Calais Port: Thickness Gauging for Ferries, Ro-Ro Ships and Dredgers

Inspection services for ships at Calais

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

Where ships can be gauged at Calais

Ferry berths are working terminals with loading ramps, passenger access and strict security. Gauging there focuses on what is accessible while the ship is in service: the structure of vehicle decks, ramps and ramp hinges, ballast and fuel tanks that the crew can release, machinery-space piping and the scrubber wash-water lines on ships that carry them. Most ferry owners prefer to carry out major steel work during a planned refit at a yard, and the measurements made at Calais become the basis for the steel scope of that refit.

In the older basins behind the lock, quays take smaller ships for longer stays, and these are the best places for slow, systematic gauging of coasters, dredgers and service craft. The port's repair resources are modest compared with large yards elsewhere on the coast, so ships needing a docking usually go to a bigger facility in another port, and a gauging programme at Calais can be timed to feed straight into that decision. Anchorage in the roads outside the harbour is available to ships waiting for berths or tide.

• Ferry terminal berths — vehicle deck, ramp and piping gauging in the gaps between sailings and during overnight layovers.
• Freight ro-ro terminals — deck, ramp and tank gauging on ships released by the operator for the longer stays.
• Outer harbour quays — hull and deck gauging on cargo ships carrying steel, timber and aggregates.
• Inner basins behind the lock — longer gauging of dredgers, coasters and service craft laid by between jobs.
• Lay-up and overhaul periods — extended access for a full ballast tank and shell programme before a refit elsewhere.
• Roads outside the port — launch-assisted work on ships waiting for berth or tide, in suitable weather.

French port state control and the Dover Strait ferry regime

In France, port state control is carried out by the Centres de sécurité des navires, the ship safety centres of the Affaires maritimes administration, under the Paris MoU. Ferries on regular crossings are also subject to the EU's special survey regime for ro-ro ferries, which brings frequent and detailed inspections, and they are classed ships whose society's rules set the extent of structural gauging. Because Calais ferries run constantly in a corrosive, wet environment, vehicle deck plating, lashing points, ramp structures and drain areas are the details that attract most attention.

Calais lies inside the SECA, so scrubber-fitted ferries and ro-ro ships run their wash-water systems on virtually every crossing. That makes overboard piping a high-wear item, and owners often add it to the gauging scope alongside the deck and tank work. The EU emissions trading scheme and FuelEU Maritime apply to these ships, and the Inventory of Hazardous Materials is required for those over the size threshold, so owners of older ferries also benefit from a steady record of steel condition to support decisions on refit, sale or replacement.

Ships trading to Calais 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 Calais

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

Paris Charles de Gaulle and Brussels are the usual long-haul arrival points, with rail or road onward to Calais; Lille Lesquin is a regional alternative. Technicians travel from India on Schengen visas applied for once the vessel's schedule is confirmed. Because Calais ships run on fixed timetables, the plan uses firm dates agreed with the operator, and passes to the ferry and freight terminals are requested through the ship's agent, who also confirms what time the spaces will be released.

• 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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