Published in: Saturday, 25 April 2009
Features > Feadship Predator (Page 1/2)

Feadship Predator

Feadship’s Predator features a big rethink on exterior architecture – but what’s inside is even more surprising

When Feadship released Predator in early 2008, it caused a small frenzy among yachtsmen and yachtspotters. Suddenly, experts and laymen alike were discussing the pros and cons of various bow designs. The very first thing you notice about Predator is the axe-bow – a vertical bow with reverse arch at the top, with a fine entry for a wave-piercing effect. The 72.8-metre boat was feted as the first yacht from the Dutch yard to feature an axe-bow. Given the attention that has been lavished on Predator, it’s likely not to be the last.

Beyond the striking appearance of Predator, the builders at Koninklijke De Vries Scheepsbouw in Aalsmeer, Netherlands are keen to point out the hidden aspects of Predator’s design which, they say, are even more amazing than her exterior lines. Predator features a very tall engine room combined with a four-engine propulsion system, very long and uninterrupted views within the superstructure, and a large draught.

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Beginnings

Feadship’s research on axe-bow design began in 2003, with an inquiry into semi-submerged boats. That led the De Vries yard and the De Voogt Naval Architects to look again at the axe-bow design that was prevalent among steamships in the late 1800s. After some delays, Feadship entered into discussions with the owner of Predator, who was seeking an aggressive new design for his yacht. The primary requirement was for the boat to reach speeds of 25 knots, but without the use of waterjet engines or turbines. For a 70+ metre yacht, this was a challenge. High speeds on such a yacht result in high propeller blade loads if a conventional diesel-propeller propulsion set-up is used, creating high levels of noise and vibration. 

Predator has a hull form with low resistance. Seeing the hydrodynamic benefits of such an efficient displacement hull design and loving the raked look, the owner opted for the axe-bow and the Predator began to take shape. 

Jaap van Keulen, chief designer at De Voogt, was responsible for all external styling, accommodation arrangements and naval architecture. Predator’s profile flows in sleek fashion and emphasises the speedy nature of the boat. The use of red, blue and white, combined with the distintive shape of Predator, make for an umistakeable boat. If instant recognition is high on the owner’s list of priorities, then mission accomplished.

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Engineering

A long and slender yacht can torque and flex around its horizontal axis. Predator‘s hull is built on a longitudinal frame system that ensures maximum rigidity. While this was under construction, the axe-bow idea was being developed further, with tests showing that the axe-bow also offered major benefits with respect to motion comfort and sustaining speeds in rougher seas. Both these attributes have since been proven in practice. 

Predator’s skipper, Greg Drewes, says that “we have been in five-metre seas and Predator throws no bow wake. The V of the bow adds sufficient displacement as the bow enters a wave to give a very soft rise through the sea. There is no pounding and in smaller seas up to four meters she is as smooth as a flat sea. The lack of vertical movement makes Predator amazingly comfortable.” Predator’s ultra-slender angle of entry, combined with a bow that has considerably less resistance when rising, has resulted in an incredibly comfortable ride.

According to Drewes, trial runs showed smooth running, with an average of 20 knots with two engines at 1500rpm. With four engines at top RPM of 1800, Predator manages just over 27 knots, depending on fuel on-board and sea state. Yet, with Predator’s powerful prop blades, she can slow to zero knots in just over twice her boat length.

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Beyond the radical bow design and the razor-sharp entry point, Predator also employs a tremendous engine set. Four MTU 16V 595 TE90 diesel engines combine for a power plant that delivers over 23,000 brake horsepower. These engines drive Rolls Royce controllable pitch, 3.2-metre propellors. One result of the sheer size of these monstor props is a draught of 3.7 metres – the deepest yet that Feadship has produced. Predator’s captain can choose to engage either two or four of the engines, depending on the operation (slow cruising, long-range ocean-crossing, fast cruising, zero movement, etc).

To improve Predator’s speed performance, a strict weight control programme was put in place. An aluminum superstructure combined with composite materials on the topsides counters the weight of the steel hull. Many of the wood panels and marble tops on the inside are mounted on to honeycomb backgrounds. An AC ducting system based on aerospace technology and weighing just one-tenth of a normal system was employed.

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