On the 23rd March the container ship Ever Given ran aground in high winds whilst in the Suez canal, generating a worldwide news story and completely stopping shipping in one of the worlds’ busiest seaways. Approximately 12% of total global trade passes through the canal and it is estimated that a daily value of $9.6 billion of goods were held up during the disruption. Images of this huge vessel trapped within the narrow confines of the waterway reminded us of just how vast modern shipping vessels have become. Back in 1969 the first British container ship, P&O’s Encounter Bay, was 227 metres long and had a cargo capacity of 1,578 TEU (TEU stands for twenty foot equivalent unit and is a measure of the volume of a single container). The Ever Given, launched nearly 50 years later in 2018, has a capacity of 20,124 TEU. Stop to consider for a moment just how big this is.....a shipping container has a floor area of 15 m^2, 6 of them equate to the average UK house size of 90 m^2. So with over 20,000 containers the largest vessels carry the equivalent of over 3,000 homes, the size of a small town with ~10,000 people. Imagine towns such as Holyhead, Monmouth or Pembroke Dock consolidated into one block and packed aboard just one ship!
The surface area of these 1000’s of containers is huge (many times greater that a football pitch) and so it is not surprising that even in moderate winds there are serious navigational problems due to wind force. Ironically it was the vast size of the Ever Given that helped in eventually freeing it from the canal bank as 2,000 tonnes of water was allowed into ballast tanks in the stern and its 400 metre length used as a huge lever, generating a torque of ~8 billion Nm that lifted the bow free (more than 10x the torque that rotates the London Eye). These vessels are also subject to fluid forces as the Bernoulli effect produces lateral pressure differences within the narrow channels of canals that can force a ship into the banks of a waterway. So, what at first might appear to be a simple matter of guiding a ship along a straight canal actually requires a significant degree of control and feedback with tight tolerance for course and speed deviations.
To find out more about the technical aspects of this event I spoke to an expert, with over 40 years of experience in maritime engineering – Henk van den Boom from the Maritime Research Institute Netherlands (MARIN). MARIN is an independent research institute and an interesting example of an organisation pursuing collaborative R&D with similar goals to the Sêr Cymru Engineering NRN in bringing together commercial organisations and university expertise. I discussed with Henk the challenges posed by the rapid growth in vessel size, the innovative solutions being developed using advanced computational simulation linked to real-time sensor data and the wider tradition of maritime engineering in the Netherlands.
As an expert was the incident a surprise to you?
Incidents with these large container ships are not new to us, for example in December 2019 the APL Mexico City broke loose from the quay in Antwerp due to strong winds and destroyed a container crane. MARIN was involved in the investigation of MSC Zoe that lost 342 containers, two years ago. Actually, over the last four months, three and a half thousand containers have been lost overboard in the Pacific, so it is quite clear that these large container vessels have safety issues.
Wind force clearly played a major role in the incident, why is it so dangerous to these large vessels?
These vessels have doubled their cargo capacity over the last 10 years, by increasing the beam of the ship and by increasing the percentage of the deck load, so 60% of their containers are stacked on deck. So, a decade ago we had eight layers on deck and now we have twelve and the windage of these vessels is enormous - you're talking about 24,000 square metres. So in the 30 knots crosswind in Suez you'll have something like 250 to 300 tonnes of wind force in the transverse direction and this has to be balanced by drifting of the vessel. That means that the pathwidth required by the vessel is something like 120 metres (Note: at the section of the incident the Suez canal is only 205 metres wide and the deep section is only 120 metres wide). Another issue would be bank suction which produces pressure differences that pull the ship off course.
It appears that the rapid increase in vessel size has not been matched by similar changes to port facilities.
Yes, the safety margins for these vessels are very tight and this is because if you order today the biggest container vessel you can have it in two years time. But all of the infrastructure takes something like 20 years to increase. The Suez Canal has not been doubled in size over the last 10 years nor have the ports, all the ports are struggling with these large vessels. What you see is that the tidal and weather windows for these vessels to pass canals and to enter port are becoming more and more narrow. Even the bigger ports, they have quite strict restrictions on wind for these vessels, like the port of Rotterdam - they only allow these vessels in if the wind is below six Beaufort (strong breeze) from the Northwest. Whereas in the past, you could enter even at seven Beaufort (high wind) or eight Beaufort (gale), with the container ships of that time.
I know on your WINDLASS project you are using lidar sensing and computational simulation to model the effects of these forces on vessel trajectory. And of course, we are familiar with autopilot on aircraft and the prospect of self-driving cars. What is the end goal of this work in the marine setting?
I think in the end we are looking for a fully automated passage in a similar way to which aircraft are landing. You could fully automate that if you have sufficient information on the weather and on the control systems and all the positioning and the orientation of the vessel. Then you could do it fully automatically, so that would be the end goal. But it is, of course, far away so for the time being we try to assist the ship officers and the pilots with relevant information.
Our industry, of course, is quite conservative so in this respect we are lagging behind aircraft and also cars. From the routes they take it is simpler for shipping than for aircraft and for cars so I don't see a reason why we should not go that way. On the other hand, we are talking about these huge structures with large capital involved, so there will be a human role for sure, these vessels will never become unmanned.
Please tell us a bit more about the Maritime Research Institute Netherlands (www.marin.nl ) that you work for.
Well, we started off in 1932 as the Netherlands Ship Model Basin (NSMB) and actually many people know us because of the model testing so scale models is still a core business. But we do a lot more than that these days, we have, of course, new nautical tools and we develop and deliver software to clients. We have quite advanced nautical simulators both for research and for training. For example we train the pilots at Milford Haven in Wales and we deliver simulators to them.
Then we also have a department which is dedicated to onboard measurements, so we have the feedback from reality to support shipping operators but also to check and verify our models. So this combination is quite powerful because you have many research institutes operating model basins doing nautical work or providing computational services, but to merge this with full scale field measurements, that is a strong combination.
The rescue of the Ever Given was led by a Dutch company, Boskalis and this is not surprising as there is clearly a great tradition and pride in maritime engineering in the Netherlands, understandably from its location on the North Sea. How is this seen within your country?
Well, we have a shared history to the UK in this respect and a similarly long maritime tradition. And we did rule the waves, for a very short period in history, as you know. But also there is the ambition, let's say, to stay active in this area. We have a strong combination of education, of innovation and of business supported by Universities, by Industry, by research organizations and also by government. The fact that we have this very strong network, I think, is key to our success.
So there is innovation and that keeps attracting also the younger people. I think there's also a very important aspect that you can have this tradition, but people will not want to spend a life following the tradition, you have to offer new perspectives. And that is something that our government also understands, so they are quite keen to support the education, to support the universities, to support the research. Actually, MARIN is also part of that educational system, and we have strong relationship with Delft University and also with other universities. There are professors that are part time in university and part time with MARIN. So, in that way, although there is no formal relationship, we have a working relationship with those universities.
Would you tell us about your career path, how did you become a maritime engineer?
Well, I have worked with MARIN for more than 41 years now. I grew up by Lake Ijsselmeer so I was always busy with boats and water. I liked sailing and sailing boats and after going to Delft University I had the opportunity to work on an America’s Cup boat. The France 3 yacht (1980) was designed by Johan Valentijn who conducted his model testing in Delft. I helped on numerical work and with the model tests themselves. But in the end the challenge of making a living in the small world of yacht design made me rethink and I took up offshore engineering, working as a trainee in Aberdeen and getting involved with the installation of the Brent Charlie production platform. After working in a shipyard and then on board an anchor handling tug in the North Sea, my final traineeship was with MARIN, at that time we had 20 ships in the shipyards and so I was on board ship a lot of the time. This experience, spent in different areas has been very valuable in my career. At MARIN through the 1980’s we developed in-house software for numerical analysis to go alongside model testing and moved into simulation of multibody dynamics. In 1990 I started the Software Engineering department as well as the Trials and Monitoring group, which I led for 27 years.
Today I am in the very nice situation of only doing special projects. These include the WINDLASS project and the TopTier Joint Industry Project to avoid container loss at sea. Both projects are part of the Vessel Operator Forum which we founded some 15 years ago.
Many thanks to you Henk, for sharing your knowledge with us and for the personal insight you have given on your long and varied career as a maritime engineer.