement will be credited to a class survey.
• Mobilisation is planned around visa lead times and the vessel's schedule; the ship's agent arranges port access, and the yard or ship arranges staging, lighting, ventilation and gas-free certificates.
• Gauging with calibrated ultrasonic thickness gauges: through sound coatings only where the gauge's through-coating mode has been verified on a coated reference, otherwise on cleaned bare steel, with every reading tied to its frame, strake and location on the sketch.
• Readings are compared with original thicknesses as work proceeds; substantial and excessive corrosion and any cracks are reported to the attending surveyor and the superintendent the same day.
• The final report is issued on the class thickness-measurement formats with sketches, a summary of locations exceeding the allowable margins, piping tables where piping was in scope, and the gauge calibration and technician certificates.

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