Ship Thickness Measurement at Avonmouth and Royal Portbury Docks

Inspection services for ships at Avonmouth

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

Berths at Avonmouth and Portbury where gauging fits

On car carriers, the team works the vehicle decks that have been cleared, starting with the lower decks and weather-deck areas the cargo plan releases first. Deck plating under lashing points, hoistable panels and their supports, ramp structure and the bottom of the stern ramp opening are common items, together with ballast tanks and engine-room piping. Bulk carriers at the feed and grain berths are handled hold by hold, with every reading tied to a frame number on the ship's own drawings so it can be compared at the next survey.

Neither dock is a repair base for merchant tonnage, so dockings are booked elsewhere, at yards in South Wales, Cornwall, on the Mersey or on the continent. Gauging at Bristol therefore tends to be preparation: a pre-docking estimate, an owner's condition survey before a charter renewal, or a targeted check after a surveyor has flagged a problem. Tankers at the liquid bulk berths are worked under the terminal's permit system and limited to areas that are safe during cargo transfer, while feeder ships get short, prepared scopes fitted to their berth windows.

• Royal Portbury car terminals — vehicle deck, ramp, hoistable deck and ballast tank gauging on car carriers during discharge and loading.
• Portbury bulk berths — hold, hopper and tank top readings on feed and grain carriers as holds are emptied.
• Avonmouth container terminal — piping, upper deck and prepared-tank checks on feeders within their berth window.
• Avonmouth general cargo and forest-product berths — hold frames, hatch covers and coamings on multipurpose ships.
• Liquid bulk berths — deck and pipe-rack measurements on product tankers under terminal permits.
• Lay-by berths in either dock — longer condition surveys while a ship waits for cargo or a repair slot.

Regulation and trade pressures at the Port of Bristol

The Maritime and Coastguard Agency carries out port state control at Avonmouth and Royal Portbury, applying the Paris MoU's risk-based targeting under UK law. Car carriers have faced closer scrutiny across the industry since a run of serious fires on vehicle carriers, and the growing number of electric vehicles has added to attention on decks and ventilation. Gauging does not address fire risk directly, but wasted deck plating and corroded ventilation trunking are among the things inspectors and charterers look at. Older bulk carriers in the feed trades face the familiar questions about hold frames and tank tops, especially once the ESP extent grows after the ship's third renewal survey.

Ships calling at UK ports are expected to carry an Inventory of Hazardous Materials under the ship recycling rules the UK retained from EU law, and owners often combine the IHM review with a broader condition check when deciding how long to keep an ageing ship. For car carriers trading between Bristol and continental Europe, the EU Emissions Trading System counts half of the emissions on each voyage to or from an EU port, one more reason owners are weighing the remaining life of older tonnage against newer, more efficient ships. A clear record of steel condition makes that decision far easier to take.

Wherever a ship is outside a sulphur emission control area, the global 0.50% sulphur cap applies, and many of the ships calling at Avonmouth meet it with an exhaust gas cleaning system rather than compliant fuel. Scrubber wash-water piping, the overboard discharge and the hull penetration around it corrode quickly in service, especially on open-loop systems, and are worth adding to the gauging scope.

How a thickness measurement job runs at Avonmouth

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

Bristol Airport handles European connections, while long-haul arrivals from India come through London Heathrow and continue by rail to Bristol Parkway or Bristol Temple Meads, then by road to the docks on either bank. The team travels on UK visas, so a first visit needs several weeks of notice. Both docks are ISPS-controlled: the ship's agent requests gate passes in advance, confirms the berth and lock times and, where a terminal runs its own induction, books it before the team arrives.

• 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