Hartmann unveils eco-friendly ethylene carrier

AUGUST 23, 2014 — Leer, Germany, headquartered ship operator Hartmann Reederei has released more details of the three Eco Star 36K design 36,000 cu.m LEGCs (Liquefied Ethylene Gas Carriers) ordered earlier this year by Norway's Ocean Yield ASA.

After delivery, Ocean Yield will charter them to Hartmann Group on 15-year "hell and high water" bareboat charters, where the first ten years have a fixed charter rate and the last five years a floating charter rate.

They will each be powered by a single MAN B&W ME-GI low-speed, diesel cycle, dual-fuel engine. The engines will run on ethane, marking the first time ethane has been used as fuel to propel an oceangoing vessel.

The ships will be built by Chinese shipbuilder Sinopacific Offshore & Engineering and are scheduled for August, October and December 2016 deliveries.

Developed in by Hartmann incooperation with engineering consultant HB Hunte Engineering, of Oldenburg, Germany, the Eco Star 36K differs fundamentally from conventional gas carriers, with its superstructure located at the bow. This results in optimized distribution of weight and, therefore, a reduced demand for ballast water, leading to reduced fuel consumption and emissions.

A new "svelte" bow design enables the vessel to improve seakeeping at higher transit speeds and improves fuel efficiency.

Hartmann says that the type of MAN B&W engine installed on board of these ships 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 also on ethane. It can also 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 design includes heavy fuel tanks of the same operating rane. If necessary, it is possible to switch over from gas to diesel fuel operation and vice versa immediately.

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 sheltered behind the superstructure. Its components will be provided by AC-INOX.

Unlike 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. Thanks to better utilization of cargo hold space, this results in higher efficiency and allows an increase in cargo capacity by nearly 30% within the same ship dimensions − leading to reduced shipping costs through higher economies of scale.

The new vessels offer a cargo capacity of 36,000 cum each for liquefied gas cargoes up to -104°C. Presently, these vessels are the largest LEG-carriers worldwide.

A long term subcharter for the three has been secured by Hartmann Group company GasChem Services with Saudi Arabian petrochemical company SABIC.

SABIC has just announced a cracker upgrade to enable its Teesside, U.K. cracker to use ethane from the U.S. as a feedstock. The Hartmann Group will conduct full vessel management for the ethane shipments, ensuring the regular deliveries to SABIC's Teesside cracker.

Main Dimensions
Length o.a.: approx. 188 m
Length b.p.: approx. 179 m
Breadth, molded: 29.00 m
Depth to main deck, moulded: 17.50 m
Depth to trunk deck: approx. 23.50 m
Design draft (ethane): 9.50 m