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The new reference for LNG propulsion

The development of emission reductions from 4,200 TEU to the present 18,800 UASC TEU ships with LNG as fuel on the Asia to Europe trading route

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Al Murraba UASC
Fuel consumption is the major cost driver in shipping. Only the most fuel efficient ships will survive in tomorrows’ markets!

Fuel consumption is the major cost driver in shipping. Only the most fuel efficient ships will survive in tomorrows’ markets! This thesis has become the challenge for UASC – the United Arab Shipping Company with their German Consultant and Ship Designer TECHNOLOG Services GmbH from Hamburg. The TECHNOLOG Consultants have been engaged by UASC to optimise the design  of their earlier UASC new-building series from1997 onwards. These have grown steadily in capacity over the years from the initial Panmax size of 4,100 TEU (A4) to 7,200 TEU (A7) and on to 13,500 TEU (A13) ships in 2010, with the last ship delivery of the series in 2012. UASC will now double its fleet capacity with eleven 15,000 TEU (A15) and six 18,800 TEU (A18) new super-efficient and environmentally friendly container vessels. High efficiency and low fuel consumption generally also means fewer emissions. These seventeen ships have been built by Hyundai Heavy Industries and Hyundai Samho Heavy Industries and classed by DNV GL.

The ships came into service between the end of 2014 and 2016. This article will demonstrate the efficiency gains and reductions in emissions by UASC over recent years up to the intended application of LNG as ship fuel. At the end of the article, an outlook/summary on the emission reduction potential through the use of LNG as fuel in these vessels is given. It should be noted that LNG will only become competitive, and therefore commercial feasible, if it can be offered at a competitive price. The IMO 0.5% S regulations coming into force in 2020 have also to be considered. The ships are operating between Asia and Europe serving AEC8 ports between Shanghai and Hamburg with their Asia to Europe service. A string of 10 number 4,100 TEU (A4 class) ships operated on this route between 1999 and 2008.

In 2008, these A4 class vessels on this route were replaced by the new larger 8 (+1) number 7,100 TEU (A7 Class) vessels. These ships were propelled by Wärtsilä 11 RT-flex 96C engines with an NCR power of 56,628 kW.

The new standard – UASC’s A15 and A18 class

The previous vessels were all standard shipyard designs that only underwent limited optimisation and were trimmed for the common high operational speeds at that time. However, the new vessels of 15,000 TEU (A15 class) and 18,800 TEU (A18 class) were developed for economy and best fuel consumption by UASC with their consultant TECHNOLOG and the tendering shipyards, later the selected builders HHI, in successful partnership. These newbuilds have the following particulars: Main Particulars A14 A18

Both vessel types follow an identical design and outfitting strategy. All of them have been designed and equipped for fuel economy with hull form optimisation. As all the vessels have their keel laying dates before the end of 2015, they are IMO Tier II compliant regarding NOX emissions. The CO2 output of the 11 number A15 class ships will be 0.80 million tons per year, while the CO2 output per TEU/nm is 63.2 grams. This is again a reduction in CO2 footprint of 22% compared to the A13 vessels.

The yearly CO2 output of the 6 A18 ships is 0.50 million tons. The CO2 output per TEU/nm is 52.3 grams, which is 36% below the CO2 footprint of the A13 vessels. When the ships are eventually retro-fitted to LNG as fuel, there will be a CO2 reduction of 25%, a NOX reduction for these IMO Tier II vessels of 25%, a SOX reduction of 97% and a Diesel particle reduction of 95%. The use of LNG as fuel will significantly reduce all emissions to the atmosphere, which may cause harm to people or contribute to the global warming effect.

Challenges related to the application of LNG as fuel compared to existing applications

These new vessels must not only be the most competitive when put into service compared to (still) conventional ships but, moreover, the most competitive in the years to come, while complying with the increasing environmental demands of IMO MARPOL VI regarding emissions of SOX, NOX, diesel particles, and CO2. With coastal countries increasing their environmental consciousness of global warming by, Emission Controlled Areas will certainly be extended. The owner has opted for LNG as a fuel rather than investing in scrubbers and SCR’s, and with this decision has accepted the role as market leader for LNG as a ship fuel with mega box container carriers and large scale bunkering.

The challenges are related to pragmatic decisions for navigation in ECA only zones or globally, endurance, suitable LNG tank size, tank construction type and costs, the location of the tank in the ship and economy of retro-fitting and the selection of fuel gas supply system (F.G.S.S.), as well as the position of bunker stations and the vent mast for the least loss of precious container stowage space. The further development of efficient bunkering logistics along the trading routes with the availability of adequate LNG bunker quantities and refuelling without lost idle time is a further demand.

Technical concept of A15 and A18 Class vessels

From the retro-fit perspective, it became evident that the cargo hold directly in front of the engine room would be the most suitable location, with short piping routes to the LNG tank. Further, a type ‘B’ tank has the greatest stowage density compared to several smaller cylindrical type ‘C’ tanks, and thus require far fewer container slot losses. The Approval in Principle (AIP) for the LNG plant design was obtained from DNV GL through technical cooperation between the owner's Newbuilding Team with HHI shipbuilders, Hyundai Engine & Machinery Division (HHI-EMD) and Japan Marine United Corporation (JMU) for the Self-supporting Prismatic-shape IMO type-B LNG Tank (IHI-SPB Tank).

This was officially presented to HHI and the owner during the SMM exhibition in Hamburg in September 2014. The retrofit concept is based on the fact that the tank will be positioned between the longitudinal hold bulkheads with a safety distance between the outside insulation of the tank to shell. The tank connection space, the Fuel Gas Supply System rooms and the LNG Bunker Stations are located above the tank. All the requirements follow the the IMO IGF-Code.

LNG as ship fuel

LNG as a fuel appears commercially the most attractive when comparing the expected prices from 2020 of low sulphur heavy fuel oil (LSHFO) or Marine Gas Oil (MGO), and the extensive long term availability of natural gas. From 2020 onwards we will have to compare the LNG prices with those for higher cost distillates or blends. It is expected that the investment costs for LNG retrofit will achieve very fast pay-back times once the fuel price differences become visible.