Ultrasonic Thickness Measurement and Ship Inspection in Hong Kong

Inspection services for ships at Hong Kong

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

Anchorages, terminals and yards in Hong Kong waters

Anchorage work is central in Hong Kong. A ship at one of the designated anchorages for bunkers, crew change or orders is out of cargo operations and, in ballast, can open holds and tanks; the agent books the launch that takes the team out. At Kwai Tsing, container ships allow deck, coaming, piping and scrubber work within their berth time, and ships at the Tsing Yi repair yards can be gauged during afloat repairs, with access to tanks and machinery spaces as the repair programme allows.

The Marine Department, as both flag and port authority, is also part of the picture. Hong Kong-registered ships are subject to flag state inspection, and ships calling at Hong Kong are subject to port state control, so a superintendent preparing a ship for either may want structure, tanks and piping gauged in advance. Ships working cargo at the mid-stream buoys are a different case again: they are busy with barges on both sides, and gauging there is limited to deck structure, fittings and piping that can be reached without entering the cargo working area.

• Kwai Tsing Container Terminals — mainline and regional container ships; hatch coaming and deck plate readings and scrubber pipe checks during the terminal's working window.
• Designated anchorages — ships stopping for bunkers, stores, crew or orders; holds and tanks gauged by a launch-borne team for sales, charters and survey preparation.
• Mid-stream buoys — deck, fitting and piping gauging on ships working cargo to barges, scheduled around the cargo operation.
• Tsing Yi ship repair yards — tank, piping and structural gauging during afloat repairs on tankers, gas carriers and bulk carriers.
• Yards elsewhere in Asia for Hong Kong-managed ships — renewal survey and CAP gauging wherever the managers have booked the docking.

Hong Kong's maritime administration and market context

Hong Kong is a member of the Tokyo MoU in its own right, separate from mainland China, and the Marine Department carries out port state control on foreign ships as well as flag state inspection on Hong Kong-registered ships. Hong Kong also applies its own fuel rules for vessels in its waters, setting a sulphur limit for the fuel ships use there. China's domestic emission control rules take over once a ship enters mainland waters, so scrubber-fitted ships trading between the two meet different regimes within a short passage.

The market is shaped more by the managers and owners who sit in Hong Kong than by the port's own traffic. Hong Kong ship managers run tankers, bulk carriers, container ships and gas carriers for owners worldwide, and lessors and banks with Hong Kong desks hold ships as owners or as security. For them, gauging is a decision tool: a pre-purchase thickness survey before a sale, CAP gauging to keep an older tanker acceptable to charterers, an off-hire record at the end of a lease, or pre-docking data to fix a yard specification. A consistent method from one ship and one yard to the next is what makes those records comparable.

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

A gauging job at Hong Kong runs the same way whatever the ship type. The sequence below is what the superintendent, the attending surveyor and the yard can expect from us.

The team lands at Hong Kong International Airport. The agent books launches to the anchorages around the ship's position and the weather; Kwai Tsing and the Tsing Yi yards need terminal or yard passes arranged by the agent or the yard. Hong Kong has its own entry rules for Indian passport holders, separate from the mainland, and we confirm what is needed for each assignment before travel. For ships docking across the boundary in Shenzhen or Guangdong, the team also needs a Chinese visa, which takes longer to arrange.

• 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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