Stable, proven solutions

Kongsberg Maritime produces a comprehensive range of retractable and non-retractable stabilisers for naval and governmental craft, as well as the commercial market.

From its manufacturing facility in Dunfermline, Scotland, the company has a long history in the manufacture of ship stability systems that pre-dates the site. That history actually dates back to 1871 in nearby Edinburgh when Brown Brothers, later acquired by Rolls-Royce Commercial Marine, was responsible for some of the most significant advances in steering gear.

As sail gave way to steam and diesel engines, manual steering became increasingly difficult and dangerous. Brown Brothers revolutionised the industry with hydraulic steering systems. During the inter-war years, the company diversified into aircraft launching systems and, notably, partnered with Denny Brothers to develop a retractable fin stabiliser – an innovation that laid the foundation for today’s advanced systems.

Today, the Dunfermline facility is the centre of production for stabilisers and naval linear actuator steering gear. For naval ships, stability is essential – not only for sensitive equipment but also for mission-critical operations such as helicopter landings.

Tailored solutions for naval platforms

Kongsberg Maritime’s commercial retractable stabilisers span fin areas from 1.4m² to 22.3m² and are built around two core families:

Aquarius
Designed for smaller ferries, cruise vessels and large yachts, Aquarius stabilisers are also widely used on smaller naval vessels. Their retractable design allows fins to be folded away when not in use, offering operational flexibility.

Neptune
Larger in size, Neptune stabilisers have been deployed on cruise ships, ferries, and naval vessels such as the UK Royal Navy’s Type 31 frigates and Queen Elizabeth Class aircraft carriers. The Type 31 is a general-purpose frigate set to replace five Type 23 warships in the Royal Navy. 
The Neptune 200 model is a key component of these platforms, and other Neptune systems have been exported to navies worldwide.

For non-retractable solutions

Gemini
Typically used on offshore patrol vessels, coast guard ships, and various military platforms. These trapezoidal stabilisers are designed to fit within the vessel’s beam.

Modular
Built to meet full military standards for noise, shock, and vibration, Modular stabilisers have been supplied to navies in Brunei, Malaysia, India, the USA, Australia and the UK. Covering fin areas from 2m² to 16.5m², these systems include a hull closing plate as an integral part of the fin unit, simplifying installation and reducing structural costs.

Meeting future demand

Kongsberg Maritime continues to support key coastguard and frigate programmes worldwide. Notably, the company has secured orders for Babcock’s export variant of the Arrowhead 140 frigate in Indonesia and Poland. These vessels will be equipped with the Neptune 200 retractable fin stabiliser system, which offers high efficiency, a longer lever arm, and installation flexibility on the widest part of the vessel’s beam. The Neptune design has evolved into the Mk2 version, originally introduced in 1993 for the commercial ferry market.
A multi-ship offshore patrol vessel (OPV) programme is also under way, with deliveries of the Gemini 20 system extending into 2027. The Gemini’s balance of technical features and Commercial Off-The-Shelf (COTS) technology helped secure the contract.

The Aquarius range remains strong, particularly for vessels operating in Arctic regions, including naval, coastguard, and fisheries protection platforms. Available in three sizes: 25, 50 and 100, the Aquarius stabilisers offer fin areas up to nearly 6m². Larger coastguard vessels have also been fitted with Neptune 200 stabilisers, with fin areas up to 7.48m².

Supporting mission-critical systems

Beyond stabilisers, Kongsberg Maritime is actively involved in global frigate programmes with its linear actuator steering gear and rudder systems. These designs meet Lloyd’s Register rules and feature baseplates tailored to specific ship configurations.

The company also provides worldwide commissioning and docking support, including seal changes, overhauls, and control system upgrades. These enhancements ensure older systems benefit from the latest technology, maintaining operational readiness and reliability.