Thickness Gauging at Södertälje for Car Carriers, Ro-Ro Ships and Mälaren Traders

Inspection services for ships at Södertälje

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

Where gauging fits in at Södertälje

Södertälje is a cargo port, not a repair harbour, so gauging is done afloat at the berths. At the vehicle terminal the useful time comes after discharge, when the car decks are empty and the ship can provide lighting and safe access to ramps and liftable decks. Container and general cargo quays give shorter windows suited to hatch covers, scrubber lines and selected tanks. Tankers at the oil product berths work under terminal rules, and any entry is limited to ballast tanks, voids and deck structure that the ship can make gas-free and permit for entry.

Ships needing a docking go to yards elsewhere, usually around the Baltic, and the lake traders in particular are often docked during the summer, away from the ice season. Södertälje is therefore most useful for pre-docking estimates, owner's condition gauging and targeted scopes in service. The lock transit itself is no time to work; the team boards at a berth, either in the port or at the next lake port of call if the ship is heading on to Västerås or Köping. Laid-up or idle ships lying at quays in the area give the longest windows for complete condition surveys.

• Vehicle terminal — car-deck, ramp and lashing-point gauging on car carriers and ro-ro ships once discharge is complete.
• Container and general cargo quays — hatch covers, holds and scrubber piping measured within the berth window.
• Oil product berths — ballast tank, void and deck readings on tankers during discharge, within the terminal's rules.
• Quays used by idle or laid-up ships — longer condition and pre-purchase gauging spread over several days.
• Mälaren ports beyond the lock — gauging continued at Västerås or Köping when the ship's next discharge is there.

Rules, ice and fresh water on the Mälaren route

Port state control at Södertälje follows the Paris MoU and is carried out by the Swedish Transport Agency, and the same applies at the lake ports beyond the lock. Ships flying a non-EU flag must carry an Inventory of Hazardous Materials when they call at an EU port under the EU Ship Recycling Regulation, a point worth checking on older coasters and car carriers that have been bought second-hand from outside Europe. Car carriers in the Swedish import trade are also part of the fleet that owners are reassessing as electric vehicles grow in share: heavier units place more load on deck plating and stiffeners, and fire-safety changes add structure that needs a baseline.

Winter navigation on Mälaren is managed by the Swedish Maritime Administration, which keeps the fairways open with icebreakers and can set ice-class requirements for ships trading into the lake when conditions are severe. Owners of lake traders therefore keep Finnish-Swedish ice class and maintain the ice belt accordingly. Fresh-water ballast changes the corrosion picture inside tanks without making it disappear: coatings still break down at edges, welds and stiffener toes, and sediment collects in the bottom of tanks that alternate between lake and sea water. Thickness readings in those areas, compared from survey to survey, show the rate at which a lake trader is actually losing steel.

Ships trading to Södertälje 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 Södertälje

A gauging job at Södertälje 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.

Stockholm Arlanda is the international arrival point, and Södertälje is reached by commuter or regional train from Stockholm, or by road. The team travels from India on Schengen visas, which also cover any onward travel to the lake ports or to a docking yard elsewhere in the Schengen area. Access to the vehicle, container and oil berths is controlled under ISPS, so the ship's agent registers the technicians with the terminals before the call, and for lake traders the agent also confirms where the ship will berth after the lock.

• 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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