Fuel Tank Damage Repair Plan for Vessel FALMOUTHBAY at Tianjin Port

On July 18, 2023, during the loading process at Tianjin Port, the vessel 'FALMOUTHBAY' experienced damage to the left side of the bottom of the No. 2 fuel tank due to improper operation by the crane operator. This resulted in a partial fuel leakage. To promptly repair the damage and resume operations, the following repair plan has been established:

1. The ship's crew will utilize the onboard transfer pump to transfer the remaining 150 tons of No. 2 fuel in the tank to other fuel tanks or ship settling tanks until the pump is no longer able to transfer fuel. The specific timing for this operation will be determined based on the pump's displacement and the ship's dynamics. The ship or port authorities will be notified, and the operation is scheduled to commence tomorrow afternoon at 12:00.

2. Once the remaining No. 2 fuel cannot be transferred by the pump (estimated to be approximately 10 tons remaining in the tank), the remaining fuel will be received and processed onshore using an oil reception facility. An oil reception certificate will be issued and delivered to the ship. This process is estimated to take 1 day.

3. Following the completion of fuel reception, continuous ventilation operations will be conducted in the sealed compartments. Mechanical and natural ventilation will be utilized. After thorough ventilation, personnel wearing isolated breathing apparatus will enter the No. 2 compartment to conduct oxygen and explosion testing at selected points using measuring instruments. This is to ensure sufficient oxygen levels, eliminate explosive gases, and meet the requirements for personnel to enter enclosed compartments for work (oxygen content in the compartment not less than 19.5%, combustible gases at 0, toxic gas hydrogen sulfide below 10mg/m3, carbon monoxide below 35mg/m3). Cleaning personnel will then enter the compartment to remove oil residue. Cleaning the tank is more challenging due to the high temperature in summer and the confined space nature of the fuel tank. As per regulations, 1 cleaning personnel will be assigned for every 2 square meters. The operating personnel will carry explosion-proof lighting equipment below 24V. Continuous ventilation (using an explosion-proof fan) must be ensured during the operation. The fan will be clearly labeled with 'Fuel Tank Ventilation, No Misappropriation'. A dedicated safety officer will continuously monitor the safety of the operating personnel, and regular testing will be conducted throughout the operation. If any abnormal conditions arise, the operation should be immediately halted, and personnel should be evacuated. The operation site will be reprocessed, and after sampling and analysis, the operation can resume. This process is estimated to take 4-5 days.

4. Once the tank cleaning operation is completed, ventilation operations will be conducted again. Oxygen and explosion testing will be carried out using measuring instruments until the data meets the requirements for hot work and welding repair operations (oxygen content in the compartment not less than 19.5%, combustible gases at 0, combustible gas concentration always below the lower explosive limit of 1%, toxic gas hydrogen sulfide below 10mg/m3, carbon monoxide below 35mg/m3).

5. A hot work permit will be obtained in advance from the Maritime Bureau to ensure subsequent welding repair operations. Scaffoldings will be erected. The work surface will be cleaned, and qualified personnel with appropriate work certificates will carry out welding repair operations once the requirements are met. The processing of grooves, assembly sequence, positioning accuracy, and assembly clearance of the components should comply with recognized process specifications. Forced assembly should be avoided to minimize internal stress in the components. If it is necessary to correct excessive groove or assembly clearance, the correction method must be approved by the surveyor. Rust, oxide scale, oil, and debris in the groove area should be removed and kept clean and dry. The number of tack welds should be minimized, and the tack welds should have sufficient height. For general strength steel, the length should not be less than 30mm. The quality of tack welds should be equivalent to that of the welds. Defective tack welds should be cleaned before welding. The excess height at the intersection of the butt welds should be ground flat, or holes should be drilled (through holes) across the butt welds to ensure close contact between the components and the plate, thereby ensuring welding quality. If there are butt welds on the belly plate of continuous fillet welds, the butt welds should be welded first, and the excess height at the fillet welds should be ground flat before performing continuous fillet welding. The specific replacement and repair range, as well as the steel grade and thickness, should adhere to the requirements of the classification society and ship drawings.

6. After the welding repair is completed and passes the visual inspection, qualified personnel with non-destructive testing qualifications will conduct ultrasonic testing. The inspection should be carried out as soon as possible, within 24 hours of completing the welding. Surface testing will be conducted according to CB T3958-2004 Ship Steel Weld Magnetic Particle Testing, and penetration testing will be carried out according to the process and quality grading. The acceptance level is Level II, which means that there should be no cracks, lack of fusion, or linear defects with a length greater than 3mm on the surface of the weld. Internal inspection of the weld will be conducted according to CB T3559-2011 Ship Steel Weld Ultrasonic Testing Process and Quality Grading. The inspection level is B level, and the acceptance level is Level II, which means that the wave height is in Zone III, and hazardous defects are assessed as Level V. The allowable indications for a single defect are T/2 with a minimum of 12mm and a maximum of 36mm, which is Level II. After meeting the requirements, verification and certification will be obtained from the classification society.

7. Personnel allocation:

• 1 safety officer
• 1 welder
• 1 onsite driver and emergency personnel
• 10 cleaning personnel
• 2 other auxiliary personnel

8. Material allocation:

• 1 oil reception vehicle
• 2 oil recovery pumps
• 2 explosion-proof auxiliary fans
• 1 220V welding machine
• 2 boxes of welding rods
• 1 piece of welding repair steel plate that meets the ship's requirements
• 2 sets of common tools
• 10 portable oxygen and explosion measuring instruments
• 1 set of magnetic particle testing equipment
• 1 set of ultrasonic testing equipment
• 40 bags of torn cloth and cotton yarn
• 5 buckets
• 2 bags of sawdust
• 5 shovels
• 5 brooms
• 5 garbage bags
• 5 bags of laundry detergent
• 1 set of scaffolding
• 2 safety belts
• 10 explosion-proof flashlights
• 50 cases of drinking water
• 20 boxes of Huoxiang Zhengqi water
• Other labor protection and safety auxiliary tools

9. Safety measures:
10. Configure on-site firefighting equipment, including portable fire extinguishers, buckets filled with clean water, and sand.
11. Provide heatstroke prevention and cooling items on-site, including drinking water and Huoxiang Zhengqi water.
12. Provide on-site emergency medical supplies, such as adhesive bandages.
13. Arrange on-site emergency personnel and vehicles.
14. Assign an on-site safety officer to closely monitor the situation of the operating personnel and eliminate safety hazards.