By Carly Fields
As designers of other types of ships salivate over the imminent – so they would have you believe – arrival of automated ships, multipurpose ships are undergoing a more modest revolution in design.
While crew-less multipurpose ships, or MPVs, remain a world away, innocuous tweaks to turbocharge cargo-carrying capacity, and little touches that make MPVs ready for whatever the future may hold, demonstrate that this understated workhorse of the ocean shipping industry still has more to offer.
With marine fuel costs eating up the second-largest share of operating costs after crewing outlay, this is unsurprisingly an area ripe for the reimagining of MPV designs. Liquefied natural gas, biofuels, hydrogen, wind, solar, even waste – all of these energy sources are looking to eat into the dominance of the bottom-of-the-barrel fuel that ships currently burn for power.
While conversations about alternative fuel sources are not new, there’s a fresh urgency to them to address the 2020 deadline for all trading ships to be burning fuel with a sulfur content no greater than 0.5 percent mass/mass. At the moment, the limit is 3.5 percent, apart from in specified emission control areas which already have stricter sulfur content rules.
Jost Bergmann, business director MPV, Ship Segments, DNV GL, recognizes that MPV owners and operators are increasingly discussing different options for ship propulsion. Liquefied natural gas, or LNG, as a power source has been a talking point for at least 10 years, but real progress has been slow.
“There was a lot of hype around LNG fuel maybe two or three years ago, but we have since realized that LNG fuel is not coming as quickly as we expected,” Bergmann said.
There is also a practical reason why LNG might not be the answer to lowering emissions and fuel optimization for MPVs. “With MPVs, trade patterns can restrict the bunkering options available, so while LNG might be available in the load port in the developed country, it may not be available in the discharge port in the developing country. Added to which, LNG fuel takes up space – almost double that of conventional fuels – space that is at a premium for ships carrying project cargoes,” Bergmann said.
One solution that might be more applicable to MPVs is fitting battery packs to reduce the need for auxiliary engine-generated power. “Combining the auxiliary generators with a larger pack of batteries could be a clever idea for peak shaving, where the peaks in the power demand could be compensated by a battery pack,” he said.
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Time For Hydrogen To Shine
While LNG was once the sole topic of propulsion-related conversations, hydrogen is fighting for greater exposure. Combining hydrogen and oxygen to produce electricity, hydrogen fuel cells offer eco-friendly ship propulsion without the need to burn anything.
Late last year, cruise ship operator Royal Caribbean said it would test fuel cells as a supplemental energy source aboard an existing ship in preparation for use on its next, new class of ships, due for delivery in 2022 and 2024. On a smaller scale, Norway’s Fiskerstrand Holding AS is working on a hydrogen-powered ferry, which it anticipates will be ready by 2020.
Hydrogen is certainly a viable alternative fuel for MPVs. Kris Hyde, technology manager at ITM Power – a company that specializes in hydrogen fuel cell products – explained: “If one makes the assumption that diesel oil will eventually be phased out due to CO2 and particulate emissions problems, then there are three alternatives:
“1) LNG: It will significantly improve the particulate emissions, but will do little for the CO2 emissions.
“2) Batteries: These will solve both of diesel’s problems, but the range is terrible with them. Plus, you have a long ‘refuel’ time.
“3) Hydrogen. This will solve both of diesel’s problems, and provides a range far in excess of batteries, with a refuel time comparable to diesel.”
In addition to the pressing 2020 sulfur cap deadline, there is also the threat of banning diesel use in cities, which would impact ports and dictate what ships could burn nearer to land. “Inland ports will probably be the first (London, Paris etc.), but the large seaports will eventually follow,” Hyde said. “There is no doubt that any ban would need to be phased, so perhaps 10 to 20 years for diesel oil to be phased out. However, as part of the ban, one would assume new vessels would need to comply in a shorter time frame.”
Once the impetus is there, hydrogen could become as popular as gasoil and distillates are now. “The only other zero carbon fuel with a decent range is nuclear, and experiments with civil nuclear powered ships haven’t been very successful. I’m not sure there are many other fuel options. Thus, it is certainly possible that it will become as popular,” Hyde said.
Waste For Fuel
Stuart Bradley, offshore renewables – strategy manager at the Energies Technology Institute, or ETI, pointed to another technology that has merit for MPV use: waste heat recovery, or WHR, using the Organic Rankine Cycle.
“It’s a well-known method of increasing the efficiency of industrial processes by converting low-grade heat into useable electrical power, and has been widely used in chemical plants and power generation onshore for years,” Bradley said.
ETI is working on the introduction of WHR for large vehicles such as construction trucks and heavy-duty vehicles, but to date it hasn’t made inroads to the marine industry. Bradley believed that was due to several reasons. “In my opinion, the cost benefit isn’t clear; there is a lack of financial information; a risk with technology; little market pull; complexity for retrofits; a lack of automation; limited training and a reluctance from ships’ staff to use it.”
In response to those hurdles, ETI has launched a project that aims to develop and demonstrate a WHR system for ships that could deliver fuel efficiency savings of at least 8 percent. UK-based Avid Technology will lead the £3.6 million project to create a cost-effective WHR system for use across all types of ships, including multipurpose. The goal is to install the system on an offshore support vessel by end of 2018, followed by six months of testing.
ETI has another project on the go, supporting Europe’s largest propeller and stern gear producer, Teignbridge Propellers International Ltd., in its design of a High Efficiency Propulsion System for ships, which aims to reduce fuel consumption by about 8 percent. This two-year project plans to develop a commercially viable system that can be retrofitted to a variety of vessel types.
ETI spokesman Nigel Richardson explained that ETI issues requests for proposals on individual projects and invites organizations or consortia to bid to take part, making targeted investments in technology projects. “However, we are unlikely to be launching any further projects in the immediate future,” he said.
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Making Use of Wind
Flettner rotors are enjoying a renaissance, having first appeared on ships in 1824. Anton Flettner’s concept used the Magnus effect in spinning bodies in vertical cylinders to produce lift and propulsion for ships. While his prototype produced good results, low fuel costs at the time meant that there was little interest in what was a comparatively expensive method of propulsion. Fast forward to today and while fuel costs are still not prohibitively high, pressure on reducing emissions has given Flettner’s rotors a new lease of life.
Maersk Tankers, Norsepower, ETI and Shell are collaborating on a project to test the claimed fuel consumption savings from use of Flettner rotor sails on a 109,647-deadweight-tonne product tanker. Marking the first installation of wind-powered energy technology on a product tanker vessel, the rotor sails will be fitted during the first half of 2018, before undergoing testing and data analysis at sea until the end of 2019. The two 30-meter-tall by 5-meter-diameter Norsepower Rotor Sails are expected to reduce average fuel consumption on typical global shipping routes by 7 percent to 10 percent.
The project is majority funded by ETI with contributions from Maersk Tankers and Norsepower.
Andrew Scott, program manager HDV marine and offshore renewable energy at ETI, said that Flettner rotors have the potential to reduce ship fuel consumption “substantially, especially on tankers and dry bulk carriers.” MPVs are included in the dry bulk carrier sector in ETIs calculations. Scott pointed out that Flettner rotors were one of the few fuel-saving technologies that could offer double-digit percentage improvements, but to date there has been insufficient full scale demonstrations on ships to prove the technology benefits and operational impact.
A full-scale demonstration could soon be available for MPVs: Dutch shipping company Switijnk contracted architects to develop a Flettner rotor-equipped, 8,000 dwt MPV in September 2016. To be known as the Flettner Freighter, the MPV will employ two rotor sails of different dimensions to create propulsive thrust. However, the vessel is still at the concept stage and there’s no official timescale for its construction.
While the rotors might have potential, Nicolas Breiding, head of research at Toepfer Transport, downplayed the suitability of Flettner rotors for geared MPVs: “Flettner rotors are always rotating, so if you have vessels with gear this could interfere with this.”
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Optimizing Carrying Capacity
With the increasing size, weight and awkwardness of project and breakbulk cargoes, carrying capacity is another design area that is often challenged by MPVs owners and operators. Here, the wind turbine industry is playing a significant role in shaping future ship designs to deal with increases in weight and length of blades and component parts. The largest blade is currently 88 meters in length, but the expectation is 110 meters before long, and even up to 130 meters in the not-too-distant future.
“The question is what do MPV vessels have to look like to carry these types of blades in hold?” asks DNV GL’s Bergmann. “Only a dozen or so MPVs today have cargo hold lengths of more than 100 meters; the majority have much less than this.”
He added that moving the accommodation section forward is becoming more and more commonplace for project carriers, as that affords them a huge, nicely protected deck and cargo hold area behind.
“From my point of view there’s a lot of very advanced designs out there already which in a way are flexible, efficient, and also take into consideration risk coming from advanced project cargoes. But there are also many standard vessels which look very similar to the designs we had maybe 20 years ago. The question is what is it the owner wants to do with their vessels? You also have to consider that what is good for one owner, is unnecessary for another. Some liner operators use project cargo as a filler to their baseload lots. Therefore, that type of operator requires higher segregation in the cargo hold.”
Increasing the flexibility of cargo carrying capacity is also sought after: more practical arrangements of ’tweendecks, fitting of ramps to handle extra-long cargoes, capability to submerged or semi-submerge for loading – all these bring benefits and the potential to raise income.
Related Story: Days are Numbered for ‘Simple’ MPPs
Out of Reach
But until the market makes a decisive turn for the better, many of these technologies will remain tantalizing out of reach for multipurpose ship operators. Toepfer Transport’s Breiding, said: “In the multipurpose market, we have virtually no activity at the moment, and I don’t think this will change for the foreseeable future because the market is so bad.”
While some owners might have got as far as discussing designs for new ships, innovation rarely tops the wish list. “Usually MPV operators are very conservative and, unlike the container sector, newbuild series are small so price is the main concern. I don’t think MPV owners are really keen to make big investments in new designs; I don’t expect any big innovation,” Breiding said.
Indeed, the latest innovation in MPV ship design was the F500, first ordered in 2015 and simply an optimization of the ubiquitous F-type. More of a gradual evolution of design than a revolution.
“Ship owners might have ideas about new designs, but somebody has to pay for that. With so many modern vessels for sale at very low prices, owners will not place new orders unless they have a specific trade in mind,” Breiding said.
The halfway house is DNV GL’s “ready concept,” where owners and operators can design a ship to be ready for a future technology without paying the hefty price tag for that technology at the design stage. Some examples of this applicable to MPVs include “dynamic positioning ready” and “crane ready.”
Not a Candidate for Automation
While autonomous ships are on the horizon for ships carrying standardized cargo – such as containers, bulk and liquid – it’s a different story for MPVs. With cumbersome cargoes, specialized longshoremen are needed in port to handle the cargo, while the MPV crew will need to manually check and tighten or refasten lashings and fixings during the voyage. “You have many different kinds of cargoes on MPV ships: yachts, engines, generators and so on – you need a lot of expertise to handle this kind of cargo,” Breiding said.
On the heavy-lift vessels, which carry demanding project cargoes, autonomy just isn’t an option, Bergmann added. “These vessels need higher attention and higher skills for their complicated operations.”
However, he believed that automation might be more easily achievable for smaller MPVs carrying more standardized cargo, but still MPVs will not blaze a trail. Instead, expect them to be begrudgingly dragged along an automation path, forged by the container ships of the future.
Carly Fields has reported on the shipping industry for the past 17 years, covering bunkers and broking and much in between.
Photo credit: DNV GL
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