Automate the Freight: Shipping Containers Sorted by Robot Stevedores

Towering behemoths are prowling the docks of Auckland, New Zealand, in a neverending shuffle of shipping containers, stacking and unstacking them like so many out-sized LEGO bricks. And they’re doing it all without human guidance.
It’s hard to overstate the impact containerized cargo has had on the modern world. The ability to load and unload ships laden with containers of standardized sizes rapidly with cranes, and then being able to plunk those boxes down onto a truck chassis or railcar carrier for land transportation has been a boon to the world’s economy, and it’s one of the main reasons we can order electronic doo-dads from China and have them show up at our doors essentially for free. At least eventually.
As with anything, solving one problem often creates other problems, and containerization is no different. The advantages of being able to load and unload one container rather than separately handling the dozen or more pallets that can fit inside it are obvious. But what then does one do with a dozen enormous containers? Or hundreds of them?
That’s where these giant self-driving cranes come in, and as we’ll see in this installment of “Automate the Freight”, these autonomous stevedores are helping ports milk as much value as possible out of containerization.

Containers Aweigh

It’s a pretty safe bet that everyone has seen shipping containers before, even if you’re nowhere near one of the massive container terminals that sprawl out from ports all over the world. That’s because standard ISO containers are designed for intermodal carriers, meaning they can go directly from ship to land carriers without ever being opened or transferred. So even far inland, stacks of containers can be seen plying railways to landlocked distribution centers, or on highways being moved by tractor-trailers.

Lying between these two modes of transportation, however, is a logistics problem that managers of ports have to deal with: how to store the containers temporarily. It’s rarely feasible to load a container directly from a ship onto a train or truck and have it whisked away to its final destination, mainly because a container ship’s cargo is intermixed. Even though container sizes are standardized, different container types are often grouped together in the ship’s cavernous holds. This is especially true for food, which is stored in refrigerated containers that need power during the voyage. Also, hazardous materials need to be segregated, the load needs to be balanced, and a dozen other factors considered that all effectively randomize the containers within a ship.

When containers come off the ship they have to be sorted for the next leg of their journey. These containers are staged since transportation of that leg isn’t always immediately available, and therein lies the problem for port managers.

Squeezing Them In

Containers take up a lot of space. ISO containers are all 8 feet (2.44 m) wide and are measured by TEUs, or twenty-foot (6.1 m) equivalent units. So, in any given load there will be a mix of 20′ and 40′ containers, plus a few oddball sizes mixed in (because standards aren’t always standard).

These boxes take up a lot of space on the ground, and the yards used for sorting them tend to be enormous. Luckily, containers stack nicely, and so port managers can achieve some space savings by piling the containers up. This requires special vehicles called straddle carriers — basically mobile cranes that can straddle a stack of containers and that are tall enough to hoist a container up over the top of the stack and carry it away.

Straddle carriers have traditionally been operated by a human driver, sitting in a cab high above the ground with a commanding view of the yard. Like other heavy equipment operators, it’s a job that requires skill and focus, lest disaster occurs. But increasingly, straddle carriers are being converted into autonomous vehicles, like the 27 units being used at the Ports of Auckland in New Zealand to increase the port’s capacity from 900,000 TEUs per year to over 1.7 million.

The pinpoint positioning that these self-driving behemoths are capable of has greatly increased the capacity of Auckland’s port, which is seriously constrained by its location in the heart of a major city.

Straddle carrier with local position system. Source: Konecranes.

Being able to squeeze more containers into the same space relies on location data that GPS would never be able to achieve, so the straddle carriers instead use a local positioning system based on time-of-flight from a series of transmitters located on poles around the yard. This allows the straddle carriers to achieve positional accuracy of 1 inch (25.4 mm).

The container terminal environment is an ideal test bed for self-driving vehicles. The environment is highly controlled, and the exact location of each vehicle within the system, manned or unmanned, is known. The lighting is controlled and even, the pavement is flat and smooth, and the task, while enormous, is well-defined and fairly simple. It’s the perfect environment for self-driving vehicles, and the gains in throughput along with the reduction in costs are more than enough justification to automate the freight.

[Featured images from Tom Scott’s excellent video on automation at the Ports of Auckland]

27 thoughts on “Automate the Freight: Shipping Containers Sorted by Robot Stevedores

  1. My favourite thing to watch when working on a vessel is the towers of Hanoi being played on the ground when the status of a box changes during loading. Huge time sink. The operators don’t usually notice, since they are running operation to operation, but quite visible from above. In the interest of keeping cheap crap cheap, the drivers of the yard tugs move FAST. Don’t step outside the walking area.

  2. Just for the fun of it, some beef from EUROGATE/Bremerhaven:

    A move (that is: picking a ISO-container up, either from ground or ship, move it somewhere else, either ship or ground) cost 260 €.
    Delivery/Receiving an ISO-container (that is: passing the gate with it) costs 107 €.
    Every transport (that is: pick up, move to different location that is not ship, put down) costs 107 €.
    Twist lock handling (that is: locking/unlocking the conti-conti-connector) costs 16,50 €.
    Lashing (that is: mostly securing with rigid rods) costs 33 €.

    If not ISO-Container, prices roughly double. Extra handling doubles again.

    And I bet they can count like a boss.

  3. I think we need a change in the design of trucks/lorries to handle containers/teus/conexes.
    Truck/trailers designed specifically to haul them, perhaps closer to the ground to reduce wind resistance for less fuel consumption and reduce lateral tipping in strong winds or cornering. For instance, a truck designed to handle only 20′ containers, instead of a 53′ truck/flatbed trailer which would be harder to maneuver in tight places.
    With such re-design, it may be possible to make container “road trains”, trucks pulling 3 containers for long distances between source and destination.
    Or, utilize the “empty space” below the trailer to carry batteries or fuel cells to power the truck.
    detachable “solar roofs” for the trailers to power HVAC for insulated containers…

    1. Meanwhile in Europe this is and has been a thing for many years.

      But all this automation. Great for profit, not having to pay those highly skilled jobs to people.
      Be a shame if someone jammed the signal.
      Sadly that’s illegal, but replacing people with robots isn’t.

      So affecting huge multinational’s profits is bad, but putting someone and their family out of work isn’t ?

        1. OK you brought it up, so how many times have ports been shut down because of labor strikes? Because striking creates hardship for labor, strikes are an action of a last resort. I have to believe there are many computer and network hackers, sympathetic to the cause of labor, they can disrupt harbor operations more easily and readily than labor strikes can. Because they have no skin in the game they will forgo the deliberate process,that’s behind labor strikes.

      1. Jobs have been eliminated by progress for eons. Not much call for chamber-pot emptiers once toilets came along, and the buggy-whip industry died pretty quickly with the car. Not sure about the “night soil remediation engineers”, but buggy-whip makers were highly skilled tradesmen who probably didn’t deserve to get cast aside. But it happens, and one either adapts or fades into irrelevance.

    2. Containers general ride on a chassis, which is designed for containers. Very seldom on flatbeds. They are at a height to clear the wheels and match up with most customers warehouse loading docks.

      1. If you drive north on the Jersey Turnpike through the post-apocalyptic hellscape of Newark, just across from the airport are Port Newark and Port Elizabeth. There you can see thousands of those intermodal road frames stacked up waiting for containers. I used to love driving through there – between the refineries belching flame and smoke into the sky to the jets on approach to Newark looking like they’re lined up to land on the highway, there was never a shortage of urban decay to behold.

        1. it may depend on where you live but they definitely exist. I live near two smaller container yards and there are both rail and road chassis around here for 20′ and 40′ varieties. The road chassis uses underneath the chassis for fuel/generators but typically don’t sit the container lower because the truck cabs often have wind deflectors set to standard trailer height and to go much lower than that would actually increase drag due to turbulence.

          https://duckduckgo.com/?q=truck+shipping+container+chassis&t=lm&iax=images&ia=images

          As for road trains, well that is more dependent on the starting point and destination as the roads need to be much wider to handle a train of trailers. This means that existing locations in tight urban locations trailer trains are not feasible, road trains are really only a thing in Australia where the destinations are far apart and there is lots of room to get in and out of the yard (getting stuff into the city is still one truck to one trailer), in Europe the roads are too small for a long train and the distances are too close to make the connecting and disconnecting worth it. In North America there is just too much congestion for it to work as the traffic is aggressive and the truck drivers already have a hard enough time moving over with only one trailer.

          1. The reason we don’t generally have “road trains” is the maximum legal length of commercial motor vehicles. This varies state to state and some toll roads have special rules as well. Generally, you will only see some doubles and occasionally triple short trailers.

            Also, the maximum vehicle weight is 80,000 lb in most locations in the states, with the notable exception being Michigan.

            If you want road trains, call your law makers.

  4. CONEX will stay with US units forever. :) Too many millions of containers and billions of dollars or any currency in existence to ever do a hard conversion to nice round SI measurements.

    We can thank the Korean War for this. The US military had the first batch of 20 foot containers built as a test for making it easier to ship supplies to and around Korea. Soon after, with minor changes, the CONEX standard was finalized and has seen few changes in over 50 years.

    40 foot containers are 40 feet long but 20 foot containers aren’t. They’re a bit shorter so there’s clearance for the door latches. They’re exactly 8 feet wide and 8.5 feet tall so the inside can be ~8 feet tall. Then there are “high cube” which are a foot taller. Standard lengths are 40 and 20 foot but there are also 45, 53, and even 8 foot long.

    Why 8 foot long? There are flatbed semi trailers equipped with rows of the twistlock holes along the edges, spaced to mount 8x8x8.5 foot containers crosswise. But why do that? So that LTL (Less Than Load) freight delivery can be done quicker, with routing independent of how the trailer is loaded. It’s like having a long trailer with a bunch of doors down one side. With little containers to offload either a container can be opened on the truck or the whole container can be picked off and set down so the truck can get onto the next stop faster. Normal LTL operation involves planning how to load a trailer front to back so that the cargo gets loaded with the stuff going the farthest at the front. Containerized LTL allows random access to the load and makes it much easier to pick up additional cargo along the way, whether or not it’s going farther than other cargo closer to the front of the trailer. Dunno why this hasn’t become the most common method of LTL shipping, especially with aluminum or composite stubby containers to save weight.

  5. ” Also, hazardous materials need to be segregated, the load needs to be balanced, and a dozen other factors considered that all effectively randomize the containers within a ship.”

    And then there are smart containers.

  6. “standard ISO containers are designed for intermodal carriers, meaning they can go directly from ship to land carriers without ever being opened or transferred.”
    But wait… doesn’t every single container have to be opened and unloaded for customs inspection purposes? How would they assess the tarrifs otherwise?

    1. Because if you don’t have a document saying what is in a specific container it doesn’t get loaded. On anything. Boat, truck, or train. Look up Bill of Lading.

  7. In a response to a comment Dan appeared not to realize that he use his use of the buggy whip analogy tended an apple to orange comparison. He mention this is progress, we should be considering a progressive to what. In every modern economy, Labor is by far the largest consumer group, making labor the economic driving force. Suppressing labor’s ability to purchase goods, in the end has to negatively affect profit.

    1. I’d argue that there’s a labour to product ratio that needs considering. If labour alone were the most important factor then let’s drop farmyard machinery and employ everyone to till fields with manual hoes or whatever the terminology is. Some of the people will be surgeons, or bankers, or engineers who could be producing more value doing something else.

      So what happens to the stevedores made redundant by automation in shipping? What skills do they have and could they produce more in a different job? If they could then automation is a good thing.

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