The ship launching balloon, also referred to in the industry as a marine launching airbag or roller bag, constitutes a vulcanized rubber cylindrical device engineered for the controlled launching, landing, and dry-docking of marine vessels. The structural composition comprises multiple layers of high-tenacity synthetic tire cord fabric—specifically 1870 dtex/2 grade with warp densities exceeding 95 cords per 100 mm in width and individual cord breaking strengths above 310 N—bonded with premium natural rubber compounds through a controlled vulcanization process.
This reinforcement layer is applied using holistic wrapping technology, wherein the cord layers are oriented at calculated angles to distribute internal pressure and external loads uniformly across the airbag surface, thereby minimizing stress concentrations and preventing premature structural failure.
The operating principle of the ship launching balloon is founded on converting static friction into rolling friction. When inflated beneath a vessel's hull, the airbag functions simultaneously as a load-bearing cushion and a rolling element, enabling the ship to move in a controlled manner down a prepared slipway. The cylindrical geometry allows the airbag to deform under load, increasing the contact area and distributing the vessel's deadweight evenly across multiple units.
This mechanism eliminates the requirement for fixed launching ways, permanent slipways, or graving docks—infrastructure that typically entails substantial capital investment and extended construction lead times. The engineering purpose extends beyond newbuild launches to include vessel repairs, dry-docking, and salvage operations, offering shipyards operational flexibility that conventional methods cannot provide.
The performance characteristics of the ship launching balloon are defined by its load-bearing capacity, pressure resistance, and environmental adaptability. Standard diameters range from 0.8 meters to 3.0 meters, with effective lengths up to 24 meters, supporting vessels from small fishing boats to ocean-going ships of up to 85,000 DWT.
The working pressure is determined by the number of reinforcement layers—classified as ordinary (3-5 layers), high-bearing-capacity (6-8 layers), and super-high-bearing-capacity (9 or more layers)—with corresponding bearing capacities verified through compression tests, burst tests, and compression-recovery tests conducted in accordance with ISO 14409 and CB/T 3795.
The outer rubber layer provides abrasion and weathering resistance, while the inner layer ensures air-tightness; together they enable operational reliability in diverse environmental conditions, from tropical shipyards to high-latitude ports.
A shipyard located on a river estuary in Southeast Asia, operating within a tidal range of approximately 3.5 meters, was contracted to construct a series of 12,000 DWT chemical tankers for regional trade routes. The vessel under construction measured 130 meters in length overall with a beam of 19.5 meters and a displacement of 12,000 tons at launch.
The engineering solution involved a comprehensive site assessment and system design. Based on the vessel's displacement, hull geometry, slipway profile, and ground conditions, the team determined that twenty units of 1.8-meter diameter, 14-meter effective length high-bearing-capacity airbags with eight layers of synthetic cord reinforcement would provide the necessary load-bearing capacity with a safety factor of 4.5:1.
The implementation process was executed in three phases: pre-launch preparation, controlled launch phase, and float-off phase. The entire operation was completed within a 2.5-hour window, well within the tidal constraints, resulting in significant efficiency improvements and cost savings.
| Product Name | Ship Launching Balloon |
|---|---|
| Material | 100% High Tensile Natural Rubber (NR) |
| Dimensions | Diameter 0.2m - 4.0m, Length 3.0m - 28.0m, or As Request |
| Working Pressure | 0.05-0.25MPA |
| Technology | Overall Winding, High Pressure, Explosion-Proof |
| Metal Parts | Q355 / SS304 / SS316 |
| Standard | ISO 17357 |
| Certificate | ABS, BV, KR, LR, GL, NK, RINA, DNV, RMRS |
| Service Life | 20 Years |
| Warranty | 36 Months |
| Diameter | Working Pressure | Working Height | Bearing Capacity (KN/m) | Bearing Capacity (Ton/m) |
|---|---|---|---|---|
| D=1.0m | 0.14Mpa | 0.6m | 87.96 | 8.98 |
| D=1.2m | 0.12Mpa | 0.7m | 94.25 | 9.62 |
| D=1.5m | 0.10Mpa | 0.9m | 94.25 | 9.62 |
| D=1.8m | 0.09Mpa | 1.1m | 98.96 | 10.10 |
| D=2.0m | 0.08Mpa | 1.2m | 100.53 | 10.26 |
* Other sizes can be provided following client's requirements.