How to Choose a Suitable Ship Launching Airbags

How to Choose a Suitable Ship Launching Airbags

Ship launching airbags are a very popular use of, especially in Asia shipyards. This drainage method greatly reduces the cost of preliminary preparation and ensures safety. Suitable for various types of ships' discharge, repair, and towing.

Ship launching airbags are currently the lowest cost and low risk ship launch solution. It overcomes the disadvantage of fixed track launching and provides convenience for ship maintenance. Currently, it is mostly used for launching small and medium-sized ships, and the shipbuilding and repair productivity of small and medium-sized shipyards is limited. Help companies in the shipbuilding and shipping industry to save energy, time, workload, and investment.

How to choose the suitable ship launching airbags? We have the following suggestions:

1. Regarding the length of airbags:

For a single row arrangement of ship launching airbags, their length should not be less than the maximum width of the vessel to be moved.

For two rows of ship launching airbags, the total length of the ship launching airbags can be estimated by adding the effective length to the diameter of the marine airbags.

2. Regarding the diameter of marine launching airbags:

The diameter of airbag is determined by the height used to support the ship.

For ship launching airbags, the most important thing is the bearing capacity, which determines the diameter and length of the rubber body.

Deyuan Marine is willing to help you find the best solution for ship launching projects.

In fact, calculating the number of launching airbags for ships is a very technical operation.

There are many force data that need to be considered in the calculation process, and the process is quite complex.

Now, Deyaun Marine shares with you the calculation method for the selection of ship launching airbags. Through this calculation guide, we hope everyone can understand how the technical personnel in Deyuan Marine provide suggestions for the ship launching airbag scheme, and check whether the scheme provided by the other party is reasonable after you received the quotation. Avoid encountering unreliable random quotes.

3. How does the ship's launching airbag works?

Before starting to understand the selection of airbags, let's take a look at how these airbags are launched.

A. Steps for Ship Launching Project:

1.1 Remove obstacles blocking the rolling of the airbags and obstacles under the ship's bottom during the ship's launch. Ensure that the slide is smooth and clean. This step is not obstructed by any objects during the ship launching process to ensure the safety of the ship launching process. There may be some sharp and hard objects such as large stones or shells rushing towards the shore. They may also puncture the ship launching airbags, so it is important to clean them and level the slide rails.

1.2 Connect strong components such as the bow and mooring column to the movable pulley block of the traction winch to tow the ship.

1.3 According to the technical personnel's operation plan, place the marine launching airbags under the bottom of the ship and inflate it to the specified pressure. When the bottom of the ship is higher than the bridge pier and all the weight of the ship is pressed against the marine launching airbags, remove all the bridge piers and deflate the marine airbag appropriately to balance the force.

1.4 All crew members related to work are prepared to board the ship.

1.5 Considering the width of the water area, choose a suitable launching position, loosen the steel wire rope to move the ship near the water area, cut the steel wire rope or unfasten the shackle when appropriate, and the ship will automatically enter the water area. Launching water with the help of sliding force.

1.6 After the hull is fully submerged, tow the ship to the dock, measure the draft at both ends, and check for any leakage in each compartment.

1.7 Retrieve all ship launching airbags and record launch information.

B. Choose The Calculation Method For Ship Launching Airbags

After understanding the general process of ship launching, let's take a look at how technical engineers in Deyuan Marine calculate the number of airbags. When our technical personnel receive your quotation request, they need to know the following information:

a. Ship type

b. Ship Length

c. Ship Width

d. Ship Deadweight Tonnage

e. Angle between ship launching ramp and ground materials

f. Tidal table, water depth, and flow velocity information in the underwater sea area

For concrete ramps, the friction coefficient of the airbag on the ramp is 0.01-0.0125. For compacted natural foundations, the coefficient is 0.0125-0.02.

After understanding the above information, technicians will calculate the number of marine airbags required for your ship's launch based on the following calculation formula:

In the formula, N is the number of marine airbags required, K1 is the coefficient of the airbag, Q is the weight of the ship, g is the acceleration of gravity, Cb is the square coefficient of the ship, R is the maximum carrying capacity of the airbag per meter, and Ld is the contact length between the airbag and the bottom of the ship (m).

All calculation technicians will repeat the calculation more than 3 times to ensure the correctness of the value. Then the customer will make a quotation based on the quantity of marine airbags they need. If you want to know the number of marine launching airbags required for your ship launching project, you can call Deyuan Marine, we can help you choose the suitable type .

With this formula, you can also calculate by yourself after accepting the selection recommendation to see whether the number of airbags recommended by the other party is reasonable. But it should be noted that when the ship is moving, 2~4 reserve airbags should be prepared. This is very important.