Floating ship airbag for ship launching have the best designed structure which consists of five different functional membranes in rubber layers.
1) Outer Rubber Layer
The outer rubber layer that covers the outside of ship airbag to protect under layers from abrasion and other external forces. This compound has sufficient tensile and tearing strength to withstand any condition and hard usage.

2) Inner Rubber Layer 
The inner rubber layer seals pressurized air inside ship airbags.

3) Synthetic-Tire-Cord Layer as Reinforcement
The reinforcement cord layers, which are made of synthetic-tire-cord commonly used in tires, are arranged at ideal angles to hold the internal pressure and distribute stress evenly. So they can provide strong efficient reinforcement. 

The bearing capacity of floating ship airbags was 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 floating ship airbag the contact area will be affected by some terms which include the carried ship condition, the different position from gravity center during the process of ship launching and pulling. So the bearing capacity of airbags will vary as well as the contact area.

The approximate bearing capacity can be calculated as follows:
F=PS
S=π x (D1-D2)/2

Mark:
F: Bearing capacity

P: Inner pressure
S: Contact area
D1: Diameter of airbags when free of loat
D2: Working height of airbags when loaded