Thinking inside the box
Shaftline and propellers are fixed while fuel tanks can be switched to allow for the future introduction of alternative fuels
Rolls-Royce Marine’s latest ship concept, the 1,000 teu Electric Blue container feeder vessel, responds to market challenges by prioritising low capital expenditure and flexibility over fuel efficiency. Gavin Lipsith reports.
Forget thinking outside the box. The real answer to the challenges of today’s shipping market, according to Rolls-Royce Marine, lies in further embracing the containers that have revolutionised the industry since the late 1950’s. Last month the company’s vice president of concepts and innovation, Oskar Levander, unveiled a concept for a 1,100 teu container feeder vessel that puts essential ship machinery and functions – including engines, fuel tanks and even accommodation blocks – inside containers.
The idea, says Levander, is driven by the set of uncertainties facing ship owners today. Most pressing for many is the fact that charter rates are near historic lows, at around US$6,000 a day for a 2,500 teu vessel as of 11 February - compared to highs of more than US$27,000 in 2008 and dip to under US$5,000 the following year. Those wild swings are in no small part due to rapidly changing global trade patterns. As these patterns show no sign of settling soon, charter rates and ship owner profits are likely to remain under pressure.
Those factors alone mean that owners will be looking to minimise capital expenditure. But when you add the emerging regulatory landscape – of which the global sulphur cap in 2020 and the looming ballast water management regime are key examples – investment choices become even more difficult. Factor in the rapid emergence of new efficiency-boosting technologies and ship owners have a serious issue to contend with: How to minimise capital expenditure while building a ship that can maintain its competitiveness, no matter what the future holds.
The solution proposed by Rolls-Royce is simple in principle. Reduce complexity built into the hull – therefore cutting ship design and construction costs – while making essential equipment and functions interchangeable. Elements such as engines, fuel tanks and batteries can be bought (or perhaps leased) separately and swapped out when needed.
“It’s a very lean investment for ship owners,” says Levander. “Everything that is in containers you don’t need to invest in immediately. Perhaps you don’t need to invest at all. You can hire it, or maybe a fuel provider will provide the tanks, for example.
“The idea was to do something future proof. Say the owner at first buys the hull and invest in the engines and diesel fuel tanks in containers. Then a couple of years later, they get a charter that requires environmental performance, or the market price has changed. They can switch to LNG engines and tanks and sell off the old engines or put them in another ship. As time goes on, if they want to install batteries, they can just put them where there are ready slots.”
The simpler hull, which also means that construction can take place at cheaper, less sophisticated yards, is achieved through several means. The lack of complex spaces such for tanks and engine rooms mean that the amount of steel used can be reduced. No cargo hatches are installed, only cell guides, meaning that no lashing is needed for the containers. Accommodation is also containerised and does not need to be built in to the hull.
Reducing other systems in the ship also results in a more cost-effective build. No cooling system is needed for the engines – Levander explains that air cooling can be used in the engine containers instead of water cooling – and no tank heating systems are required if there is no heavy fuel onboard. Steam generation is not required and water generation and sewage treatment are also disposed of – water is bunkered at port, and waste disposed of for treatment on land.
“We’ve tried to remove as many systems as possible,” says Levander. “The containers need to be able to manage without any support systems so need to be modified – lube oil and cooling systems all need to be inside container, for example. You will connect fuel in, electricity out, plus control cables. That means much less cabling and piping around the vessel.”
The hull form itself can also contribute to lower building cost, notably by eliminating the need for ballast water management systems, which can easily cost US$1 million. A ballast-free hull can be achieved by a wider beam – offering greater stability and meaning draught changes less when unloaded. The reduced change in draught means a shallower ship can be built, but full available draught is used at the bow, which is extended downwards to reduce slamming when the ship is not loaded.
The twin-screw propulsion set up enables Rolls-Royce to counter another factor that usually requires ballast – keeping the propellers in the water. As it is propeller area that determines propulsion efficiency, with two propellers the area is doubled and the diameter of each can be reduced. By positioning these further than usual down the shallow aft of the hull – equivalent to the depth that they would be placed at for a vessel with a conventional draught - the smaller propellers will always stay in the water whether the ship is fully loaded or not.
“Ballast water management is complicated and expensive,” notes Levander. “It is tricky for certain ship types to be ballast free, but for container feeders you don’t need ballast as they are never completely empty. These small adaptations mean we can have an extremely efficient hull but one that doesn’t need any ballast.”
Another innovative feature of Electric Blue both saves on construction cost and fulfils the other mission of the concept, preparing the vessel for future technologies. Strikingly, Electric Blue feature no deck house. There is a deck though, situated aft under cargo containers. That might seem like a bold step, but Levander explains that the technology is already available to provide automatic look-out from a bridge that does not have a natural vantage point. “We have built in the bridge setup that we have designed for remote operations, but instead of being shore-based and linked by satellite, we will use it on the ship instead.
“We have all the same sensors – cameras and infrared cameras fused together with lidar, radar and other sensors to build up a holistic view. When we were testing this experienced captains come in to see what we were doing they couldn’t believe it was possible. They had a better view than they did on their ships.”
The bridge concept means that when the regulations are in place for remote control of ships – Levander believes that may be just five years away – operators can take out the deck aboard (freeing up more room for cargo) and replicating the same setup on shore. At that stage, the containerised accommodation could be disposed, increasing cargo capacity even further.
The propulsion arrangement is also designed to reduce cost. Most strikingly, Electric Blue is designed to use high-speed engines rather than the medium- or low-speed prime movers traditionally associated with these vessels. Rolls-Royce envisions two to four gensets in containers on deck depending on the speed required.
“High-speed engines are smaller, lighter and easier to put in container,” Levander explains. “We have a version with a mid-speed engine so don’t rule that option out. We can make a taller container, but ideally want it in standardised – the important thing is that we can put cargo on top of it.
“It’s a trade off on fuel efficiency – with medium-speed engines you would of course have better fuel efficiency. But the attractiveness of this concept is that it is future proof and easy to buy. If you have high-speed and electrical propulsion you will not have the most fuel efficient vessel on the market. The idea is not all about lower operating costs, it is about capex and flexibility.”
The idea is to employ diesel- or gas-electric propulsion, with permanent magnet motors driving the two propellers. Permanent magnet motors offer greater efficiency than traditional induction motors, particularly at part loads, Levander explains.
Under normal operation, the generators alone would provide propulsion power, although batteries can be installed, in slots prepared toward the bow to improve vessel trim. That would offer the possibilities of hybrid propulsion – using batteries to take peaks in power demand or smooth out load fluctuations - or even full electric propulsion, depending on the requirements of the owner and the size of the batteries installed.
Engines in containers are not a new invention – they have already been used in the offshore sector for FPSOs, for example – but do require some extra equipment such as sprinkler systems and fire extinguishers inside the container to fulfil regulatory requirements. In other ways, such as the escape routes from a deck-based engine, the concept actually makes safety compliance simpler.
While the concept is focused on reducing capex, the modular nature of ship equipment proposed would also have maintenance benefits. Engines, tanks and batteries could easily be taken off the vessel to be serviced on shore, at much smaller cost.
“It’s also about minimising what you do on the ship,” adds Levander. “If you want to make a lean ship with a lean crew, you need to reduce maintenance onboard.”
Compared with a similarly capable newbuild built in the conventional way, Rolls-Royce estimates that Electric Blue would result in a saving of around €2.5 million (excluding batteries, redundant machinery and a remote operating system). A significant portion of that saving is found in the reduction in steel – around 1,000 tonnes less than a conventional newbuild. Reefer capacity is equivalent, at 200 units, while the reduction of systems onboard means that installed power requirements are lower by around 1.7MW. The simplicity also translates to a reduction in crew of between five and 13 people depending on the type of operation.
Rolls-Royce is already considering further concepts – a counterpart in the offshore sector could dramatically reduce the scale of ROV support vessels, for example, and a bigger feeder ship of 4,000 teu is already being planned.
The container feeder concept is a step into a new market for Rolls-Royce, but one that Levander says is a natural fit for the company. “Rolls-Royce has been strong in offshore but we want to expand our presence and position ourselves in other sectors. We see potential to strengthen in certain markets, and short-sea feeders is one where our experience could be valuable.”
While the company’s recent history is in more complex vessels, the portfolio extends from deck winches and propellers right through to engines and automation solutions. And the use of high-speed engines, through Rolls-Royce’s recent acquisition of MTU, adds further value. Levander believes that the coming sulphur regulations will generate more interest in the high-speed engine sector, with some operators who have previously used smaller medium-speed generators considering switching.
FUTURE BUSINESS MODELS
Rolls-Royce has also suggested that the marine sector could, like aviation, move to a ‘power by the hour’ model, where engine makers take overall responsibility for running and maintaining an engine, charging operators only for the power they consume. Electric Blue, with its containerised engine solution, makes this approach very easy to comprehend.
“It’s one potential version of power by the hour,” Levander agrees. “It could also be done with a conventional power configuration. But the modular arrangement gives very clear boundaries.”
The bigger idea behind Electric Blue though goes far beyond one ship. “It’s about building a fleet,” says Levander. “Then you can share modules between vessels and provide standard packages. So, when a ship goes on a route that needs slower speed you can take an engine off and use somewhere else – you don’t need to invest in full capability for all ships.”
Modular thinking is part of the drive towards standardisation that Levander thinks will be essential to smart shipping in the future. Standardised equipment on standard hull forms will enable operators to reduce costs, compare performance across their fleets easier, improve safety and operate more efficiently. Thinking in modules makes that standardisation easier, and means that unanticipated changes – in trading pattern, operational profile, regulations or technology – can be responded to faster.
One of those changes that Rolls-Royce has invested heavily in is the move towards vessel autonomy and remote control. And again, the ability to switch in new technology in modular form will be valuable. “The key is modularity and ensuring vessel is efficient through life,” Levander concludes. “Operators need a ship that can adapt with the times and with technology. “There are already ‘LNG ready’ ships out there. This is ‘remote operations ready’.”