Procedure of Launch a ship by rubber airbags

1.Pre-launch preparation work for shipyard

Slipway Enhancement

Water survey

Vessel skeg enhancement

Ground anchor

Seal thruster holes if there are.

2.Basic equipments needed for ship launching

Rigging equipments: Winch, Pulley, Swivel, Lug, Shackle, Wire sling, Ground Anchor

Inflate equipments: Air Compressor, Inflating Pipe

Airbag moving equipments: Forklift, mobile crane

3.Crew preparation

4.Rigging Arrangements

5.Lifting the blocks

6.Move vessel forward

7.Vessel Launching

The requirements of launching ship and relevant equipments.

1.Ship

The engineering work under water line shall wholly be finished, especially those equipments, valves and others that are to be installed at the openings under ship waterline, the installations should be approved by inspection. All the burrs, welding beading and the like on the ship bottom or appendages should be ground away. All the welds on the shell plate must pas inspection and tightness test. The main dimensions of the ship should be measured up and the mark of loadline must pass inspection. All the paint work of the shell plate has been finished.

2 Ramp way 

The ramp way on which the airbags will rolling should be cleaned and be clear of sharp fends such as iron nail. The ramp way should be leveled and the level error from left to right should less than 80mm. The ground caved in should be filled up and the ground bearing capacity should be relatively equalized. The ramp made of mud land, sanded land, sands or concrete, however, its bearing capacity should be twice as big as the working pressure of airbags. The slope of ramp is to be determined according to the size of the launching ship and is generally no bigger that 1/7. In the range of the whole length of the ramp way, the shape may be of multiple combination with slope line, are line and others. However, the ship bottom should not contact the ground even when the airbags are at their lowest working height. The ramp way should extend into water for certain length.

3.Winch 

In general, a slow winch is to be selected, its veering speed is about 9-13/m/min. The moving speed of a ship must not be more than 6m/min with the control of hauling force of winch wire. If the ship weight is less than 200t, the moving speed can be increased properly. The wire must be inspected and replaced regularity.

4.Air compressor 

The type and capacity of the air compressor is to be selected according to the total volume of all the airbags provided for the launching and time required for air filling and the air pressure. The gas tank of air compressor should be installed with adjustable pressure limiting valve.