## Thursday, January 20, 2011

### Oasis of the Seas Bulbous Bow

Oasis of the Seas is currently the largest cruise ship in the world. With a cruising speed of 22.6 knots, this ship needs large propulsion power. In this short article, I want to discuss a little bit about her bulbous bow.
Bulbous bow of the Oasis of the Seas is a bulb located at the front of the cruise ship just below the waterline. This bulbous bow is an integral part of the ship's hull. People cannot easily see it from above the surface of the water. If the cruise ship is at a harbor or being repaired at a dry dock, we can walk to the front area of the ship and then see the bulbous bow. The material of the bulb is the same as the material for the ship's hull which is steel. Its form is not like a soccer ball but streamlined oval. This kind of form helps the sea water to flow around the hull without creating big waves that are part of the sea water resistance of the ship. When I was still in junior high school, I thought that the bulb was made to break ice. After studying Naval Architecture at Pattimura University in the Moluccan islands of Indonesia, I finally know that the bulbous bow is made not to break ice layers in the polar seas but to minimize the wave resistance of a ship. Today most large displacement ships have bulbous bow installed at their front part of their hulls.
 Bulbous bow
Theoretically the effective power that is needed to propel a ship at certain speed is determined by the total resistance that it has to overcome. For the simplicity of explanation, the total resistance of a ship consists of frictional resistance and wave making resistance. In the form of formula, we can write it as Rt = Rf + Rw. If the size and form of bulbous bow has been carefully calculated and tested before it is constructed at the bow (or front) part of the ship, it will significantly reduce the component of wave making resistance of the ship.
Bulbous bow at the cruise ship Oasis of the Seas is not a new invention. Most of large merchant vessels have bulbous bows installed at the front area of their hulls including the Thomson Celebration Cruise Ship from the Bahamas. With bulbous bow installation, the naval architects and marine engineers who design the ship can improve the ship's overall propulsive efficiency meaning that she can have better fuel efficiency. The purpose of this writing is to help customers of cruise ships understand the technical aspects of the ships without having to understand complicated formulas that are usually studied by students of naval architecture before they do more complicated tasks which are designing and constructing their dreamed ships.
I write this article to make introduce the study of naval architecture to anybody who is interested in cruise ships and other marine vehicles in general. If you come to this blog to find information related to Oasis of the Seas cruise deals and tickets, you have arrived on a wrong place. Please go to the official website of the Royal Caribbean International to get the required info.
Oasis of the Seas motor vessel
From the aerial view of this cruise ship, we cannot see the bulbous bow structure that is located at the front area of the cruise ship below the waterline