Kongsberg Kamewa waterjets – 40 years and counting

Waterjets have become the de facto standard for high-speed vessels both large and small, especially those required to operate in shallow waters, and this year Kamewa waterjets celebrates 40 years as a driving force within the waterjet industry. Now part of the KONGSBERG group, Kamewa’s steel and aluminium waterjets – with powers from 260kW to a massive 36,000kW – can be found on high-speed military, leisure and transport craft across the globe.

Kongsberg Kamewa waterjets road to becoming a major player in the waterjet industry began in Sweden in the 1880s when Karlstads Mekaniska Werkstad, a manufacturer of water-driven turbines, contracted the nearby Kristinehamn Mekaniska Werkstads Aktiebolag to assist in the fabrication of turbine parts, and later bought the company. Founded in 1849, the Kristinehamn factory had started as a railway wagon repair shop, but by the time of its purchase had diversified into shipbuilding as well as making steam machinery for transport, agriculture and shipping. The newly-formed company – which would become known as Kamewa – continued to develop water turbines, acquiring sole rights to the adjustable-pitch Kaplan turbine in 1913. This led to further diversification into propulsion, with the launch of a controllable-pitch propeller in the 1940s and tunnel and azimuthing thrusters in the 1970s.

This expertise in turbines and propulsion was the perfect grounding for waterjet development, and Kamewa delivered its first contract – two steel 1,200kW units for the Hongkong Macau Hydrofoil company’s new catamaran ferry Apollo Jet – in 1980. Orders for three sister vessels soon followed, and by 1984 Kamewa had 50 units in service or on order across Europe and southeast Asia, with power deliveries up to 10,000kW. In 1986, Kamewa became part of the Vickers Group.

Meanwhile FF Jet – based in Kokkola, Finland – had developed their own aluminium waterjets, launched in 1985 and delivering lower powers but with lighter weights than the steel units from Kamewa. Vickers purchased FF Jet in 1994, integrating the two portfolios to form the basis of the current Kamewa waterjet range. Vickers became part of Rolls-Royce in 1999, who were later acquired by KONGSBERG in 2019.

Kongsberg Kamewa waterjets today

Today, Kongsberg Kamewa waterjets remains proud of its heritage and continues to operate in both Kokkola and Kristinehamn. The current waterjet range is split into two broad categories, following the original division between the founding companies: those using all-steel construction and mixed-flow pumps, and aluminium waterjets with axial flow pumps.

The steel units are now in their fourth generation since that first contract in 1980, and many customers will be familiar with popular S2 series, which launched in 1989 and stayed on the market for an impressive 16 years. The range now comprises the flagship S4 models, introduced in 2013, and the lower cost but still highly efficient S3/CA range, launched in 2009 and based on the 2005 S3 generation of pumps. They are fitted to a wide range of high-speed craft including fast ferries, luxury yachts and military vessels such as the US ‘Freedom’ class Littoral Combat Ships (LCS). The 10,000th unit entered service in 2018 on Seastreak Commodore, one of four jets which combine to propel the 765-seat ferry to 39 knots.

For some time, the axially-pumped FF series aluminium jets – with all components except the impeller shaft and steering/control rods made from aluminium – coexisted with the A-series, a hybrid solution with a lightweight aluminium structure teamed with the stainless steel mixed-flow pumps from the S-series and a stainless nozzle. The ‘FF’ designation, which harked back to the earliest days of Kamewa, finally retired together with the mixed-flow A-series in 2018 when the new A5 pump was launched. Similar to the FF pumps, with aluminium construction and an axial pump, the new design provides greater thrust in a footprint approximately 20% smaller.

Looking to the future

The team at Kongsberg, some of whom have been at the company since that first installation in 1980, work closely together across both sites to keep Kongsberg Kamewa waterjets at the forefront of technology. Significant investment was made into the product centre in Kokkola in 2017, and the hydrodynamic research facility in Kristinehamn was key to the development of the A5 waterjet, carrying out extensive Computational Fluid Dynamics (CFD) analysis and model scale testing. As part of Kongsberg Maritime, known globally as a forward-looking force in the maritime industry, the motivated team of specialists at Kamewa can both look back with pride on a notable success story in innovative propulsion with over 10,000 units delivered, and ahead to a future at the forefront of waterjet design.

“Forty years is a great milestone for our waterjet business and I am thankful to our fantastic customers for their trust in our products and services. With over 10.000 waterjets delivered, we are most proud to be part of so many of our customer’s success stories: From large trimarans and catamarans to super yachts and smaller Special Forces delivery crafts. Waterjet technology is young compared to more conventional propulsion systems; however, it has quickly proven itself as the leading solution for high-speed crafts. Together with our great team and business partners, we are determined to continue to deliver propulsion solutions for application where safety, efficiency, reliability, and high maneuverability are important.”

Tomas Renlund, SVP Waterjets

“From day one, we have been dedicated to being the front-runner in Waterjet technology and are fully dedicated to continuing to provide our customers with the latest and greatest products. Our new home with Kongsberg positions us perfectly to provide you with new solutions for future high-speed craft demands by combining Kamewa Waterjets top mechanical and hydrodynamic engineering skills with the strong digital and electrical capabilities of Kongsberg.”

Fredrik Appel, General Manager Product, Waterjets