Thickness Measurement for Ferries, Bulk Ships and End-of-Life Vessels in Grenaa

Inspection services for ships at Grenaa

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

Where gauging takes place at Grenaa

For the ferry and cargo trades, gauging is afloat work at the ship's own berth. The Halmstad ferry can be measured when it lies over at Grenaa outside the timetable or during planned maintenance, with car decks clear and tanks prepared by the crew. Bulk carriers and coasters at the cargo quays offer windows during discharge and loading: hatch covers, coamings, deck plating and accessible ballast tanks can be measured while cargo is worked in other holds, and empty holds can be gauged once discharge is complete. Crew transfer vessels and service ships at the wind-farm base are reached directly from the pontoons and quays they use between trips to the turbines.

Ships arriving at the recycling yard are a separate case. Once a ship has been delivered to the yard, its structure is the recycler's concern and gauging is rarely needed; the useful readings are taken before the voyage, often at the ship's last trading port, when the owner, the insurer or the surveyor assessing a tow wants assurance that the hull will hold together on the passage. Grenaa has no large dry dock for merchant ships, so dockings for the ferry and the cargo vessels go to yards elsewhere in Denmark or abroad, and readings taken alongside at Grenaa feed the yard's steel estimate before the ship arrives.

• Ferry berth for the Halmstad route — car-deck, ramp, door-fitting and ballast tank gauging during lay-overs or planned maintenance.
• Bulk and general cargo quays — hatch cover, coaming, hold and ballast tank readings on bulk carriers and coasters during discharge or loading.
• Offshore wind service base — deck fittings, fendering structure and fuel tanks on crew transfer and service vessels between turbine trips.
• Project cargo quays — tank-top and deck strengthening checks on heavy-lift ships after loading or discharging large components.
• Recycling yard arrivals — condition readings arranged before the final voyage, at the ship's last port or lay-up position, when the voyage needs them.

Ship recycling rules, Kattegat trade and port state control

Denmark applies port state control under the Paris MoU through the Danish Maritime Authority, and as an EU state it applies the EU Ship Recycling Regulation. Under that regulation, EU-flagged ships may only be recycled at yards on the European list, of which Fornæs is one, and every ship above the size threshold calling at an EU port, whatever its flag, must carry an Inventory of Hazardous Materials. The IHM and the recycling plan are documentation tasks rather than thickness measurement, but they run alongside the condition decisions that gauging supports, and an owner planning a ship's last voyage to Grenaa deals with both at once. The Hong Kong Convention on ship recycling entered into force in June 2025, adding an international layer to the same process.

For the working fleets, the drivers are the familiar ones. The Halmstad ferry is inspected under the EU regime for ro-ro passenger ships on regular services as well as by class, and ships above the size threshold report emissions under the EU ETS, which has applied to shipping since 2024, and FuelEU Maritime, from 2025. Many of the bulk carriers calling at Grenaa are smaller short-sea ships, where corrosion in holds and ballast tanks is the main structural concern and where an intermediate or renewal survey can decide whether a ship keeps trading. Ice is rarely a factor in the Kattegat, though coasters that also load in the northern Baltic in winter carry ice-strengthened shell plating worth including in their plans.

Ships trading to Grenaa 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 Grenaa

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

Aarhus Airport, on Djursland between Aarhus and Grenaa, has limited international connections, so the team usually arrives through Copenhagen or Billund and continues by road or rail; the light-rail line from Aarhus ends at Grenaa. Denmark is in the Schengen area and the team needs Schengen visas issued in India, which take time to arrange. Port access is arranged by the ship's agent, and work at the recycling yard or the wind-farm base follows that site's own safety rules.

• 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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