Sailing back to the future
Japanese sail innovation could soon change the way we think about moving cargo. Stevie Knight highlights four projects harnessing the country's enthusiasm for wind-assisted propulsion.
Firstly, take UT Wind Challenger. This has already climbed over many of the hurdles to realisation and a panamax size, wind-plus-engine bulk carrier will likely be delivered for trials at the beginning of 2020.
The idea centres on massive, crescent-section rigid sails 60m in height, 15m in width and 4m thick, set along the vessel’s centreline and individually angled to make the most of the wind direction.
The effect is similar to upended aircraft wings but creating pull instead of lift explains Tokyo University’s Professor Kazuyuki Ouchi – therefore a side wind is much more effective than a following wind.
The forces are as big as the sails: given the optimum 15m/s crosswind this 900m2 area yields 15 tonnes of force. Although the first ship will be fitted with a single sail to trial, four of these sails mounted between each hatch should, in favourable conditions, generate enough forward thrust to drive a 180,000 DWT bulk vessel at 14 knots.
Even considering less favourable cases, one sail in average 8m/s wind speeds could yield between 7% and 8% fuel savings, four sails on a North Pacific route might save 30% per year. More, a four-sail ship in 10m/s winds typical off southern offshore Australia and Africa could slash the fuel bill by half.
However, the routes with most potential are also noted for extreme weather events. Therefore each of the sails is made of five fibre-reinforced composite sections mounted on a sturdy, hydraulically retractable steel mast, allowing the whole to telescope down to the deck in rough conditions – or on cargo discharge in port.
There’s been a three-year land trial on a fully-functional, 20m by 8m version “so we are very confident about our data and the capability of the sail” says Prof Ouchi. The windy site contributed a little extra: “We have had three typhoons through here in that time,” he explains, adding it’s proven the structure will still ‘reef down’ in challenging situations.
Despite the novelty, the concept is moving toward realisation: studies determining the relative advantages of a retrofit vs newbuild are underway says Prof Ouchi, adding “maybe Mitsui OSK Line (MOL) would have the first ship fitted with the Wind Challenger Sail.
However, there’s been a hiccup around the sail’s manufacture: “This is a similar size to a 15 storey building,” says Prof Ouchi, adding that the lack of suitable, cost-effective Japanese fabricators has resulted in the project searching further afield: it’s presently considering boat builders with large-scale composite experience in places like Taiwan.
However, another variation of this concept could both generate and transport low-cost energy.
Prof Ouchi explains the force from 20 or so sails on the ‘Wind Hunter’ design could turn large diameter water turbines on the bow, creating electricity via a dynamo. However, he points out that to push out electricity requires cabling, so the next element is to generate hydrogen, a fairly straightforward business using electrolysis.
But rather than storing it under pressure or cryogenically, it’s reacted onboard with toluene to make methyl-cyclo-hexane (MCH). At the other end of the journey the hydrogen is extracted and the toluene is regenerated, enabling it to be reused in the next cycle.
It’s an easy way to transport hydrogen as MCH is liquid at ambient temperature and pressure, with 1/500 of the volume of hydrogen gas says Prof Ouchi, avoiding cryogenic’s expensive, technically demanding issues.
So far, initial results show that using this ship as a massive, mobile energy collection device may, despite the novelty, be workable – supporting the emergence of hydrogen as a clean, ethical fuel.
Another wind power build has added solar to the mix: in fact, the EnergySail system is something of a Japanese tour de force.
Fukuoka-based Eco Marine Power (EMP) had already begun presenting its EnergySail concepts “when we were approached by the third generation owner of Teramoto Iron Works who told us they’d been involved in developing JAMDA rigid sails back in the 80s”, explains Greg Atkinson, EMP’s CTO. “They are one of the few companies in the world that already has a history with this technology.”
Of course the collaboration has given EMP the benefit of some very useful insights as well as a capable manufacturer. It’s constructed both EMP’s prototypes and the versions that will soon be installed onboard a capesize bulk carrier for 12 to 18 month trials – most likely from the fleet of strategic partner Hisafuku Kisen KK “although we are still looking at the moment” says Atkinson.
The (patented) composite design has a grid structure below the skin holding it in shape, for simplicity, the whole thing can pivot to the deck instead of folding or cascading down.
By scale, these are not quite as big as, say, Wind Challenger’s, but will eventually be arranged in pairs around the perimeter rather than singly down the centreline. However, EMP’s sails are set with solar panels, making the most of the surface area “which is something we wouldn’t be talking about five years ago” says Atkinson, “it needed the price of flexible photovoltaics to come down in price per kilowatt to make it worthwhile”.
Making the most of this extra feed is a 50kWh energy storage system – and no, it’s not lithium ion. “We sat down with the Furukawa Battery Company and they said, ‘we do lithium, but if you’re mainly interested in storing the charge from the renewables, you don’t need it’. Instead, they came back with their sealed lead-acid ‘Ultra’ battery, a very robust, much cheaper and much simpler variety that will do the job with far less to go wrong. And you can transport it by air.”
The underpinning control architecture is provided by another patented EMP innovation, the Aquarius MRE, based on a well-proven platform by Japan’s KEI Systems. This allows for a modular approach, more sails can join the first pair and there’s potential for adding other energy sources such as wind generators.
Most importantly, it meshes the various elements so there’s little decision making by crew: “The whole thing will be fully automated apart from engaging or disengage the system,” says Atkinson.
Given this, EMP is looking toward another emerging technology: AI, with its learning ability, could result in more efficient automation algorithms, resulting in improved control of the ever-fluctuating renewable sources onboard.
The Japanese-incubated Greenheart project, by contrast, could be described as innovation on a shoestring.
This concept strips out the big, expensive technology till what’s left is only a lightweight outline that comes with next-to-zero running costs – for very good reason. “It’s aimed at the markets that have been left off the traditional shipping routes,” explains Greenheart lead, Pat Utley.
Greenheart is basically a cargo-carrying version of a hybrid sailing boat that’s been shaped by naval architect Haruhiko Kaku, senior designer for DECK Inc from an initial concept by director Pat Utley and well-known engineer and artist Seiichi Kunikata. The project is aiming at a vessel just 32m in length, 7.5m beam with a 220 tonne displacement that can take three containers or 70 tonnes on pallets or bags.
Although the design can be maintained without specialist intervention that doesn’t mean it’s lacking in innovation. Research into modern yacht technology – assisted by the Japanese Sail Association - yielded an easy-to-handle 400m2 sail surface mounted on A-frame masts with roller-furling staysails. Interestingly, the masts also have another trick up their sleeve: they can pivot and fold down, firstly to allow for getting through confined areas, but secondly to be used as a crane, giving the vessel built-in heavy cargo handling capability.
Greenheart’s ethos is also highlighted by the energy storage: about 600kWh of dependable (and recyclable) deep-cycle lead-acid traction batteries will have enough power to get the ship through windless pinchpoints like the Panama Canal using a pair of 150kW electric motors – their 20 tonnes of weight doubling up as ballast. Tests by Prof Takeshi Kinoshita (lead technical advisor) in his Toykyo University hydrodynamic lab underlined that the shallow, low resistance hull would make 5kn using less than 100kW of power in benign conditions.
More, the twin bilge keels protect the bottom and even act as a skid so that it can be utilised in shallow waters or even where there’s no real infrastructure – a rear ro-ro ramp opens for loading and unloading.
However, Utley explains that the project is open source “with no patents – and no business plan” to allow easy adoption by any small community in need.
So it had to be underpinned by goodwill as there was little budget: “The innovation culture is very receptive: even though organisations like the Sail Association are very technically exacting, it’s acted as a very comfortable incubator,” says Utley. “In a more cynical environment I think we would have met barriers from the very beginning.”
What’s probably needed now is for a charity to pick up the idea and make it available to the people it was designed for says Utley. It would be worth it: payback time, calculated by how much Greenheart would save over traditional deliveries, should be within five years.
Finally, all these sail ships pose a bigger challenge to the traditional cargo carrier concept than just a novel form: this sail technology has to be paired with networked maritime information and weather forecasting. In short, the routes – and in some cases, timing - will have to be optimised for the most efficient rather than the shortest path.
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