Tips from our expert: The total seal package for Cutter Suction Dredgers

Do you operate or work on a Cutter Suction Dredger (CSD)? Then you know the most important thing is to keep the operation going. To minimise the downtime of the vessel and to deliver Peace of Mind, we offer several sealing solutions that are suitable for CSDs.


  • For the propulsion of your vessel we advise using the Supreme SeaGuard Ventus®
  • Our Liquidyne® pump shaft seal is applicable on the dredge and jet pumps
  • For protecting the machine rooms we advise the Pump Gear Bulkhead seal and Cutter Gear Bulkhead seal
  • To seal the pump and cutter gearbox and (thrust)bearings our customized Supreme seal is the most reliable solution

For propulsion: The Supreme SeaGuard Ventus with advanced options

CSDs often operate in waters that contain many large abrasive particles and therefore we advise the Supreme SeaGuard Ventus. This air-type seal guarantees zero emissions of oil, enables Condition Monitoring and gives you extra security against oil leakage into the marine environment. How? – With the aid of a redundant lip seal.

The chamber between the two oil-repellent lip seals is pressurised by the stern tube header tank. This way the pressure on both sides of the fourth lip seal remains equal. By closing off the oil supply to this chamber, the fourth lip seal can be used as a new oil-repellent lip seal. In case of leakage, docking and maintenance can be postponed by putting this redundant (fourth) seal to work.

We advise this sealing solution with the addition of the following options:

To lengthen the lifetime of the liner, we advise adding a HML to the seal (picture 1, position 7). The HML is formed with a high adhesive strength and a porosity of less than 1% and prevents crevice corrosion which can occur on ceramic layers.

Picture 1: Lagersmit’s customised options

For pumps: The Liquidyne pump shaft seal

On a dredge vessel several types of pumps are on board. For the dredge pumps we advise using our Liquidyne 3-Stage WA. This seal is especially designed for dredge pumps up to a discharge pressure of 45 bar and works with a water flow that enables the Condition Monitoring function.

Other benefits are:

  • Maximised maintenance interval
  • Low energy consumption
  • Low cost of ownership

The Liquidyne is also applicable on jet pumps and the seal type depends on the pump water. If the pump water is relatively clean, our Liquidyne 2-Stage is the ideal solution. Are you pumping water that contains a relatively large number of abrasive particles? Then we advise the Liquidyne 3-Stage.

For the bulkheads: The Cutter and Pump Gear Bulkhead seal

Need protection for the cutter gear machine room? Our seal expert advises the Cutter Gear Bulkhead seal.


  • Flexibility and (bearing) support to manage 5 mm of radial displacement
  • Minimal wear on lip seals and the support bearing
  • The ability to operate above the water line with proper lubrication


Contact our account manager responsible for the dredging market, Mr Jan Willem Bongers, to find out how our sealing solutions deliver you Peace of Mind.