Risky Business

 In the civilian world, when we think about ships being used outside of the military, three major uses that come to mind are:

1. shipping of goods (e.g. cargo ships or tankers)

2. “roll on, roll off” vehicle transport (a.k.a. ferries)

3. research efforts 

Ferries and maritime research vessels may experience some similar risks as shipping vehicles, but for right now, let us focus on cargo container ships which are used to transport goods over the ocean. Specifically, let us address the recent push to develop unmanned shipping vessels. To clarify, “unmanned” is a term which can have multiple connotations, and can be misinterpreted to mean “fully autonomous”. In this context, unmanned ships will have high levels of automation, such as navigation and obstacle avoidance. They may or may not be remotely operated, and they may or may not have any crew aboard at all. Unmanned here does not mean fully autonomous.

In The Ocean-Going Autonomous Ship—Challenges and Threats, Felski and Zwolak (2020) discuss real world complications of navigating unmanned ships within busy shipping lanes. 90% of all goods (APANEWS, 2019), and nearly 60% of all food (Ritchie, 2020), are transported by ship every year, making many routes quite congested. For an example, look no further than the recent debacle with the Ever Given, a ship which became wedged in a narrow area of the Suez Canal. This one ship crippled a shipping route that is so popular, the loss of its use represented $15 million per day of lost revenue to the country of Egypt, and millions more lost to companies whose livestock perished, foods spoiled, and schedules were upset by the error (Nagourney, 2021). Overseas shipping is big business.

Global Positioning System (GPS) and Global Navigation Satellite Systems (GNSS) are required in order for ships to navigate safely and accurately through the oceans. On a standard system, the same satellite communication array that ships utilize for their GPS and GNSS navigational data are also utilized by the ship’s remote operators to command the vessel. This lack of redundancy is more than a risk of non-redundancy; it can also cause misalignment with the navigational system.

The satellite-tracking functions of the satellite communication terminal use not only raw GNSS and heading data, but augment it with inertial motion units (IMU) and process the positioning information using the algorithms based on Kalman filtering to ensure the proper satellite tracking. Therefore, the lack of GNSS position input will not cause the malfunction of the satellite communication immediately, but the accuracy of the tracking solution will decrease with time. (Felski & Zwolak, 2020, p. 6)

The authors state, and I agree, that the mitigation strategy for this risk should be to duplicate the satellite communication links so that there is both a backup system and a separation between navigation and communications. But there are other threats that exist to the use of GNSS itself.

“Radio frequency interference can be unintentionally emitted by commercial high power transmitters, ultra-wideband radar, television, very-high frequency (VHF), mobile satellite services and personal electronic devices.” (Felski & Zwolak, 2020, p. 6). As the Earth becomes more connected via technology, the presence of potential sources of interference will also increase. On a more sinister note, there have already been documented instances of intentional jamming of GNSS signals against sea-going vessels. The very idea of exploiting unmanned navigational tools is a real threat to the widespread adoption of unmanned shipping.

Here, the authors discuss two potential ways to lessen the impact of GNSS dependence: swarm communication to prevent collision, and pre-planned routes (Felski & Zwolak, 2020, p. 10). In order to combat jamming, though, the author has recommended using 3 separate receivers spread out such that they would be able to identify and compensate for any attempt to jam.

Clearly, the maritime world has a lot to consider when it comes to transitioning ocean shipping to fully automated and remote operated ships. In our next post, I’ll touch on the positives of this move. With all new technology there will be “growing pains”. If we keep looking forward, while learning from what’s behind us, I feel that these issues can be mitigated in a way that makes international maritime shipping safer, better for the environment, and eventually faster.

More later...

(sources)

APANEWS. (2019, June 10). 90 percent of world trade is by sea- Official. Apanews.Net. http://apanews.net/en/news/90-percent-of-world-trade-is-by-sea-official

Felski, A., & Zwolak, K. (2020). The Ocean-Going Autonomous Ship—Challenges and Threats. Journal of Marine Science and Engineering, 8(1), 41. https://doi.org/10.3390/jmse8010041

Nagourney, E. (2021, March 30). With the Suez Canal Unblocked, the World’s Commerce Resumes Its Course. The New York Times. https://www.nytimes.com/live/2021/03/29/world/suez-canal-stuck-ship

Ritchie, H. (2020, January 28). Very little of global food is transported by air; this greatly reduces the climate benefits of eating local. Our World in Data. https://ourworldindata.org/food-transport-by-mode