Thickness Measurement for London Ship Managers and Thames Terminals

Inspection services for ships at London

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

Where gauging happens on the Thames and how London jobs are set up

Ultrasonic thickness gauging on the Thames is almost always done alongside, because nearly every working berth on the river is a quay or a jetty; launches are needed only for ships in the estuary anchorages. Tide shapes the day. The Thames has a large tidal range, and at the upriver wharves a ship can sit low against the quay at low water, which changes gangway access and how quickly the team reaches upper-deck structure such as hatch coamings and crane pedestals. The cargo plan matters even more than the tide, since holds and tanks become available in the order cargo comes out.

For London-managed ships outside the UK, the facility that matters is the report rather than the berth. A thickness report laid out on the class TM formats, with readings tied to the frame and strake references on the ship's own drawings, lets a superintendent compare this survey with the last renewal survey without re-keying anything. We agree that reference system, the scope and the deliverables with the London desk before the team travels, so the readings go straight into the ship's planned maintenance and survey records.

• DP World London Gateway — in-service gauging of container ships during cargo windows: upper deck, hatch coamings, lashing bridges, and scrubber and sea-water piping in the engine room.
• Port of Tilbury and Tilbury2 — ro-ro and bulk ships alongside long enough for vehicle-deck plating, ramp-hinge crack detection and cargo hold gauging between discharges.
• Upriver aggregate and bulk wharves — hold and hopper gauging on aggregate dredgers and bulk carriers working cargo at riverside berths, planned around the tide.
• Lower Thames fuel and liquid bulk jetties — deck and external piping gauging on product tankers, with tank entry only when the terminal and master confirm gas-free status.
• Thames Estuary anchorages — deck and air-pipe readings on ships held outside the river for a berth or the tide, with the launch booked by the agent.
• Owners' and managers' technical departments in the City — where scope, TM plans and drawing references are agreed before the team travels to the vessel.

Regulation, vetting and insurance pressure in a London context

Ships on the Thames are inside the North Sea and English Channel SOx Emission Control Area, so they burn 0.10% sulphur fuel or run an exhaust gas cleaning system. Scrubber-fitted container ships and bulk carriers calling at London Gateway and Tilbury are natural candidates for wash-water and overboard pipe gauging, because wastage there concentrates where acidic wash water meets the overboard valve and shell penetration, which is hard to see from inside. On the Thames, as at every UK port, inspections of foreign ships are the Maritime and Coastguard Agency's responsibility. Since Brexit the UK has run PSC under its own legislation while remaining a Paris MoU member, and a thin deck or a holed air pipe on an older ship is exactly what an inspector looks for.

The London market adds commercial reasons to gauge that have nothing to do with the river. Oil-major vetting under OCIMF's SIRE 2.0 regime and charterers' requests for CAP ratings drive tanker gauging. Hull and machinery underwriters and P&I clubs ask for condition evidence on older tonnage before cover is placed or renewed. Charter-party disputes heard before London arbitrators can turn on the condition a ship was in at delivery or redelivery, and contemporaneous thickness records are among the few objective data points either side has.

Ships trading to London 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 London

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

For Thames work the team flies into Heathrow, Gatwick, Stansted or London City, depending on which bank and how far downstream the berth lies, and continues to the terminal by road. London Gateway, Tilbury and the river wharves all operate ISPS-controlled gates, so the ship's agent arranges passes against the technicians' names and passports; estuary anchorage jobs need a launch booked the same way. Our technicians travel from India on UK visas, which are applied for once the job is scoped, so we ask for the vessel's schedule as early as it is known.

• 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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