... and landing , the caissons lifting movement, the removal of other heavy objects, underwater installation work buoyancy aid and ... of wreck salvage, pontoon bridge installation, dock building, underwater transmission pipeline installation, etc. in many ways.3.Ship ... 4 ton1.8m0.4mpa0.8m22.5 ton18 tonAir lifting bags ,ship airbag ,salvage ,lift ,lifting ,airbag ,pontoon ,floating pontoon,salvage , ...