Thread

The Return of Sail Power: Cargo Ships Are Turning Back to the Wind

193 points · 136 comments · gumby

darksaints · 1789670926 · focus · HN ↗
As both a sailor and a wingsail designer, I've followed this space for a long time. I've gotta say this is just one of the thousands of trial PR announcements for different companies which develop something and think it's gonna save the world.
<a href="https://www.paulgraham.com/submarine.html" rel="nofollow">https://www.paulgraham.com/submarine.html
We've been seeing these every other year or so ever since the walker wingsail back in the mid 80's:
<a href="https://www.change-climate.com/Transport_Land_Sea_Sustainable/Assisted_Ships_Sails_Solar_Projects_Marine_Pollution/Walker_WingSails.htm" rel="nofollow">https://www.change-climate.com/Transport_Land_Sea_Sustainabl...
As to why they are never successful, I don't exactly know. Most of the companies that put these on trial just quietly retire them without adoption, and never explain why. It's not about ease of use, plenty of designs have near 100% automation and simple design. It's not really about maintenance, plenty of designs have almost maintenance-free design as well.
My best guess is that sails/wingsails/rotorsails have inherent height, which interferes with bridges and gantry cranes, and requires furling/stowing capabilities which them makes the systems a lot more complex. My next best guess is that in order to get meaningful propulsion, you introduce heeling, which is bad for container ships and potentially catastrophic for dry bulk.
1. pge · 1789671316 · focus · HN ↗
  My understanding was that it was not just the height but also the deck space and depth (the vertical sails have to extend down through the decks). Giving up that much cargo volume (in addition to issues at the dock you note) is not worth it.
2. sandworm101 · 1789672787 · focus · HN ↗
  Unpredictability. The sails do reduce costs/fuel but they do so in a rather unpredictable manner. Cargo hauling is all about rigid scheduals and precalculated costs: contracts to deliver at an exact time and load an exact amount of fuel. Unpredictable elements, even if on average mostly good, do not mesh with that culture.
  1. darksaints · 1789673332 · focus · HN ↗
    Delivery at an exact time is of course a constraint, but I’ve never seen any sort of constraint on the exact fuel usage. This isn’t anything like aviation where excess fuel has to be dumped in order to land safely. If you don’t use the fuel for your voyage, you just fill up less for your next voyage. Weight effects are countered via water ballast, as they always have been.
    And sails for power augmentation do not complicate timelines at all. If there’s not enough wind, you use more fuel. Nobody has meaningfully proposed relying 100% on wind propulsion.
  2. dofm · 1789674074 · focus · HN ↗
    It's not about schedules. These things don't change when you arrive; they change how much it costs to arrive and how heavy you arrive.
    So the only logical explanation is that they don't do that by enough to be worth installing and maintaining, or for fuel market systems to adapt to an amount of oversupply.
    The industry clearly adapts to an amount of undersupply; ships are fairly often going to burn more fuel than the route might ordinarily need due to being held up or weather or the need to reroute, are they not? So it doesn't seem implausible that the market would adapt to this; it's going to average out quite quickly. It is presumably therefore about the juice not being worth the squeeze.
    This doesn't rule out illogical explanations.
    (Belated edit for clarity)
  3. trog · 1790027309 · focus · HN ↗
    Heh, I work for a freight forwarder and spent half the day yesterday explaining to customers that the margin of error on their containers is currently between 1 to 2 weeks.
3. moffkalast · 1789675488 · focus · HN ↗
  Not sure where I've read this, one of the main causes is supposedly ship ownership. Firms that operate ships pay for the fuel and would benefit from the retrofit for some specific routes. Outside a few that operate their own fleet, most are rented and mounting something expensive for no benefit to themselves and questionable benefit outside of areas with trade winds would be pretty idiotic from that perspective.
  What would make it successful is some kind of mandate for a certain percentage of power needing to come from wind. The invisible hand of the market keeps burning the cheapest thing all day long if you leave it to its own devices.
  The bottom line is though that cargo shipping is a time sensitive thing in today's world and wind does not cooperate with timetables. Saildrones and sailing yachts are the only good fits for it, since neither is in much of a hurry. Commercial shipping probably needs renewably generated biofuel to run carbon neutral and still function as we know it.
4. arwineap · 1789736796 · focus · HN ↗
  > in order to get meaningful propulsion, you introduce heeling
  I think that in order for this to work we would have to take on more traditional downwind trade routes, which would avoid a lot of the traditional heeling

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