Bulbous bow

The flare or bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability.

For a vessel that is small or spends a great deal of its time at a slow speed, the increase in drag will not be offset by the benefit in damping bow wave generation.

The bow design did not initially enjoy wide acceptance, although it was used in the Lexington-class battlecruiser to great success after the two ships of that class which survived the Washington Naval Treaty were converted to aircraft carriers.

[9] In 1935 the French superliner Normandie was designed by Vladimir Yurkevich combining a bulbous forefoot with massive size and a redesigned hull shape.

A far more radical bulbous bow design solution was incorporated into their massively large Yamato-class battleships, including Yamato, Musashi and the aircraft carrier Shinano.

Inui based his research on earlier findings by scientists made after Taylor discovered that ships fitted with a bulbous forefoot exhibited substantially lower drag characteristics than predicted.

Inui's initial scientific papers on the effect of bulbous bow on wave-making resistance were collected into a report published by the University of Michigan in 1960.

Experimentation and refinement slowly improved the geometry of bulbous bows, but they were not widely exploited until computer modelling techniques enabled researchers at the University of British Columbia to increase their performance to a practical level in the 1980s.

The higher the speed, the bigger the benefit of the bulbous bow in diminishing the necessity for a longer water line to achieve the same power requirement.