Their delivery is scheduled from the second half of 2016 onwards.
The revolutionary design was developed by Leer-based shipowning concern Hartmann Reederei together with engineering consultants HB Hunte Engineering.
This new concept- ECO STAR 36K - differs from conventional gas carriers, Hartmann claimed, as its superstructure will be located at the bow. This results in optimised distribution of weight and, therefore, a reduced demand for ballast water − which at the same time leads to reduced fuel consumption and emissions.
The new ‘svelte’ style bow design enables the vessel to improve seakeeping at higher transit speeds and gives more fuel efficiency, the company said.
ECO STAR 36K will be powered by the latest generation of MAN Diesel & Turbo’s dual fuel 2-stroke engine. Its low emissions meet the requirements of IMO Tier II.
They will be able to operate on HFO, MDO and gas oil, as well as LNG and, as a first, on ethane. Furthermore, they will be able to utilise the boil-off gas from their cargoes. The vessels’ separate gas fuel tanks are constructed to hold both ethane and LNG and will give an operating range of about 10,000 nautical miles. In addition, the design encompasses heavy fuel tanks fitted for the same distance. If necessary, it is possible to switch over from gas to diesel operation and vice versa immediately.
Each vessel will be fitted with an MAN Kappel propeller and a rudder bulb system plus a twist-flow rudder developed by HB Hunte Engineering. Ship model tests at Hamburgische Schiffbau-Versuchsanstalt (HSVA) resulted in reduced energy loss and improved propulsion efficiency for this system, Hartmann said.
The gas plant, which was also jointly developed by Hartmann Reederei and HB Hunte Engineering and will be located in a sheltered space aft of the superstructure. Its components will be provided by AC-INOX.
A long-term agreement was secured by Hartmann Group company GasChem Services with Saudi Arabian petrochemical company SABIC to operate the first three vessels. The Hartmann Group will conduct full vessel management for the ethane shipments.