K Line gives first form to ‘Drive Green’ project

K Line’s 'Drive Green Highway': raising the bar in both economic and environmental performance K Line’s 'Drive Green Highway': raising the bar in both economic and environmental performance

The latest entrant to the Japanese-controlled vehicle carrier fleet hosts a considerable and innovative combination of energy-saving technologies and measures, writes David Tinsley.

A determination to continually enhance vessel design and raise construction productivity in target sectors of the market, coupled with the sustained strength and reach of the Japanese-owned mercantile fleet, has underpinned the resilience of the Japanese shipbuilding industry. Indeed, 2015 saw Japanese yards continue to gain ground in key fields, as regards the volume of new work secured, notwithstanding severe competition from long-ascendant South Korea and China.

That industrial will is encapsulated in the pure car/truck carrier (PCTC) Drive Green Highway, recently handed over by the Ariake yard of Japan Marine United (JMU). The vessel encapsulates not only the philosophy of continuous improvement (kaizen), manifested in so many fields of Japanese endeavour, but also the preparedness of the industry and government to act collectively to raise product value through new initiatives on technological development and integration.

The central theme of the Drive Green research project is environmental conservation, which can today be allied with the pragmatic objectives of securing new levels of operating efficiency and meeting ever-tougher environmental legislation. The initiative is supported by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and ClassNK.

Key elements of the research brought to fruition in K Line’s new ship include an innovative, composite NOx and CO2 emissions reduction system, hybrid SOx scrubber, auxiliary engine exhaust gas recovery (EGR), one of the largest solar power arrays at sea, wind resistance reduction design, an energy saving appendage aft, low-friction paint and a raft of other mechanical, electrical and electronic measures.

Reduced carbon impact

The new, deep-sea vehicle/ro-ro carrier gives expression to the overarching goal of the industry’s Drive Green Project in achieving a 25% cut in CO2 impact per transported unit relative to Panamax PCTCs, along with significant reductions in NOx and SOx across the operating profile. Economies of scale, applied through the larger and optimised hull envelope, go some way in reaching that objective, of course.

Drive Green Highway embodies not only a very high intake capacity, rated at 7,500 car-equivalent units (CEU), but also an extensive capability for the gamut of transport and industrial vehicles, plus heavy, high, and awkward-sized ro-ro cargo and other wheelborne freight.

While the ship’s overall length has been limited to within 200m so as to ensure access to many Japanese loading berths, the hull envelope differs markedly from standard Panamax PCTCs of 199.9m x 32.2m main dimensions  by virtue of a breadth of 37.5m. This confers increased trading and routing flexibility, allowing K Line to take advantage of the scope offered by the new, larger Panama locks.

K Line’s PCTC fleet development programme comprises 10 post-Panamax vessels of 7,500 CEU. Although two slightly different designs from two shipyards are involved, a common feature is an extensive capability for heavy, high and awkward-sized ro-ro cargo, including agricultural and power generation machinery, rail traction and rolling stock, mining and construction equipment,  in addition to cars, pick-up trucks, sports utility vehicles (SUVs), vans and commercial vehicles.

Four of the new generation have been contracted from Shin Kurushima Dockyard and six were ordered from JMU. Drive Green Highway is in fact the third of the 10 newbuilds, and the first of the sextet to be delivered by JMU’s Ariake yard. The initial completions in the K Line series were made last year, in the shape of the Hawaiian Highway and Hamburg Highway, which were the first pair from Shin Kurushima’s Onishi premises.

Technological advances

Hawaiian Highway and her sister signalled a substantial advance in transportation efficiency, providing a 20% increase in car capacity relative to the company’s previous largest Panamax PCTCs. But the Green Drive Highway has taken technological development in application to the deepsea ro-ro/PCTC segment a further, major stage forward through an even more comprehensive design approach to environmental protection and energy saving.

Whereas the Hawaiian Highway-type employs the latest Mitsubishi two-stroke propulsion engine technology, in the shape of a 7UEC60LSE-Eco-A2 diesel, the Drive Green Highway is powered by an ME-series engine produced by Kawasaki Heavy Industries under licence from MAN Diesel & Turbo. The contractual rating for the 7S60ME-C8.2 prime mover is understood to be somewhat less than the model’s nominal maximum continuous output of 16,660kW.

The MAN main engine incorporates the debut application of the Kawasaki Heavy Industries (KHI)-developed K-ECOS (‘Kawasaki Ecology and Economy System’) hybrid solution for reducing emissions of both nitrogen oxides (NOx) and carbon dioxide (CO2). The innovative nature of K-ECOS lies in its integration of turbocharger cut-out, water-emulsified fuel, and exhaust gas recirculation (EGR), enabling the highest prevailing standard for NOx emissions from two-stroke diesel engines to be met at economical running cost.

By activating all three technologies in combination, the IMO Tier III limit on NOx emissions can be achieved without penalising fuel consumption and CO2 production. Utilising only the turbo cut-out and water-emulsion fuel elements of the system is sufficient to meet Tier II NOx criteria at a lower fuel consumption rate than that of engines without K-ECOS, it is claimed.  

In the fuel and water mixture, the water is dispersed in small particle form throughout the fuel. When the fuel is injected into the combustion chamber, the water particles capture and remove heat as they evaporate. This reduces the combustion temperature inside the cylinder, thereby decreasing the formation of NOx. Moreover, enhanced fuel spray atomisation as well as increased air injection improves combustion while reducing fuel consumption and CO2. The system was thoroughly tested over a four-year period on a KHI-built, 58,000dwt bulker operated by K Line.

The packaged EGR system curbs NOx production by redirecting part of the exhaust gas back to the engine, and lowering the internal combustion temperature.

Testing support

In-service testing of the K-ECOS system onboard Drive Green Highway is government-sponsored through MLIT as a next-generation, marine environment-related technology development assistance project. It is also backed by ClassNK as a joint research theme. The at-sea test and demonstration will enable KHI to evaluate system performance, durability and safety with a view to commercial release during the 2016 fiscal year.

Drive Green Highway also hosts a SOx exhaust gas cleaning system designed and supplied by Mitsubishi Heavy Industries (MHI) and Mitsubishi Kakoki Kaisha (MKK). While European companies have been in the vanguard of SOx scrubber technology and sales, K Line placed its requirement with MHI/MKK so as to help foster development of a domestic product, and to accumulate know-how related to maintenance and operation for the benefit of both shipowner and equipment maker.

The scrubber is a hybrid, in that it combines both a recirculating freshwater loop and also a one-pass flow system using seawater. The freshwater side is designed to be capable of removing SOx from the combustion of heavy fuel oil (HFO) with a 3.5% sulphur content to the equivalent emission level of 0.1% sulphur fuel, while the seawater side scrubs the exhaust gases to a level corresponding to 0.5% sulphur content fuel.

Contributing to the aggregate advance in energy efficiency achieved with the new vessel is one of the largest solar energy systems installed on any ship to date. More than 900 solar panels of the CIS type developed and manufactured by Tokyo-headquartered Solar Frontier at Miyazaki are fitted on the uppermost deck. The array offers a total 150kW-peak of electrical generating capacity, used to power all LED (light emitting diode) lighting on the vehicle decks.

High yield solar

According to Solar Frontier, K Line favoured the CIS modules because they offer a higher electricity yield (kilowatt hours per kilowatt-peak) than crystalline solar panels in actual operating circumstances, not least the salt-mist environments and hot climatic conditions encountered by a ship engaged in worldwide trade. The system is expected to provide stable power generation over the long-term. The CIS designation denotes the copper, indium and selenium used in the thin-film modules.

Drive Green Highway is fitted with a jumbo quarter ramp, supplemented by a smaller side ramp, from MacGregor Japan, which also supplied the inter-deck access ramps and covers.  

Three of the ship’s 12 cargo decks are of hoistable type, increasing both the loading capacity for ‘high and heavy’ vehicles, equipment and machinery, and payload permutations. The main, threshold deck offers the requisite clearance not only for larger, heavier items of freight but also for lengthy cargoes, such as growing Japanese exports of rail traction and rolling stock. The configuration of the cargo spaces and inter-deck ramp arrangements in conjunction with the hull structural arrangement promotes cargo handling efficiency.

With their high-sided, slab-like forms, vehicle carriers present considerable windage compared to other merchant vessels. In K Line’s new generation of PCTCs, the extremely bluff bow, which contributes to capacity optimisation of the forward part of the hull envelope, has been designed to reduce wind resistance so as to save propulsive energy. In addition to a high-efficiency propeller, Drive Green Highway is fitted with JMU’s proprietary Surf-Bulb (‘Swept-back, up-thrusting, rudder fin with bulb’) device, which converts rotational energy behind the propeller into thrust force.

Other constituents of the shipowner’s energy-saving strategy and Drive Green R&D programme applied to Drive Green Highway include inverter control of the engine room ventilation equipment and seawater cooling pump, and the incorporation of an exhaust gas heat recovery system for the Daihatsu auxiliaries. The vessel is also carries an onboard decision support system and real-time fuel consumption indicator.

An unusual, but welcome development introduced by K Line with its latest fleet entrant, in the long-term interests of crew wellbeing, is the adoption of a hydroponic cultivation system for growing a variety of vegetables on-board.

Following completion at Ariake shipyard, the Panamanian-registered Drive Green Highway was officially introduced in February at a ceremony held in nearby Nagasu port.


Length overall










Gross tonnage


Vehicle capacity, car-equivalent

7,500 CEU

Propulsion power (nominal MCR)


Service speed

20 knots



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