Ship Thickness Measurement in Brest's Dry Docks

Inspection services for ships at Brest

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

Where gauging takes place in Brest

The three dry docks of Damen Shiprepair Brest are in the commercial port, with repair quays alongside for work afloat before and after docking. Ultrasonic thickness gauging in Brest is mostly done in these docks: the ship is dry, tanks are cleaned and ventilated for the repair contractors, and staging or access equipment is already in place for the yard's steelwork. The gauging team works to the yard's sequence, measuring tanks as soon as they are released and reporting by compartment so that renewal decisions are made early in the stay rather than in its last days.

The repair quays and the Rade anchorage are the other locations. A tanker or LNG carrier waiting for its dock slot can be gauged in its ballast tanks and on deck while alongside the repair quay or at anchor, so the steel list is known before the ship enters the dock. Weather counts in Brest: Atlantic depressions coming in past Ushant can halt launch work in the roadstead, and the yard's programme, not the team's travel plan, sets the date the work starts.

• Damen Shiprepair Brest dry docks — docking and renewal-survey gauging of shell, tanks and internal structure on LNG carriers, tankers, cruise ships and bulk carriers.
• Repair quays of the commercial port — pre-docking and post-docking gauging afloat, including ballast tanks and deck structure, while the ship waits for or leaves the dock.
• Rade de Brest anchorage — launch-served readings on ships waiting for a dock slot, subject to Atlantic weather in the roadstead.
• LNG carriers in dock — gauging of ballast tanks, the inner hull from the ballast side, cofferdams and deck structure during the docking.
• Cruise ships and ferries in dock — gauging of shell plating, tanks and vehicle or open decks alongside the yard's refit and steel programme.

ECA boundary, port state control and Brest's place on the route

Brest is a useful reminder that the North Sea ECA has a western edge. Its limit in the Channel approaches runs along 5°W and 48°30'N, and Brest lies just south of that line, so a ship arriving from the Channel leaves the 0.10% sulphur area near Ushant. That changes in 2028. IMO adopted the North-East Atlantic ECA at MEPC 84 in 2026, covering the waters off France's Atlantic coast among others, with entry into force on 1 September 2027 and the 0.10% sulphur limit applying twelve months later. For scrubber-fitted ships docking at Brest, the coming ECA is a reason to have wash-water and overboard piping gauged while the ship is dry.

France is a Paris MoU state, and a ship leaving a Brest docking with its steel renewed and its readings on file is in a stronger position at its next port state control inspection. For tankers, a Brest docking often coincides with a renewal survey under the ESP Code: IACS UR Z10.4 for double-hull oil tankers and Z10.3 for chemical tankers set out the gauging and close-up survey, which grow sharply from the third renewal survey at about 15 years. Older tankers facing vetting can add CAP gauging to the same stay; once a tanker is past about 15 years, charterers and oil-major vetting departments frequently expect it. LNG carriers are not ESP ships; their hull gauging follows UR Z7 and the classification society's rules for gas carriers.

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

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

Brest Bretagne Airport has connections from Paris, so the usual route is an international flight to Paris Charles de Gaulle followed by a domestic flight or a high-speed train to Brest. The yard and the ship's agent arrange access to the commercial port and the dry docks; the naval areas of the Rade are closed to civilians and play no part in the job. France is a Schengen state, so each technician needs a Schengen visa before travel, and we apply once the dock date is confirmed, with an invitation letter from the owner or yard naming the ship. If the dock date moves, the team's travel moves with it.

• 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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