drag. At greater speeds and in larger vessels it is the bow wave that is the greatest force impeding the vessel's forward motion through the water. 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. As the wave counter effects are only significant at the vessel's higher range of speed, bulbous bows are not energy efficient when the vessel cruises outside of these ranges, specifically at lower speeds. Bulbous bows may be configured differently, according to the designed interaction between the bow wave and the countering wave from the bulb. Design parameters include: a) upward curvature (a "ram" bulb) versus straight forward (a "faired-in" bulb), b) bulb position with respect to the waterline, and c) bulb volume. Bulbous bows also decrease a ship's pitching motion, when they are ballasted, by increasing the mass at a distance removed from the ship's longitudinal centre of gravity. Development Towing tests of warships had demonstrated that a below-water ram shape reduced resistance through the water before 1900. The bulbous bow concept is credited to David W. Taylor, a naval architect who served as Chief Constructor of the United States Navy during the First World War and who used the concept (known as a bulbous forefoot) in his design of the , which entered service in 1910. The bow design did not initially enjoy wide acceptance, although it was used in the to great success after the two ships of that class which survived the Washington Naval Treaty were converted to aircraft carriers. This lack of acceptance changed in the 1920s, with Germany's launching of and . They were referred to as Germany's North Atlantic greyhounds, two large commercial ocean liners that competed for the trans-Atlantic passenger trade. Both ships won the coveted Blue Riband, Bremen in 1929 with a crossing speed of , and Europa surpassing her in 1930 with a crossing speed of 27.91 knots. The design began to be incorporated elsewhere, as seen in the U.S. built SS Malolo, SS President Hoover and SS President Coolidge passenger liners launched in the late 1920s and early 1930s. Still, the idea was viewed as experimental by many shipbuilders and owners. In 1935 the French superliner was designed by Vladimir Yurkevich combining a bulbous forefoot with massive size and a