Norden Ship Design’s Super Efficient General Cargo Vessel
Norden Ship Design was established almost a decade ago in Istanbul, Turkey and since then has provided design, engineering and consultancy services to ship owners, shipyards and other marine related companies. The company’s latest project is its ECO1 series – the first vessel of which is already in operation. The 79m Pirgos, with its RINA Green+ notation, is a general cargo vessel that has unrivalled environmental qualifications.
Green Credentials
From day one, Norden Ship Design’s approach has been to deliver innovative, cost effective and client-oriented design solutions. The company structure is versatile and enables the forming of individual teams to support different projects in parallel.
Norden actively invests in R&D activities to create new concepts that are more efficient, cost effective and environmentally friendly. The company’s portfolio comprises more than 30 ship designs which, to meet project requirements, are all unique. A prime example of the company’s successful R&D programme is its Norden ECO1 series – a vessel that has unmatched environmental credentials.
New Bow Form
“We started to develop the concept of this new series in 2013,” informs Norden Ship Design Business Development Manager Haldun Yildiz. “The first one that went into construction was the Pirgos – a 9,000dwt general cargo vessel. The original design capacity was 7,600dwt, but our efforts made it possible to meet more stringent damage stability requirements and classed the vessel as ‘Type B-60’. This allowed the vessel to have 60 percent reduced freeboard, hence the capacity increase.”
The hull shape, especially the new bow form, was created in-house. “Our design has been verified with CFD analysis, followed by model tank tests,” continues Mr Yildiz. “The bow shape reduced the wave resistance almost down to zero, while maintaining excellent sea-keeping characteristics.” In addition, the lack of a bulbous bow gives greater flexibility in the economic speed range. FE Analysis optimised the lightship weight of the vessel.
Sea Trials
Verified by model tests, the vessel was expected to sail at 13.5 knots with a two stroke 2,260kW main engine. “The engine is mated to a specially designed high efficiency propeller with Boss Cap Fins, which breaks the hub vortex,” explains Mr Yildiz. “This alone has reduced the fuel consumption by 7 percent compared to more traditional propeller setups.” Exceeding the model testing expectations, during sea trials the Pirgos achieved a top speed of 13.9 knots at ballast draft and 13.5 knots while fully loaded.
The vessel continued to surpass design expectations during her maiden voyage: “She sailed fully loaded at an average speed of 12 knots and consumed only 7 tons of HFO per day – and that is including the consumption of auxiliary generators.”
Class-A Efficiency
What is outstanding about the Pirgos’ design, however, are her environmental qualifications. “We have obtained the voluntary RINA Green+ notation and Green passports complying with IMO Ship Recycling Recommendations. Our design is the first in the world to obtain Green+ notation in this tonnage, and the second cargo vessel that has ever received this notation.”
The vessel is the world’s most efficient general cargo ship between 8,000 and 10,000dwt, according to ShippingEfficiency.org. This web-based initiative aims to increase the awareness regarding the energy efficiency of international shipping. In measuring a ship’s efficiency, it considers a number of factors such as fuel consumption and CO2 emissions. By slowing down to 10 knots (50 percent MCR + 5 percent sea margin), she uses just 5.5 tons of HFO.
“The major factor behind the efficiency figure is the hull form,” highlights Mr Yildiz. “This scalable form is used in our eco series design from 2,000 up to 23,000dwt, which is applied to dry cargo vessels and tankers.”
Solar at Port
“Although hull design and engine selection obviously both play a major role in how efficient a ship is, there are more onboard systems that effect a vessel’s consumption figures whether directly or indirectly,” says Mr Yildiz. “As part of the goal of creating a green vessel with low emissions, the Pirgos also features additional technologies and systems.” For example, the wheelhouse has a 20kW solar panel capacity and the vessel is also capable of cold ironing at port. By combining these two characteristics, the vessel achieves zero emissions while at port. Furthermore, the Pirgos has computerised fuel consumption monitoring and software to achieve the most efficient draught and trim in addition to frequency converters for pumps and main engine ventilation fans and low energy consuming lights.
