Ship Launching Airbags

Ship launching airbags, known as roller bags or ship launching balloons, are made of heavy-duty synthetic-tire-cord layers with inner and out rubber layers in a long cylindrical balloon shape. Ship launching airbags can be used for the ship launching, ship launching work.

Ship launching or upgrading using marine airbags is an innovative ship launching technology. It overcomes the disadvantage of “end-on launching”, “side ship launching”, “float-out”. This ship launching technology overcomes the restrictions of the fixed launching track of side-launch.

This flexible ship launching technology is accepted by more shipyards worldwide because of its advantages of saving time, saving investment, flexibility, safety. DOOWIN is constantly innovating in terms of design, material usage, & manufacturing technologies throughout the years to ensure flexibility, safety, and reliability.

Up to now, more cargo vessels, barges, chemical tankers, tugboats, AHTS vessels, floating docks, and even construction caissons have all been launched using our rubber airbags. The biggest vessel launched by ship launching airbags up to 100,000DWT.

DOOWIN ship launching airbag is the No.1 choice by companies in Southeast Asia, Europe, Turkey, Middle-East, North America, Africa, South America.

ship launching airbags

— ISO 14409:2011 Ships and marine technology — Ship launching air bags
— ISO 17682:2013 Ships and marine technology — Methodology for ship launching utilizing air bags
— CB/T 3795-2009 Air bag for ship up to or down to launching way (Shipbuilding Industry Standard, PRC)
— CB/T 3837-2011 Technological Requirements for ship Upgrading or Launching Relying on Airbags (Shipbuilding Industry Standard, PRC)

Construction Features of Ship Launching Airbags

Rubber airbags are constructed of an out rubber layer, multilayer synthetic-tire-cord layers, and inner rubber layer vulcanized firmly. Rubber airbags are cylindrical balloon body, with two conical head and end mouth. Swivels and air inlet kits are screwed with end mouth.

rubber airbags-structure

Synthetic-tire-cord layer

  • 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. DOOWIN 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.

synthetic-tire-cord layers
Donot be mislet by low price, which use recycled rubber, weak cords with lower number of true layers and more.

Inner and Outer Rubber

  • Prior to the air bag production, the outer and inner rubber layers shall be tested to meet the criteria in accordance with the test methods given in the International Standards listed below.

    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.

No. Test Item Value Standard
1 Tensile Strength, Mpa ≥ 18 ISO 37
2 Elongation at break, % ≥ 400 ISO 37
3 Hardness, ° (shore A) 60±10 ISO7619
4 Tear strength, N/cm  ≥ 400 ISO34-1
5 Compression set, % (70℃±1℃,22h) ≤ 30 ISO815
6* Holding of pull lengthening, % ≥ 80 ISO188
7* Holding of elongation at break, % ≥ 80 ISO188
8* Change of hardness, ° (Shore A) ≤ 8 ISO7619
9 Static ozone aging at 40℃ x 96h, extension 20% No crack ISO1431

*After thermal ageing at 70℃±1℃, 96 h

Ship Launching Airbags Specification

From the raw materials to the highly skilled production process, our engineering team constantly improves. 

compressed-ship-launching-airbag

Lifting Capacity Principle

The bearing capacity of ship launching airbags were calculated based on the working pressure, contact area. Herein, working pressure was got upon the burst pressure and safety working factor.

Because of the flexibility of rubber airbag, the contact area will be effected by some terms. It inludes carried shipcondition, the different position from gravity center during the process of ship launching and landing. So the bvearing capacity of rubber airbags will vary as well as the contact area.

The approximate bearing capacity can be calculate as follows:

F=PS    S=π x (D-H)/2

Where:

F is the bearing capacity
P is the working pressure
S is the contact area
P is the percentage of deformation (%);
D is the original diamater of the air bag (m);
H is the height of the compressed air bag (m)

rubber air bags pecification

Ship Launching Airbags Lifting Capacity

Ship Launching Rubber Airbags Accessories

DOOWIN PVC ship launching airbags provide the perfect solution for the light light-weight boat. Their strength, durability and excellent resistance to extreme conditions, makes them ideal as ship launching airbags.

rubber ballon accessories

1. The end of airbag body                                               2. End flange (Q235 H.D.G)
3. Sealing Washer to strength the tightness                4. Three-direction connector at the inflate end (Q235 H.D.G)
5. 3/4′ Ball Valves at the inflate end (Brass)                 6. Hose connection at the inflate end (Q235)
7. High quality Pressure Gauge at the inflate end.      8. End plug at the tightness end (Q235 H.D.G)

Ship Launching Video

Why DOOWIN rubber airbags?

THREE-OUR OWN! The whole production process is under ISO 9001:2008 control.
From the raw materials to the highly skilled production process, our engineering team constantly improves.
DOOWIN rubber roller are manufactured and tested to comply with ISO 14409, certificated by CCS, LR, DNV.

ship-launching-airbags-production

Ship Launching Projects

DOOWIN ship launching rollers provide the perfect launching solution.
Their strength, durability, and excellent resistance to extreme conditions, makes them ideal for ship launching.

What you have to know

There are a lot of industry secrets that manufacturers don’t want to tell you.

The weight of ship launching airbags is calculated by airbag surface area. When you care too much about weight, you may be misled by some manufacturers. Please remember “It’s not that the heavier the airbag, the better the quality. Weight is not a good indicator of quality.”

Generally speaking, the number of layers refers to the number of layers of the skeleton material, that is the number of layers of the synthetic-tyre-cord fabric layer. The number of layers mentioned by some small manufacturers refers to the number of layers of cord fabric plus the number of layers of rubber. This is very incorrect. They cheat consumers by confusing concepts.

It is very easy to distinguish between used and new airbags. If there are abrasions on the airbag’s body, then it is used. For the new airbags, its surface maybe looks ugly and dirty. It is because we use French chalk in the vulcanization process. When the water vapor in the vulcanization tank is mixed with French chalk, the surface will appear very dirty.

Our unique overall winding technology is different from the current mainstream airbag production technology. We innovate and improve on the basis of mainstream production technology. The airbag produced by the optimal winding angle technology can exert the maximum effect of the material, save the cost, and have a stronger lifting force.

We will provide the Manufacturer Certificate and Certificate of Compliance. Meanwhile, we also can provide BV, CCS, LR, ABS third party certificate upon buyer’s request.

Ship Launching Airbags. Also known as inflatable marine airbags, roller bags, air lift bags, and salvage bags. Airbags range in size from 0.8 to 2.5m diameters, with lengths of 5.0m to 25.0m ‘effective length’. Airbags are used for ship launching, haul-outs, loading, and floating.

All Doowin Marine ship launching airbags are manufactured and tested fully compliant with ISO 14409 “Ships and marine technology – ship launching airbags“, certificated by BV, CCS, LR, ABS. There are two Chinese standards and two ISO standards for ship launching airbags production and use.

  1. CB/T 3837-1998 Technological Requirements for ship Upgrading or Launching Relying on Airbags (Shipbuilding Industry Standard, PRC)
  2. CB/T 3795-1996 / CB/T 3795-2009 Air bag for ship up to or down to launching way (Shipbuilding Industry Standard, PRC)
  3. ISO 14409: 2011 Ships and marine technology — Ship launching air bags
  4. ISO 17682:2013 Ships and marine technology — Methodology for ship launching utilizing air bags

Marine rubber airbags are not single-use products. It can be used for many times. But cannot define the exact number. General speaking marine airbags have 5~8 years lifespan under the correct usage and proper maintenance.

General speaking marine airbags have 5~8 years lifespan under the correct usage and proper maintenance. But it also depends on how frequently airbags were used and how they are maintained and stored. After using 3~5 years, the rubber airbags must be fully inspected to determine if the airbag can continue to be used.

The storage influences the airbag’s lifespan. So, it is very important. Ship launching airbags should be cleaned with fresh water and dried then powdered with French chalk powder. Ship launching airbags should be stored in cool, dry sheltered place, kept away from chemicals, gasoline, solvent etc. Ship launching airbags can be piled for storing.

Choose the suitable airbags for your vessel.

Please contact our professional team!

Mobile: +86-185 5486 9267 (WhatsApp)
Email: sales@doowincn.com

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heavy lifting rubber airbags

Heavy Lifting Airbags

Ship launching airbags, also known as roller bags or ship launching balloons, are made of heavy-duty synthetic-tire-cord layers with inner and outer rubber layers in a long cylindrical balloon shape. Marine rubber airbags can be used for ship launching, ship landing work.

Ship launching relying on marine rubber airbags is an innovative ship launching technology, comparing with “end-on launching”, “side ship launching”, “float-out”. This ship launching technology overcomes the restrictions of the fixed launching track of side-launch. More and more shipyards accept ship launching rubber airbags worldwide because of its huge advantages.

>> See more information about Heavy Lifting Airbags

marine salvage airbags

Marine Salvage Airbags

Through listening to our customers, DOOWIN has developed heavy-duty marine rubber airbags, which are the toughest marine salvage airbags.

DOOWIN marine rubber airbags are the system of choice where reliable, controllable buoyancy is required. They are particularly suited for installation buoyancy on pipeline float-out, beach pulls, and river crossings. Our marine rubber airbags have also been used in applications such as vessel and platform draught reduction in limited water depths. And as salvage pontoons for temporary bridges and docks. The salvors can use marine rubber airbags to salvage the shipwreck, rescue the floating bridge, and dock construction.

>> See More Information