New Lightness

Photo | Baltic Yachts
Marginal Column

Above: Right on course: the Hetairos sets new standards in naval architecture and technical equipment.
Photo: Baltic Yachts

Photo | Bosch Rexroth AG

Baltic Yacht's Hetairos

November 2012


The largest yacht ever built with lightweight materials is pointing the way to the future of shipbuilding. Also on board are leading-edge hydraulic systems made by Rexroth.


Baltic Yachts, specializing in high-performance cruisers, long kept developments under wraps. The only leak from the dock­yards at Pietarsaari, Finland, on the Gulf of Bothnia, was: an imposing yacht was being built using lightweight composites. Its name: Hetairos, an ancient Greek word for “companion”.

Unique due to high tech

Measuring 67 meters in total length, with the taller of the two masts reaching 62.5 meters into the salt air, the dimensions of the Hetairos are certainly phenomenal, but that’s not what’s actually so unusual. The ship is built using carbon fiber composites throughout: hull, deck and superstructures, even certain assemblies, engine mounts, piping and exhausts. This has never been seen before. The marine architects have saved an enormous amount of weight; the ship displaces just 230 tons. In modern yachts of a similar type, that figure is more than double.

A bit more keel?

The heart of the yacht is the integrated hydraulic system engineered for dual use. It drives not only the yacht itself, but the on-deck systems, as well. That means less weight and more space. The drive system comprises two 360-degree rotatable propellers (OYS), making for precise control when maneuvering in tight harbors. The engines also accelerate Hetairos up to 15 knots, or about 28 kilometers per hour. Usually, however, this vessel upholds the traditions of its class and moves exclusively with the force of the wind. To ensure that the ship glides over the waves with less underwater resistance, both the drives can be retracted into the hull. The keel is similar. Depending on the depth of the water and the desired degree of stability, it can be extended from three and a half to six or nine meters.

Marine & Hydraulics Finland, a system integrator for Bosch Rexroth, worked closely with Baltic Yachts to develop the inno­vative tailor-made hydraulic system by using standard components by Rexroth. They also provided support during testing and commissioning. Four main engines (more than one hun­dred hydraulic devices on board) heed the commands of a Marex OS II system. A BODAS control unit, normally utilized in land vehicles, is integrated here between the Marex system, the main engine and the propulsion units. It coordinates both of the tasks assigned to the hydraulics: propulsion and control.

Thus the Hetairos sets new benchmarks in naval architecture, not only in terms of the engineering, but also in regard to the technical equipment. This also has been acknowledged by the yachting world at the World Superyacht Awards with the exclusive prize for “for her notable contribution to the technical ad­vancement of sailing superyachts.”