Damen, Hydromaster Develop New Ferry Thruster

In 2020, Damen signed a contract with Blue Amigo for the delivery of nine passenger vessels to operate between Rotterdam and the Drecht cities in the Netherlands in a service known as the Waterbus. Damen identified that six of the vessels – hybrid carbon fiber water buses that will operate fast, inter-city routes – would require a unique thruster solution, a fully azimuthing, 360-degree thruster to make docking easy and propulsion fast.

“It’s actually the kind of thruster you would expect to see on a pleasure craft,” says Damen design and proposal engineer Ferries Jan van Ooijen. “On a passenger vessel, though, we needed something more maneuverable and robust.”

Damen approached Hydromaster, a company with decades of experience in the field of steerable propulsion. Renowned for its sturdy, fully-mechanical design, Hydromaster thrusters propel hundreds of ferries, ships, barges and pontoons globally.

The two companies joined forces to develop this new thruster, as Hydromaster commercial manager Jan Terlouw explains. “We had already been working on something that would meet these requirements. A 375kW thruster, able to operate at speeds of up to and beyond 25 knots and durable enough to cover over 4,000 hours each year. But we had never built it. Once Damen signed its contract with Blue Amigo, we got the green light to go ahead.”

Before that, however, Hydromaster went to MARIN. The Maritime Research Institute Netherlands worked together with Hydromaster to develop the hydromechanics necessary to produce the thruster. MARIN was able to provide the detailed calculations that would facilitate a computational fluid dynamics (CFD) study and the fine-tuning of Hydromaster’s design.

MARIN was able to come up with the solution – a propeller of 840mm diameter with a clearance of 23% diameter from the hull -reducing vibration to a minimum and allowing for increased efficiency. For control of the thruster, Damen has developed in-house a single joystick controller.