World’s First Ethane Fuelled, Eco-friendly LEG Carrier
In co-operation with engineering consultants HB Hunte Engineering, Hartmann Reederei of Leer developed a unique, new type of vessel: Ethylene Carrier ECO STAR 36K with “Svelte”-bow design.
The new vessel type differs fundamentally from conventional gas carriers: As the first of its kind, its superstructures will be located at the bow. This results in optimized distribution of weight and, therefore, a reduced demand for ballast water − which again leads to reduced fuel consumption and emissions at the same time. The new “Svelte” bow design enables the vessel to improve sea keeping at higher transit speeds and improved fuel efficiency.
The latest generation of the MAN B&W dual fuel 2-stroke engine on diesel combustion principle will be installed on board of these ships. This type of engine is characterized by its particularly high reliability and low fuel consumption. Its low emissions meet the requirements of IMO Tier II.
ECO STAR 36K will be able to operate on HFO, MDO and gas oil, as well as LNG, and, as a world novelty, on ethane. Furthermore, it can utilize the boil-off gas from its cargo. The vessel’s autonomous gas fuel tanks are constructed for ethane and LNG and enable an operating range of about 10,000 nautical miles.
Additionally, the novelty design encompasses heavy fuel tanks for the same distance. If necessary, it is possible to switch over from gas to diesel operation and vice versa immediately.
The propulsion efficiency will be further improved by adopting a MAN Kappel propeller with rudder bulb system and 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.
The gas plant, which was jointly developed and realized by Hartmann Reederei and HB Hunte Engineering, will be located in a sheltered place behind the superstructure. Its components will be provided by AC-INOX.
The cargo tanks present another world innovation. Compared to conventional gas carriers with cylindrical or bilobe tanks, ECO STAR 36K adopts a new tank design developed by Hartmann Reederei: the „Star-Trilobe“-tank. This design consists of three cylinders combined into one. Due to better room utilization of the cargo holds, this results in higher efficiency and allows an increase in cargo capacity by nearly 30% at the same ship dimensions − leading to reduced shipping costs through higher economies of scale.
The new vessels offer a cargo capacity of 36,000 cbm each for liquefied gas cargoes up to -104°C. Presently, these vessels are the largest LEG-carriers worldwide.
In co-operation with the Norwegian ship owning company Ocean Yield, three vessels of this type have already been ordered at the Chinese shipyard Sinopacific.
Their delivery is scheduled from the second half of 2016 onwards.
For the first three vessels of this type, a long-term agreement was secured by Hartmann Group company GasChem Services with Saudi Arabian petrochemical company SABIC. The latter just announced a cracker upgrade to using ethane from the U.S. as feedstock in their cracker in Teesside, United Kingdom.
The Hartmann Group will conduct full vessel management for the ethane shipments, ensuring the regular deliveries to SABIC’s Teesside cracker.
Length o.a.: approx. 188 m
Length b.p.: approx. 179 m
Breadth, moulded: 29.00 m
Depth to main deck, moulded: 17.50 m
Depth to trunk deck: approx. 23.50 m
Design draught (ethane): 9.50 m