Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Maersk installed 100-foot-tall rotating sails on one of its tankers

wsj.com

Post reply on HN
Print view View original

191–200 of 233 posts

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#191

Post by mabbo »

sandworm101 wrote: post #155
mabbo wrote: post #103

Earlier quoted context omitted.

I've long imagined some fun possibilities for this. I picture a small-ish shipping ship, say something moving 20 or 30 containers only, fully autonomous (100% crewless) with sails and solar only powering it. Solar electric motors handling the near-land operations and "not enough wind" conditions, sails otherwise. If you had autonomous loading and unloading, you would have zero variable/operational cost. I am certain…

Unless someone has spent time at sea they cannot appreciate all the maintenance a large ship requires. Crewless ships are pipe dream. But captainless ships, ships operated without officers to navigate them, are a real option. You keep the tiny crew for fixing things but the operation of the ship is handled from afar. Crews are cheap. Ships' masters are not.

Alternatively, the repair crew don't stay on the ship. Have a mobile team on a faster boat going ship to ship rescuing and repairing ones that can't make it to port again.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#192

Post by sandworm101 »

mabbo wrote: post #191
sandworm101 wrote: post #155

Earlier quoted context omitted.

Unless someone has spent time at sea they cannot appreciate all the maintenance a large ship requires. Crewless ships are pipe dream. But captainless ships, ships operated without officers to navigate them, are a real option. You keep the tiny crew for fixing things but the operation of the ship is handled from afar. Crews are cheap. Ships' masters are not.

Alternatively, the repair crew don't stay on the ship. Have a mobile team on a faster boat going ship to ship rescuing and repairing ones that can't make it to port again.

Maintenance is not repairs. The work needed to prevent repairs has to happen ever day. A crew at sea doesnt sit around waiting for an alarm. They are tending to equipment, verifying sensors ... even touching up paint is an essential daily task.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#193

Post by mabbo »

sandworm101 wrote: post #192
mabbo wrote: post #191

Earlier quoted context omitted.

Alternatively, the repair crew don't stay on the ship. Have a mobile team on a faster boat going ship to ship rescuing and repairing ones that can't make it to port again.

Maintenance is not repairs. The work needed to prevent repairs has to happen ever day. A crew at sea doesnt sit around waiting for an alarm. They are tending to equipment, verifying sensors ... even touching up paint is an essential daily task.

Interesting perspective. I hadn't considered that.

Part of me starts to wonder now about building boats that are more resilient, but then I remember that salt water is terrible and surely by now someone would have if it were possible, since we spend so much money on humans doing that maintenance!

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#195

Post by oliveshell »

village-idiot wrote: post #181
cwkoss wrote: post #127

Earlier quoted context omitted.

Isn't hydrogen difficult to store? I've heard that it will leak out of just about everything.

You might be thinking of helium, which becomes a zero viscosity superfluid when cold enough.

Hydrogen can diffuse through certain metals and weaken them [1]. Currently, hydrogen storage is costly and tricky for a number of reasons [2]. It’s also very important to avoid leaks into enclosed areas since it’s extremely flammable.

[1]: https://en.wikipedia.org/wiki/Hydrogen_embrittlement

[2]: https://www.energy.gov/eere/fuelcells/hydrogen-storage-chall...

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#196

Post by usrusr »

lostlogin wrote: post #159
kenneth wrote: post #51

Earlier quoted context omitted.

Regular sails actually work similarly to a wing, in that pressure differentials on either side create a force we call lift on a plane, rather than simply being "pushed from the back" by directly catching the wind. That's why a sailboat can go in almost any direction regardless of which direction the wind is blowing.

Watching bleeding edge yachts sail is always interesting. Hydrofoils achieve speeds greater than 3x wind speed though their stability doing it is a bit alarming. https://www.odt.co.nz/sport/yachting/how-fast-can-americas-c...

The imaginary future where huge cargo ships foil under city-sized kites is more impressive than anything I've seen with spaceships.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#197

Post by kemiller »

jessaustin wrote: post #140
abtinf wrote: post #18

Some years ago I read The Box by Marc Levinson, a history of containerized shipping. Highly recommend it. If you live in SF and have wondered about the numerous barely used piers, this book explains their history as well - and why the major container terminal ended up in Oakland instead. One of the painful early lessons for the industry was the discovery that minimizing operational costs (particularly fuel and mainte…

...why the major container terminal ended up in Oakland instead. Whatever the reason, I'm sure everyone who uses a bridge in SF is happy about this.

The reason is that it was much easier to terminate the transcontinental railroad on the eastern shore of the bay. Not unrelated to your point.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#198

Post by Steko »

ethagknight wrote: post #97
mvpu wrote: post #91

Wonder why ships aren't trying solar panels and electric motors and auto-pilot... they're out in clear Sun, have a large surface area, and no traffic...

Two problems with boats and solar propulsion: 1) they need 24/7 power. 2) Using a random LG 330 W panel on top of the Edith Maersk, it would take an array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW engine power output. Edith is 1/4 mile long and 3/100ths of a mile wide. Quite a gap, and thats before you start factoring in batteries for the night, structure to support the array, storms...

> 2) Using a random LG 330 W panel on top of the Edith Maersk, it would take an array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW engine power output. Edith is 1/4 mile long and 3/100ths of a mile wide.

Back of the envelope math says we're short by a factor of ~108. We can get savings in a few places:

(1) We don't have to match the full engine output with solar. Many container ships use super slow shipping at a fraction of the power, [1] says 10% engine load. With batteries you can still increase throughput substantially when needed.

(2) Panels can exceed current ship dimensions, perhaps greatly (tow a long tail of solar panels on floats?). Let's just go for double width and length for now.

(3) Efficiency gains. We're at 20% in back of envelope above but I can get that for my house. Let's say Maersk ponies up for 30% cells.

Still some ground to make up but at least we're in bullshitting distance of claiming it's viable.

[1] http://articles.maritimepropulsion.com/article/Turbocharger-...

> thats before you start factoring in batteries for the night, structure to support the array

Presumably there's some space/weight savings in not having an 80MW engine.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#199

Post by JshWright »

heywire wrote: post #50
jherdman wrote: post #33

Earlier quoted context omitted.

You might enjoy "Containers", an eight episode podcast about the shipping industry too. https://medium.com/containers

Two non-technology related containers story on the front page of hacker news, and they're both actually really interesting! Happy Friday!

Hmm... I've seen a couple shipping related stories, but nothing container related.

This one is about tankers, and the other was about bulk carriers.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#200

Post by juhanima »

jessewmc wrote: post #64
abtinf wrote: post #18

Some years ago I read The Box by Marc Levinson, a history of containerized shipping. Highly recommend it. If you live in SF and have wondered about the numerous barely used piers, this book explains their history as well - and why the major container terminal ended up in Oakland instead. One of the painful early lessons for the industry was the discovery that minimizing operational costs (particularly fuel and mainte…

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

Fun trivia: when windjammers were going out of style, some businessmen still bought them for the low cost.

https://en.wikipedia.org/wiki/Gustaf_Erikson

For a while in 1930's small Åland had the largest sailing fleet in the world.

Post reply on HN