Advantages and disadvantages of ship launching with airbags

airbag ship launching technology originated in China. Due to its economy, convenience, reliability and other advantages, it is warmly welcomed by ship building and repair shipyards all over the world. The tonnage of ships that can be launched with marine airbags has also grown from a few hundred tons at the earliest to tens of thousands or even hundreds of thousands of tons. The types of ships launched with launching airbags cover almost all types of civilian ships and some warships on the market.

So what is the charm of airbag ship launching that can attract more and more shipyards to use this technology? What are the advantages and disadvantages of airbag ship launching?

First of all, let’s take a look at the application scenarios of airbag ship launching:
The ship is built on top of supporting blocks standing on a ramp with a certain angle. When complete hull construction, inflate airbag lift the hull first, remove keel blocks, and then get rid of holding wire ropes, the ship will enter the water with rolling airbags due to its gravity force. Airbag launching can be summarized into four elements: launch ramp, launching airbags, control system and water level.

We will analyze the advantages and disadvantages of airbag launching from the four major elements of airbag launching.

Advantages of airbag launching

Launching ramp:
Airbag ship launching ramp has simple requirements: flatness, proper angle, and sufficient ground bearing capacity. Usually it is easy to meet these requirements by modifying natural ground or beach. Compared with the slide launch ramp, marine airbag has a larger contact area with ship bottom and ground, so the requirement for ground bearing capacity is much less.So the construction cost and period of airbag ship launching ramp will be much saved. In addition, airbag launching ramp has almost no need for post-maintenance work.

Airbag:
People can stagger airbags for different width ships’ launching. Ship launching airbag can be used repeatedly, with an average life span of 6 years. Even if the airbag is punctured or cut during use, the airbag performance and safety are almost unchanged after good repair. The cost of airbags can be almost negligible when it is averaged to the cost of dozens of launches.

Control System:
The airbag launching control system generally refers to the system that controls the movement of ship consisting of winches, pulleys, wire ropes. On a properly designed ramp, the airbag ship launching system requires relatively low pulling force provided by winch system.

Water level:
Being able to adapt to big scope of water level is a great advantage of airbag ship launching. For traditional slide launching, if the water level is insufficient, accidents such as stern fall are prone to cause damage to the hull structure. However, ship launching with airbags can realize the safe launching of the ship under a wide range of water level changes.

Disadvantages of ship launching with airabgs

One disadvantage of airbag ship launching is that the safety of launching is greatly affected by the quality of marine airbag. It can be seen from the four major elements of airbag ship launching that airbags are the most prone to problems and accidents in the entire system. Choosing high-quality airbags with a high safety factor plays a decisive role in the safety of the launch project.
Airbag manufacturers are all located in China, and the Chinese market is particularly complicated: there are both very good quality products and very poor quality products. Therefore, it is very important to choose a reliable airbag manufacturer.

Another disadvantage of ship launching with airbags is that in some cases, vessel bottom paint may be damaged by airbags during the launching process.
But if the hull paint is completely dry and launching conditions are good, vessel bottom paint can not be damaged. The solution to avoid vessel bottom painting damage during launching is simple: find a way to reduce the friction between vessel bottom and launching airbags, which usually can be achieved by increasing the working height of launching airbags.