Ultrasonic Thickness Measurement at Bahrain's Ship-Repair Yard and Ports

Inspection services for ships at Bahrain

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

Where thickness gauging at ASRY and around Bahrain takes place

The bulk of the work is done at the ASRY ship-repair yard, either in dry dock or at the repair berths before and after docking. Thickness measurement at Hidd starts, where possible, before the ship enters dock: readings taken at anchorage or at the repair berth let the superintendent and the yard agree steel quantities early, which protects the docking schedule. In dock, we follow the yard's sequence of tank cleaning, ventilation and staging, report substantial and excessive corrosion as each tank is completed, and return for confirmation readings once new steel is fitted.

Away from the yard, container ships calling at Khalifa Bin Salman Port can have piping, deck and limited tank gauging during longer stays, and product tankers lying idle off Sitra can be gauged at anchorage with launch access through the agent. Tugs, workboats and supply vessels working in Bahraini waters are gauged at their own berths or during their docking periods when their renewal surveys come round. The short distances on the island mean a team at the yard can usually reach a second vessel at the port or an anchorage launch point on the same day.

• ASRY dry dock — full renewal-survey programmes on VLCCs, Suezmaxes, gas carriers and bulk carriers, including the ESP extent in cargo and ballast tanks
• ASRY repair berths — pre-docking gauging and afloat tank readings before the ship enters dock, plus confirmation readings after steel renewal
• Khalifa Bin Salman Port — piping, deck and hatch-coaming gauging on container and general cargo ships during port calls, with ISPS passes via the agent
• Off Sitra and the refinery terminal — condition gauging on product tankers between cargoes, within the terminal's permit system
• Bahrain anchorages — pre-purchase and on-hire gauging on tankers and bulkers lying at anchor ahead of an ASRY slot or awaiting orders
• Workboat and offshore craft berths — renewal-survey gauging on tugs, crew boats and offshore support craft working in the central Gulf

Port state control, ESP surveys and Bahrain's role in the Gulf

Bahrain belongs to the Riyadh MoU, and ships calling at its ports are inspected under that regime. Many of the ships docking at ASRY are crude and product tankers or bulk carriers in the ESP category defined by SOLAS chapter XI-1 regulation 2, with the 2011 ESP Code setting the survey programme, so the extent of gauging is set by IACS UR Z10.1, Z10.2, Z10.4 or Z10.5 depending on ship type, and increases markedly from the third renewal survey onwards. Getting the TM plan right before the docking, with compartments, sections and points agreed at the survey planning meeting with the attending surveyor, is one of the biggest factors in keeping the yard schedule.

There is no emission control area in the Gulf, so MARPOL Annex VI's 0.50% global sulphur cap applies, and scrubber-fitted tankers and bulk carriers docking at ASRY can have their wash-water and overboard piping measured while the system is shut down. The central Gulf's climate is hard on ships: shallow, warm and highly saline water, intense summer heat on decks and humid nights accelerate coating breakdown in ballast tanks and corrosion of deck structure. Bahrain's position between Saudi Arabia, Qatar and the UAE, and its road link to the Eastern Province, also make it practical for owners combining a docking with port calls across the region.

Wherever a ship is outside a sulphur emission control area, the global 0.50% sulphur cap applies, and many of the ships calling at Bahrain meet it with an exhaust gas cleaning system rather than compliant fuel. Scrubber wash-water piping, the overboard discharge and the hull penetration around it corrode quickly in service, especially on open-loop systems, and are worth adding to the gauging scope.

How a thickness measurement job runs at Bahrain

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

Technicians arrive at Bahrain International Airport (BAH) on Muharraq, which is served directly from several Indian cities and lies close to Hidd; King Fahd International Airport in Dammam, reached over the causeway, is an alternative when the team is coming from a job in Saudi Arabia. The owner's site team sets up yard access at ASRY, Khalifa Bin Salman Port requires ISPS passes arranged by the agent, and anchorage work needs a launch. Bahraini visas are sorted out before the team travels, which is why we like to confirm the job the moment the docking slot is booked.

• 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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