Thickness Measurement and Hull Gauging in Dunkirk (Dunkerque)

Inspection services for ships at Dunkirk

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

Gauging locations in the western and eastern ports

For drydock gauging in Dunkirk, the Damen Shiprepair Dunkerque docks are the centre of activity. A ship in dock gives full access to the bottom and side shell, sea chests and the internal structure of tanks once they are cleaned and ventilated, and the readings can be turned round quickly enough for the yard to cut and renew steel within the same stay. The yard's dry docks and floating dock between them cover ferries, dredgers, offshore vessels and oceangoing cargo ships.

In the western port, gauging is fitted around cargo work. Ore and coal carriers discharge with grabs in the holds, so the team works in the hopper, topside and double-bottom ballast tanks while discharge continues and reaches each hold only once it is cleared. LNG carriers at the terminal are subject to its gas-safety rules, and container ships follow the usual short-call pattern of ballast tanks and deck structure first. The Dover Strait traffic separation scheme is on the doorstep, so a ship transiting the strait can divert into Dunkirk for a docking or a gauging call with little deviation from its route.

• Damen Shiprepair Dunkerque dry docks — renewal-survey and docking gauging of bottom, side shell, tanks and internal structure while the ship is in dock.
• Damen floating dock — refit-period gauging on ferries, dredgers, offshore vessels and smaller cargo ships, including vehicle decks, ramps and sea chests.
• Western port ore and coal quays — hopper, topside and double-bottom tank gauging on large bulk carriers during discharge, with holds gauged once clear.
• Dunkerque LNG terminal, Loon-Plage — ballast-tank and hull structure gauging on LNG carriers within the terminal's safety rules.
• Western port container and ro-ro terminals — short-call gauging of ballast tanks, deck structure and scrubber piping on container ships and car carriers.
• Eastern port basins behind the locks — lay-by gauging for pre-purchase, off-hire or condition surveys that need several days of uninterrupted access.

Port state control, SECA and the steel-and-energy trades at Dunkirk

Dunkirk lies inside the North Sea SOx ECA, at the narrow eastern end of the Channel, and France applies port state control under the Paris MoU. The Dover Strait is among the busiest shipping lanes in the world, and the ships using Dunkirk's western port tend to be large and hard-worked: bulk carriers in the ore and coal trades, whose holds and hopper tanks see grab damage and the corrosion that wet coal cargoes promote, and LNG carriers on regular European discharge rotations. Both are ship types on which port state control inspectors look closely for wastage and cracking at structural details.

Bulk carriers are ESP ships. Under SOLAS chapter XI-1 regulation 2 and IACS UR Z10.2 or Z10.5, the third renewal survey at about 15 years and later surveys bring extensive gauging of holds, hopper and topside tanks and transverse bulkheads, which is where measured readings taken during an earlier discharge pay off. Ferries and container ships are surveyed under UR Z7 and their society's rules. The EU ETS (since 2024) and FuelEU Maritime (since 2025) apply to every call, and the cross-Channel ferries show the SECA's effect on piping most clearly: a scrubber-fitted ferry that never leaves the ECA runs its wash-water system on every crossing.

Ships trading to Dunkirk are inside a sulphur emission control area, where fuel must not exceed 0.10% sulphur unless an exhaust gas cleaning system (scrubber) is fitted. Scrubber wash-water piping, the overboard discharge and the hull penetration around it are among the fastest-corroding parts of a modern ship, so they belong in the gauging scope at every docking and, on open-loop systems, between dockings.

How a thickness measurement job runs at Dunkirk

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

The usual routes are Paris Charles de Gaulle with rail connections north through Lille, or Brussels Airport with an onward road transfer along the coast. The ship's agent requests ISPS passes for the named technicians at the western port terminals, and yard access for a docking is arranged with Damen Shiprepair Dunkerque. Each technician travels on a Schengen visa applied for in India once the docking slot or berth date is firm; an invitation letter from the owner or yard naming the vessel supports the application. Because yard slots can move, flights are confirmed against the yard's latest schedule rather than the original booking.

• 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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