13 ms·

Electric ferry uses a long extension cord [video]

338 points by zdw 4y ago

oh_sigh 4y ago
Notably, this ferry is driven on a chain which crossed the channel already. I suspect they would have gone for batteries if the route wasn't already anchored in
- ok_dad 4y ago
  Yea, they only use 150-200 kWh per day, that's not a lot of batteries to store on a large ship like that (it's like ~5-10 EVs worth of batteries maybe? not the whole car, just the batteries!), even if you couldn't charge between sailings (which you could). I think it was probably a cost thing, too, as this system with a cable is probably way cheaper than batteries. edit: I was trying to reinforce here that, although this application could easily have used batteries due to the low energy needed per day, it didn't because there was a better solution due to the pre-existing cable infrastructure. Certainly this cable method isn't useful for most ferries, and most ferries will be traveling further and faster and require way more batteries.
  - yafbum 4y ago
    Also safety, I'd guess. Fire has much worse consequences on ships than on land...
  - karamanolev 4y ago
    They use so little because the use the (steel) cable for traction (as I understand it) and not water. If they had to use a propeller in the water to cross a river, the consumption would be much more. So in essence, there's symbiosis between electricity and running a cable-guided ferry. Otherwise you'd need more energy, therefore bigger batteries, etc.
    - algo_trader 4y ago
      I really dont think so. There are just crossing 500m at 2-3 knots several times a day. This is basically less than a semi rolling resistance which is maybe 1/5kwh/km? EDIT: even so, x10 batteries 2mwh are still very reasonable for a boat which cycle daily
    - rz2k 4y ago
      When he mentioned the steel cable, I wondered why they don't use an arrangement more like cable cars. It sounded like it is in case they break loose during a storm or emergency, so it useful to have the engine on board along with the back up generators. Are the cables actually used for traction, or just a countermeasure against having to fight the cross current?
      - ok_dad 4y ago
        Yea, they pull themselves along the cable. The commenter above you was correct, it is way more efficient than props, plus it's way more efficient for high currents like this river. My comment was simply that they could have used batteries, but for this particular application a cable was perfect. I was reinforcing that this was a great confluence of constraints that enabled this.
      - ricksunny 4y ago
        I was also wondering this, you beat me to asking. If there is precedent for two cables why not connect them to make a long narrow loop of them like on a ski-lift; place an electric-powered winch on one end and an idler on the other? Was neat to see the video, and I’m sure they have their reasons.
        matsemann 4y ago
        One reason may be that the cable sinks to the ground, which makes it possible for other boats to cross. If it was like a ski lift, the cable had to be more tensioned I guess, thus obstructing?
  - brink 4y ago
    > it's like ~5-10 EVs worth of batteries maybe? not the whole car, just the batteries! Batteries are heavy, batteries need recharging, batteries can explode, batteries wear out, batteries cost a lot to replace.. or you can have a cable that might snag, but probably won't if you keep tension on it.
    - dredmorbius 4y ago
      And batteries in marine environments age much more quickly than those in dry-land applications. Salt loves anodes and cathodes.
  - l1tany11 4y ago
    Some teslas have 100kwh batteries. The Hummer EV has ~200kwh battery. Depending on how much extra capacity is needed to optimize for longevity of the pack, and charging, it might be far less than 10 cars worth of batteries. Potentially as little as 1. Makes you think that there might be quite a few river ferries that could be converted quite economically.
  - ortusdux 4y ago
    The Ford F150 Lightning comes with either 98kWh or 131kWh of batteries depending on the package.
    - hathawsh 4y ago
      Wait a minute... in theory, there could be a ferry that depends on power from an electric vehicle driven onto the ferry. That would solve the logistics problem of moving heavy batteries on and off the ship. The ferry could initially use consumer vehicles and switch to customized vehicles when the economics make sense.
      - ortusdux 4y ago
        Unless something changes, I think the F150 lightning will be my next vehicle purchase. The electrical grid in my area can be spotty, and one of the big selling points for me is the ability to tie the truck into your house for use as a battery backup. The larger capacity truck would be the equivalent of over 10 powerwalls!
  - rz2k 4y ago
    Furthermore you could charge them during the middle of the day and at night, and use the batteries during morning and evening commutes, which is pretty ideal. As for the additional mass and displacement, the video mentions boats having to push water out of the way, but water also fills in behind the boat, so there isn't as much physical work involved as it sounds like.
  - martinmunk 4y ago
    Worth noting is, the subtitles said "The ferry uses, each day, about 150-200 kWh" whereas the speaker said "the ferry uses today between 150 and 200kW". I'm guessing Tom Scott had him clarify later, but the units, and what could be assumed to be a timeframe or not, is not the same.
tlavoie 4y ago
Newer ferries run by BC Ferries (in British Columbia, Canada) are being set up as optionally-electric. Two will be in service where I live soon, replacing a slightly larger single ship today. The new ones have diesel engines running a generator, for electric propulsion. Once the mainland infrastructure is in place, they can be upgraded to run as plug-in electrics. I had a tour on one recently. Where there is one bank of lithium cells along one wall today, the room has space for another three or so. FWIW, these are short trips, ~10 minutes each way. Under diesel power, they've made their way from a shipyard in Romania to get to Canada.
bilsbie 4y ago
Thinking outside the box a bit I think there could be lots of applications for “long extension cords”. Especially when you consider how light and thin a cord could be when you use high voltage.
- Arrath 4y ago
  While annoying to route around trees and a bit of a hazard considering the possibility of running the cord over, using a corded electric lawn mower worked passably well for a small yard.
  - jakear 4y ago
    Seems like ideal use case for a battery. Use 1/week max, rest of time plugged in. I had one at my house and it was perfect for my small-ish yard.
    - Arrath 4y ago
      Perhaps, my own yard is just on the cusp: one battery charge with a cordless mower gets me about 75% of the way there. One decent length extension cord gets it done in one go, and I'd much rather have it done at once rather than wait for a charge cycle.
  - jimjimjim 4y ago
    yep, they are very light and maneuverable and not have a battery pack allows for more interesting designs. but I have run over the cord before. things went quiet for some reason.
  - muti 4y ago
    This is an application where I find the old tech does a better job: push mowers. I recently replaced my mower with an old push mower [1], someone local restores them and sells them for a reasonable price (much less than anything new or even a petrol or electric second hand mower. It works so well I wouldn't go back unless I had more than about 200 sqm to mow. Modern push mowers are junk and put me off in the past, but the older ones are much heavier and better built. They cut grass cleaner than a rotary mower which is supposedly better for the grass too. [1]: trademe.tmcdn.co.nz/photoserver/full/1857940265.jpg
dredmorbius 4y ago
Electrified marine transport is an interesting challenge, though there are a few options available. Notably, canal and river traffic can rely on electric traction provided by onshore "mules". That terminology is borrowed from the original practice of having mules haul barges along canals, and reveals the immense enhancement in efficiency of water-borne transport. A single mule might haul a cart weighing a tonne or so across level land (and far less climbing any sort of grade). The same mule could haul a barge on a flat and still canal carrying 20--40 tonnes of cargo or passengers. For passengers, the comfort of canal travel (no jostles, bumps, or broken axles as with a coach) was an immense improvement. The effect of the Erie Canal, a four-foot-deep (1.2 m) ditch from the Hudson river to Lake Erie was immense in opening up the US interior in 1825. Further, canals and their locks mean that the work of lifting (or lowering) cargo is done by the "roadbed) (the river) itself. In the case of the Erie Canal, 172m (565 ft) of elevation gain in net.
- js2 4y ago
  This is the origin of the term towpath: https://en.wikipedia.org/wiki/Towpath https://en.wikipedia.org/wiki/Towpath
  - jwiz 4y ago
    This is the only context I have ever heard "towpath" in. What other contexts are there?
    - js2 4y ago
      Oh, only that context, it's just that when I first heard of the C&O towpath I didn't understand why it was called that.
- azepoi 4y ago
  https://en.wikipedia.org/wiki/Chain_boat_navigation https://en.wikipedia.org/wiki/Chain_boat_navigation Not a new idea: Chevaux électriques, meaning "Electric horses" (electric towpath tractors, halage=tow). https://de.wikipedia.org/wiki/Treideln#/media/Datei:Courchelettes_chevaux-electriques.jpg https://de.wikipedia.org/wiki/Treideln#/media/Datei:Courchel... https://de.wikipedia.org/wiki/Treidellokomotive https://de.wikipedia.org/wiki/Treidellokomotive http://ronfleur.centerblog.net/6408563-halage-des-peniches-par-traction-electrique http://ronfleur.centerblog.net/6408563-halage-des-peniches-p... https://www.ronquieres.org/le-village-de-ronquieres/vieilles-photos-du-village/le-halage-des-bateaux/ https://www.ronquieres.org/le-village-de-ronquieres/vieilles... (last image bottom right) http://www.traitsensavoie.fr/spip.php?article308 http://www.traitsensavoie.fr/spip.php?article308 http://www.traitsensavoie.fr/IMG/jpg/cheval_electrique_bethune-2.jpg http://www.traitsensavoie.fr/IMG/jpg/cheval_electrique_bethu... http://papidema.fr/traction_vn_extra.php#chevaux-elec http://papidema.fr/traction_vn_extra.php#chevaux-elec
zwieback 4y ago
We have 3 electrical ferries in Oregon crossing the Willamette but they use 3 overhead wires to deliver 3phase AC. Works great for short hops.
- pinot 4y ago
  https://img.atlasobscura.com/dmMEj9y780YXqaTupI_kf8Iin74JjtDthHum0ZXCI-k/rt:fit/h:390/q:81/sm:1/scp:1/ar:1/aHR0cHM6Ly9hdGxh/cy1kZXYuczMuYW1h/em9uYXdzLmNvbS91/cGxvYWRzL3BsYWNl/X2ltYWdlcy83NzM2/NWI4Mi04YTM4LTQ4/N2YtYTNlOS00M2Mx/MmY0NjFjZWI1YmRi/ZjFhYmJmYTY0YzEx/NDdfSU1HXzE3MTAu/SlBH.jpg https://img.atlasobscura.com/dmMEj9y780YXqaTupI_kf8Iin74JjtD... For example, the Canby ferry
- elihu 4y ago
  I used to ride the Wheatland ferry as a shortcut into Salem sometimes growing up. I don't remember if the version I rode was electric, but apparently the most recent version has been de-electrified: > "This most recent ferry differs from its predecessors in that it has a capacity of nine cars, rather than the six Daniel Matheny IV carried, and it has its own self-contained diesel-electric generator. As its source of electricity is now an onboard generator, the current ferry is no longer reliant on electricity from overhead wires. The overhead cable serves the sole purpose of bracing the ferry against the current." https://en.wikipedia.org/wiki/Wheatland_Ferry https://en.wikipedia.org/wiki/Wheatland_Ferry
- dendrite9 4y ago
  Oh man! My girlfriend is gonna hate this but hitting all 3 looks worth a slight delay on the next drive through. They are close enough together that it could be a fun bike day as well. I have wanted to get the Cathlamet ferry for some time but for whatever reason it never works well with other travel plans. https://en.wikipedia.org/wiki/Wahkiakum_County_ferry https://en.wikipedia.org/wiki/Wahkiakum_County_ferry
  - zwieback 4y ago
    The ferries are great for bike rides, only $1 for Buena Vista and Wheatland and $3 for Canby. You can easily do all three in a day and it's beautiful countryside. Best to check before you go, they do break down from time to time.
todd3834 4y ago
This is pretty cool. I wonder what the effort would have been to instead have a battery charging / swapping process on one end. It would still be clean energy, charged on shore. I'm sure the batteries wouldn't be super light but you could have them in modules and you could engineer solutions for moving them. Perhaps for situations where it isn't already cable guided this is still a practical approach. I'm pretty ignorant when it comes to the weight of the batteries and how much energy they can provide + etc… but if my Tesla is any indicator it doesn't seem too hard vs managing that cable back and forth
- deleted 4y ago
  [deleted]
- todd3834 4y ago
  The batteries could even be attached cars themselves so moving them on and off would be really simple
  - hawski 4y ago
    Or with a thicker cable they could charge cars while they cross the channel.
- chowells 4y ago
  Rechargeable batteries are not 100% efficient. I'd put good odds on this system being cheaper.
- bentcorner 4y ago
  The captain said they use 150-200kwh a day, which would be around 2-3 EV batteries' worth (Model S has a 100kwh battery). That's split up between 88 trips, so there's plenty of opportunity to swap batteries. So they could probably have some kind of battery system but I'm guessing since it's already "tethered" with a line just to cross, stringing an electrical cable was already easy to do and has simpler logistics than managing batteries.
- Thlom 4y ago
  Around a quarter of the ferry crossings in Norway are electrified. Usually there's one or two electric ferries and one diesel ferry. They charge while unloading and loading and during the night when there's fewer crossings. Before they had to take breaks during the day to charge, but now days I think they run all day.
MichaelCollins 4y ago
Did anybody else know this would be a Tom Scott video before clicking it? He always finds the oddest most interesting things to show off.
- Aardwolf 4y ago
  Yes! I expected "this is going to be a Tom Scott video" before clicking the link. He has a niche in interesting esoteric infrastructure.
Epa095 4y ago
For those interested in this, there is also a quite large battery powered ferry operating in Norway. >The Bastø Electric is 139.2-metre-long and 21-metre-wide and was built by the Turkish Sefine Shipyard and has room for 600 passengers and 200 cars or 24 trucks. >Bastø Electric uses batteries with a capacity of 4.3 MWh. The fast-charging system has a capacity of 9 MW. https://www.electrive.com/2021/03/02/worlds-largest-electric-ferry-yet-goes-into-service-in-norway/ https://www.electrive.com/2021/03/02/worlds-largest-electric...
- pifm_guy 4y ago
  I wonder if these electric ferries have diesel backup systems? A little 100 horsepower backup engine wouldn't use much space/weight/cost, but would still be enough to get the ship slowly home in case of other failures. The energy required to move a ship isn't proportional to speed - so just a little slower saves a lot of energy.
- Thlom 4y ago
  Around a quarter of all ferry connections in Norway have been electrified. Often there's one electric and one regular diesel ferry operating in tandem. Bastø Electric is still the biggest one though.
  - mstade 4y ago
    While not fully electric, there's also the Color Line ferry operating between Sandefjord and Strömstad[0]. I happened it be in town for its inaugural voyage and it turned out to be a quaint little trip. As far as I understand it though, they more or less only run on electric power when navigating out of port, and back to diesel when at see and arriving. Enjoyable trip nonetheless! [0]: https://www.colorline.com/sandefjord-stroemstad/color-hybrid https://www.colorline.com/sandefjord-stroemstad/color-hybrid
    - Thlom 4y ago
      Hurtigruten also have two exploration cruise ships that with hybrid propulsion. I think they mainly use the electric part when close to shore and in harbour.
encoderer 4y ago
Sort of off topic but the war in Ukraine has brought to my attention that we actually fire missiles with giant miles-long extension cords. Missiles. With extension cords.
- sidewndr46 4y ago
  I think those are just for control & telemetry. The actual missile has a battery on it usually.
  - mjevans 4y ago
    Hardlines sound much harder to hack, except literally. Which brings chain-shot (I think they did this in cannons at some point) back to mind.
- hnlmorg 4y ago
  Anyone got a source for this? I’d be interested to learn more
  - modeless 4y ago
    https://en.wikipedia.org/wiki/Wire-guided_missile https://en.wikipedia.org/wiki/Wire-guided_missile I think the TOW missile is the most prominent example.
    - adwww 4y ago
      MILAN is very slightly older and probably just as widely used - especially out of US.
  - nuccy 4y ago
    Those are wire-guided missiles, usually used to destroy tanks and other armed vehicles. The length of the wire is just few kilometers. The wire is needed to actually tell the rocket where to steer [1]. More modern approach to anti-tank missiles are those with lasers being used for highlighting the target [2], while the missile has a battery and a camera to find the spot. The other approach is to do on-the-fly image recognition [3]. Edit: interesting fact: DART space craft sent by NASA to hit an asteroid used a missile derived technology to recognize the image and steer itself into the target, since direct control from Earth was not possible due to communication lag [4] (also try googling "dart mission" to see google's doodle on the topic). 1. https://en.wikipedia.org/wiki/Wire-guided_missile https://en.wikipedia.org/wiki/Wire-guided_missile 2. https://en.wikipedia.org/wiki/Laser-guided_bomb https://en.wikipedia.org/wiki/Laser-guided_bomb 3. https://en.wikipedia.org/wiki/FGM-148_Javelin https://en.wikipedia.org/wiki/FGM-148_Javelin 4. https://www.nasa.gov/press-release/nasa-confirms-dart-mission-impact-changed-asteroid-s-motion-in-space https://www.nasa.gov/press-release/nasa-confirms-dart-missio...
hnlmorg 4y ago
I found this video about another type of crossing using a cable: https://youtube.com/watch?v=OW24yLHmC20 https://youtube.com/watch?v=OW24yLHmC20
- rmason 4y ago
  I've ridden on one of those boats when I was in Basel. It was incredibly calming to cross the river with no noise from a motor. There are also I think five different cable cars in the immediate Basel area that offer some incredible views as well.
  - hnlmorg 4y ago
    You’ve now convinced me that I need to Basel :)
    - gpvos 4y ago
      There is a link below the video to a Wikipedia article with similar ferries all over the world.
rmason 4y ago
Though I am a big fan of Elon Musk's Boring company I think his used of modified Tesla's to transport people in the tunnels isn't the best idea. The old streetcars, like in Detroit, used to attach to an overhead wire to power themselves. I think you could have normal train cars using this method. In other words use the electric grid as opposed to batteries. I can't imagine a battery fire in an enclosed area like a tunnel. Much better than NYC's subway using a live third rail which I believe has killed more people falling on to the tracks than the trains themselves.
- TheLoafOfBread 4y ago
  Subway makes perfect sense, except when you are CEO of a car company. Then they are your direct competitor and suboptimal solution of Tesla's in the tunnel is used instead.
- mikeyouse 4y ago
  These are super common - all of SFs MUNI system is built using the overhead wires -- batteries in the individual cars are interesting because there's a ton of cost involved in electrifying the entire length of the tunnel to deliver as much power as a train needs. All of the substations, the physical electrical cables themselves, etc add a ton of cost to tunneling projects and long-term wear items that will require endless maintenance that often shuts down the lines. Building a dumb cheap concrete tunnel and leaving the expensive parts in the cars themselves could be a very cost effective method of urban transport. Though I think the "use Teslas" is a dumb addition since a purpose built train car similar to the airport shuttles at Denver would be much more efficient and handicap accessible.
  - tshaddox 4y ago
    To clarify, the light rail (Muni Metro) and electrified bus lines use overhead 600 volt DC, but most of the bus lines are not electrified.
- WaitWaitWha 4y ago
  Electric trolleybus have been running in some cities pre-WWII [0]. I have seen them in Budapest, São Paulo, and Malatya. [0]: https://en.wikipedia.org/wiki/Trolleybus https://en.wikipedia.org/wiki/Trolleybus
expazl 4y ago
With this setup I wonder why even have the motor on the ship? It's using an extension cord to get power to the ship so it can pull on the wire guides, but you might as well just have put the engine pulling the wire on the shore and have a "dumb" platform in place of the boat.
- AdamJacobMuller 4y ago
  The wire would need to be parallel to the water at just above or below it and would always obstruct other traffic. This arrangement allows the wire to fall onto the seabed so ships can easily pass in front of and behind the ship, given reasonable clearances.
- TheRealPomax 4y ago
  You want the engine in a place where the people who need to control it, or even kill it in an emergency, can feel what the engine's doing, and have control over that engine.
- johnwalkr 4y ago
  Cables are indeed pulled, the boat does not have a propeller. But the winch part is on the boat, not the shore. If on the shore the cables would either need incredible tension or incredible power to overcome the friction of the seafloor. By having the winch part on the boat, the boat can pull itself along without having to overcome the friction in the cable between itself and the shore. This way also has the advantage that the cables can be easily rested on the sea floor to allow other ships to pass by.
willcipriano 4y ago
If I was in Hollywood I'd call Tom Scott and give him whatever he needs to make whatever he wants. Imagine something like a long form road trip documentary, stopping in at interesting places and doing interesting things but with the pull and budget of a studio behind him.
- dncornholio 4y ago
  How to destroy a YouTubers career in 2 easy steps.
- paxys 4y ago
  There is a long line of very popular YouTube stars who have tried to transition to making more "mainstream" entertainment content (TV, movies) and have failed spectacularly. Large YouTube channels have fine tuned all aspects of their production to be surfaced by YouTube algorithms and consumed by YouTube audiences. Making engaging content for Netflix/HBO or a movie theater is a completely different problem.
  - MarcelOlsz 4y ago
    Just upload it on YouTube. Problem solved.
    - adamparsons 4y ago
      Yeah whenever I've seen a favourite creator put up an out-of-place piece of long form content, it sometimes even gets a calendar entry so I can give it my full attention later
  - mhh__ 4y ago
    Tom Scott tried to transition into TV years ago, once you view his delivery and not-liking-of memes through that lens it gives his character a new angle.
- DaiPlusPlus 4y ago
  > If I was in Hollywood... Hollywood essentially destroys almost everything it touches: the people that invest in film production insist on maximising their RoI at the cost of petty things like artistic integrity, historical accuracy, and such. I enjoy independent video producers ("creators" is the term now, I gather?) on YouTube (and Vimeo, etc) like Tom Scott precisely because it isn't Hollywood.
jguimont 4y ago
For those mega cargo ships, why is civil nuclear power vessels are not a thing? Seems they would massively reduce the footprint while providing better clearner power.
- mediaman 4y ago
  Servicing marine nuclear reactor units requires very special skills and is expensive. So is the initial capital cost. Servicing large marine diesel systems uses labor that is much more available globally.
- Gwypaas 4y ago
  Because it's all about cost. Those 400m container ships are ran by a low cost crew of 15-25 with some 3rd party maintenance personnel sprinkled in. Try fitting a more expensive fuel and more maintenance into that. On top of all safety concerns. For ocean crossing vessels they are more closely looking at e-fuels and hydrogen since that gives the same benefitd at cheaper cost with not a too large change in the shore side infrastructure.
- Markoff 4y ago
  https://youtube.com/watch?v=cYj4F_cyiJI https://youtube.com/watch?v=cYj4F_cyiJI
  - dredmorbius 4y ago
    On the NS Savannah, an interesting story.
- coryrc 4y ago
  Because they don't pay for pollution.
- dredmorbius 4y ago
  Answered in large part here: <https://news.ycombinator.com/item?id=33631996 https://news.ycombinator.com/item?id=33631996> Cost, safety, scale (there are 80,000+ commercial vessels), reliability, crew training and costs, etc. Combustion's highly proved, reliable, and safe technology. Range is sufficient for transoceanic transport. Emissions (both CO2 and other factors) are an issue, but could be mitigated with synthetic fuels, possibly biofuels (though even shipping would strain capacities required).
tjoff 4y ago
When I clicked on this I thought, why not just have a cable-guided ferry instead? (Which already is a common thing) I assumed they'd have to make maneuvers not possible with a cable. But it already is?! Then why not just tug the cable instead, much better efficiency then propellers. Edit: ok, it is. Though what I've seen is that the motors are pulled from shore rather than on the boat. Which seems simpler, but this is maybe easier to retrofit.
distrill 4y ago
I have to admit, it sounds a lot crazier before you learn that there are already cables running along the channel that the boat uses. This also means that this can't generalize outside of channels that already have cabled crossings. Given that constraint, I wonder about operating these ferries more like a ski lift then. If we're already stringing cables across the channel might it make more sense to keep them on shore away from the water?
simon_000666 4y ago
Cool - another option could be beaming power to the ferry using microwaves, millimeter waves or lasers. The power transfer efficiency would be lower but saves the cable complexity and slacking/maintenance.
- MarkMarine 4y ago
  I think the losses on both sides of that invisible death ray would be more complex than a long extension cord.
- system2 4y ago
  That sounds like a good way to get cancer.
tpmx 4y ago
I think this ferry between Helsingborg (Sweden) and Helsingør (Denmark) does it in the coolest way. Since 2018 the ferry has been running on batteries. Whenever it docks into any of the two ports, an ABB robot connects the charging cable. One real cool thing here is that they have gotten it to work for 4 full years in a northern climate. That means a lot of extreme weather edge cases. https://youtu.be/l93i87pZWhY?t=13 https://youtu.be/l93i87pZWhY?t=13
- djcannabiz 4y ago
  thats awesome it looks straight out of a scene from walle
clouddrover 4y ago
They say the ferry uses 150-200 kWh a day. If those numbers are right that wouldn't be a very big battery pack. The Hummer EV, for example, has a 212 kWh usable pack: https://www.youtube.com/watch?v=ORKuZxrFr6A https://www.youtube.com/watch?v=ORKuZxrFr6A https://www.youtube.com/watch?v=F9IUOR8lG3E https://www.youtube.com/watch?v=F9IUOR8lG3E Still, it's a cabled ferry anyhow so also having a power cable makes sense.
- system2 4y ago
  Battery packs degrade so fast with constant use. They would replace it every year if not every month.
  - jillesvangurp 4y ago
    Nonsense; they are good for many thousands of cycles which generally translates into many years of continuous use. Mostly batteries degrade on a very predictable scale as well and very gradually. All of this is well known and anticipated by companies that deploy batteries in ferries, and other short range boats. It's just economics. You have energy savings and a battery that is good for a given number of cycles and engine hours. Either that adds up or it doesn't. Basically, it will be years before you need to service them and you can just use math to calculate whether that's economic or not. Apparently it does. That's why the use of batteries in short range nautical applications is booming. You have some range constraints but anyone operating within those constraints is looking at switching over already. Battery longevity is not the concern here generally.
newpavlov 4y ago
Why not simply pull the ferry using the steel cables? In other words, put traction systems on both riversides and move the ferry using them. It even should be more efficient than a propeller-based propulsion system.
- matsur 4y ago
  The ferry in the video uses cable based propulsion.
  - bbstats 4y ago
    This is why hn needs a downvote button LOL
    - javawizard 4y ago
      HN has one, it's just only accessible to those who have reached a karma threshold (501 I believe).
  - javawizard 4y ago
    It pulls itself along the cables rather than using a propeller, yes, but the motor that's doing the pulling is on the ferry rather than on the shore. To answer GP's question: I don't know, but given that this was a retrofit of an existing diesel-powered ferry I could guess that this was the cheaper way of doing it.
  - nippoo 4y ago
    Yes, but the propulsion is on the boat rather than at shoreside like OP suggested (ie the cables are static)
  - newpavlov 4y ago
    The point is that on the current system motors which are powered by the electric cable are on the ferry, so it uses propellers to move. The proposed alternative is to use steel cables (which are already present) without any electric ones to pull the ferry, such system should be more efficient power-wise and easier to service.
daneel_w 4y ago
Sort of common in the nordics. We have lots of them in Sweden, the self-service type for short crossings to sparsely populated islands, but the power cable usually drives a winch attached to a steel cable.
willhinsa 4y ago
I’ve never seen this video but just from the description I thought, “That sounds like something Tom Scott would make a video about.”
tgsovlerkhgsel 4y ago
If the ferry uses 150-200 kWh/day, that's two Tesla batteries assuming no recharging during the day (so realistically, you could run it on one, since the ferry presumably isn't constantly moving). Of course, the fixed cable avoids having to replace the battery every couple years, might be lighter/cheaper etc. - but it could absolutely be implemented using batteries. (This assumes the numbers are accurate, the 100 liters of fuel vs. only needing 200 kWh seems odd.)
- sharkster711 4y ago
  It would increase the weight of the boat though, by quite a bit so you'd end up needing a bigger battery. The battery also does not have 100% efficiency so add in another 10% for losses. You'd also need downtime to charge that battery up - about 15-20 hours if you use level 2 charging. Yes, 200 kwh seems oddly low.
  - mrb 4y ago
    Have you seen the massive size of that drum of electric cable on the boat? It weights definitely more than 1200 lb, which is the weight of a Tesla 100 kWh battery. So the boat would be actually more lightweight after replacing that drum with a battery.
Animats 4y ago
Oh, it's a cable-guided ferry. Since it already has a guide cable, it may as well be cable powered, too. That's not uncommon, but usually the power is transmitted mechanically, like a ski lift. Brighton Beach in England once had an electric-powered sea-going railroad with an 18 foot gauge. A ferry running on railroad tracks. More of an amusement ride than a means of transportation, like some Disney water rides that run on tracks.
deleted 4y ago
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mrb 4y ago
The boat used to consume 100 liters of diesel daily, which is equivalent to 1000 kWh in energy (10 kWh per liter). But after electrification they claim only 150-200 kWh usage per day. This doesn't add up. Were the diesel engines idling all day even when the boat was not moving?
- exyi 4y ago
  It seems ok to me, EVs have about 13kWh/100km efficiency while an older gasoline car would consume 10l/100km. And yes, it's quite plausible that the engine was running during loading and unloading
  - mrb 4y ago
    You are right. I forgot to account for the fact combustion engines have a terrible thermal efficiency: about 20%, which gives the boat only 2 kWh per liter of diesel, meaning it was using 200 kWh daily, more in line with the electrical version.
johnwalkr 4y ago
Something about many comments rub me the wrong way, which seems common on hackernews on some topics --lots of speculative or "why don't they just.." comments when one can easily look up the reasons for cable ferries existing. Cable ferries (which this is) are simple and well-established. Cables guide the ferry from one side of water to the other, making operation safe, simple and repeatable, even in fast moving water. They deliberately have the cables lying on the floor. This keeps them out of the way of passing ships, and is the simplest solution. The winch part of the system must be on the ship, not the shore. It's very efficient for the ferry to pull itself along the cable. There have even been handcrank operated cable ferries. It has some other benefits, like acting as an anchor perpendicular to currents. No take up is required on the other side. It's scalable to long distances without having to add piers or towers. In this case, a power cable from one shore was simply added to replace power from diesel generators. This seems to throw people off into a tangent about batteries. Why don't they just put batteries on the ferry? This mostly assumes that the ship is driven by a propellor and the cable is adding an unnecessary tether. But cables are already there serving other purposes, so it's a simple solution to lay a power cable along the same route and no real benefit to use batteries instead. Why don't they just pull it from the shore? You would have to overcome the drag of the cables all the way from the shore to the ferry, the power and size of the cable would have to increase dramatically and it would be impossible to scale beyond some (short, I suspect) distance. Why don't they just make the cable higher like a ski lift on each side to pull the boat? This would require a massive amount of tension, again increasing the size of the cable required. Like a ski lift, in practice you'd need the cable to go from one shore to the other and back in a continuous loop. This is definitely more complex, and loses some benefits of the cables, especially easily letting them rest for passing ships. The engineering problem and safety aspects, considering water level and side load from current would be much more difficult. It's not scalable without adding something like towers or piers.
- rkangel 4y ago
  Yes, the "pull the cable from shore" thing doesn't work well for simple reasons. This is what the cable looks like with the ferry pulling itself across: _-OOOO-_ ____________/ \__________ This is what it looks like if it is being pulled from shore: ---------------OOOO-_ \__________ The cable has quite a lot of friction with the bottom and can pull the ferry without lifting up and blocking half the river. Boats still need to be very careful around ferries like this, but they can still coexist. These ferries traditionally used to be "chain ferries" which had even more friction between chain and river bottom.

338 points by zdw 4y ago

Notably, this ferry is driven on a chain which crossed the channel already. I suspect they would have gone for batteries if the route wasn't already anchored in

ok_dad 4y ago
Yea, they only use 150-200 kWh per day, that's not a lot of batteries to store on a large ship like that (it's like ~5-10 EVs worth of batteries maybe? not the whole car, just the batteries!), even if you couldn't charge between sailings (which you could). I think it was probably a cost thing, too, as this system with a cable is probably way cheaper than batteries. edit: I was trying to reinforce here that, although this application could easily have used batteries due to the low energy needed per day, it didn't because there was a better solution due to the pre-existing cable infrastructure. Certainly this cable method isn't useful for most ferries, and most ferries will be traveling further and faster and require way more batteries.
- yafbum 4y ago
  Also safety, I'd guess. Fire has much worse consequences on ships than on land...
- karamanolev 4y ago
  They use so little because the use the (steel) cable for traction (as I understand it) and not water. If they had to use a propeller in the water to cross a river, the consumption would be much more. So in essence, there's symbiosis between electricity and running a cable-guided ferry. Otherwise you'd need more energy, therefore bigger batteries, etc.
  - algo_trader 4y ago
    I really dont think so. There are just crossing 500m at 2-3 knots several times a day. This is basically less than a semi rolling resistance which is maybe 1/5kwh/km? EDIT: even so, x10 batteries 2mwh are still very reasonable for a boat which cycle daily
  - rz2k 4y ago
    When he mentioned the steel cable, I wondered why they don't use an arrangement more like cable cars. It sounded like it is in case they break loose during a storm or emergency, so it useful to have the engine on board along with the back up generators. Are the cables actually used for traction, or just a countermeasure against having to fight the cross current?
    - ok_dad 4y ago
      Yea, they pull themselves along the cable. The commenter above you was correct, it is way more efficient than props, plus it's way more efficient for high currents like this river. My comment was simply that they could have used batteries, but for this particular application a cable was perfect. I was reinforcing that this was a great confluence of constraints that enabled this.
    - ricksunny 4y ago
      I was also wondering this, you beat me to asking. If there is precedent for two cables why not connect them to make a long narrow loop of them like on a ski-lift; place an electric-powered winch on one end and an idler on the other? Was neat to see the video, and I’m sure they have their reasons.
      - matsemann 4y ago
        One reason may be that the cable sinks to the ground, which makes it possible for other boats to cross. If it was like a ski lift, the cable had to be more tensioned I guess, thus obstructing?
- brink 4y ago
  > it's like ~5-10 EVs worth of batteries maybe? not the whole car, just the batteries! Batteries are heavy, batteries need recharging, batteries can explode, batteries wear out, batteries cost a lot to replace.. or you can have a cable that might snag, but probably won't if you keep tension on it.
  - dredmorbius 4y ago
    And batteries in marine environments age much more quickly than those in dry-land applications. Salt loves anodes and cathodes.
- l1tany11 4y ago
  Some teslas have 100kwh batteries. The Hummer EV has ~200kwh battery. Depending on how much extra capacity is needed to optimize for longevity of the pack, and charging, it might be far less than 10 cars worth of batteries. Potentially as little as 1. Makes you think that there might be quite a few river ferries that could be converted quite economically.
- ortusdux 4y ago
  The Ford F150 Lightning comes with either 98kWh or 131kWh of batteries depending on the package.
  - hathawsh 4y ago
    Wait a minute... in theory, there could be a ferry that depends on power from an electric vehicle driven onto the ferry. That would solve the logistics problem of moving heavy batteries on and off the ship. The ferry could initially use consumer vehicles and switch to customized vehicles when the economics make sense.
    - ortusdux 4y ago
      Unless something changes, I think the F150 lightning will be my next vehicle purchase. The electrical grid in my area can be spotty, and one of the big selling points for me is the ability to tie the truck into your house for use as a battery backup. The larger capacity truck would be the equivalent of over 10 powerwalls!
- rz2k 4y ago
  Furthermore you could charge them during the middle of the day and at night, and use the batteries during morning and evening commutes, which is pretty ideal. As for the additional mass and displacement, the video mentions boats having to push water out of the way, but water also fills in behind the boat, so there isn't as much physical work involved as it sounds like.
- martinmunk 4y ago
  Worth noting is, the subtitles said "The ferry uses, each day, about 150-200 kWh" whereas the speaker said "the ferry uses today between 150 and 200kW". I'm guessing Tom Scott had him clarify later, but the units, and what could be assumed to be a timeframe or not, is not the same.

tlavoie 4y ago

Newer ferries run by BC Ferries (in British Columbia, Canada) are being set up as optionally-electric. Two will be in service where I live soon, replacing a slightly larger single ship today. The new ones have diesel engines running a generator, for electric propulsion. Once the mainland infrastructure is in place, they can be upgraded to run as plug-in electrics. I had a tour on one recently. Where there is one bank of lithium cells along one wall today, the room has space for another three or so. FWIW, these are short trips, ~10 minutes each way. Under diesel power, they've made their way from a shipyard in Romania to get to Canada.

bilsbie 4y ago

Thinking outside the box a bit I think there could be lots of applications for “long extension cords”. Especially when you consider how light and thin a cord could be when you use high voltage.

Arrath 4y ago
While annoying to route around trees and a bit of a hazard considering the possibility of running the cord over, using a corded electric lawn mower worked passably well for a small yard.
- jakear 4y ago
  Seems like ideal use case for a battery. Use 1/week max, rest of time plugged in. I had one at my house and it was perfect for my small-ish yard.
  - Arrath 4y ago
    Perhaps, my own yard is just on the cusp: one battery charge with a cordless mower gets me about 75% of the way there. One decent length extension cord gets it done in one go, and I'd much rather have it done at once rather than wait for a charge cycle.
- jimjimjim 4y ago
  yep, they are very light and maneuverable and not have a battery pack allows for more interesting designs. but I have run over the cord before. things went quiet for some reason.
- muti 4y ago
  This is an application where I find the old tech does a better job: push mowers. I recently replaced my mower with an old push mower [1], someone local restores them and sells them for a reasonable price (much less than anything new or even a petrol or electric second hand mower. It works so well I wouldn't go back unless I had more than about 200 sqm to mow. Modern push mowers are junk and put me off in the past, but the older ones are much heavier and better built. They cut grass cleaner than a rotary mower which is supposedly better for the grass too. [1]: trademe.tmcdn.co.nz/photoserver/full/1857940265.jpg

dredmorbius 4y ago

Electrified marine transport is an interesting challenge, though there are a few options available. Notably, canal and river traffic can rely on electric traction provided by onshore "mules". That terminology is borrowed from the original practice of having mules haul barges along canals, and reveals the immense enhancement in efficiency of water-borne transport. A single mule might haul a cart weighing a tonne or so across level land (and far less climbing any sort of grade). The same mule could haul a barge on a flat and still canal carrying 20--40 tonnes of cargo or passengers. For passengers, the comfort of canal travel (no jostles, bumps, or broken axles as with a coach) was an immense improvement. The effect of the Erie Canal, a four-foot-deep (1.2 m) ditch from the Hudson river to Lake Erie was immense in opening up the US interior in 1825. Further, canals and their locks mean that the work of lifting (or lowering) cargo is done by the "roadbed) (the river) itself. In the case of the Erie Canal, 172m (565 ft) of elevation gain in net.

js2 4y ago
This is the origin of the term towpath: https://en.wikipedia.org/wiki/Towpath https://en.wikipedia.org/wiki/Towpath
- jwiz 4y ago
  This is the only context I have ever heard "towpath" in. What other contexts are there?
  - js2 4y ago
    Oh, only that context, it's just that when I first heard of the C&O towpath I didn't understand why it was called that.
azepoi 4y ago
https://en.wikipedia.org/wiki/Chain_boat_navigation https://en.wikipedia.org/wiki/Chain_boat_navigation Not a new idea: Chevaux électriques, meaning "Electric horses" (electric towpath tractors, halage=tow). https://de.wikipedia.org/wiki/Treideln#/media/Datei:Courchelettes_chevaux-electriques.jpg https://de.wikipedia.org/wiki/Treideln#/media/Datei:Courchel... https://de.wikipedia.org/wiki/Treidellokomotive https://de.wikipedia.org/wiki/Treidellokomotive http://ronfleur.centerblog.net/6408563-halage-des-peniches-par-traction-electrique http://ronfleur.centerblog.net/6408563-halage-des-peniches-p... https://www.ronquieres.org/le-village-de-ronquieres/vieilles-photos-du-village/le-halage-des-bateaux/ https://www.ronquieres.org/le-village-de-ronquieres/vieilles... (last image bottom right) http://www.traitsensavoie.fr/spip.php?article308 http://www.traitsensavoie.fr/spip.php?article308 http://www.traitsensavoie.fr/IMG/jpg/cheval_electrique_bethune-2.jpg http://www.traitsensavoie.fr/IMG/jpg/cheval_electrique_bethu... http://papidema.fr/traction_vn_extra.php#chevaux-elec http://papidema.fr/traction_vn_extra.php#chevaux-elec

zwieback 4y ago

We have 3 electrical ferries in Oregon crossing the Willamette but they use 3 overhead wires to deliver 3phase AC. Works great for short hops.

pinot 4y ago
https://img.atlasobscura.com/dmMEj9y780YXqaTupI_kf8Iin74JjtDthHum0ZXCI-k/rt:fit/h:390/q:81/sm:1/scp:1/ar:1/aHR0cHM6Ly9hdGxh/cy1kZXYuczMuYW1h/em9uYXdzLmNvbS91/cGxvYWRzL3BsYWNl/X2ltYWdlcy83NzM2/NWI4Mi04YTM4LTQ4/N2YtYTNlOS00M2Mx/MmY0NjFjZWI1YmRi/ZjFhYmJmYTY0YzEx/NDdfSU1HXzE3MTAu/SlBH.jpg https://img.atlasobscura.com/dmMEj9y780YXqaTupI_kf8Iin74JjtD... For example, the Canby ferry
elihu 4y ago
I used to ride the Wheatland ferry as a shortcut into Salem sometimes growing up. I don't remember if the version I rode was electric, but apparently the most recent version has been de-electrified: > "This most recent ferry differs from its predecessors in that it has a capacity of nine cars, rather than the six Daniel Matheny IV carried, and it has its own self-contained diesel-electric generator. As its source of electricity is now an onboard generator, the current ferry is no longer reliant on electricity from overhead wires. The overhead cable serves the sole purpose of bracing the ferry against the current." https://en.wikipedia.org/wiki/Wheatland_Ferry https://en.wikipedia.org/wiki/Wheatland_Ferry
dendrite9 4y ago
Oh man! My girlfriend is gonna hate this but hitting all 3 looks worth a slight delay on the next drive through. They are close enough together that it could be a fun bike day as well. I have wanted to get the Cathlamet ferry for some time but for whatever reason it never works well with other travel plans. https://en.wikipedia.org/wiki/Wahkiakum_County_ferry https://en.wikipedia.org/wiki/Wahkiakum_County_ferry
- zwieback 4y ago
  The ferries are great for bike rides, only $1 for Buena Vista and Wheatland and $3 for Canby. You can easily do all three in a day and it's beautiful countryside. Best to check before you go, they do break down from time to time.

todd3834 4y ago

This is pretty cool. I wonder what the effort would have been to instead have a battery charging / swapping process on one end. It would still be clean energy, charged on shore. I'm sure the batteries wouldn't be super light but you could have them in modules and you could engineer solutions for moving them. Perhaps for situations where it isn't already cable guided this is still a practical approach. I'm pretty ignorant when it comes to the weight of the batteries and how much energy they can provide + etc… but if my Tesla is any indicator it doesn't seem too hard vs managing that cable back and forth

deleted 4y ago
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todd3834 4y ago
The batteries could even be attached cars themselves so moving them on and off would be really simple
- hawski 4y ago
  Or with a thicker cable they could charge cars while they cross the channel.
chowells 4y ago
Rechargeable batteries are not 100% efficient. I'd put good odds on this system being cheaper.
bentcorner 4y ago
The captain said they use 150-200kwh a day, which would be around 2-3 EV batteries' worth (Model S has a 100kwh battery). That's split up between 88 trips, so there's plenty of opportunity to swap batteries. So they could probably have some kind of battery system but I'm guessing since it's already "tethered" with a line just to cross, stringing an electrical cable was already easy to do and has simpler logistics than managing batteries.
Thlom 4y ago
Around a quarter of the ferry crossings in Norway are electrified. Usually there's one or two electric ferries and one diesel ferry. They charge while unloading and loading and during the night when there's fewer crossings. Before they had to take breaks during the day to charge, but now days I think they run all day.

MichaelCollins 4y ago

Did anybody else know this would be a Tom Scott video before clicking it? He always finds the oddest most interesting things to show off.

Aardwolf 4y ago
Yes! I expected "this is going to be a Tom Scott video" before clicking the link. He has a niche in interesting esoteric infrastructure.

Epa095 4y ago

For those interested in this, there is also a quite large battery powered ferry operating in Norway. >The Bastø Electric is 139.2-metre-long and 21-metre-wide and was built by the Turkish Sefine Shipyard and has room for 600 passengers and 200 cars or 24 trucks. >Bastø Electric uses batteries with a capacity of 4.3 MWh. The fast-charging system has a capacity of 9 MW. https://www.electrive.com/2021/03/02/worlds-largest-electric-ferry-yet-goes-into-service-in-norway/ https://www.electrive.com/2021/03/02/worlds-largest-electric...

pifm_guy 4y ago
I wonder if these electric ferries have diesel backup systems? A little 100 horsepower backup engine wouldn't use much space/weight/cost, but would still be enough to get the ship slowly home in case of other failures. The energy required to move a ship isn't proportional to speed - so just a little slower saves a lot of energy.
Thlom 4y ago
Around a quarter of all ferry connections in Norway have been electrified. Often there's one electric and one regular diesel ferry operating in tandem. Bastø Electric is still the biggest one though.
- mstade 4y ago
  While not fully electric, there's also the Color Line ferry operating between Sandefjord and Strömstad[0]. I happened it be in town for its inaugural voyage and it turned out to be a quaint little trip. As far as I understand it though, they more or less only run on electric power when navigating out of port, and back to diesel when at see and arriving. Enjoyable trip nonetheless! [0]: https://www.colorline.com/sandefjord-stroemstad/color-hybrid https://www.colorline.com/sandefjord-stroemstad/color-hybrid
  - Thlom 4y ago
    Hurtigruten also have two exploration cruise ships that with hybrid propulsion. I think they mainly use the electric part when close to shore and in harbour.

encoderer 4y ago

Sort of off topic but the war in Ukraine has brought to my attention that we actually fire missiles with giant miles-long extension cords. Missiles. With extension cords.

sidewndr46 4y ago
I think those are just for control & telemetry. The actual missile has a battery on it usually.
- mjevans 4y ago
  Hardlines sound much harder to hack, except literally. Which brings chain-shot (I think they did this in cannons at some point) back to mind.
hnlmorg 4y ago
Anyone got a source for this? I’d be interested to learn more
- modeless 4y ago
  https://en.wikipedia.org/wiki/Wire-guided_missile https://en.wikipedia.org/wiki/Wire-guided_missile I think the TOW missile is the most prominent example.
  - adwww 4y ago
    MILAN is very slightly older and probably just as widely used - especially out of US.
- nuccy 4y ago
  Those are wire-guided missiles, usually used to destroy tanks and other armed vehicles. The length of the wire is just few kilometers. The wire is needed to actually tell the rocket where to steer [1]. More modern approach to anti-tank missiles are those with lasers being used for highlighting the target [2], while the missile has a battery and a camera to find the spot. The other approach is to do on-the-fly image recognition [3]. Edit: interesting fact: DART space craft sent by NASA to hit an asteroid used a missile derived technology to recognize the image and steer itself into the target, since direct control from Earth was not possible due to communication lag [4] (also try googling "dart mission" to see google's doodle on the topic). 1. https://en.wikipedia.org/wiki/Wire-guided_missile https://en.wikipedia.org/wiki/Wire-guided_missile 2. https://en.wikipedia.org/wiki/Laser-guided_bomb https://en.wikipedia.org/wiki/Laser-guided_bomb 3. https://en.wikipedia.org/wiki/FGM-148_Javelin https://en.wikipedia.org/wiki/FGM-148_Javelin 4. https://www.nasa.gov/press-release/nasa-confirms-dart-mission-impact-changed-asteroid-s-motion-in-space https://www.nasa.gov/press-release/nasa-confirms-dart-missio...

hnlmorg 4y ago

I found this video about another type of crossing using a cable: https://youtube.com/watch?v=OW24yLHmC20 https://youtube.com/watch?v=OW24yLHmC20

rmason 4y ago
I've ridden on one of those boats when I was in Basel. It was incredibly calming to cross the river with no noise from a motor. There are also I think five different cable cars in the immediate Basel area that offer some incredible views as well.
- hnlmorg 4y ago
  You’ve now convinced me that I need to Basel :)
  - gpvos 4y ago
    There is a link below the video to a Wikipedia article with similar ferries all over the world.

rmason 4y ago

Though I am a big fan of Elon Musk's Boring company I think his used of modified Tesla's to transport people in the tunnels isn't the best idea. The old streetcars, like in Detroit, used to attach to an overhead wire to power themselves. I think you could have normal train cars using this method. In other words use the electric grid as opposed to batteries. I can't imagine a battery fire in an enclosed area like a tunnel. Much better than NYC's subway using a live third rail which I believe has killed more people falling on to the tracks than the trains themselves.

TheLoafOfBread 4y ago
Subway makes perfect sense, except when you are CEO of a car company. Then they are your direct competitor and suboptimal solution of Tesla's in the tunnel is used instead.
mikeyouse 4y ago
These are super common - all of SFs MUNI system is built using the overhead wires -- batteries in the individual cars are interesting because there's a ton of cost involved in electrifying the entire length of the tunnel to deliver as much power as a train needs. All of the substations, the physical electrical cables themselves, etc add a ton of cost to tunneling projects and long-term wear items that will require endless maintenance that often shuts down the lines. Building a dumb cheap concrete tunnel and leaving the expensive parts in the cars themselves could be a very cost effective method of urban transport. Though I think the "use Teslas" is a dumb addition since a purpose built train car similar to the airport shuttles at Denver would be much more efficient and handicap accessible.
- tshaddox 4y ago
  To clarify, the light rail (Muni Metro) and electrified bus lines use overhead 600 volt DC, but most of the bus lines are not electrified.
WaitWaitWha 4y ago
Electric trolleybus have been running in some cities pre-WWII [0]. I have seen them in Budapest, São Paulo, and Malatya. [0]: https://en.wikipedia.org/wiki/Trolleybus https://en.wikipedia.org/wiki/Trolleybus

expazl 4y ago

With this setup I wonder why even have the motor on the ship? It's using an extension cord to get power to the ship so it can pull on the wire guides, but you might as well just have put the engine pulling the wire on the shore and have a "dumb" platform in place of the boat.

AdamJacobMuller 4y ago
The wire would need to be parallel to the water at just above or below it and would always obstruct other traffic. This arrangement allows the wire to fall onto the seabed so ships can easily pass in front of and behind the ship, given reasonable clearances.
TheRealPomax 4y ago
You want the engine in a place where the people who need to control it, or even kill it in an emergency, can feel what the engine's doing, and have control over that engine.
johnwalkr 4y ago
Cables are indeed pulled, the boat does not have a propeller. But the winch part is on the boat, not the shore. If on the shore the cables would either need incredible tension or incredible power to overcome the friction of the seafloor. By having the winch part on the boat, the boat can pull itself along without having to overcome the friction in the cable between itself and the shore. This way also has the advantage that the cables can be easily rested on the sea floor to allow other ships to pass by.

willcipriano 4y ago

If I was in Hollywood I'd call Tom Scott and give him whatever he needs to make whatever he wants. Imagine something like a long form road trip documentary, stopping in at interesting places and doing interesting things but with the pull and budget of a studio behind him.

dncornholio 4y ago
How to destroy a YouTubers career in 2 easy steps.
paxys 4y ago
There is a long line of very popular YouTube stars who have tried to transition to making more "mainstream" entertainment content (TV, movies) and have failed spectacularly. Large YouTube channels have fine tuned all aspects of their production to be surfaced by YouTube algorithms and consumed by YouTube audiences. Making engaging content for Netflix/HBO or a movie theater is a completely different problem.
- MarcelOlsz 4y ago
  Just upload it on YouTube. Problem solved.
  - adamparsons 4y ago
    Yeah whenever I've seen a favourite creator put up an out-of-place piece of long form content, it sometimes even gets a calendar entry so I can give it my full attention later
- mhh__ 4y ago
  Tom Scott tried to transition into TV years ago, once you view his delivery and not-liking-of memes through that lens it gives his character a new angle.
DaiPlusPlus 4y ago
> If I was in Hollywood... Hollywood essentially destroys almost everything it touches: the people that invest in film production insist on maximising their RoI at the cost of petty things like artistic integrity, historical accuracy, and such. I enjoy independent video producers ("creators" is the term now, I gather?) on YouTube (and Vimeo, etc) like Tom Scott precisely because it isn't Hollywood.

jguimont 4y ago

For those mega cargo ships, why is civil nuclear power vessels are not a thing? Seems they would massively reduce the footprint while providing better clearner power.

mediaman 4y ago
Servicing marine nuclear reactor units requires very special skills and is expensive. So is the initial capital cost. Servicing large marine diesel systems uses labor that is much more available globally.
Gwypaas 4y ago
Because it's all about cost. Those 400m container ships are ran by a low cost crew of 15-25 with some 3rd party maintenance personnel sprinkled in. Try fitting a more expensive fuel and more maintenance into that. On top of all safety concerns. For ocean crossing vessels they are more closely looking at e-fuels and hydrogen since that gives the same benefitd at cheaper cost with not a too large change in the shore side infrastructure.
Markoff 4y ago
https://youtube.com/watch?v=cYj4F_cyiJI https://youtube.com/watch?v=cYj4F_cyiJI
- dredmorbius 4y ago
  On the NS Savannah, an interesting story.
coryrc 4y ago
Because they don't pay for pollution.
dredmorbius 4y ago
Answered in large part here: <https://news.ycombinator.com/item?id=33631996 https://news.ycombinator.com/item?id=33631996> Cost, safety, scale (there are 80,000+ commercial vessels), reliability, crew training and costs, etc. Combustion's highly proved, reliable, and safe technology. Range is sufficient for transoceanic transport. Emissions (both CO2 and other factors) are an issue, but could be mitigated with synthetic fuels, possibly biofuels (though even shipping would strain capacities required).

tjoff 4y ago

When I clicked on this I thought, why not just have a cable-guided ferry instead? (Which already is a common thing) I assumed they'd have to make maneuvers not possible with a cable. But it already is?! Then why not just tug the cable instead, much better efficiency then propellers. Edit: ok, it is. Though what I've seen is that the motors are pulled from shore rather than on the boat. Which seems simpler, but this is maybe easier to retrofit.

distrill 4y ago

I have to admit, it sounds a lot crazier before you learn that there are already cables running along the channel that the boat uses. This also means that this can't generalize outside of channels that already have cabled crossings. Given that constraint, I wonder about operating these ferries more like a ski lift then. If we're already stringing cables across the channel might it make more sense to keep them on shore away from the water?

simon_000666 4y ago

Cool - another option could be beaming power to the ferry using microwaves, millimeter waves or lasers. The power transfer efficiency would be lower but saves the cable complexity and slacking/maintenance.

MarkMarine 4y ago
I think the losses on both sides of that invisible death ray would be more complex than a long extension cord.
system2 4y ago
That sounds like a good way to get cancer.

tpmx 4y ago

I think this ferry between Helsingborg (Sweden) and Helsingør (Denmark) does it in the coolest way. Since 2018 the ferry has been running on batteries. Whenever it docks into any of the two ports, an ABB robot connects the charging cable. One real cool thing here is that they have gotten it to work for 4 full years in a northern climate. That means a lot of extreme weather edge cases. https://youtu.be/l93i87pZWhY?t=13 https://youtu.be/l93i87pZWhY?t=13

djcannabiz 4y ago
thats awesome it looks straight out of a scene from walle

clouddrover 4y ago

They say the ferry uses 150-200 kWh a day. If those numbers are right that wouldn't be a very big battery pack. The Hummer EV, for example, has a 212 kWh usable pack: https://www.youtube.com/watch?v=ORKuZxrFr6A https://www.youtube.com/watch?v=ORKuZxrFr6A https://www.youtube.com/watch?v=F9IUOR8lG3E https://www.youtube.com/watch?v=F9IUOR8lG3E Still, it's a cabled ferry anyhow so also having a power cable makes sense.

system2 4y ago
Battery packs degrade so fast with constant use. They would replace it every year if not every month.
- jillesvangurp 4y ago
  Nonsense; they are good for many thousands of cycles which generally translates into many years of continuous use. Mostly batteries degrade on a very predictable scale as well and very gradually. All of this is well known and anticipated by companies that deploy batteries in ferries, and other short range boats. It's just economics. You have energy savings and a battery that is good for a given number of cycles and engine hours. Either that adds up or it doesn't. Basically, it will be years before you need to service them and you can just use math to calculate whether that's economic or not. Apparently it does. That's why the use of batteries in short range nautical applications is booming. You have some range constraints but anyone operating within those constraints is looking at switching over already. Battery longevity is not the concern here generally.

newpavlov 4y ago

Why not simply pull the ferry using the steel cables? In other words, put traction systems on both riversides and move the ferry using them. It even should be more efficient than a propeller-based propulsion system.

matsur 4y ago
The ferry in the video uses cable based propulsion.
- bbstats 4y ago
  This is why hn needs a downvote button LOL
  - javawizard 4y ago
    HN has one, it's just only accessible to those who have reached a karma threshold (501 I believe).
- javawizard 4y ago
  It pulls itself along the cables rather than using a propeller, yes, but the motor that's doing the pulling is on the ferry rather than on the shore. To answer GP's question: I don't know, but given that this was a retrofit of an existing diesel-powered ferry I could guess that this was the cheaper way of doing it.
- nippoo 4y ago
  Yes, but the propulsion is on the boat rather than at shoreside like OP suggested (ie the cables are static)
- newpavlov 4y ago
  The point is that on the current system motors which are powered by the electric cable are on the ferry, so it uses propellers to move. The proposed alternative is to use steel cables (which are already present) without any electric ones to pull the ferry, such system should be more efficient power-wise and easier to service.

daneel_w 4y ago

Sort of common in the nordics. We have lots of them in Sweden, the self-service type for short crossings to sparsely populated islands, but the power cable usually drives a winch attached to a steel cable.

willhinsa 4y ago

I’ve never seen this video but just from the description I thought, “That sounds like something Tom Scott would make a video about.”

tgsovlerkhgsel 4y ago

If the ferry uses 150-200 kWh/day, that's two Tesla batteries assuming no recharging during the day (so realistically, you could run it on one, since the ferry presumably isn't constantly moving). Of course, the fixed cable avoids having to replace the battery every couple years, might be lighter/cheaper etc. - but it could absolutely be implemented using batteries. (This assumes the numbers are accurate, the 100 liters of fuel vs. only needing 200 kWh seems odd.)

sharkster711 4y ago
It would increase the weight of the boat though, by quite a bit so you'd end up needing a bigger battery. The battery also does not have 100% efficiency so add in another 10% for losses. You'd also need downtime to charge that battery up - about 15-20 hours if you use level 2 charging. Yes, 200 kwh seems oddly low.
- mrb 4y ago
  Have you seen the massive size of that drum of electric cable on the boat? It weights definitely more than 1200 lb, which is the weight of a Tesla 100 kWh battery. So the boat would be actually more lightweight after replacing that drum with a battery.

Animats 4y ago

Oh, it's a cable-guided ferry. Since it already has a guide cable, it may as well be cable powered, too. That's not uncommon, but usually the power is transmitted mechanically, like a ski lift. Brighton Beach in England once had an electric-powered sea-going railroad with an 18 foot gauge. A ferry running on railroad tracks. More of an amusement ride than a means of transportation, like some Disney water rides that run on tracks.

deleted 4y ago

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mrb 4y ago

The boat used to consume 100 liters of diesel daily, which is equivalent to 1000 kWh in energy (10 kWh per liter). But after electrification they claim only 150-200 kWh usage per day. This doesn't add up. Were the diesel engines idling all day even when the boat was not moving?

exyi 4y ago
It seems ok to me, EVs have about 13kWh/100km efficiency while an older gasoline car would consume 10l/100km. And yes, it's quite plausible that the engine was running during loading and unloading
- mrb 4y ago
  You are right. I forgot to account for the fact combustion engines have a terrible thermal efficiency: about 20%, which gives the boat only 2 kWh per liter of diesel, meaning it was using 200 kWh daily, more in line with the electrical version.

johnwalkr 4y ago

Something about many comments rub me the wrong way, which seems common on hackernews on some topics --lots of speculative or "why don't they just.." comments when one can easily look up the reasons for cable ferries existing. Cable ferries (which this is) are simple and well-established. Cables guide the ferry from one side of water to the other, making operation safe, simple and repeatable, even in fast moving water. They deliberately have the cables lying on the floor. This keeps them out of the way of passing ships, and is the simplest solution. The winch part of the system must be on the ship, not the shore. It's very efficient for the ferry to pull itself along the cable. There have even been handcrank operated cable ferries. It has some other benefits, like acting as an anchor perpendicular to currents. No take up is required on the other side. It's scalable to long distances without having to add piers or towers. In this case, a power cable from one shore was simply added to replace power from diesel generators. This seems to throw people off into a tangent about batteries. Why don't they just put batteries on the ferry? This mostly assumes that the ship is driven by a propellor and the cable is adding an unnecessary tether. But cables are already there serving other purposes, so it's a simple solution to lay a power cable along the same route and no real benefit to use batteries instead. Why don't they just pull it from the shore? You would have to overcome the drag of the cables all the way from the shore to the ferry, the power and size of the cable would have to increase dramatically and it would be impossible to scale beyond some (short, I suspect) distance. Why don't they just make the cable higher like a ski lift on each side to pull the boat? This would require a massive amount of tension, again increasing the size of the cable required. Like a ski lift, in practice you'd need the cable to go from one shore to the other and back in a continuous loop. This is definitely more complex, and loses some benefits of the cables, especially easily letting them rest for passing ships. The engineering problem and safety aspects, considering water level and side load from current would be much more difficult. It's not scalable without adding something like towers or piers.

rkangel 4y ago
Yes, the "pull the cable from shore" thing doesn't work well for simple reasons. This is what the cable looks like with the ferry pulling itself across: _-OOOO-_ ____________/ \__________ This is what it looks like if it is being pulled from shore: ---------------OOOO-_ \__________ The cable has quite a lot of friction with the bottom and can pull the ferry without lifting up and blocking half the river. Boats still need to be very careful around ferries like this, but they can still coexist. These ferries traditionally used to be "chain ferries" which had even more friction between chain and river bottom.