Underwater Lift Bags are specialized buoyancy devices designed to provide controlled lifting force for underwater operations. They are widely used in marine salvage, shipyard maintenance, offshore engineering, and underwater construction projects where heavy submerged objects must be raised safely and efficiently.
Hongruntong Marine Underwater Lift Bags are manufactured using high-strength PVC coated polyester fabric combined with reinforced load-bearing webbing structures. This construction provides excellent mechanical strength and ensures stable load distribution during lifting operations. The materials offer strong resistance to abrasion, seawater corrosion, ultraviolet radiation, and extreme marine environments.
A harbor maintenance contractor successfully recovered a 30-ton service vessel that had sunk near a dock using multiple Hongruntong Marine Underwater Lift Bags. Divers attached lift bags with capacities ranging from 5 to 10 tons along the vessel's hull structure.
Compressed air from diving cylinders was gradually introduced into the bags, generating sufficient buoyant force to lift the vessel slowly from the seabed at 11 meters depth. The controlled inflation process maintained vessel stability throughout the operation. After approximately one hour, the vessel reached a floating position and was successfully recovered without structural damage.
| Product Name | Underwater Lift Bags |
|---|---|
| Raw Material | TOP Grade PVC Coating Fabric |
| Type | Pillow |
| Size | 500kg, 1000kg, 5000kg, 10000kg, etc |
| Thickness | 0.4-1.2mm, or as request |
| Color | Yellow, Blue, Black, etc |
| Density | 0.33-0.9g/cm³ |
| Safety Factor | 7:1 |
| Accessories | Valve, Inflatable Tube, Repair Material |
| Warranty | 3 Years |
| Tolerances | ±0.03 on densities, ±0.2mm on thickness, ±0 to +3mm on width/length |
| Model | Capacity (kg) | Capacity (lbs) | Length (mm) | Width (mm) |
|---|---|---|---|---|
| HM-ULB100 | 100 | 220 | 1,020 | 760 |
| HM-ULB250 | 250 | 550 | 1,320 | 820 |
| HM-ULB500 | 500 | 1,100 | 1,300 | 1,200 |
| HM-ULB1000 | 1,000 | 2,200 | 1,550 | 1,420 |
| HM-ULB2000 | 2,000 | 4,400 | 1,950 | 1,780 |
| HM-ULB3000 | 3,000 | 6,600 | 2,900 | 1,950 |
| HM-ULB5000 | 5,000 | 11,000 | 3,230 | 2,030 |
Note: Other sizes can be customized according to requirements.