Hull Cleaning Equipment

Hull cleaning: The invisible battleground that determines navigational safety and operating costs

Rust removal is not just a cosmetic issue; it is a key factor in the structural safety and operating costs of ships.

The rate of corrosion faced by ships in the marine environment far exceeds people’s imagination. Data shows that an untreated hull can corrode to a depth of 0.15 millimeters per year, equivalent to a 5% loss in steel plate thickness annually. An investigation into the 2021 fuel spill on the USS Villa Bay, a U.S. Navy cruiser, revealed that the fuel tanks were perforated by rust in just three years, directly resulting in $120 million in repair costs and six months of downtime.

The image shows details of localized rust on the hull, with a rust layer thickness of 2-3 millimeters and visible signs of flaking.

Waterjet technology: A revolution in ship cleaning, contributing to safer navigation. Waterjet technology promises to revolutionize ship cleaning. It can remove contaminants with extremely high efficiency, prevent structural damage and safety hazards caused by corrosion, and ultimately ensure safe navigation.

The core advantages of waterjet technology in rust removal and cleaning of ship hulls

Waterjet technology, especially ultra-high pressure (UHP) waterjet systems (≥100 MPa), combines purely physical cleaning without the need for any abrasive or chemical media , making it ideal for meeting the stringent requirements of ship hull maintenance. Its main advantages include:

1. Environmentally friendly and fully compliant with maritime regulations

• Using only water — without chemicals, abrasives, dust, or secondary waste—eliminates the risk of marine pollution and protects the health of crew members
  (fully compliant with the International Maritime Organization’s Convention on the Protection of the Marine Environment) .

• Wastewater can be filtered and recycled to ensure no secondary pollution occurs—ideal for ports, dry docks, and environmentally regulated shipyards.

2. No damage to the ship’s base material, maintaining structural integrity.

• Ultra-high pressure water jets remove rust, marine organism attachments (barnacles, algae), and old coatings through impact-driven stripping action , rather than through abrasion.

• Effectively cleans steel plates, welds, and coating substrates without reducing the thickness of the steel plate or damaging the welds ;

• Compared to dry blasting (which typically results in surface scratches and metal loss), waterjet erosion is negligible, thus extending the service life of the container .

3. High-efficiency integrated surface treatment

• High-energy water jets can penetrate deep into welds, joints, rivets, and gaps to remove:

  • pitting

  • Layered rust

  • Calcified marine organisms

  • Aging antifouling and protective coatings

• Cleanliness level up to SA 2.5–SA 3 (ISO 8501-1) ;

• It can form a uniform micro profile ( Ra 40–80 μm ) and can be directly coated without additional grinding , thereby reducing docking time and increasing productivity;

• The cleaning efficiency of each cubicle is 30-50% higher than that of traditional methods .

4. Excellent flexibility, enabling all-around hull operations.

• Adjustable pressure and flow rate allow for seamless transitions between the following:

  • Low-pressure deck and oil stain cleaning

  • Used for ultra-high pressure hull descaling and coating removal

• Compatible with handheld fish finders, robotic arms, and remotely operated vehicles (ROVs) , supporting:

  • External hull and propeller

  • Cargo holds and ballast tanks

  • Constrained space and complex geometry

  • Sensitive components such as radar and navigation systems

• Ensure comprehensive coverage with no blind spots .

5. Multifunctional integration reduces total cost.

• The system integrates functions such as rust removal, paint stripping, marine dirt removal, and surface treatment ;

• Eliminate costs associated with abrasive procurement, logistics, disposal, and environmental treatment;

• Water, as a consumable, can reduce operating costs— compared to dry blasting and chemical cleaning, it can reduce total cost of ownership by 20% to 40% over the long term.

6. Improve operational safety

• Cold cutting and cleaning process – no sparks, no open flames, no risk of explosion;

• Ideal for use in enclosed spaces such as cargo holds and fuel tanks ;

• Remote-controlled robot solutions can significantly reduce the following associated risks:

  • Working at heights outside the hull

  • Underwater propeller maintenance

Equipment Specifications

thing	unit	Model QSM-3-1T/bS	Model QSM-3-15/bS
Machine Model	Megapascal	QSM-3-1T/bS	QSM-3-15/bS
Work pressure	liters per minute	6～30	6～30
motor power	kilowatt	11	15
Operating voltage	exist	380	380
Water supply	liters per minute	15～45	20～60
Depth of cut	millimeters	120	120
Cutting speed	mm/min	80~100	90～120
Machine noise	decibel	90	90
Pump weight	Kilogram	370	450
aspect	millimeters	1150×900×850	1200×900×900
Mixing tank capacity	Kilogram	90	100
External dimensions	millimeters	660×299	750×299
Water tank capacity	L	70	80
Abrasive storage	L	30	40
Lubricating oil tank	Kilogram	80	100
Continuous working time	Minimum	50 minutes (true)	60 minutes (really)
medium	/	Clear water, stone sand	Clear water, stone sand
Sand grain size	net	80	80
Sand flow rate	kg/min	1.5 ~ 2.0	2.0 ~ 2.5
Nozzle diameter	millimeters	Cutting: 0.8–1.0; Flushing: 2.0–3.0; Cleaning: 3.3–5.0	Cutting: 0.8–1.0; Flushing: 2.0–3.0; Cleaning: 3.3–5.0
Frequency range	hertz	Cutting 20-30; rinsing 30-50; washing 40-60	Cutting 20-30; rinsing 30-50; washing 40-60
Water supply	liters per minute	Cutting 15; Rinsing 30; Cleaning 45	Cutting 20; Rinsing 40; Cleaning 60
Work pressure	Megapascal	Cut 25-30; Rinse 6-12; Wash 6-10	Cut 25-30; Rinse 6-12; Wash 6-10