Ultrasonic Thickness Measurement for Container Ships at Felixstowe

Inspection services for ships at Felixstowe

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

Where gauging is done in the Haven ports

At Felixstowe, the team boards through the terminal's ISPS gate and works while cranes are moving, which closes some areas and opens others. Hatch covers and coamings can be reached between crane moves on bays already worked; engine-room and scrubber piping is unaffected by cargo; and tanks can be entered when the chief officer's ballast plan allows one to be emptied and ventilated without affecting stability during cargo operations. Because the terminal is a busy working quay, the ship's officers and the terminal both need to know where the team is at all times.

Harwich and Ipswich offer different windows. Ro-ro and freight ships at Harwich work to timetables that a superintendent can plan around, and bulk carriers loading grain or discharging aggregates at Ipswich are often alongside long enough for holds and tanks to be gauged in sequence. Thickness gauging at Harwich and Ipswich can therefore go deeper into tank structure than a single container call allows. Ships waiting for a berth sometimes anchor off the Haven, which allows launch-borne access through the agent in suitable weather, although the southern North Sea can close that option quickly.

• Port of Felixstowe deep-sea berths — hatch coaming, upper-deck and lashing bridge inspection, plus scrubber and sea-water piping UT, during the cargo window.
• Felixstowe feeder and short-sea berths — gauging on smaller container ships, which can include older ships approaching their renewal surveys.
• Harwich International — ro-ro and freight ferry structure, vehicle decks and ramps, inspected around fixed sailing schedules.
• Port of Ipswich — hold, hopper and tank gauging on bulk carriers loading grain or discharging aggregates over several days alongside.
• Anchorages off the Haven — short launch-borne scopes on ships queued for a Felixstowe berth, called off quickly if the North Sea gets up.

Regulatory and market context for container ships calling at Felixstowe

Felixstowe lies well inside the North Sea SOx Emission Control Area, so the ships here either burn 0.10% sulphur fuel or run scrubbers. Large container ships were widely fitted with exhaust gas cleaning systems, many of them around the start of the global 0.50% sulphur cap in 2020, and those systems have now been in service for several years. Wash-water and overboard piping, the scrubber casing and the overboard valve area are where wear shows first, and wall-thickness readings help a technical department decide whether to repair at the next call or plan renewal at the next docking.

Port state control at Felixstowe is the Maritime and Coastguard Agency's responsibility, and the UK has applied the Paris MoU regime under its own law since leaving the EU; a container ship with corroded lashing bridges or a leaking overboard line is an obvious inspection finding. Commercially, a good share of the container ships calling here are chartered from non-operating owners to liner companies, so on-hire and off-hire condition records matter, and a Felixstowe call on the way into or out of a charter is a practical place to take them. Voyages between Felixstowe and EU hubs such as Rotterdam or Antwerp also count half their emissions under the EU ETS.

Ships trading to Felixstowe 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 Felixstowe

A gauging job at Felixstowe 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 ship inspection in Suffolk the team flies into Heathrow, Stansted or London City and travels to Felixstowe by road; Stansted is the closest of the London airports to the Haven ports. Felixstowe, Harwich and Ipswich each run ISPS-controlled gates, and the ship's agent requests passes before the call; anchorage work needs a launch arranged the same way. Our technicians come from India on UK visas, so we work from the liner schedule, book the call we will join early, and keep a later rotation in reserve in case the first one slips.

• 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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