Bulbous Bow Benefits

Ever since the 62 was built, P.A.E started to do a large-scale tank testing on their newer hull models in order to determine the hydrodynamic features of the hulls focusing on the “seakeeping” and resistance qualities. Most of the displacement hulls of Nordhavn’s have been tested using bulbous and conventional bows. The bulbous bows have been around for some time now where they are commonly used on freighters, tankers, and other large fishing vessels because the bows minimize hydrodynamic drag at the regular speed of most ships, which in turn, provide the ship with bigger savings when it comes to fuel throughout the lifespan of the ship.

The interest of P.A.E on bulbous bows was initially focused on improving the ship’s efficiency, minimizing resistance, and boosting its range. By tweaking the bow wave, there is a noticeable 3 to 15 percent in reduction of resistance depending on the model of the hull including its traveling speed. This particular resistance reduction in making waves minimizes horsepower usage depending on the speed of the boat while at the same time increasing its range and reducing engine noise and engine rpm. Although the main purpose of bulbous bows was to boost the efficiency of the hulls, the tests showed that there was a reduction in the pitch of the hulls on certain Nordhavn models. The Nordhavn 62’s pitch amplitude was reduced up to 20% while the acceleration of the pitch was reduced up to 18%, which contribute greatly to the boat’s “seakindliness” regardless of the sailing conditions.

Today, the bulbous bow is being offered as an option for those who are interested in buying larger Nordhavn ships starting with their very own N76. For the N120, on the other hand, a wave reduction up to 10% was determined after tank testing. A buyer’s decision to purchase a bulbous bow can be influenced by different factors such as cruising locations and habits plus most of the larger Nordhavn boats already have a bulb installed when they are removed from the factory. As a matter of fact, all N86 boats have a bulb built in.

However, for smaller yachts, the presence of the bulbous bow is actually more of an inconvenience because of the amount of noisy slapping or pounding on the hull especially when traveling on rough seas. Nordhavn has opted to not install bulbous bows on their smaller boats to minimize noise when cruising regardless of how it can help improve fuel economy on the N55, N47, and other smaller boats in their fleet.