Ultrasonic Thickness Measurement for Coasters at the Port of Pärnu

Inspection services for ships at Pärnu

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

Where coasters are gauged at Pärnu

All of our Pärnu work is planned alongside at the river quays. Timber and peat coasters are measured hold by hold before loading begins or during pauses, with hatch covers, coamings and deck plating done while the cargo is being brought to the quay. Ballast tanks and the double bottom are entered once the crew has ventilated them and issued an entry permit. On these small ships the plating is thin and corrosion gathers in the lower holds, the ballast tanks and around the hatch coamings, so the reading pattern is dense and every reading is tied to a frame number on the sketch.

We do not plan dockings at Pärnu, so the coasters that trade here go elsewhere when they need one: Tallinn Shipyard on Estonia's north coast, or repair yards in Klaipėda, Gdańsk and other Baltic ports that take small cargo ships. A Pärnu call is useful as the step before: the owner can have the ship measured, receive a steel estimate and ask yards to plan the work on real figures rather than guesses. Anchorage work in the shallow bay is not something we plan.

• River cargo quays — timber, wood-product and peat coasters; hold, hatch cover and ballast-tank gauging during loading
• Quays handling general and bulk imports — small general cargo ships; hold and tank-top measurements as the cargo is discharged
• Ships waiting on the river for a cargo — owner's condition or pre-purchase gauging arranged through the agent
• Repair yards in Tallinn, Klaipėda or Gdańsk — in-dock verification of readings taken first at Pärnu

Inspection, ice and the coaster trade from Pärnu

Pärnu is an Estonian port, so port state control is carried out by the Estonian Transport Administration as part of the Paris MoU. General cargo coasters are not among the regime's highest-risk ship types, but age and a poor inspection record raise a ship's risk profile, and many of the coasters calling here are old enough for that to count. Deficiencies on ships of this kind often involve hatch covers, corroded air pipes and vents, and structural wastage in holds and ballast tanks, which is exactly what a sensible gauging scope covers. Owners who know their ship's condition before an inspection are better placed to answer an inspector's questions.

The timber and peat trades bring their own wear. Timber deck cargoes put lashing loads into deck plating, coamings and lashing points, peat is acidic and its wet dust settles in hold corners, and repeated loading by grab or loader damages hold sides and tank tops. In winter, ice in Pärnu Bay and the Gulf of Riga wears the bow and waterline, and the ice restrictions for the port decide which coasters can keep trading through the cold months. Ships calling from outside the EU need an Inventory of Hazardous Materials on board under the EU Ship Recycling Regulation, a document that matters when an older coaster is sold or finally goes for recycling.

Ships trading to Pärnu 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 Pärnu

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

The team flies into Tallinn Airport, or Riga Airport across the Latvian border, and drives to Pärnu, which lies on the main road between the two capitals. Estonia and Latvia are both Schengen states, so one Schengen visa covers our technicians from India on either route, and we apply as soon as the loading date is firm. The ship's agent arranges access to the river quays. Because coaster schedules shift with weather and cargo readiness, we stay in close contact with the agent in the days before boarding.

• 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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