RORO Vessels: Driving Cars Across The Ocean

Roll-on/roll-off vessel docking

YouTube does a pretty good job of making itself a target for criticism, but one thing you can say about their algorithms: when they work, they really work. Case in point, the other day I found a suggestion in my feed for a very recent video about salvaging a shipwreck. I can’t begin to guess what combination of view history and metadata Google mined to come to the conclusion that I’d be interested in this video, but they hit the nail on the head.

But more importantly, their algorithmic assessment of my interests must have been a goldmine to them — or it could have been if I didn’t have a minefield of ad blockers protecting me — because I fell down a rabbit hole that led me to a bunch of interesting videos. As it turns out, the shipwreck in that first video was of a cargo ship that was carrying thousands of brand-new automobiles, which were all destroyed in the fire and subsequent capsizing of a “roll-on/roll-off” (RORO) vessel off the coast of Georgia (the state, not the country) in 2019.

Thus began my journey into RORO vessels, on which automobiles and other bulky cargo are transported around the world. And while my personal assessment of the interests of Hackaday readers probably is not as finely tuned as Google’s algos, I figured there’s a better than decent chance that people might enjoy tagging along too.

RORO Your Boat

The stern ramp of the MV Golden Ray
The MV Golden Ray in happier times, showing the stern ramp. Source: Farid Mernissi, CC BY-SA 4.0

Coming into that first video without any context was a little rough, since it was mostly drone footage of a rusting section of what was once the MV Golden Ray sitting on a dry-dock barge. The section had contained hundreds of cars, the rusted remains of which were now being plucked out by a very skilled grapple operator. The scale of each of the seven sections the vessel was cut into during salvage was staggering, so naturally I looked up the Golden Ray to see what such a monstrous vessel looked like, at least in better days.

RORO ships are designed to carry anything that can be driven onto them, either under their own power or with the help of some kind of tug or tractor. A lot of passenger ferries fall into this class of vessels, but behemoths that move cars and trucks are the stars of the class. The largest RORO right now, the MV Tønsberg, is 265 meters long, 32.27 meters in the beam, and can carry 41,000 tons of cargo. Depending on the mix of cargo, that’s somewhere in the neighborhood of 8,000 cars.

Like most cargo vessels, ROROs are extremely optimized for the kind of cargo they carry, and since they’re intended to have vehicles drive on and off them, they look very much like floating parking garages. They are aggressively unattractive vessels, boxy and angular, but unlike their equally ungainly container vessel cousins, ROROs store all their cargo below decks. ROROs are designed to be berthed alongside a quay, which gives rise to their most distinctive feature — the stern ramp. Built into an angled section of the stern quarter, the ramp is no mere gangway. It’s really a folding two-lane highway on-ramp, some 12 meters wide and capable of carrying hundreds of tons. The lower half of the ramp also serves as the watertight door when it’s stowed, and so it’s a very complex and important piece of equipment.

Cargo Operations

Once the ramp is open, cargo operations can begin. ROROs typically make stops at multiple ports during a voyage, and so cargo is usually both loading and unloading at the same time. This leads to an absolutely fascinating ballet of movement, as sometimes hundreds or thousands of cars are shuffled around. The logistics involved are just mind-boggling — extreme care has to be taken to load cars such that they aren’t obstructed by cargo destined for a later port-of-call, since that would lead to “shifting”, a time- and resource-intensive process of moving vehicles out of the way temporarily.

The amount of labor needed to load and unload a RORO is staggering. Each vehicle has to be driven on or off the ship, so the more drivers, the faster it goes. Everything needs to be carefully choreographed so that cars are constantly in motion, and that no accidents occur. Drivers typically operate in small squads; each squad is accompanied by a large passenger van that can shuttle them quickly back on or off the ship when they’re done unloading or loading a car. That maximizes the number of pieces of cargo each driver can handle in a shift.

While the bread-and-butter of most RORO operators lies in shipping new passenger cars and trucks, that’s far from the only cargo they’ll carry. Many ROROs have the ability to adjust sections of their decks and ramps to accommodate “high and heavy” cargo. This can run the gamut from tractors to buses to heavy construction equipment, or anything that can be wheeled through the stern door.

No matter what rolls onto a RORO, it has to be secured before the voyage starts. RORO decks have cutouts for lashing straps, and there are exacting specifications for lashing each vehicle. The vessel’s crew has to walk the decks and check each and every lashing strap once every three days while underway, to tighten up any straps that slacken due to vibration. Given that cars are often packed with only a few centimeters of space between them, this requires a certain degree of nimbleness.

Deep Dive

If you’ve got the time to spare, I found the documentary below with a detailed look into RORO operations — and as a bonus, a look at the complex process of a Panama Canal passage. It’s always satisfying to learn a little more about how the world’s supply chains work, and cases where it doesn’t work too.

[Featured images: Höegh Autoliners News and Press Releases, Free Documentary]

27 thoughts on “RORO Vessels: Driving Cars Across The Ocean

  1. There is (or at least used to be) a ferry service across Lake Michigan between Ludington and Manitowoc where the ferry is this behemoth of a steam powered icebreaker whose original job was to ferry shiploads of rail cars full of coal across the lake in all weather.

    It’s an interesting ride, and while it’s “only” 125 meters long, riding it gives you an idea of the ridiculous scale of this kind of vessel given that this is a “small” one.

    1. Used to watch the Viking, Badger and City of Milwaukee (hope I remembered them right!) ferries depart and arrive in Frankfort, Michigan during the 1970’s-80’s. To see such a large ship pull into the harbor, then swing the bow around nearly 180 degrees to line up with the dock was always a wonder. They usually carried a mix of passenger vehicles and rail cars. No matter where you were in town, the “tooooot-toot” of the ships horn would tell you it had just docked.

      Link to a nice photo showing the loading dock:

    2. There’s quite a few that operate between the UK and mainland Europe, so it was the main way my family went on holiday as kids.
      Drive the car (and caravan) down to Portsmouth, drive onto the ferry, then 5-6 hours later drive off into France.

      1. I took a bus trip from Germany to London in the 80’s. We crossed the channel on a ferry (after visiting Amsterdam) and slept in cabins overnight. We returned va Brussels. Cool trip overall.

  2. Some years back, one of these car transports was in port, and for some reason, open to the public. It was like a big, empty, parking garage.

    Clive Cusler featured a robotic ship in one of his books. Didn’t turn out so well.

  3. “.. when they work, they really work.”
    I have used YouTube every day for over a decade and it has never, not even a single time, suggested something to me that I actually wanted to watch. And it is SO clearly profit motivated that it’s insulting. I have spent dozens of hours over the years gutting their UI of ‘suggestions’ and other irrelevant marketing crap, simply so I don’t have to feel like I’m at a used car lot with a high pressure salesman trying to chat me up every 3 minutes.

    It’s also just bad at its job.

    Oh? Did you just watch a 90 minute video and leave a comment? And the video was about reverse engineering, memory forensics, and kernel debugging?

    But it used a video game as an example for one section. So I’m going to fill your suggestion feed with PewDiePie, Markiplier, or some 13 year old screaming at Minecraft for the next 4 months. Enjoy.

    1. They never suggest anything near what I regularly watch as most of those are demonetized. Instead, the top suggestion is the same for about a year or more. Event though I never selected it!

      They use the most brain dead AI I’ve ever encountered :)

      1. It isn’t an AI, and it isn’t trying to suggest things you’ll like. It’s a set of filters, metadata, and algorithms, heuristically suggesting monetized videos you’re less likely to click away from.

        1. And that’s where they fail. I’m most likely to click away from anything I didn’t specifically go looking for. My mentality resides firmly in their blindspot.

          There was probably a meeting and someone said, “but if people do X,Y, and Z, none of this will work and it will probably piss them off.”
          Then another someone probably said, “nah, no one does that.” or “who cares about one person?”

          That’s what I do. I’m X, Y, and Z all over, and Youtube is a constant source of frustration.

  4. One of my favourite wrecks is that of the Zenobia, a 172 m long Swedish RoRo that sank off the coast of Larnaca, Cyprus on her maiden voyage. Caused by troubles with the relatively modern computer operated ballast tanks.
    Often ranked as one of the top ten wreck diving sites in the world. Over a hundred articulated lorries are still on board and can be admired.

  5. I almost NEVER use Facebook but the other day I was checking on something and decided to click on the News Feed (if that’s the right term) and 100% of the articles were of interest to me.
    The only way Facebook could have done that is if they were getting data from my Google account which I NEVER use either which means they were getting stuff from the Google account that I do use or directly from my Chrome browser history.

    Anyone who thinks for a second that anything they do on the Internet is “private” in any sense of the word is delusional. I don’t care how many VPNs, privacy settings, and privacy browsers/apps you use, if “they” want YOUR information, “they” WILL get it.

      1. Nope. Doesn’t stop a thing. If they want it, they get it. And don’t forget the 30 years of data you have NOT been protecting since you got that AOL account in 1990.
        Privacy is a myth. Mozilla might not track you but your ISP does. And those sites that promise not to are lying.
        At best you slow them down.
        Fish swim in schools so they have a slim chance they are not the one eaten today.

  6. I thought this was going to be about some boats that have some dynamos of some sort that the cars turn with their tires, thus providing propulsion to the ferry. Wow, my imagination really worked overtime to fill in the gaps until I finished reading what this was really about. Nothing is driving cars anywhere. It’s just regular surface shipping. =( That title is somewhat clickbaity.

  7. I had the privilege of helping with speed trials on a new roro last year. The remark about inspecting the lashing every three days makes sense: these ships are built for speed and capacity, not comfort, so the vibrations can be significant. Especially doing trials on an empty vessel, it felt like riding in a shopping cart at 18knots. One of network switches I was using in the engine bay literally came apart from the vibration, the four screws popped out!

  8. I recently travelled (as a foot passenger) from Genova to Sardiniä and later back to Toulon. What surprized me was:
    – The large amount of empty space on those ships, as only a few trucks were on the bottom “high” deck. I have seen ships with movable decks, such that one truck deck can be moved into two car decks (for the whole or half of the deck)
    – The skill which which the deckhands persuade untrained tourists to park their cars to a tight packing
    – The large amount of empty time the ships sit still in port (e.g. the Moby Aki took 10 hours of sailing from Genova to Olbia, yet makes a roundtrip once every two days – I would have expected it to sail every day, maybe alternating with a shorter route (e.g. Genova-Corsica) to give it a much higher sailing efficiency. The ship I turned back on made a stopover in Ajaccio (Corsica), taking less than 2 hours to berth, unload and load part of the trucks and cars and then load again, even with three decks of cars.

    Earlier I have been on a ship from Denmark to Norway and the deck structure were no flat decks with ramps, but basically two intertwined spirals such that you always had to go all the way to the top and to a full 7.5 turns to get into the ship and back out.

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