Why autonomous

Why do people invest time and money in developing autonomous ships? And for that matter, what exactly is an autonomous ship? On this page, we try to answer some questions on the topic of autonomy and unmanned ships. References to external sources are marked with numbers in square brackets, and in the last section, you will find a list of all the references.

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 has been a steady increase in new investigations and concept studies. The Yara Birkeland vessel is currently at the forefront and is planned to demonstrate autonomy in 2021 (Yara Birkeland 2018).

Autonomous, unmanned and smart ships

Today, autonomous ship is a collective term mainly used to describe a merchant ship with some ability to operate independently of a human operator. This covers the whole spectrum, 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 generally used to describe ships completely independent of a human operator or supervisor. This typically means that there is no one on board to steer and control the ship. Today, this is extremely difficult to achieve, with some exceptions in unique and simplified cases. One of the challenges is to provide sufficiently advanced and well-tested technology to take over all the operators' tasks; Firstly, today's legal framework requires a human to be responsible for the ship and its operations. Secondly, it is unappealing to send a valuable and expensive asset on its way without keeping an eye on it from shore. In other words, almost all autonomous ships will be partly or constrained autonomous (Rødseth, Ø.J.; Nordahl, H.; Hoem, Snilstveit Å. 2018). Also, in almost all cases, a shore control center will continuously monitor the ship and have the ability to intervene when necessary. Thus, it is probably not cost-effective to give the ship automation above a certain level. With a person being available in almost all cases, it makes sense to use this person in operational scenarios where it is too costly or difficult to provide automatic systems.
  • An unmanned ship has no crew onboard to operate certain functions, such as bridge and engine, and thus requires some degree of autonomy. For instance, communication between the ship and the shore control center may be lost, and the ship must be able to temporarily and safely operate on its own. Unmanned ships will also benefit from higher degrees of autonomy by allowing operators at shore control centers to monitor and control more than one ship.
  • Autonomy requires a high degree of automation, but high degrees of automation do not necessarily mean autonomy. A smart ship is generally understood as a normally manned ship, but with advanced automatic functions and decision support. Of course, advanced automation may be used to reduce manning in some cases. However, the ship will still be conventional as it will follow current legislation related to manning and watchkeeping.

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

The emphasis on unmanned ships

Much of the interest in autonomous ships 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 in parts of the maritime transport business. Some of the important possibilities that are inherent in unmanned ships are briefly described as (Rødseth, Ø. J. 2018).

  • Improved working conditions: Autonomy and automation are first and foremost applied at tasks that are "3D"; Dirty, Dangerous, or Dull. One can question which onboard jobs fall into the 3D 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 onboard, 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 are relatively unharmful, and typically associated with collisions with port structures. However, repairs and off-hire will still be costly. Whether it is human errors, poorly designed control systems, or fatigue due to lack of rest and boring work, that causes these incidents, can be argued. Regardless, there is good reason to believe that improved and increased degrees of automation will help to avoid many incidents.
  • Reduced crew costs: One generally accepted benefit of unmanned ships is that crew costs will be reduced. This is a truth with some modifications, for instance, if increased shore maintenance and the need for a shore control center are taken into account. 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 large-scale benefits, to smaller transport units and more flexible transport systems.
  • Slow steaming: An interesting issue related to operational cost is the ability to operate at lower speeds to save fuel costs; 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 available 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, nor most of the deckhouse. It does not need any life support or personal safety systems, such as a galley, laundry, heat and ventilation, water, sewage, lifeboats, and many other costly sub-systems. The removal of these systems will also reduce the ships' weight, or it 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.
  • New ship designs: The removal of the deckhouse 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 is pervasive in the industry.
  • Better environmental performance: Weight reduction, or increased cargo capacity, will consequentially improve energy efficiency. The removal of the hotel section and associated power drains will further increase the efficiency. Removal of deckhouses will also decrease air drag, and general optimizations to the hull may also contribute to better energy efficiency.

These benefits are, however, offset by increased costs. Some major issues are the increased need for maintenance and off-hire, as no maintenance can be done during operation. Related to this is the fact that the use of heavy fuels may need to be abandoned, as they normally require significant human attention. Additional infrastructure is also needed in ports and possibly fairways, and the cost of a shore control center must be included in the equation as well.

The dimensions and elements of risk are far from clear, and sufficient safe operation will require additional investments. More advanced ICT systems, including new sensors, will most likely further increase costs. Finally, the regulatory framework will have to be addressed. In reality, a lot is possible when autonomous ships are operated in national waters (as with Yara Birkeland), or even regional waters where bilateral agreements between flag states, coastal states, and port states can be made However, general international shipping will be difficult to achieve without significant changes in today's regulations and contractual arrangements.


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.