Ship Launching Airbags, also known as roller bags or ship launching balloon, are made of heavy-duty synthetic-tire-cord layers with inner and out rubber layers in long cylindrical balloon shape. Ship launching airbags can be used for the ship launching or ship landing of tanker, tugboat or barges, carrying vessel, carrier, ferry and other special vessels (AHTS, DSV) and so on. The biggest vessel launched by ship launching airbags up to 85,000 DWT.
Ship Launching Airbags Performing
Ship launching relying on ship launching airbags is a innovative ship launching technology, comparing with “end-on launching”, “side ship launching”, “float-out”. This ship launching technology overcomes the restrictions of fixed launching track of side-launch. Ship launching airbags are accepted by more more shipyard world wide because of its advantages of saving time, saving investment, flexible, safety.
Construction Features of Ship Launching Airbags
Ship launching airbags are to be constructed of an out rubber layer, multilayer heavy-duty synthetic-tire-cord layers, and an inner rubber layer vulcanized firmly. Ship launching airbags are cylindrical balloon body, with two conical head and end mouth. Air tightness swivel and air inlet kits are screwed with end mouth.
1.warp 2.weft
• Synthetic-tire-cord layer is reinforcement layer of the ship launching airbags which are made of rubber coated synthetic-tire-cord fabrics. Many synthetic-tire cord layers are twined at ideal angles by unique and patented “Holistic Wrapping Technology“. To hold the internal pressure and to distribute the stress evenly. Evergreen Maritime use the 1870 dtex/2 type synthetic-tire-cord fabric. The warp is over 95 cords per 100 mm in width. The breaking strength is more than 310 N per cords.
• The outer rubber layer covers the outside of ship launching airbags. To protects the cord layers from abrasion and other external forces. This compound has sufficient tensile and tear strength to withstand any weather condition and hard usage.
Our properties requirements of outer and inner rubber material comply with ISO 14409.
Classification of Ship Launching Airbags
Ship launching airbags are categorized by “ordinary airbags”, “high-bearing capacity airbags”, and “Super-high-bearing capacity airbags” according to the bearing capacity. We use “YT” as the type code.
• YT-QP Ordinary airbags — the air bag with 3, 4 or 5 layers of cord fabric • YT-QG High-bearing capacity airbags — the air bag with 6, 7 or 8 layers of cord fabric • YT- QS Super-high-bearing capacity airbags — the air bag with 9, 10 or more layers of cord fabric
The standard diameter of ship launching airbags (D) varies such as 0.8m, 1.0m, 1.2m, 1.5m, 1.8m and 2.0m, etc. The standard effective length of air bag (EL or L) is from 6m to 18m, which should be specified by the user. Other specification ship launching airbags also can be supplied upon request.
Ship Launching Airbags Performance Parameters
The follow show the performance of YT-6 (6 layers type), 7 layers, 8 layers, 9 layers, and 10 layers ship launching airbags. For the performance of over 10 layers airbags, please feel free to contact with us.
Note: 1. Rated working pressure may deviate ±5%. Compress deformation may deviate ±2%. 2. For the bearing capacity at different compress deformation, please refer our catalogue.
Acceptance Test for Commercial Ship Launching Airbags
Evergreen Maritime test the ship launching airbags purchased based on the test items indicated below:
• The appearance of each Evergreen Maritime ship launching airbag is smooth, glossy and without blemish such as crack, blister, delamination, pits or impurities.
• The length and diameter of each Evergreen Maritime ship launching airbags are measured with the rated working pressure and is within ±3%.
• The gas-tightness is tested without carrying any load as per ISO 14409. The pressure loss is less than 5% of rated working pressure within 1 hour.
Evergreen Maritime ship launching airbags are type approved. This means we have demonstrated the performance of ship launching airbags to independent inspectors CCS. Type Approval Test is the essential and necessary qualification of qualified manufacturer of ship launching airbags. In addition to the requirements for the material, appearance and dimensional tolerances, “Gas-tightness Test”, “Compression Test”, “Bearing Capacity Test”, “Bursting Test”, and “Compression-recovery Test” are carried out.
All Evergreen Maritime ship launching airbags are manufactured and tested comply with ISO 14409 “Ships and marine technology – ship launching air bags“, certificated by CCS, LR, DNV. There are two more China industrial standards and one ISO standard for ship launching airbags:
— CB/T 3837-1998 Technological Requirements for ship Upgrading or Launching Relying on Airbags (Shipbuilding Industry Standard, PRC) — CB/T 3795-1996 / CB/T 3795-2009 Air bag for ship up to or down to launching way (Shipbuilding Industry Standard, PRC)
— ISO 17682 Ship sand marine technology —Methodology for launching ship utilizing air bags
