Ultrasonic Thickness Measurement for Ships Repairing at Schiedam

Inspection services for ships at Schiedam

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

Docks, floating docks and repair berths at the Schiedam yard

The Schiedam yard combines dry docks, one of them covered, with two floating docks and a row of repair berths along the river. In dock, the gauging team works from the yard's staging and access platforms, follows the class TM plan where a survey is due, and keeps pace with the surveyor's close-up programme. Lighting and ventilation of tanks are provided by the yard under the superintendent's contract, and enclosed-space entry follows the yard's permit system as well as the ship's own. Readings are logged as they are taken and shared daily, because at a repair yard a reading that arrives late can hold up the steel crew for a day.

The team is engaged by the ship's owner or manager and enters the yard on the yard's own induction and site rules. Before arrival the superintendent receives a plan setting out which spaces will be gauged in which order, matched to the yard's sequence for cleaning, blasting and staging. During afloat periods at the repair berths, the programme concentrates on what can be reached safely: piping systems, decks, internal structure and tanks that the ship can empty and ventilate. Owners whose ships trade regularly to Rotterdam sometimes book a Schiedam berth for a few days of afloat repair, and those days suit a focused gauging scope on a known problem.

• Covered drydock — bottom shell, sea chest and tank gauging sheltered from the weather, useful when bare-steel readings need dry surfaces.
• Open drydocks — full renewal and docking survey programmes on larger merchant and offshore vessels, worked from yard staging.
• Floating docks — bottom and side shell readings on smaller ships, dredgers and workboats lifted for maintenance.
• Repair berths on the Nieuwe Maas — afloat gauging of piping, decks, internal structure and tanks during voyage repairs.
• Riverside quays where offshore vessels lie for crane and equipment work — pedestal, foundation and deck-structure gauging with magnetic particle testing.

Class surveys, port state control and refit decisions at Schiedam

A ship in a Schiedam dock is usually there because a survey is due or because the owner is changing what the ship does. In both cases the classification society's surveyor sets the extent of close-up survey and thickness measurement required, and the owner's superintendent decides how much more to gauge for their own planning. Conversions add another layer: a vessel converted for offshore wind work, a dredger lengthened or a ship being prepared for decommissioning needs its structure assessed against new loads or new rules, and thickness data is the starting point for the naval architect's calculations.

Paris MoU port state control applies to merchant ships throughout the Rotterdam area, Schiedam included, and a deficiency that must be rectified before departure can bring a ship to a Schiedam repair berth at short notice. EU rules shape the work as well. The EU Ship Recycling Regulation requires an Inventory of Hazardous Materials for ships calling at EU ports, and a refit or conversion is the moment when that inventory has to be updated. Owners facing EU ETS and FuelEU Maritime obligations increasingly combine structural repairs with efficiency work in a single docking, which makes the steel survey one part of a larger plan for the ship.

Ships trading to Schiedam 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 Schiedam

A gauging job at Schiedam 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.

Rotterdam The Hague Airport is a short drive from Schiedam, and Amsterdam Schiphol, the main long-haul arrival point, has rail connections to Schiedam Centrum. The yard controls its own gate and induction, so the superintendent or the ship's agent registers the technicians with the yard before they arrive. Team members travelling from India need Schengen visas; for dockings the date is normally known weeks ahead, which gives time to secure visas and fix travel to the yard's planned start.

• 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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