United Kingdom: Classification society DNV has unveiled a new crude oil tanker concept. The Triality concept VLCC is fueled by LNG, has a hull shape that obviates the need for ballast water and very greatly reduces local air pollution.
The new crude oil tanker has a hull shape that removes the need for ballast water and will almost eliminate local air pollution. This concept vessel also recovers hundreds of tonnes of cargo vapours on each voyage and represents a major step towards the new environmental era for the tanker shipping industry, according to DNV.
The new crude oil concept vessel, named Triality, has been developed through a DNV innovation project.
DNV CEO Henrik O. Madsen, who presented the new concept in its VLCC version in the UK, said: "I am convinced that gas will become the dominant fuel for merchant ships. By 2020, the majority of owners will order ships that can operate on liquefied natural gas (LNG)."
The Triality concept VLCC has been compared to a conventional VLCC. Both ships have the same operational range and can operate in the ordinary spot market. Compared to the traditional VLCC, the Triality VLCC will emit 34 percent less CO2, and use 25 percent less energy.
The new concept tanker has two high-pressure dual fuel slow speed main engines fuelled by LNG, with marine gas oil as pilot fuel. The next phase of the Triality concept development will review the use of dual fuel medium speed engines and pure gas engines.
Two IMO type C pressure tanks capable of holding 13,500 cubic-metres of LNG – enough for 25,000 nautical miles of operation – are located on the deck in front of the superstructure. The generators are dual fuel (LNG and marine gas oil) while the auxiliary boilers producing steam for the cargo oil pumps operate on recovered cargo vapours (VOCs).
The new V-shaped hull form and cargo tank arrangements completely eliminate the need for ballast water in the VLCC version. There will also be much less need for ballast water on other kinds of crude oil tankers, such as Suezmax, Aframax and smaller ships. The new hull shape results in a reduced wetted surface on a round trip and has a lower block coefficient and thus a more energy efficient hull.
The Triality VLCC can collect and liquefy more than 500 tons of cargo vapours during one single round trip. These liquefied petroleum gases will then be stored in deck tanks and up to half will be used as fuel for the boilers during cargo discharge, while the rest can be returned to the cargo tanks or delivered to shore during oil cargo discharge.
