Boat Like a Self-Righting Bath Toy

The latest rescue vessel commissioned by the Royal Netherlands Sea Rescue Institution (Koninklijke Nederlandse Redding Maatschappij, KNRM) from Damen Shipyards has passed a number of capsize trials with great results. 

The KNRM’s rescue vessels, which have to be deployable in all weather conditions, are being designed to the most rigorous standards. This latest vessel’s self-righting capability was created by its low point of gravity and the air bubble in the wheelhouse which enables the capsized ship to right itself quickly, like a self-righting bath toy. The engines and equipment on board are designed to continue operating even after the vessel has capsized.

In its nearly 200-year history, the KNRM has lost 69 rescuers to drowning. Most of those drownings occurred when rescue rowboats capsized in the first 100 years. The advent of motorized, self-righting rescue vessels not only increased safety, but deployability as well. Nowadays, rescue missions under weather conditions that would have forced rowboats to abandon their mission can simply continue. This means that risks have increased as well. 

Since 1990, at least twelve rescue vessels have capsized. Two of them, from Terschelling and Ameland, were examples of the largest category of rescue vessels and were able to handle extremely poor weather conditions. Thanks to their unique features, the rescue vessels were able to continue sailing and bring their crews of volunteers safely back to shore. 

The KNRM expressed its need for a completely new type of rescue vessel in 2008. Thanks to a donation to the KNRM from Dutch insurance company Noordhollandsche 1816 (NH 1816), the design phase could begin in collaboration with Damen, the Maritime Technology faculty at Delft University and De Vries Lentsch Naval Architects.

The vessel features an aluminium hull, composite wheelhouse and a modified Sea Axe Bow which cuts through waves, reducing vertical g-forces by 45 per cent and enabling top speeds of over 30 knots, radically transforming seaworthiness. The Sea Axe was originally designed by prof. Lex Keuning (Delft University of Technology) and Damen Shipyards Group. 

In addition to the Axe Bow, the NH 1816 is outfitted with retractable rear fins that can be lowered for more course stability, or raised to give extra maneuverability. In the wheelhouse, state-of-the-art fully integrated electronics permit real-time data exchange for ship-to-shore communications (an earlier version of this system is already approved by the RNLI in the UK). Crew working conditions have been considerably enhanced by not only limiting the slamming motion of the vessel, but also by a host of ergonomic features, such as specialized chairs, climate control, improved visibility and reduced vibration and noise levels.

The vessel’s dimensions are generous, giving extra space not only on deck, which can accommodate 125 people, but also in the engine room. This gives staff better access to machinery, improving maintenance conditions and effectiveness.

The official delivery ceremony will take place in April when the KNRM will deploy the SAR NH 1816 from IJmuiden with a permanent captain and an on-call crew.