Ship launching or lading by using airbags is an innovative technology. It is widely used in shipbuilding.
Advantage of ship airbag
- It overcomes the shortcomings of the fixed launching track, which limits the productive capability of small and medium-sized shipyards.
- Using the ship launch airbag becomes a flexible launching technology. The airbag has the advantage of saving time and labour.
- It has the characteristics of flexibility, reliability and safety in ship launch operation. It is also economic.
Construction of the airbag launching
The vessel bags consists of an airbag body and ends of iron pieces. The wall of the airbag consists of a rubber layer and a fabric layer after the process of forming and vulcanization.
At both ends of the lifting ship launch airbag, there are two airbag balloon ship mouths. We can pump the air into or release the air from the water airbag end mouths. The vessel airbags mouths are made of metal materials and melted into the fender rubber main body.
Note:
A and B: Airbag mouths（Material: carbon steel or stainless steel）
F: Airbag end section（Cone shape）
E: Airbag body section（cylindrical shape）
Every airbag consists of fabric and a natural rubber layer. All the material is solidified by the vulcanization.
As per the reinforced material, the density of the fabric should be （90±5）pc/100mm width, and the single line of the fabric must be not less than 205N.
| Break Strength | Adhesive strength | Elongation at break | Diameter |
| ≥205.8N/pc | 137.2N/CM | 23%±2.0 | 0.65±0.04 |
Applications of the shipping airbag
Our team developed high-strength shipping launching and landing airbags. We made a lot of ship launch airbag launcher burst tests and compression performance tests. All the data is over the relevant international and our country standards and also exceeds the shipping line standard.
Besides the shipping launching and landing purposes, our rubber airbags are also used for lifting and moving heavy items, shipping salvage etc.
Specifications of the airbag for shipping
| Model | Specification(D×L) | For Small and medium-sized ships up to or down to launching way and moving objects |
| 3-layer | Diameter(D):
0.8m, 1.0m, 1.2m, 1.5m, 1.8m，2m etc. Length(L): ranging from 5m to 18m (Diameter and length can customize by the requirements of customers） | For large and medium-sized ships up to or down to launching way and moving objects |
| 4-layer | For the larger ship up to or down to launching way and moving objects | |
| 5-layer | For large ships up to or down to launching way and supporting the key parts during operation | |
| 6-layer or more | For large ship up to or down to launching way and supporting the key parts during operation |
Executive Standard:
《ISO 14409 2011 Ship and Ocean Technology-ship launching airbag》
《CB/T3837-1998 Shipping Airbag Launching and Landing Process Requirement》
Dimension Tolerance and Appearance
The length and the diameter of the ship launch airbag should be measured by the rated working pressure, the allowed tolerance is ±3%. The outer appearance of the shipping launching airbag should be smooth, and bright without the crack, bubbles, separated layers, pits or points.
Our company’s new integrated marine launching airbag adopts special rubber formula. And each rubber and fabric layer is integrated with each other. The launch balloon head uses two layers more than the airbag body. This improves the work pressure of the airbag and enhances the strength of the marine airbag. Our airbags have good tightness, safety, and a longer life cycle. The use life is twice longer as the airbags in the market of our special rubber formulations.
Tests for Ship Launch Airbag
Air tightness test
Fill the air into the pneumatic lifting bags to a certain internal test pressure without any load. After one hour, measure the internal pressure again. By comparing with two times data, the pressure loss should be less than 5%.
Performance test
Without any load, fill the air into the airbag balloon by the airbag standard data form or by clients’ requirements.
We will do a strict inspection before the delivery for the outer appearance and the air loose test. If it is unqualified, can not release definitely.
Blasting test
This test should give the minimum burst pressure value of the airbag, as listed in the airbag performance table burst pressure. In order to be safe, since the airbag belongs to the pressure vessel, it is necessary to use water flushing while filling the airbag until the airbag bursts. The water pressure during airbag blasting should be larger than or equal to the values
Compression-recovery test
In order to verify the recoverability of the airbag, the airbag should be repeatedly and rapidly compressed and released in a short time. Due to the limitation of the airbag length and the limitation of the compression recovery equipment, the compression recovery test can be reduced by the same number of layers. The airbag is inflated to make the internal pressure reach the pressure of the airbag performance data. And the airbag is vertically compressed until the compression deformation reaches 75%. Keep this state for 1 minute. The pressure is then released and the balloon diameter should be restored to more than 97% of its original diameter within 5 minutes.
Storage of the ship launching airbag
When we don’t use the marine airbag roller for a long time, it should be washed and dried. Should use the external talcum powder on the lifting airbag surface. Should put the airbag in a dry, ventilated room away from the light source. Keep away the shipping airbags safe to avoid stretching, compression and deformation.
Keep the airbag away from heat sources.
Can not contact the airbags launching to acids, alkalis, greases and organic solvents.
When the airbag ship is not in use, we should keep it in the status of stretched flat, not stacked, and no heavy objects piled on it.
Notice during the use of the ship balloon:
While the shipping air launching airbags are in use, strictly control the pressure, and prohibit the use of exceeding the work pressure.
The surface in contact with the shipping lifting airbag must not have a sharp protruding hard object to prevent the airbag skin from being pierced.
Try to avoid distortion in the length of the airbag.
Should avoid the inflatable load after we have in charged the air into the airbag.
For example, when the ship is erected, when the lifting airbag has lifted most of the hull, remove most of the pier and fill the rolling airbag. If there are 1-2 piers still under compression, the internal pressure between the airbags should be adjusted so that the ship can be removed from the side of the ship. And the pier can not be manually used. Otherwise, the ship may be forced to impact the airbag that has been filled.
Another example is the collision with other objects for various reasons during the ship transfer process. In severe cases, the impact airbag may be damaged.
Before a long time of no use or re-use after repair, we should carry out the air filling test again. The air internal pressure should be the same as the factory test value of our factory. The test worker should keep away three meters from the airbag during the test. If the airbag is repaired by a large area of damage, we should decrease the use pressure. Therefore, the airbag often used, still need the above test once a year.
Do not drag the ship launch airbag on the hard ground.
Airbag air charge tools
