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What is bulbuous bow ? Discuss its advantages and disadvantages.

  • A bulbous bow is a feature of many modern ship hulls
  • It is characterized by a protruding bulb at the bow (or front) of the ship below the waterline. Due to this, a bulbous bow is usually only visible when a ship is in drydock.
  • The presence of this bulb modifies how water flows around the hull, thereby reducing drag and affording an increase in speed, range, and fuel efficiency.
  • In ships that have had bulbous bows fitted, gains in fuel efficiency of between 12-15% are standard. As these factors are particularly important for almost all applications of maritime vessels, bulbous bows have seen widespread adoption since their development.
  • Despite their advantages, bulbous bows only achieve maximum effect at a narrow range of speeds, and at speeds exclusively over 6 knots .
  • At other speeds outside the range for which they were designed, bulbous bows can have the opposite effect and actually increase the drag. 
  • Finally, bulbous bows have the greatest effect when applied to large ships such as freighters, cruise ships, and navy vessels. 
  • Bulbous bows are rare on recreational boats as these vessels have wide speed ranges and are often designed to plane over the water at high speed.
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