The Motorship’s low-speed review of the year
Dashed off in two-strokes of the pen by our resident engine bore, The Motorship presents its low-speed marine engine highlights of 2017. Normal service will resume on 2 January 2018 after scheduled maintenance and a not-so-dry docking.
‘Low-speed’ is a misnomer when it comes to developments in the marine two-stroke market in 2017. True, there was no standout engine launch in 2017, and very few line extensions. But that reflects the state of the newbuilding market more than any lack of innovation from engine developers. Elsewhere, the pace of development – notably in new fuels and digitalisation – has been electrifying.
We are entering a new era of ship propulsion. After nearly 100 years of diesel, new cleaner fuels are emerging. The low-speed engine is adapting to these; as one expert tells me, “the two-stroke was designed to eat anything”.
Electronic engine control emerged at just the right time to help make this leap, controlling (for example) the intricate valve timings that help prevent knocking in gas engines or squeeze the most efficiency from a turbocharger. Now digitalisation is further empowering operators to monitor, operate and maintain their engines more efficiently than ever before.
But however efficient the two-stroke engine becomes, it is clear that internal combustion will not be the only path to a cleaner, more renewable future. These engines must learn to ‘play nicely’ with a range of other power sources – be it wind, solar, fuel cells or shore power - and energy storage systems.
Electrification, hybridisation and digitalisation are not empty buzzwords, but bywords for improving efficiency. With electrification comes greater control of engines; with hybridisation comes the ability both to burn new fuels and to cooperate with external power sources; and with digitalisation comes improved visibility into engine performance and condition, the usefulness of which we have barely begun to tap.
Please enjoy this review with our seasonal compliments. We’ll be back with our regular news, analysis and comment on the ship propulsion and machinery market in 2018.
EXPANDING ENGINE FUELS
What comes after LNG and methanol? The next step for MAN Diesel & Turbo is ethane, which in 2017 became the latest fuel to power the developer’s ME-GI engines. In collaboration with Hartmann Reederei the engine designer tested its new ME-GIE engine – that’s GIE as in gas-injection ethane – onboard the 36,000m3 liquid ethylene gas carrier Gaschem Beluga in April.
The successful test is important not just because it adds another fuel to the growing list that can be burned in a two-stroke engine. According to MAN, it also paves the way for the burning of volatile organic compounds or VOCs, the mixture of gasses given off when oil products loaded, unloaded and transported. The ability to burn VOCs would be a huge boon for shuttle tankers, enabling them to reduce their fuel bill considerably by using the boiled-off VOCs as fuel.
The technology behind LNG-fuelled two-stroke engines may now be mature, but improvements continue. While Winterthur Gas & Diesel (WinGD) scooped some of the biggest commercial victories in gas engines this year (see below), MAN continued to push technological boundaries. Its greater installed base of dual-fuelled engines – recently passing 100,000 hours in operation – enabled it to make fuel-saving adjustments, particularly in the area of pilot fuel. Teekay Gas noted that post-installation improvements to pilot fuel injection had led to a saving of around one tonne of fuel per day on four gas carriers powered by ME-GI engines.
As the video below reveals, there are indications that MAN’s focus on pilot fuel has led to another breakthrough. The company has yet to release more details, but the video below suggests it has broken through another gas challenge and is now able to start at least some of its engines using no pilot fuel at all.
Preparing two-stroke engines to play a part in a multi-fuel, multi-power source future is an important focus of development work. Judging by progress in 2017, enabling the two-stroke engine to act as an electricity provider is the latest step in this direction.
Transmission and gear specialist Renk launched its debut hybridisation concept for two-stroke engines in April. The MARHY system features a tunnel gearbox and propeller shaft clutch enabling the two-stroke engine to be connected to an electrical motor. This allows for four modes of operation: power take off, power take in, switching off the main engine to rely entirely on electrical propulsion, and disengaging the propeller so that the main engine acts purely as a generator.
The versatility of the Renk system is what makes it intriguing. Combined with a battery system, MARHY offers full redundancy required for ‘safe return to port’ notifications as well as allowing operators to reduce the number of generators they operate.
The use of the main engine as a generator is also something picked up by MAN Diesel & Turbo in a recent study. With battery storage company PBES the company explored the use of a two-stroke engine instead of four-stroke engines as auxiliary engines on a gas carrier. With batteries supporting the ramp-up and ramp-down of engine load, the idea was seen as feasible: As demand for electric propulsion increases, perhaps two-stroke engines could have a role even in this market
After nearly a decade of slow steaming, ABB Turbocharging has delivered a concept that will enable ship operators to optimise fuel efficiency while operating at part load. The solution, labelled ‘sequential turbocharging’, works by bypassing one turbocharger when the engine is operating at low load – thereby maximising the scavenge air pressure generated through the single operational turbocharger and boosting efficiency.
It seems like a simple solution and it is. Sizing of turbochargers must be recalculated, but one of the few physical modifications needed is specially designed cut-off valves, which are flow-optimised and integrated with turbocharger casings. ABB is working with WinGD to introduce the system on all its X engines (excluding dual-fuel versions) and anticipates fuel savings of up to almost 5% depending on vessel type and operational profile.
Two-stroke engines trail their four-stroke cousins considerably in the field of digitalisation – most likely a factor of the far greater number of four-stroke engines on the market, as well as their use in more sophisticated vessel segments such as cruise, offshore and research. But over the course of 2017, the big two-stroke developers have been aiming to put that right.
Early in the year MAN Diesel & Turbo announced a deal to provide online services for four-stroke engines on two ro-pax ferries operated by Stena Line. Constant monitoring of engine and turbocharger data will enable Stena to optimise operation of the engines, while PrimeServ specialists will provide further recommendation for maintenance and repairs. To date the service is only available for four-stroke engines, but the next phase will include the roll out for two-stroke engines.
WinGD has powered ahead in its digital offering in 2017 thanks to two key partnerships, with data monitoring hardware specialist Enamor and with software company Propulsion Analytics. The combination of the two partnerships – in a proprietary system that is soon to be available on all WinGD engines - will enable WinGD to offer insights into operational parameters of vessel, main engine and other vital ship systems as well as providing analytical tools for the ship’s crew and personnel ashore.
CONTROLLING CYLINDER CONDITION
Development never stops in the fiercely competitive field of cylinder lubrication, where many of the major players benefit from close links with fuel suppliers – enabling them to tap into the issues facing end users of marine fuels. In last year’s review we noted the emergence of automation in cylinder lubrication, including the automatic adjustment of BN or feed rate. The trend continued in 2017.
Onboard blending, including the ACOM system developed by MAN Diesel & Turbo and others, really needs an ultra-high base number (BN) stock to dilute using other low BN oils. Chevron duly obliged this year with the first OEM-approved BN140 oil. As well as being ideal for onboard blending, Chevron Special HT Ultra also offers another heavy-duty option to cylinders suffering from cold corrosion.
Another important development in lubrication was the introduction of Shell’s Marine Integrated Lubrication and Expert Solutions (MILES) programme, intended to optimise and streamline purchasing and services. While scant on detail at the launch, the underlying vision is clear: Shell is positioning itself for digital transformation whereby it will be able to offer customers an all-encompassing service – including restocking and cylinder monitoring – that will take the job of cylinder lubrication almost entirely away from ship operators. Look out for more details as Shell’s digitalisation drive continues.
Bypassing the digital hubbub, this year’s standout cylinder condition initiative is far more traditional. Parker Kittiwake’s ‘Gold Guide’ to fuels and lubricating oils is a print and paper affair (albeit oil-proof paper to protect from engine room mess). But in terms of tackling the biggest problem in engine condition – an informed and educated crew – it is streets ahead of other solutions. The book provides vessel owners and operators with information on all aspects of fuel, lube, and hydraulic oil from first principles to testing, monitoring, characteristics and specifications. The work behind it is impressive, and the impact on any ship whose crew can get hold of a copy is likely to be immediate.
ENGINE DESIGN CONCEPTS
Two-stroke engines have been around a long time and it’s not often you see something that genuinely reshapes how the inside of the cylinder will function. One such improvement is Diesel United’s variable compression ratio system.
Comprising a hydraulic cylinder in the lower part of the piston rod which can be used to adjust cylinder height, the system enables compression ratio to be adjusted to get the best fuel efficiency depending on engine load, or the best combustion characteristics for gas fuels (where the air-fuel mix needs to be adjusted depending on gas quality).
According to Diesel United, the fuel savings can be dramatic, and the engine builder is working with licensor Winterthur Gas & Diesel (WinGD) to bring the system to market as an option for WinGD two-stroke engines as soon as possible.
DEALS OF THE YEAR
Two big business developments come to mind as highlights of 2017. First is the trio of deals struck by Winterthur Gas & Diesel that could well mark a ‘deep sea coming of age’ for the LNG sector.
In March, Sovcomflot ordered dual-fuel two-strokes for four Aframax newbuilds, the first big, deep-sea trading tankers ordered with gas as fuel. Days later AET Tanker announced that up to four of the Aframaxes it had already ordered from Samsung Heavy Industries would also feature Winterthur Gas & Diesel’s (WinGD) low-pressure, dual-fuel X-DF technology.
With both AET and Sovcomflot outlining wider LNG transformation plans for their fleets, the Aframax deals represented a breakthrough – the first potentially globally tramping vessels to feature dual-fuel propulsion. On the strength of such announcements, bunkering infrastructure decisions are made.
Those deals were followed in November by the announcement that French containership owner CMA CGM would power nine ultra-large containership newbuilds with the same X-DF technology. Destined for the Europe-Asia trade – and boasting 18,600m3 gas fuel tanks (the biggest ever built) – these vessels prove the viability of trading on global routes while bunkering at only one location. That WinGD will play a role in both breakthrough projects is a major coup.
The year had barely started when the embattled Mitsubishi Heavy Industries announced that it was combining its two-stroke engine business – under which it developed the UE engine range – with that of former licensee Kobe Diesel. The combined Japan Engine Corp (J-Eng) business may represent less than five percent of the marine two-stroke engine market, but as one of only three low-speed engine designers (along with MAN and WinGD) the change of ownership is significant.
Early indicators suggest a new dynamism at the Japanese engine designer. In a year when engine launches were few and far between J-Eng managed two, each justified with a convincing rationale: the MGO-only UEC50LSH-Eco-C2-MGO engine, designed to address the engine condition challenges of operating on low-sulphur fuel oil; and the 10UEC50LSE-Eco-B1, the company’s debut 10-cylinder, 500mm bore engine – perfect for ships such as roros with high power demand but limited engine room height, thus demanding more cylinders and limited stroke.
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