Tag: bulbous bow

The observative ones may have wondered, what do these propellers near the vessel’s bulbous bow do?

Ships are extraordinary designs, which can amaze with their size. But there is one specific element of a ship’s design that stands out: the bulbous bow.

MOL confirmed that its wind resistance-reducing windshield for containerships reduces emissions of carbon dioxide by an average of 2%, after completing a in-service demonstration. The windshield, co-developed by MOL, was installed on the bow of its operated containership, MOL Marvel, for the demonstration test.

Walvis Bay-based Elgin Brown & Hamer Namibia undertook the repair of a collision-damaged bulbous bow of an oil product tanker, the Huascar. When a vessel needs to be repaired, the time taken by the shipyard to complete the project is critical, as every day that it is out of commission could potentially result in substantial lost revenue.

Mitsui O.S.K. Lines, Ltd. announced the hull design for the “FLEXIE”, its next-generation car carrier, which will be built at Minaminippon Shipbuilding Co., Ltd. and delivered in 2017.

  By 2016, 24 of the largest ships in Hapag-Lloyd’s fleet will get a new bulbous bow, and some will also be fitted with optimised propellers. This will enable the vessels to consume less fuel and produce fewer emissions. It’s as high as a truck, weighs about 250 tonnes and is a prominent feature at the very tip of the bow of modern container ships. This has little to do with aesthetics and much more to do with fuel efficiency. The bulbous bow – the nose of the ship – displaces water in a manner that mini-mizes or even completely eliminates a bow wave. The lower the water resistance on the hull, the less fuel a ship needs in order to travel at the same speed. If a ship’s fuel consumption decreases, its emissions also drop. “For this reason, we continuously analyse how to make our ships even more efficient,” explains Richard von Berlepsch, Managing Director Ship Management. As a result, this distinctive part of the vessel is now being retrofitted in four of Hapag-Lloyd’s biggest ship classes. One by one, the 13,200 TEU ships in the “Hamburg Express” class and the 8,750 TEU vessels in the “Colombo Express,” “Prague ...

  Maersk has issued a sustainability update to announce its target that by 2020 Maersk is committed to reduce CO2 emissions by 60% (in comparison with 2007 levels). Also, the company explains how radical upgrades of the existing fleet has improved fuel efficiency New, larger and more fuel- efficient vessels such as the Triple-E have captured industry headlines in recent years for their cutting- edge innovation. However, with an asset lifespan of around 20-30 years, the existing fleet should not be overlooked in all the excitement. Maersk Line is taking a close look at older ships in its fleet and applying new and existing fuel- saving technologies in order to enhance their efficiency and reduce their emissions. In September 2014, Maersk Line announced it would be investing up to USD 1 billion over five years in upgrades of existing vessels. This upgrade programme covers approximately 100 vessels and includes Maersk Line owned as well as leased vessels on long- term contracts. The technical upgrades will radically boost the fuel efficiency and significantly reduce the CO2 emissions.  At the same time, lower fuel consumption ensures that Maersk Line vessels stay cost competitive. Maersk Line sees an opportunity in upgrading of existing ...

Image Credit: WikipediaThe bulbous bow (bulb) is a very important part of the hull as it can potentially reduce the hull resistance considerably, or affect the resistance in a negative way.According to ABS 'Ship Energy Efficiency Measures Advisory' , the properly designed bulbous bow reduces wave-making resistance by producing its own wave system that is out of phase with the bow wave from the hull, creating a canceling effect and overall reduction in wavemaking resistance. The flow is more horizontal, reducing eddy effects at the forward bilge. Physical factors considered in bulb optimization include volume, vertical extension of the center of volume, longitudinal extension and shape. A bulb with a reverse pearshaped section is primarily effective at the design condition, pear-shaped bulbs work best for drafts below the design draft (i.e. ballast draft or partial load draft) and cylindrical shaped bulbs offer a compromise solutionThe characteristics of the bulbous bow must be carefully balanced with the shape of the entrance and the transition towards the forward shoulder and bilge. Bulbs are most effective at certain Froude number (speed-length ratio) and draft. Changes in speed and draft significantly change the wave created, such that reductions in draft or speed can actually lead ...