Hull Thickness Gauging and Ship Inspection at Sohar Port and Freezone

Inspection services for ships at Sohar

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

Where Gauging Takes Place at Sohar

Sohar has no drydock of its own, so work here is done afloat. The iron ore terminal gives the longest access, as holds empty during a discharge that runs over several days; we work behind the discharge, gauging each hold once the grabs have cleared the tank top and the stevedores allow access. On tankers at the liquid berths, the terminal's rules limit what can happen alongside, and cargo-area work is usually better done at the anchorage. General cargo and dry bulk berths offer stays long enough for hold and deck gauging on smaller bulk carriers and multipurpose ships, and container ships at Hutchison Ports Sohar can take selective gauging inside the cargo window.

When a Sohar ship needs a drydock, the usual options are Asyad Drydock at Duqm, further down the Omani coast, or the UAE yards to the north. Gauging the holds and ballast tanks during the Sohar discharge, while the ship is empty and the holds are open, gives the repair yard a measured steel list before the ship sails for docking. That matters most for large ore carriers, where steel renewal in the hold area can be extensive and the yard needs time to prepare plate and labour.

• Iron ore terminal — hold, tank top, hopper plate and frame gauging on very large ore carriers as each hold is cleared during discharge
• Liquid bulk berths — deck, piping and accessible tank gauging on product and chemical tankers, within the terminal's safety rules
• Hutchison Ports Sohar container terminal — selective deck, hatch coaming and scrubber piping gauging on container ships during the cargo window
• General cargo and dry bulk berths — hold and deck gauging on bulk carriers and multipurpose ships carrying steel, aluminium and other industrial cargo
• Sohar anchorage — condition, pre-purchase and on-hire gauging on ships waiting for a berth, reached by launch
• Asyad Drydock, Duqm — pre-docking gauging done at Sohar for ships continuing down the coast to dock; see our Duqm page

Port State Control, Sulphur and Owner Context at Sohar

Oman is a member of the Riyadh MoU, and port state control inspections at Sohar follow that regime. The Gulf of Oman is not an emission control area, so the global 0.50% sulphur limit applies, and many of the large ore carriers and tankers calling at Sohar run exhaust gas scrubbers. Scrubber overboard lines and wash-water piping on these ships carry acidic water at high temperature and are a regular gauging item, especially where the overboard penetration passes through ballast or void spaces. Rules on discharging open-loop wash water vary between ports and change over time, so confirm the current position for Sohar with the ship's agent.

Much of the ore carrier fleet serving the Vale distribution centre is owned and managed in East Asia and works under long-term contracts, and both the owners and the charterer watch hold structure closely. Owners of bulk carriers approaching the third renewal survey, with its extensive gauging of holds and ballast tanks, gain from having condition data well before the survey date. For tankers, oil-major vetting and CAP requests apply here as anywhere else. For owners looking for thickness measurement in Oman, Sohar's position also makes it easy to coordinate with work at the Fujairah anchorage just up the coast or with a later docking at Duqm.

Wherever a ship is outside a sulphur emission control area, the global 0.50% sulphur cap applies, and many of the ships calling at Sohar 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 Sohar

The sequence for a thickness measurement job at Sohar is short and written down, so the yard, the surveyor and the superintendent know who arranges what.

Teams fly into Muscat International Airport, which has direct services from many Indian cities, and drive north along the Batinah coast to Sohar. Sohar Port and the freezone are security-controlled, so the ship's agent arranges passes for the technicians and their equipment, and launch transfers for anchorage work. Indian technicians need an Omani visa for business travel, which we apply for once the ship's arrival is confirmed. Ore discharges are usually scheduled well ahead, which helps when booking flights and passes for an India-based team.

• 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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