Shipbuilding industry is awesome. Marcin Ryngwelski on active and passive stabilizers

Roll motion cannot be eliminated, because it results directly from how the hull interacts with wind and waves. However, it can be significantly reduced. Properly integrated stabilizers allow a vessel to maintain operational capability and comfort in a seaway. Marcin Ryngwelski, CEO of PGZ Naval Shipyard, explains how stabilizers work and why their installation is structurally and technologically demanding.

business education maritime economy work at mare shipbuilding industry shipbuilding industry is awesome equipment and technology news

10 november 2025   |   09:18   |   Source: Gazeta Morska   |   Prepared by: Kamil Kusier   |   Print

fot. Marcin Ryngwelski / PGZ Stocznia Wojenna

Roll motion as a design consideration

- Every vessel will roll. This is a natural hydrodynamic response, says Ryngwelski.

Roll is the rotation of the hull around its longitudinal axis and depends on hull form, weight distribution and metacentric height. The engineering goal is not to remove roll entirely but to limit its amplitude and rate.

Why stabilizers must be planned early

Stabilizers influence hull geometry, internal layout and system routing.

- A stabilizer has to be included already in the design phase. The intended operating waters and mission decide which solution is suitable. A frigate operating in the North Atlantic and a passenger vessel in the Mediterranean will have different requirements, notes Ryngwelski.

Passive vs. active systems

System	Key features
Passive stabilizers	Use hydrodynamic resistance or fluid movement; examples include bilge keels and anti-roll tanks. No active control required.
Active stabilizers	Use powered actuation to counter roll in real time. The most common are fin stabilizers, positioned below the waterline and controlled automatically.

Fin stabilizers — precision work below the waterline

Fin stabilizers are usually placed amidships. Their installation requires hull cutouts, structural reinforcement and watertight integration.

-The tolerances are in millimeters. Welding below the waterline must meet the highest strength and watertightness standards. It requires specialized teams who perform this type of work regularly, Ryngwelski explains.

Integration includes:

• hydraulic or electromechanical actuation,
• electrical power and control connections,
• gyro-based control logic and calibration.

Every step is documented and verified by the classification society.

Performance verification

Expected roll behavior is often tested before ship construction, including model basin tests at the Ship Design and Research Centre in Gdańsk.

After installation, stabilizers undergo:

• harbour acceptance tests (HAT),
• sea acceptance trials (SAT).

- Sea trials confirm that stabilizers deliver the expected performance in real sea conditions.

Stabilizers do not eliminate roll but manage it effectively. Their performance results from coordinated naval architecture, precision hull fabrication and controlled testing.

Buy us a coffee, and we’ll invest in great maritime journalism! Support Gazeta Morska and help us sail forward – click here!

PGZ Stocznia Wojenna Polska Grupa Zbrojeniowa Marcin Ryngwelski Przemysł stoczniowy jest sztos przemysł stoczniowy

comments

---

enter content

COMMENT

nick

Add the first comment