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Oshima develops LNG bulker

The Naval Architect: July/Aug 2015

A new environmentally friendly bulk carrier design has been developed by Japan’s Oshima Shipbuilding Company which recently received approval in principle for a new LNG-fuelled Kamsarmax bulk carrier from classification society DNV GL.

The new design complies not only with DNV GL class rules, but with all current and upcoming regulations, including the new emission control regulations and the draft IGF Code for fuel with a low flashpoint.

As regulations on harmful ship emissions such as sulphur become stricter, reducing SOx, NOx, CO2 and particulate matter is at the top of the agenda for many players in the maritime industry. As a result, shipowners and operators are increasingly looking into the use of alternative fuels to ensure compliance for their fleet, now and in the future.

“LNG is emerging in a number of ship sectors and has great potential. We were very pleased to work on this innovative design with Oshima. It offers customers a flexible, safe, future-proof solution and the opportunity to almost eliminate SOx emissions and particulate matter, cut NOx by 80% with EGR (Exhaust Gas Recirculation) and reduces CO2,” says Morten Løvstad, DNV GL bulk carrier business director.

As space on deck is limited on a bulk carrier, the design includes changing the ship’s superstructure to a U-shape that can accommodate the LNG tank in its centre. This approach allows the accommodation deck house to be completely separated from the LNG storage tank and scalability in terms of the amount of LNG storage onboard. Meanwhile, a tank cover adds an additional safety barrier and ensures compliance with the draft IGF Code. The bunkering stations for LNG, heavy fuel oil (HFO) and marine diesel oil are located at the side of the accommodation deck house, DNV GL explains.

Tatsurou Iwashita, director and general manager of the design department at Oshima, points out: “One of the main factors for shipowners and operators considering the use of LNG as a ship fuel is the space required to store LNG on board. But as a result of our changes to the superstructure, our design does not reduce the vessel’s cargo capacity. Combined with its dual fuel capabilities, this should make the design very attractive for charterers, especially for trade routes where the LNG fuel price is competitive to HFO and substantially cheaper than marine gas oil (MGO).”

The Kamsarmax vessel is designed for dual fuel operation, using both LNG and HFO to power the main engine, the generators and the boiler. The LNG handling system for receiving agreement in principal was supported by Mitsubishi Heavy Industries. Oshima’s latest Panamax/Kamsarmax hull design provided the basis for the vessel’s shape. This design has proved successful, and its fuel performance is well documented, providing the experts with important operational data they could use to adapt the design to LNG operation, DNV GL says.

The vessel’s parameters are also based on data generated in a DNV GL feasibility study from 2014 that examined the use of LNG in a trade route between Europe and North America from a technological and economic perspective. “Taking all relevant factors into account, we found that a LNG-fuelled Kamsarmax bulk carrier, which only uses LNG in Emission Control Areas, would require 500­700m3 of LNG and one bunkering operation for a round trip between Europe and North America,” says Løvstad. If it were powered with LNG for the entire voyage, it would require 2,000­2,500m3 of LNG.

Oshima Shipbuilding and DNV GL had already co-operated on several innovative bulk carrier concept designs in the past, and Oshima already had a Kamsarmax design which was highly optimised from a hull resistance and cargo capacity point of view, and so the two parties decided to  join forces again  in order to develop a state-of-the art LNG fuelled Kamsarmax design.

A joint development project was started with the objective to develop a commercially attractive and flexible design that can accommodate any LNG volume requirement up to about 2,500m3 (in case of an IMO type C-tank) and about 3,000m3 (in case of an IMO type B-tank) as well as being able to accommodate both LNG type C and type B tanks at the same dedicated deck space.  This means it is possible to keep the same cargo capacity as a conventional oil fuelled bulk carrier. The most significant modifications are done on the superstructure and in the engine room, DNV GL explains.

On a bulk carrier, the available space on deck is limited and therefore major modifications were required in the superstructure in order to accommodate the LNG tank(s) with the main priority to keep the existing vessel cargo capacity. The LNG tank(s) (either IMO type C or B, depending on the required LNG volume) are protected by a steel cover forming a box which is part of the hull structure and provides additional safety in case of dropped objects, gas leakage or fire. This arrangement allows the accommodation deck house to be completely separated from the LNG storage tank. The tank cover also adds an additional safety barrier and offers full compliance with the draft IGF Code.

The bunkering stations for LNG, HFO and marine diesel oil are located at the side of the accommodation deck house. Main and auxiliary engines are dual fuel as well as the boiler. From the storage tank, LNG flows to the gas preparation room which is located at the port side of the vessel offering additional safety with regards to the position of the free fall lifeboat. Following the gas preparation room, gas is fed to the dual fuel engines for combustion.

The vessel has been designed on an existing, already successful hull design, meaning that the vessel fuel performance is already well documented. The vessel can be ordered as gas fuelled or gas ready. By using the DNV GL GAS READY notation the vessel is prepared for future retrofit of LNG equipment.

This gives the flexibility for the owner to postpone a major part of the additional CAPEX, but still having the flexibility to install the LNG tank and gas fuel supply system at a later stage without incurring significantly extra costs compared to doing such installation during vessel construction. Further, the innovative accommodation arrangement makes retrofit installation easier than for a conventional design, and will have a competitive advantage in the future.

As far as compliance with existing regulations are concerned, according to Alex Chiotopoulos of DNV GL, owners choose which engine manufacturer they want, for example Wärtsilä or MAN,  as each manufacturer has its own technical solutions in order to comply, for example with US environmental requirements. The main advantage he says is that the performance of the vessel is maintained while large quantities of gas can be carried.

Meanwhile Deltamarin has received an order from Vulica Shipping for its B.Delta68 SUL (self-unloading) vessels design. The order for the two bulk carriers was placed with the Chinese Jiangsu Hantong Ship Heavy Industry.

Deltamarin’s contract with Hantong shipyard covers design approval, procurement handling and site assistance. The contract value is about €3 million (US$3.3million) and the estimated contract period is 10 months. Delivery of the vessels is planned to take place before July 2017.

The B.Delta68 SUL is a Panamax-sized self-unloading bulk carrier featuring a state-of-the-art, fuel efficient and environmentally friendly design. The vessel design is developed by Deltamarin and tailor-made for the customer’s special purposes. The ships will comply with the most stringent environmental regulations, Deltamarin says.

The design is based on the fully tested hull of the larger B.Delta82, but with shallower draught. The overall length of the vessel is 229m, 32m across the beam with a maximum draught of 12.8m. The guaranteed service speed shall be at least 13.5knots. According to Konstantinos Fakiolas, sales director at Deltamarin: “Once launched the vessel will be the most efficient and modern SUL bulk carriers on a worldwide scale”.

The B.Delta Series comprises a design family with capacities ranging from 25,000dwt up to 210,000dwt. The designs cover both standardised industry sizes (handy, handymax, ultramax, kamsarmax, newcastlemax) and cargo-volume sized ships for more niche markets. As a result of the flexibility of the design, the ships can be tailor-fitted for various cargo types, ice-class notations, Laker versions, self-unloaders and other specialised trades. The B.Delta designs offer advantages like low fuel oil consumption, low emissions, EEDI compliance, high deadweight intake and optimised lightweight particulars.

The current orderbook of the B.Delta family includes 121 ships, mostly of the B.Delta37 and B.Delta43 types, but also self-unloader and Laker ships. B.Delta derivatives, such as chemical tankers, are also under construction in China.

In total, already 40 B.Delta ships have been delivered from six different shipyards in China to nine shipowners.

Meanwhile Turkey-based Ecoships recently included a customised version of the Six Sigma DMAIC as a means of optimising the energy efficiency of ships under its management.

The company says fuel efficiency is 15% greater with much reduced emissions of CO2, NOx and SOx emissions.

One vessel it has under management is the 25,000dwt bulk carrier Bulk Rose which was delivered from Turkey’s Cicek Shipyard in 2011 which was initially consuming 840g/dwt of fuel per day. It now consumes 750g/dwt/day.

The DMAIC technique was used to identify energy efficient practices including trim optimisation and weather routing software, Bulk Rose was fitted with a shaft generator and the company estimates that energy efficiency has been improved by 11%.

Six Sigma DMAIC, a set of techniques used to Define, Measure, Analyse, Improve and Control operational performance and processes, was first developed by Motorola in 1986.

Another recent development has been Green Dolphin 84S ­ a concept developed by the Shanghai Merchant Ship Design & Research Institute (SDARI), with support from DNV GL. “The main objective of DNV GL’s assistance during the development of the Green Dolphin 84S was to help create confidence in the concept design proposed by SDARI for a wide-beam, shallow draught 84,000dwt vessel. DNV GL’s scope included developing an expected operating profile, analysing the hydrodynamic performance of the hull shape, calculating the propulsion efficiency and estimating the fuel oil consumption,” the class society explains.

The operating profile was determined based on the trade volume distribution for this bulk carrier segment ­ looking into trade volumes, voyage distances and the number of voyages for the various cargoes. Sample trades were studied to estimate average voyage speeds and data on draft limitations for a country/port and the relevant cargo-lifting restrictions were taken into consideration when developing the operating profile for the concept design.

SDARI had developed a candidate design and W Marine asked DNV GL to assess the hull with regard to resistance and wake. The assessment focused on the design point in addition to four main operating points from the operating profile. The detailed flow characteristics were carefully studied for possible improvement potential.

“The assessment concluded that the bare hull resistance and wake properties were as expected for a well optimised design with the required main dimensions and fullness, i.e. there was little or no room for improvement of the hull received from SDARI. It was noted that it might be worthwhile to implement trim guidance at light cargo drafts due to the typical transom flow behaviour,” according to DNV GL.

The class society says the wake is considered good and again representative of a mature and fuel efficient design, but the high block design puts limits on the wake quality and the design may benefit from a wake equalising duct or propulsion improvement device with a similar effect. W Marine hired DNV GL to assist in the further assessment of an optimal propulsion improvement device that would best match the design propulsion characteristics.

Several main engine and propeller options were also assessed in terms of propulsion efficiency to ensure a lowest possible fuel oil consumption.

Dr Olav Rognebakke, who has been in charge of DNV GL’s team, gave credit to the work done by SDARI when he stated: “It is interesting to note that our scope of work has shifted from pure optimisation to verification,” adding: “It’s encouraging to see that our work has helped to reduce some of the risks involved in ordering a new design and that this design has already been ordered!”

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