Why autonomous

Why do people invest time and money in developing autonomous ships? For that matter, what exactly is an autonomous ship? These pages will try to answer some of these questions. The text contains references to external sources, they are marked with a number in square backets and the reference can be found in the last section.

Some history

The concept of autonomous or unmanned ships is not new. Japan investigated remote control of ships in the "Highly reliable intelligent ship" project from 1982 to 1988. Other transport modes have researched autonomous vehicles since the 1970s. One can even argue that the idea may originate from Nicola Tesla's demonstration of a "radio-controlled" model boat in New York's Madison Square in 1898.

The first large scale study on unmanned and autonomous merchant ships was the EU-project MUNIN, running from 2012 to 2015 (Ø.J. Rødseth and H.C. Burmeister 2012). The purpose of the study was to assess the possibility of converting a Handymax dry bulk carrier into an unmanned ship. It turned out that this was unrealistic from a commercial point of view, but that a fully unmanned and autonomous vessel would be feasible in other operations. Since then, there have been a steadily increase in new investigations and concept studies. Yara Birkeland is currently at the forefront and is planned to demonstrate autonomy in 2021 (Yara Birkeland 2018).

Autonomous, unmanned and smart ships

The term autonomous ship is today generally used to mean a merchant ship that has some ability to operate independently of a human operator. This covers the whole specter from automated sensor integration, via decision support to computer-controlled decision making. In other words, autonomy implies a high degree of automation.

The term fully autonomous is used to describe ships that are completely independent of a human operator or supervisor. This will typically also mean that there is no one on board to steer and control teh ship. Today, this is extremely difficult to achieve, except in very special and simplified cases. Difficulties will be found in supplying sufficiently advanced and well tested technology to take over all of the operators' tasks; in today's legal framework that requires a real person to be responsible for the ship and its operations; and in sending a very valuable asset on its way without keeping an eye on it from shore. In other words, almost all autonomous ship will be partly or constrained autonomous (Rødseth, Ø.J.; Nordahl, H.; Hoem, Snilstveit Å. 2018). There will also almost always be a shore control centre that continuously monitors the ship and which can intervene when necessary. This also means that it is probably not cost-effective to give the ship automation above a certain level. As there is a person available in any case, it makes sense to use this person in operational scenarios where it is too costly or difficult to provide automatic systems.

An unmanned ship is a ship without crew to operate, typically bridge and engine functions, that needs a certain degree of autonomy, e.g. when communication with a shore control center is lost. An unmanned ship will also benefit from increased autonomy by allowing operators in the shore control center to monitor and control more than one ship.

Autonomy requires a high degree of automation, but high degrees of automation does not necessarily mean autonomy. A smart ship is generally understood as a normally manned ship, but with advanced automatic functions and decision support. One may of course use the advanced automation to reduce manning in some cases, but the ship will still be "conventional" in that it will follow current legislation related to manning and watchkeeping.

Thus, there will be a parallel development of smart and unmanned ships with additional contributions from non-merchant sectors like defence, survey ships, workboats and others.

The emphasis on unmanned ships

Much of the interest in autonomous ship is in fact driven by the new possibilities that fully unmanned ships offer. In fact, these possibilities have the potential to create completely new maritime transport systems and may very well prove to be disruptive on parts of the maritime transport business. Some of the important possibilities that are inherent in unmanned ships are briefly described below (Rødseth, Ø. J. 2018).

  • Improved working conditions. Autonomy and automation is first and foremost applied in tasks that are "3D": Dirty, Dangerous or Dull. One can question what on-board jobs fall into this category, but it has been shown that working on a ship is often much more dangerous than working in similar jobs on land. This is mainly due to work related accidents on board, including exposure to harmful substances
  • Lower damage related costs. It has been argued that the human factor is responsible for a majority of the incidents and accidents that happen at sea. Most of these are relatively small and, e.g. associated with allisions with port structures. However, repairs and off-hire will still be costly. Whether it is it is human errors or rather the effects of poorly designed control systems, fatigue due to little rest and boring work, that cause these incidents can be argued. Regardless, it is good reason to believe that improved automation will help to avoid many of these incidents.
  • Reduced crew cost. One generally accepted benefit of unmanned ships is that crew cost will be reduced. This is a truth with some modifications, e.g. as more shore maintenance and the need for a SCC. However, crew related cost reductions are very relevant for smaller ships. This supports a transition from today's very large ships that are driven by the benefits of larger scale, to smaller transport units and more flexible transport systems.
  • Slow steaming. An interesting issue related to operational cost is to operate at lower speeds to save fuel costs, i.e. slow steaming. This requires a trade-off between time dependent costs such as capital expenses and crew and the speed dependent cost of fuel. Unmanned ships reduce crew dependent costs, but the balance depends heavily on the costs of fuel and capital. For smaller and less expensive vessels, it may be a good business case. Again, defeating the "economy of scale" is an important part of the picture.
  • Lower structural costs. An unmanned ship will not need a hotel section and most of the deck house. It does not need any life support or personal safety systems, such as galley, laundry, heat and ventilation, water, sewage, life boats and many other costly sub-systems. The removal of these systems will also reduce the light-weight of ship or can be used to increase cargo capacity. If a ship can be built for completely unmanned operation, there are obvious benefits in construction costs and increased cargo capacity of the ship.
  • New ship designs. The removal of the deck house and other crew related features allow for more innovative designs of ships. Unmanned ships will in particular lend themselves to smaller, more flexible and more efficient ship designs that may defeat the general "economy of scale" thinking, which today is pervasive in the industry.
  • Better environmental performance. Reduction in light weight or increase in cargo capacity will increase energy efficiency. The removal of the hotel section and associated power drains will further increase the efficiency. Removal of deck house will also decrease air drag and general optimizations of the hull may also contribute to better energy efficiency

These benefits are, however, offset by increased costs. Some major issues are extra need for maintenance and off-hire as no maintenance can be done during operation. Related to this is that one can probably not use heavy fuel as that normally requires significant human attention. One will also need additional infrstaructure in ports and possibly fairways, and teh shore ocntrol centre will also incur costs. The risk picture is far from clear and sufficient safe operation will require additional investments. More advanced ICT systems, including new sensors will also most likely add to costs and, finally, the regulatory framework will hvae to be adressed. In reality, one may go a along way when autonomous ships are operated in national (as Yara Birkeland) or regional waters where one can manage with bilateral agreements between flag state, coast staes and port states, but general international


Ø.J. Rødseth and H.C. Burmeister (2012) Developments toward the unmanned, ship, Proceedings of International Symposium Information on Ships - ISIS. Vol. 201..

Yara Birkeland (2018) e.g. http://yara.com/media/stories/yara_birkeland_vessel_zero_emission.aspx, (Retrived 2018-03-06).

Rødseth, Ø.J.; Nordahl, H.; Hoem, Snilstveit Å. (2018) Characterization of Autonomy in Merchant Ships. In: Proceedings of, MTS/IEEE Oceans'18, Techno-Ocean 2018 - OTO'18. IEEE 2018 ISBN 978-1-5386-1653-6.

Rødseth, Ø. J. (2018) Assessing Business Cases for Autonomous and, Unmanned Ships. In: Technology and Science for the Ships of the Future. Proceedings of NAV 2018: 19th International Conference on Ship & Maritime Research.. IOS Press 2018 ISBN 978-1-61499-870-9.