In a recent report from the McKinsey Consulting Group there was a fascinating article about imagining the container shipping industry fifty years from now. I think they are absolutely correct to assume that 50,000 TEU vessels will come, but I think this will be much sooner than 2067.
In this article I will explore some of the potential changes that will need to take place and the technical issues that will have to be overcome.
From a technical and naval architecture standpoint, there isn't any limit on the size of a container ship can be. There are currently 3 major limitations that a shipping line has to consider when building new vessels.
1) Terminal Infrastructure Limits
2) Draft Restrictions
3) Length Overall
Currently there are vessels sailing close to the 22,000 TEU mark. This is something that was unimaginable 10 or 15 years ago. I'm not saying that we can expect a doubling in size within the same timeframe but it's definitely coming.
Vessels are currently built primarily with Terminal Infrastructure and Draft Restrictions in mind. It's all very well scaling a 22,000 TEU vessel up to 50,000 TEU but how do you do it? Well, you can extend the length of the vessel, you can increase the width, you can increase the vessel draft beyond the 16-17m limit and, with a bit of creative thinking, you can probably go from loading 10-12 high containers on deck to 20 high. Maybe by re-introducing the "TweenDeck Concept", except you would effectively have the tweendeck suspended above the 10th Tier on deck and secured to the lashing bridge.
Container Lines are always reluctant to extend the length of the vessel because then the berthing fees increase into the next "100m bracket". This can be see by the fact that all mega vessels have not had a length above 399.99m, despite their increases in capacity. If owners are going to breach the 400m barrier, then it is only logical to move to something like 450m in length. That would allow sufficient additional capacity to offset the increase in berthing fees.
So why is this not currently possible?
For a start, if you simply increase the length of the vessel, then you begin to create the problems of vessel torsion that the Classic Panamax vessels were particularly prone to. They had a Width to Length ratio of approximately 1:9. Combined with the fact that the bays on these vessels were mostly limited to being split into two compartments, it was very difficult to avoid torsion issues without clever planning and ballast water.
So why don't you make the vessels wider and longer to avoid this problem? This is where the terminal infrastructure comes into play. The most modern gantry cranes available right now can reach 23/24 rows across the vessel. If you exceed this limit then you either have to load cargo for another port in the extra rows or you have to turn the vessel around part way through the operation. This is both costly and time consuming so not a practical option if you have to do it in every port.
The current terminal gantry crane (below) also faces the same problem. You can't just keep scaling them up in size because they eventually cannot cope with the strains and stresses of their own weight. Something new is needed.
I would look to the port of Salalah as inspiration here. They have been using a vacuum mooring system for several years now. The vessel berths along the quay, the vacuum system extends from the quay and locks onto the ship. No more dangerous mooring operations for a start. The system is also designed to move up and down as the vessel gets lighter or heavier and the tide rises and falls.
Perhaps this could be the answer to the gantry crane problem. If the crane was fitted with a single, extendable boom that reaches out over the full length of the vessel. A vertical support could then be lowered down the offshore side of the vessel and, if fitted with a similar vacuum system, could clamp onto the hull of the vessel. Since it would employ the same "adjustable" technology as the mooring system it could remain locked in place during cargo operations.This would negate the need for the gantry crane to entirely support it's own weight plus the containers during cargo operations.
I think it is also safe to assume that by this stage, crane operations will be fully automated so the fact that the vessel is so much deeper will not cause the problems we see today because the crane operator is further and further away from the containers they are loading or discharging. This automation should speed up operations dramatically because it could apply dynamic calculations to determine the distance the next container to be loaded or discharged.
The below diagram illustrates the problem of visibility that crane operators currently face:
Let's say that you increase the draft of the vessel. The latest generation of mega vessels can load 11-12 tiers of containers under deck. You can extend this but then you start to run into problems that were discovered when Nedlloyd built hatches vessels in the 1990's. No longer were the stowage planners limited by the stack weight limit that the vessel could handle, the limiting factor became the amount of weight that the container at the bottom of the stack could support.
The concept was brilliant.....on paper. The reality was that the unsupported cell guides that can be see above the hull were very prone to damage during cargo operations which meant that, as the vessels got older, the problems increased. This concept has been largely abandoned today.
Draft also comes into play when you are looking at both terminals and, perhaps more importantly, the Suez Canal and Malacca Straits. Is it possible to build a vessel so big that these two major arteries can be transited?
It is perhaps a good idea to take a look at the Oil industry for inspiration. The largest ULCC's have drafts in excess of 20m, cannot transit the Suez Canal and cannot berth in a traditional terminal. Their solution......move everything offshore.
Oil Tankers sail to a destination but offload their cargo to a pipeline that can be miles out to sea. They rarely call in an actual terminal. The question is, can something similar be done with container terminals?
Look to Shanghai as a partial glimpse into the future. The Chinese have built a deepwater terminal several miles from the coast by basically attaching it to a series of natural islands and then building outwards. But what if we forget the idea of a terminal being located in a fixed position?
Again, I look to the Oil Industry for inspiration. Deep Water Oil Rigs are not physically connected to the sea floor. They are held in place with dynamic positioning GPS.....no human interaction required. We have a lot of experience in reclaiming land from the sea so could that knowledge be turned to Floating Offshore Container Terminals?
For a start, these could be modular in design. As the container volumes grow, additional modules can be added to keep pace with demand. Clearly the technology to deploy these would need to be developed but there's nothing like a challenge to get engineers excited.
There is another factor that comes into play here. I cannot predict how technology will develop in the next 5 decades. It is almost certain that autonomous ships will be plying the seas within a few years from now. Straight away that gives you a capacity intake increase because you can eliminate the need to have a superstructure that combines crew accommodation and the bridge.
The engine room is a little trickier, but let's assume that propulsion design has moved away from the fuel powered vessels of today. It's entire possible that vessels will be able to operate on renewable energy sources and any maintenance can be carried out by onboard robotics.
I'm not going to make a prediction about when we are likely to see vessels of 50,000 TEU and beyond but I firmly believe we will see it long before 2067.