Ultrasonic Thickness Measurement off the Skaw and in Skagen Harbour

Inspection services for ships at Skagen

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

Where gauging is practical at Skagen

At the anchorage, all work is done by launch. The ship's agent books the boat, the team climbs a pilot or accommodation ladder, and the kit is limited to what technicians can carry up it, so the scope and the equipment are settled before the boat leaves the harbour. Ballast tanks must already be emptied, ventilated and certified safe for entry by the crew, because a few hours at anchor leave no time to prepare them once the team is aboard. Work stops whenever the swell makes the ladder unsafe, which is why the readings that matter most are always placed first on the list.

Inside the harbour, the shipyard Karstensens Skibsværft builds and repairs fishing vessels and other specialised craft, and vessels under repair there can be gauged alongside or out of the water. Large merchant ships do not dock at Skagen; those that need a dry dock after an anchorage stop usually go to Ørskov Yard in Frederikshavn, to Fayard on Funen, or to yards in Poland, Germany or Norway. Coasters and cargo ships at the commercial quays can be measured while they work cargo, and fishing vessels between trips at their regular berths in the fishing harbour.

• Skagen anchorages — deck, hatch coaming, air-pipe and ballast tank gauging by launch on ships stopping for bunkers, stores or crew change.
• Tankers waiting or transferring cargo off Skagen — ballast tank, void space and deck gauging over longer stays, within the ship's gas-safety rules.
• Karstensens Skibsværft — hull, deck and tank measurement on fishing vessels and specialised craft in for repair.
• Fishing harbour berths — shell plating, refrigerated sea-water tank and fish-hold gauging on trawlers between trips.
• Commercial and cruise quays — holds and tanks on coasters during cargo work, and machinery-space piping on cruise ships.

Ships that never berth: inspection drivers at the Skaw

Ships calling at Skagen harbour are subject to Paris MoU port state control carried out by the Danish Maritime Authority, but many of the vessels stopping off the point never come alongside in Denmark at all. For those ships the reasons for a gauging request come from elsewhere: a class recommendation due before the next port, a charterer's vetting, a buyer's inspection or the owner's own condition programme. Danish authorities have also stepped up checks on older tankers anchoring in the waters around Skagen, and a ship whose hull records are current and complete is better placed if she is boarded.

Bunker calls off Skagen bring together ships of every age and flag, and the questions owners ask about them are commercial as well as technical. Danish ports are EU ports, so the EU ETS from 2024 and FuelEU Maritime from 2025 apply to the voyages that end in them, and ships of 500 GT and above that call at them need an Inventory of Hazardous Materials. Ice is not a feature of the Skagen anchorage, but ships heading on to the northern Baltic in winter carry ice class, and an anchorage stop is a last chance to check the parts of the ice belt that sit above the waterline when the ship is in ballast.

Ships trading to Skagen 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 Skagen

A gauging job at Skagen 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.

Aalborg Airport is the nearest airport with international flights; from Aalborg, trains run north to Frederikshavn and a local line continues to Skagen, or the team travels on by road. Copenhagen and Billund are the usual long-haul arrival points. Launches for the anchorage are booked by the ship's agent, who also handles boarding notifications, while the fishing and commercial quays are reached through the port's normal access arrangements. The team comes from India on Schengen visas, so owners who use Skagen stops regularly benefit from having visas in place before a particular call is fixed.

• 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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