Hull Gauging and Weld Inspection for Wind Farm and Cargo Vessels in Grimsby

Inspection services for ships at Grimsby

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

Where wind vessels and cargo ships are checked in Grimsby

Crew transfer vessels are inspected alongside their operators' pontoons in the Royal Dock. On an aluminium hull, the team gauges deck and hull plating from inside the hull spaces and from the deck, and examines welds at fender attachments, the bow transfer area, engine foundations and the joints between hulls and the wet deck with dye penetrant. Small fuel and water tanks are gauged from outside where internal access is impossible. When a vessel is lifted out of the water for its periodic hull work, the outside of the hulls can be examined as well, which is the best moment for a complete survey.

Steel ships are worked differently. Car carriers are inspected at the ro-ro berths during a discharge, with ramps and lower car decks reached once vehicles are clear, and short-sea cargo ships are gauged around their cargo operations. Grimsby has no drydock for merchant ships that we would plan around; smaller steel vessels based here can dock at Dunston's graving dock across the river in Hull, and larger ones go to the Tees, the Tyne or a yard across the North Sea. Readings taken in Grimsby beforehand let that yard plan the steel work.

• Royal Dock operators' pontoons: crew transfer vessel hull, deck and weld inspection on weather days or planned maintenance days.
• Ro-ro berths for vehicle imports: stern ramp, hinge lug and car-deck checks during a discharge call.
• Cargo berths: hold and deck gauging on short-sea general cargo ships around their cargo work.
• Fish docks: older fishing vessel and workboat hulls checked before a sale or a refit.
• William Wright Dock graving dock in Hull: the nearest drydock for smaller steel vessels based in Grimsby.

Workboat rules, port state control and the wind market

Most crew transfer vessels in UK waters are small enough to be certified under the Maritime and Coastguard Agency's Workboat Code rather than full merchant ship conventions, and many are also built and maintained to a classification society's rules for high-speed or light craft. Either way, hull structure is examined at periodic surveys, and an aluminium hull that has spent years slamming into short seas is where those surveys find trouble. Foreign-flagged ships calling at Grimsby, such as car carriers and cargo ships, are subject to port state control by the Maritime and Coastguard Agency under the Paris MoU.

Many of the crew transfer vessels built during the first offshore wind boom are now more than a decade old. Aluminium does not corrode the way steel does in sea water, but it suffers fatigue cracking at welds, local thinning from galvanic attack where it meets steel fittings, and impact damage at the bow and fenders. Wind farm operators and vessel charterers expect high availability, and a crack found on a weather day can be repaired before it takes a vessel off contract. For owners selling older vessels to new operators, a condition record also supports the sale.

Ships trading to Grimsby 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 Grimsby

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

Humberside Airport is the closest airport but has few routes, so most teams fly into Manchester, Leeds Bradford or a London airport and continue by rail to Grimsby Town, with connections through Doncaster. Technicians travel from India on UK visit visas, applied for well ahead, which matters because weather days cannot be booked in advance: a campaign is planned for a period rather than a single day. Access to operators' pontoons is arranged through the operator, and to ABP's ro-ro and cargo berths through the ship's agent.

• 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.

Related