DET NORSKE VERITAS (DNV) is an autonomous and independent foundation whose goal is to protect life, property, and the environment at sea and on land. DNV undertakes classification, certification and other verification and consulting services related to the quality of ships, offshore equipment and facilities, and onshore industries worldwide, and conducts research related to these functions.
The DNV 2.7-1 certified offshore container is specifically designed for dynamic hoisting with eye pad devices and DNV certified slings fitted with shackles.
They are checked during the design phase, material procurement, production, and final loading and NDE testing. Not only are prototypes tested, but a specific number of units are randomly selected from each batch for testing at a rate five times the rate of ISO standard container testing.
The containers have a solid steel structure, including floors. They weigh almost twice as much as an ISO container of the same size, which is critical to their ability to maintain an upright position while being transported in rough seas. They must be equipped with DNV approved slings, stronger steel, stricter production specifications and have all the test documentation to prove their reliability in harsh offshore conditions.
Classification societies certify containers
The DNV 2.7-1 certified offshore container is specifically designed for dynamic hoisting with eye pad devices and DNV certified slings fitted with shackles.
They are checked during the design phase, material procurement, production, and final loading and NDE testing. Not only are prototypes tested, but a specific number of units are randomly selected from each batch for testing at a rate five times the rate of ISO standard container testing.
The containers have a solid steel structure, including floors. They weigh almost twice as much as an ISO container of the same size, which is critical to their ability to maintain an upright position while being transported in rough seas. They must be equipped with DNV approved slings, stronger steel, stricter production specifications and have all the test documentation to prove their reliability in harsh offshore conditions.
Classification societies certify containers
- 1. Design evaluation: details of materials, cargo handling, container lifting and cargo tightening inside the cantainer.
- 2. Manufacturing process: certified inspectors authenticate and test raw materials to confirm that welder qualification, welding process and non-destructive carbon damage work meet the requirements
- 3. Test: Four-point lift, two-point lift, tilt test and drop test
Offshore containers should be inspected regularly every year. Regular inspections should be performed on the inside and outside of the container when it is empty. TLS has prepared tips for you to check including:
- Inspection of signs and nameplates.
- Weld inspection of main structural members to confirm that there are no visible defects.
- Inspection of lifting lugs and lashing points for deformation, mechanical damage, or other dangerous defects.
- Inspect all structures for corrosion, deformation, mechanical damage, or other dangerous defects.
- Check the condition of the container floor, including the bottom drainage facilities and drainage holes.
- Check for corrosion and mechanical damage inside the fork pockets (where applicable).
- Check the door, frame, seal, hinge, door lock, etc., and confirm the opening and closing of the door.
To facilitate the loading and unloading of the cargo, the bottom of TLS offshore containers is usually designed with fork pockets, which are required as follows:
1. If provided, the fork pockets shall be arranged in the bottom structure with the top closed to penetrate the bottom and prevent the offshore container from overturning from the fork tine.
2. The net opening size of the fork pocket of the offshore container shall not be less than 200mm×90mm.
3. Considering the length, height, width, and rated weight of the offshore container, the position of the fork pocket should ensure the stability of the container when it is transported by the forklift. The fork pockets should be as far apart as possible, generally not less than 900 mm from the center, but not more than 2,050 mm.
4. The bottom plate of the fork pockets can be closed completely, but openings are recommended for maintenance and to reduce the risk of loose items being left in the fork pockets, thereby preventing items from falling during the lifting process. Where openings are provided, the size and position of the opening should be set to avoid jamming or being damaged by the tines The opening at the bottom of the fork pockets are not allowed at the bottom side rails, and the distance between the opening and the bottom side rails should not be less than 200mm.
5. The weakening of vertical shear strength of bottom side rails by fork pockets opening should be taken into account when calculating the bottom side rails strength. In general, a reinforcement plate should be attached to the top of the bottom side rail. The reinforcement plate should be in the same plane as the bottom side rails web. The reinforcement plate should be extended by at least 100mm at both ends. At this point, the weld between the reinforcement plate and the bottom side rail should be completely melted through.
1. If provided, the fork pockets shall be arranged in the bottom structure with the top closed to penetrate the bottom and prevent the offshore container from overturning from the fork tine.
2. The net opening size of the fork pocket of the offshore container shall not be less than 200mm×90mm.
3. Considering the length, height, width, and rated weight of the offshore container, the position of the fork pocket should ensure the stability of the container when it is transported by the forklift. The fork pockets should be as far apart as possible, generally not less than 900 mm from the center, but not more than 2,050 mm.
4. The bottom plate of the fork pockets can be closed completely, but openings are recommended for maintenance and to reduce the risk of loose items being left in the fork pockets, thereby preventing items from falling during the lifting process. Where openings are provided, the size and position of the opening should be set to avoid jamming or being damaged by the tines The opening at the bottom of the fork pockets are not allowed at the bottom side rails, and the distance between the opening and the bottom side rails should not be less than 200mm.
5. The weakening of vertical shear strength of bottom side rails by fork pockets opening should be taken into account when calculating the bottom side rails strength. In general, a reinforcement plate should be attached to the top of the bottom side rail. The reinforcement plate should be in the same plane as the bottom side rails web. The reinforcement plate should be extended by at least 100mm at both ends. At this point, the weld between the reinforcement plate and the bottom side rail should be completely melted through.
