Future technologies on ships that are approaching maturity
Most of the technology related headlines in shipping today are occupied with the subject of autonomous ships. Since at least one vessel – the 120teu Yara Birkeland – is planned to commence construction this year, the concept will soon become reality.
However, one or more prototypes is no guarantee that the idea will achieve the widespread acceptance that its proponents are predicting. There are though several technologies that are approaching maturity and which are looking to be successful additions to ship building and equipment.
Battery power, either as the sole energy source onboard or used for recovering waste energy, is probably the most likely to succeed. Currently there are four vessels in service that are powered only by batteries. All of these are passenger ferries – three operating in Norway and one in Finland. In addition, 14 more are planned or under construction; again all but a small number are ferries for domestic Norwegian service.
Battery power provides for emission free operation but unless the power used to charge the batteries from shore comes from renewables then the pollution is merely moved upstream. Norway, which is self sufficient in hydroelectricity is therefore better positioned than many nations to make use of battery technology when it is the sole power source for the vessel.
Battery power as energy storage has a much wider sphere of application and offers advantages for many ship types. In these situations, the battery allows auxiliary or main engines to be run at optimum speeds and excess power to be stored in the battery. This stored power can be used either to level out load demand from systems such as dynamic positioning or it can be used to provide emission free operation in ports and harbours.
At the present time there are 34 ships in service where energy storage systems are in use. The mix of types includes tugs, offshore vessels, ro-paxes and ro-ro cargo ships. A further 20 ships are under construction and include all or the above types as well as chemical tankers, research ships and expedition cruise vessels.
Most of the in-service ships fitted with batteries have had them retrofitted as additions to existing equipment although in a small number of cases including a quartet of 1997-built Scandlines’ ro-pax ferries, one of the multiple original engines was removed.
Another new technology that is forecast to revolutionise shipping is the use of fuel cells. It has to be said that the experience to date has been below expectations and for a while most companies that were pursuing the idea seemed to have put it on the back burner. Only a handful of fuel cells have been installed and all have been of quite low output considering the typical demands of the ships they were installed on.
The latest development in the potential use of fuel cells for shipping came in November 2017 when Royal Caribbean and ABB announced a pilot installation on board a Royal Caribbean Icon class vessel scheduled for delivery in around four years’ time. “This pilot installation demonstrates that fuel cell technology is now firmly in sight of the cruise industry,” said Juha Koskela, Managing Director, ABB Marine & Ports. “Fuel cells have been the next big thing for 25 years, but now they are reality.”
The pilot installation, including control, converter and transformer technology from ABB, will generate 100kW of energy, and has been fully developed, marinised, assembled and tested by ABB Marine & Ports. ABB selected an FCvelocity proton exchange membrane (PEM) pure hydrogen fuel cell engine from Ballard Power Systems for its pilot system. Adoption by the cruise sector may encourage interest for other ship types but the footprint of fuel systems relative to power produced is high and may prove a negative aspect for the time being.
Wind and solar applications
Once the main propulsion force of shipping, wind power was long ago abandoned in favour of mechanical power but there have always been those with a plan to continue to make use of the wind as a complement to the diesel engine. Normally these ideas have been formulated following one of the many fuel crises that have hit shipping over the last 50 years. In most cases, the crisis has passed before any owner could be found to invest and the economic case for a return to sail was undermined.
The latest project announced was in January 2018 by Japanese company Eco Marine Power (EMP) and involves a rigid sail system that the company hopes to bring to commercialisation in the near future. Like most of the wind power projects that have foreseen bulk carriers and tankers as the most likely candidates for installations, the EMP also targets such ships.
Previously there had been trials of the German Skysails system by the likes of the now defunct operator Beluga Shipping. Although some successes were claimed for the system it has not sparked excitement among shipowners.
More successful has been the re-awakening of interest in the Flettner rotor by the likes of Finnish organisation Norsepower. Marketed as the Rotor sail system, Flettner rotors are not sails in the true sense of the word.
The rotor must be powered in some manner – usually by electric motors – and the rotation produces a pulling force on an edge of the rotor. The strength and direction of the force is dependent upon the wind direction meaning that a rotor system will not work if the wind is in the wrong direction and when it does work, the saving in energy use will be offset to a small extent by the power needed to drive the rotor.
Solar power assistance for ships can already be achieved by use of photovoltaic panels just as on land but clearly they are not suited to all ship types. Only ships with large unobstructed areas of space could be considered candidates which is why car carriers have so far been the potential candidates. The EMP rigid sails project mentioned above also proposes that the surface area of the sails could be used to house solar panels giving addition energy increase when in use.
Some proponents of solar power overlook the fact that unlike solar panels in land-based situations, the weight of the panels themselves and any ancillary equipment will prove to be a factor that must be considered as it will require additional energy to move the ship at all times even when no power from the panels is being generated. That said there are pioneering owners willing to test the concept and despite the low efficiency of solar panels, there may be some situations where they do indeed prove beneficial.
New materials and manufacturing
Steel has been considered the main material for shipbuilding for well over a century although other materials have been tried at various times. Today, any ship not built of steel will almost certainly be a smaller fast vessel type where aluminium is the material of choice. Attempts to reduce the weight of vessels have so far mainly been done by way of using lighter high tensile steel or more controversially reducing steel weight by eliminating design features. The latter options having been used by class societies to compete for business were blamed for several vessel losses and have since been abandoned as class societies developed their common structural rules.
Composites and plastics have been proposed as building materials for ships and components and although not present in commercial ships to any great degree they have been used in naval, yacht and boatbuilding for a considerable period. Composites are considered to be able to provide structural integrity and to confer weight savings on any ship which made extensive use of them. Additional benefits could come from the lack of corrosion issues that invariably affect all steel used in ship construction.
Several academic and industry research projects have been conducted particularly in Europe funded by EU grants but despite the money invested very little return has yet been seen unless small scale vessels such as the innovative Norwegian ferry Vision of the Fjords completed in 2016 by local builder Brodrene Aa are counted. The builder, which uses composites for several small vessel types, did have ambitions of building offshore vessels using composites but the problems of that sector caused by the 2014 slide in crude oil prices has put most offshore newbuilding on hold and nothing further has developed.
Some success has been achieved for the sandwich plate system (SPS) developed by the UK firm Intelligent Engineering, but this has been almost solely in the repair of ships rather than in new construction. SPS is a structural composite material comprising two metal plates bonded with a polyurethane elastomer core but sometimes in ship repair situations an overlay process is employed where the original steel structure of the vessel is used as one of the outside elements. The attraction of SPS is that it can be installed without the heat needed for welding or cutting away. References include gas carriers, bulk carriers, ferries, cruise ships and FPSOs.
Composites have also been employed in projects other than the ships structure and some believe that this is a more promising area. In 2014, a Japanese project involving ClassNK and Nakashima Propeller fitted a composite propeller to a small commercial vessel of 499gt. The following year ClassNK formulated rules for composite propellers. Despite this, there has so far been nothing to suggest that the idea has achieved commercial acceptance.
Additive manufacturing – a new dimension.
Looking to attract more attention than many previous innovations, additive manufacturing – better known as 3D printing – is one technology that could prove successful. Although in its infancy, 3D printing has been used to produce spare parts for ships ranging from small plastic components to a working metal propeller.
While it has yet to progress to full commercial exploitation, 3D printing is being explored in almost every area of ship equipment. It is expected that eventually it will allow local production of spare parts for ships saving on urgent delivery expenses of production parts. There are many hurdles to overcome but the time and money being invested together with the fact that many shore-based industries are well along the road to commercial exploitation is probably a sign that shipping will not be far behind.