Hongruntong Marine Buoyancy Bags are industrial underwater lifting systems developed for marine construction contractors, dredging operators, offshore maintenance companies, and underwater recovery service providers requiring controlled buoyancy performance in complex subsea working environments. The product is engineered using high-density reinforced composite fabric combined with multilayer structural reinforcement technology, enabling stable lifting performance during offshore deployment, submerged positioning, and underwater transportation operations.
The buoyancy system operates through controlled compressed air inflation, generating adjustable lifting force for submerged structures, marine machinery, dredging components, underwater pipelines, and steel assemblies. The cylindrical configuration improves hydrodynamic efficiency during underwater movement while maintaining stable load distribution throughout lifting procedures. Internal load-bearing webbing structures enhance structural integrity under dynamic operational conditions involving fluctuating pressure, current movement, and repeated deployment cycles.
The external material system incorporates corrosion-resistant marine coatings optimized for long-term exposure to seawater, ultraviolet radiation, sediment abrasion, and offshore contamination environments. Reinforced seam fabrication technology improves pressure retention capability and reduces operational risk during prolonged underwater lifting procedures. The equipment is compatible with standard offshore rigging assemblies and can be integrated efficiently into diving support systems, marine recovery operations, and underwater construction workflows.
A large-scale harbor expansion and dredging modernization project conducted at a commercial shipping terminal in the Middle East required the underwater recovery of several submerged cutter head assemblies and steel dredging support structures following severe operational damage during storm conditions. The damaged equipment was located within an active navigation channel where prolonged obstruction could disrupt port logistics operations and international cargo traffic.
The project contractor faced multiple engineering challenges including limited heavy-lift vessel availability, unstable seabed sediment conditions, restricted underwater visibility, and continuous vessel movement within the operational zone. Conventional crane-based lifting operations were considered operationally inefficient due to navigation restrictions and the requirement for rapid recovery implementation.
Hongruntong Marine Buoyancy Bags were selected as the primary underwater lifting solution for the recovery operation. Engineering personnel configured multiple buoyancy units according to the structural weight distribution characteristics of the submerged dredging assemblies. Commercial divers installed the buoyancy bags around reinforced lifting points while underwater pressure stabilization procedures were monitored from the support vessel.
The controlled inflation process enabled the lifting system to gradually separate partially buried steel structures from compacted sediment layers without generating excessive stress concentration or uncontrolled structural displacement. Once neutral buoyancy conditions were achieved, tug support vessels repositioned the recovered assemblies toward a nearby maintenance platform for repair and inspection procedures.
The buoyancy-assisted recovery operation significantly reduced project interruption duration and minimized fuel consumption associated with large offshore crane deployment. Operational safety also improved because the controlled lift characteristics reduced unpredictable underwater movement during ascent and repositioning procedures. Following successful completion of the project, the terminal authority integrated Hongruntong Marine Buoyancy Bags into its long-term marine emergency response and dredging maintenance equipment inventory.
| Product Name | Buoyancy Bags |
| Raw Material | PVC coating fabric |
| Type | Cylindrical |
| 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 |
| Tolerances | +/- 0.03 on densities, +/- 0.2 mm on thickness, +/- 0 to +3mm on width, +/- 0 to +3mm on length |
| Model | Buoyancy [kg] | Buoyancy [lbs] | Diameter [mm] | Length [mm] | Appr. Weight [kg] |
|---|---|---|---|---|---|
| HM-ULB01 | 200 | 441 | 500 | 1,000 | 5 |
| HM-ULB02 | 500 | 1,103 | 800 | 1,000 | 8 |
| HM-ULB03 | 1,000 | 2,205 | 1,000 | 1,500 | 11 |
| HM-ULB04 | 2,000 | 4,410 | 1,300 | 1,500 | 20 |
| HM-ULB05 | 4,000 | 8,820 | 1,600 | 2,000 | 50 |
| HM-ULB06 | 6,000 | 13,230 | 2,000 | 2,000 | 66 |
| HM-ULB07 | 8,000 | 17,640 | 2,000 | 2,600 | 75 |
| HM-ULB08 | 10,000 | 22,050 | 2,400 | 2,400 | 80 |
| HM-ULB09 | 15,000 | 33,075 | 2,600 | 3,000 | 110 |
| HM-ULB10 | 20,000 | 44,100 | 3,000 | 3,000 | 130 |
| HM-ULB11 | 30,000 | 66,150 | 3,000 | 4,500 | 170 |
| HM-ULB12 | 50,000 | 110,250 | 4,000 | 4,000 | 220 |
| HM-ULB13 | 70,000 | 154,350 | 4,000 | 5,700 | 310 |
| HM-ULB14 | 100,000 | 220,500 | 4,000 | 8,000 | 450 |
| HM-ULB15 | 150,000 | 330,750 | 5,000 | 8,000 | 660 |
| HM-ULB16 | 200,000 | 441,000 | 5,000 | 10,000 | 900 |
Note: Other sizes can be customized according to the requirements.
