Hull and Hopper Thickness Measurement at Shoreham Port, West Sussex

Inspection services for ships at Shoreham

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

Gauging berths, the dry dock and lay-by time at Shoreham

The wharves on the Canal are the natural place for gauging: the water is impounded, the ship sits steady at the quay, and cargo work proceeds in a predictable order. On a timber or steel coaster, holds come free as discharge progresses, and the team follows the stevedores with tank-top, frame and hatch cover readings. On an aggregate dredger the hopper is the priority, and it can only be gauged once it is fully discharged and washed down, so that work is planned for the end of a discharge or for a day when the dredger is held in port.

The port's dry dock is small and suited to fishing vessels, workboats and similar craft rather than seagoing cargo ships, so the dredgers and coasters trading here dock at yards elsewhere on the south coast, in other British ports or on the Continent. Gauging at Shoreham then becomes the step before the docking: a steel estimate for the hopper, double bottom and shell, or a condition check that decides whether the docking can wait. When a dredger is held in port for maintenance, several days become available for her tanks, pump room and pipework, which is the fullest survey Shoreham normally allows.

• Aggregate wharves on the Canal: hopper plating, hopper structure and discharge system gauging on dredgers once the cargo is out.
• Timber, steel and grain berths on the Canal: hold-by-hold tank-top, frame and hatch cover gauging during discharge.
• Western arm river quays: deck and accessible tank work on smaller ships, planned around the tidal rise and fall.
• The port's small dry dock: shell and sea chest readings on fishing vessels, workboats and similar craft while they are dry.
• Lay-by berths inside the lock: longer tank, pump room and pipework scopes on dredgers held in port for maintenance.

Port state control, dredging licences and how dredgers age

Foreign-flagged coasters and dredgers at Shoreham are inspected by the Maritime and Coastguard Agency under port state control, which the UK has continued in line with the Paris MoU since leaving the EU. Many aggregate dredgers are UK-flagged, so the MCA meets them as flag state instead, through survey and inspection under UK regulations. Marine aggregate extraction in English waters is licensed by the Marine Management Organisation, and the industry records where its ships dredge through electronic monitoring, so a dredger's operating history is well documented even when her structural history is thinner.

Aggregate dredgers age in a particular way. The hopper and its discharge system take continuous abrasive wear, ballast tanks alongside the hopper are repeatedly wetted and dried, and the suction pipe gantries and their supports carry heavy, cyclic loads. Some dredgers on the south coast have worked for decades, and owners weighing a renewal survey against a replacement need evidence of how fast the steel is going. For coasters on timber and steel trades the familiar questions apply: hatch cover weathertightness, air pipes and ventilators, and tank tops under heavy cargo, all of which inspectors examine on older ships.

Ships trading to Shoreham 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 Shoreham

A gauging job at Shoreham 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.

For Shoreham the team usually flies into London Gatwick, the nearest major airport, or Heathrow, and travels on by rail or road; Shoreham-by-Sea, Southwick and Portslade stations are all on the coast line close to the port. Technicians travel from India on UK visas, so we ask for the ship's expected dates early and keep them updated through the agent. Access to the wharves is controlled by the port and the wharf operators; the agent arranges passes against each technician's passport and confirms the locking time.

• 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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