Structure
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.

Material
Ship rubber airbags for docking and undocking are constructed of synthetic-tire-cord layers; inner and outer rubber layers are sometimes added. All materials used are vulcanized.
Air tightness test: Without carrying any load, fill the air bag till the internal pressure of the air bag reaches rated working pressure. After 1 hour. The pressure loss should be less than 5 % of initial pressure.
Bursting test: Fill the air bag with water until the air bag bursts. The water pressure at the time of bursting shall be no less than three times of rated working pressure.