Cord layers: 4,5,6,7,8,9,10, layers
Accessories: Pressure gage, Inlet valve, Pipe fitting and seal end ring.
1) Choose the best quality of imported natural rubber, such as smoked sheet rubber and 3L natural rubber form Thailand and Malaysia, which has good elasticity, ageing resistance. And will not take off layer. Meanwhile, During the process of produce rubber, we using efficient stabilizer to make rubber more environment friendly and no cracks.
|No||Test item||Required value||Test method|
|1||Tensile strength, MPa||>=18||ISO 37|
|2||Elongation at break, %||>=400||ISO 37|
|3||Hardness, (Shore A)||60±10||ISO7619-1|
|4||Tear Strength, N/cm||>=400||ISO34-1|
|5||Compression set, %(70ºC±1 ºC 22h)||<=30||ISO815-1|
|6||After thermal ageing at 70ºC±1 ºC, 96h||Holding of pull lengthening, %||>=80||ISO188|
|7||Holding of elongation at break, %||>=80||ISO188|
|8||Change of hardness, (Shore A)||<=8||ISO7619-1|
|9||Static ozone aging test at 40ºCx96h||No crack||ISO1431|
Standard size of Marine Rubber Airbags:
Diameter (D): 0.8m-2.0m
Effective length (EL): 6.0m-18m
Total Length (TL): 7m-20m
Cord layers: 4,5,6,7,8,9,10, layers
|Medium Pressure |
|Test Pressure ||0.14-0.16||0.12-0.14||0.10-0.12||0.08-0.10||0.07-0.09|
|Working Pressure ||0.12-0.14||0.10-0.12||0.08-0.10||0.07-0.09||0.06-0.08|
|Test Pressure ||0.22-0.26||0.20-0.24||0.15-0.20||0.13-0.16||0.12-0.15|
|Working Pressure ||0.20-0.24||0.17-0.22||0.13-0.18||0.11-0.14||0.10-0.13|
Ship Launching Process
All obstacles shall be cleared along the way of the airbags, including the ship bottom.
The now of the ship shall be tied to the windlass with mooring steel wire ropes. One end of the steel wire rope shall be tired to the strength member of the ship such as a bollard or a special horn, the other end shall be tired to the pulley set of the towing system.
Airbags shall be placed underneath the ship
The airbags are to be filled from the stern to the bow. Initially, the airbags are not to be fully inflated. Having inflated all airbags and ensured that they made contact with the ship's bottom, the airbags shall be filled to the specified pressure (0.10Mpa-0.11Mpa).
When the ship bottom is lifted higher than the docking blocks and the airbags are removed, adjust the internal pressure of the airbags to make the force balance.
After the workers and other personnel who are going to stay on board during the launching have boarded the ship, remove the ladders and gangways and so on.
All the airbags should be centered the ship and upright to the launching operation.
Start the towing winch to release the ship slowly. When the first airbag leaving from the bow, move it to the stern and place it at the planned position. Repeat the former process until move ship to the sea shore.
Depending on the conditions of slipway and area water, one of the following launching methods may be used:
If the area water is wide enough, one can launch the ship by moving the ship to the water,s edge, disengage the windlass, remove or cut the tow line and let the ship slides into the water by itself.
If the area water is not wide enough, use the windlass to control the launching speed and let the ship glide into the water slowly.
If the stern of the ship is built directly over the water and no windlass is available, the ship shall be secured to the ground anchor by the rope before filling the airbags. The minimum water depth needed for launching is to be calculated. The ship may be launched by herself into the water by cutting off the rope or letting off the ground anchor when there is enough water length.
If the ship is very large, it is necessary to install the slip stopper.
After use, all airbags shall be reclaimed.
Ship Lifting Process
The ship should be fasten with guy rope or cable attached firmly with the winch.
After the ship fasten with winch, choose a reasonable position near the bottom of bow to insert one or more airbags which act as the fulcrum for winch to move the ship when inflated and life the bow. If it is difficult to insert airbags at the bottom of bow, we can also insert airbags from one side to another side. However, for heavy ship, the quantity of bow lifting airbags should be added until they can lift the bow. For V shape bow ship, the bow lifting airbags should be insert at the position where they can have bigger contact area with the bottom of ship. Beside that, we can also place the airbags at the appropriate positions at low tide and pull the ship upon airbags at high tide, then inflate airbags to lift the ship. In one ward, the ship landing process should be depend on the actual situation.
When the ship,s bow is lifted, people should start the winch to pull ship towards land and insert more airbags to the space between ship bottom and land until the full ship is pull upon the slipway.
Adjust the airbags' pressure to lift ship bottom higher, then insert the docking blocks and withdraw the airbags.
After use, the airbags should be cleaned up and dried in the sun, then they should be coated with talcum powder to store in dry place.