Ship Thickness Measurement and Hull Gauging in Helsinki

Inspection services for ships at Helsinki

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

Where gauging is done in and around Helsinki

Most gauging in Helsinki happens alongside. On the passenger harbours, work is fitted into the hours when vehicle decks are empty and tanks have been ventilated and certified safe by the ship's crew. At Vuosaari, deck and hold work runs in parallel with cargo operations, with the terminal's safety rules and the stevedores' plan setting the order. Ships at anchor are reached by launch, which in winter depends on ice and weather on the day. For ferries, the useful unit of work is one lay-by: we size each visit so that a complete deck, tank group or drainage section is closed off before the ship sails, rather than leaving half-measured areas to be picked up later.

Dry-docking is a different matter. The yard at Hietalahti concentrates on icebreakers and other ice-going newbuildings, and many ferries and cargo ships trading from Helsinki are docked at repair yards elsewhere around the Baltic. Gauging in Helsinki before the ship leaves gives that yard a measured steel list instead of an allowance, and lets the owner compare yard offers on the same basis. Ultrasonic thickness gauging in Finland before the ship sails also means the surveyor at the yard starts from known figures.

• West Harbour and Katajanokka — Tallinn and Stockholm ro-pax, gauged in stages during night lay-bys or scheduled service breaks
• South Harbour — overnight Stockholm ferries with a working day alongside; vehicle decks, ballast tanks and voids gauged between arrival and departure
• Vuosaari Harbour — container, ro-ro and Germany-route ro-pax ships; deck, hatch-cover and accessible tank gauging during cargo operations
• Katajanokka icebreaker berths — state icebreakers resting through the summer; hull and ice-belt gauging during their maintenance season
• Hietalahti — Helsinki Shipyard's site for ice-going newbuildings; repair and conversion work there can call for UT of welds and crack detection
• Anchorages off Helsinki — ships waiting for a berth or ice escort; gauging teams transferred by launch when ice and weather allow

Ice class, SECA and port state control in Helsinki

Finland is a Paris MoU state, and ships calling at Helsinki are targeted for inspection according to their Paris MoU risk profile, so older tonnage with a history of structural deficiencies sees more attention. Since 1 January 2015, fuel used in the Baltic SOx Emission Control Area has been limited to 0.10% sulphur, and Baltic ro-pax and ro-ro operators answered it with a mix of compliant fuel, LNG propulsion and exhaust gas scrubbers. Where scrubbers are fitted, the acidic wash-water and overboard discharge lines become a gauging item in their own right. Voyages between Helsinki and other EU ports are fully inside the EU ETS for shipping, which applies from 2024, and FuelEU Maritime from 2025; both make owners of older ferries think hard about steel renewal against replacement, and the gauging record is the factual basis for that decision.

Ice class is the local constant. The Finnish-Swedish Ice Class Rules set the classes IA Super, IA, IB and IC, and each winter the Finnish authorities publish traffic restrictions that limit which ice classes and sizes may call at each port and receive icebreaker assistance. Keeping a ship's ice class means keeping ice-belt structure within the class requirements, and the ice-class scantling formulas include an addition for abrasion and corrosion that the winter steadily consumes. Ice belt thickness measurement each spring tells the owner how much of that addition is left.

Ships trading to Helsinki 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 Helsinki

The sequence for a thickness measurement job at Helsinki is short and written down, so the yard, the surveyor and the superintendent know who arranges what.

Our team flies into Helsinki-Vantaa Airport and reaches the passenger harbours, Vuosaari or Hietalahti by road. Port access is arranged through the ship's agent: ISPS gate passes for terminal berths, and a launch for ships at anchor. Finland is a Schengen country, and the visa our technicians need has to be applied for well before the job; we fix dates against the ship's docking or lay-by window as early as possible. In winter we also allow for ice and short daylight when planning any external hull work.

• 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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