Hull and Hold Thickness Measurement for Forest Product and Container Ships in Sundsvall

Inspection services for ships at Sundsvall

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

Gauging at Tunadal and the other Sundsvall berths

Tunadal is where most ships calling at Sundsvall now berth, and it offers room alongside for a team to work around cargo operations. On forest product ships, holds are gauged as the loading plan reaches them, with tank tops, frames and lower bulkheads measured and any cargo-handling damage recorded before the first units go in. Container ships offer shorter windows, suited to hatch covers, coamings, scrubber lines and selected ballast tanks. Smaller quays around the bay serve local industry and are useful for coasters and general cargo ships lying for longer periods.

Sundsvall has no drydock for seagoing ships, so dockings take place at yards elsewhere, around the Baltic or beyond, chosen by the owner and frequently planned for summer when the ice has gone. That makes Sundsvall a natural place for pre-docking gauging: readings taken during a loading show where steel renewal is likely, so the yard specification and the surveyor's close-up plan can be prepared in advance. In winter, work on open decks and the external shell is slowed by frost, wind and short days, while measurements inside holds, tanks and machinery spaces carry on largely unaffected.

• Tunadal container and breakbulk port — hold, tank-top and hatch cover gauging on forest product ships during loading.
• Tunadal container berths — hatch covers, coamings, scrubber lines and selected ballast tanks on feeders within the berth window.
• Industrial quays around the bay — hold and ballast tank measurements on coasters and general cargo ships serving local industry.
• Ships lying idle between cargoes — full condition and pre-purchase gauging over several days.
• Docking yards around the Baltic — completion of renewal survey programmes, built on readings taken in Sundsvall.

Ice-class rules, cargo care and regulation at Sundsvall

Ships calling at Sundsvall are inspected under the Paris MoU by the Swedish Transport Agency. In winter the Swedish Maritime Administration sets traffic restrictions for ports along the Bothnian Sea when ice forms, and only ships meeting the minimum ice class and size receive icebreaker assistance. For owners, that turns ice class into a commercial asset for the forest trade, which ships out through the winter. Keeping it means the ice belt and the frames behind it must remain within the margins of the Finnish-Swedish ice-strengthening rules, and wastage or damage found at a spring gauging is usually repaired at the summer docking.

Forest product shippers are demanding customers. Pulp, paper and sawn timber must arrive dry and undamaged, so charterers look closely at hatch covers, coamings, cross-joints and drainage, as well as at holds free of sharp edges and loose scale. Thickness readings on hatch cover plating and coaming structure, together with a record of tank-top and frame condition, give an owner evidence of a well-kept ship when a contract is renewed. Ships under non-EU flags also need an Inventory of Hazardous Materials on board under the EU Ship Recycling Regulation, and the larger ships in this trade now report emissions under the EU ETS.

Ships trading to Sundsvall 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 Sundsvall

A gauging job at Sundsvall 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.

Most teams fly into Stockholm Arlanda and continue on a domestic flight to Sundsvall-Timrå Airport, north of the city, or travel north by train along the coast. Technicians come from India on Schengen visas, applied for once the loading date is known with reasonable confidence. Port access at Tunadal and the other terminals is controlled, so the ship's agent registers the team before the call. For winter jobs we plan travel with some margin, because ice can delay arrival and short daylight limits the working day on deck.

• 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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