Wallenius Oceanbird: Wind-powered cargo vessel
oceanbirdwallenius.com
oceanbirdwallenius.com
> The ship will be equipped with five retractable, telescopic wingsails that can rotate 360 degrees. The masts will measure 80 m (260 ft) for a total height above the waterline of 45 to 105 m (148 to 344 ft). That would also make it the tallest ship in the world. The rigging will be made from steel and composite materials and resemble airplane wings. An auxiliary engine will be used to navigate harbors and provide emergency power.
> While the design is meant to be usable for different types of ships, the first version is planned to be a 200 m (660 ft) long roll-on/roll-off ship with a capacity of up to 7,000 cars. Such ships will be used on transatlantic routes and are expected to perform the journey in 12 days, longer than the current average of eight.
> Open-sea trials with a 7 m (23 ft) prototype were conducted in the summer of 2020 and are scheduled to continue during the fall. Commercial orders are expected to start in 2021, with an entry into service in late 2024.
Also, what percent of the total cost of shipping today is fuel versus other costs like crew and port logistics, etc?
The boat is 200m long and the sails only occupy about half of that. The all-down configuration is 45m and the all-up is 105m so I'd guess the sails are about 70m tall. So 70 x 100 = 7000 sqm of sail area. That's approx. equivalent in area to a wind turbine with an 83m diameter rotor. Doing one of those online wind turbine calculators with an efficiency of 40% (limit of 59% ala Betz) comes up with about 1.5MW or a little under 2000 horsepower.
Most of the big boats like this start around 10,000 hp and only go up from there so I can't help but wonder what's going on here. I guess it could have a very efficient shape and go slower but that seems unlikely to make that big of a difference to me.
I 100% get that half speed = 1/4 drag and thus 1/4 power. That makes sense.
But I'm not sure how to reconcile half speed with not at least doubling the trip duration. New York to London is 3000 nautical miles. At 10 knots that's 300 hours or 12.5 days. If there are boats doing 20 knots then they should arrive in ~6 days rather than the 8 quoted.
My guess is that the idea is that in low winds they use the engine to boost speed.
For reference, see this document [1] from the US Naval Acadamy.
"It will be observed from the figure that the doubling of speed of the Navy YP from 7to 14 knots increases the power by a factor of 10!" [1] p.7
"Ship power is roughly proportional to the cube of the speed" [1] p.8
Hence the installed power you estimate may just work out.
I do have many questions about the about sail handling and rigging. Stowed and raising these things are non-trivial! Telescopic mechanisms can have all sorts of issues, especially when loaded - like in a building storm!
So while the entire concept really excites me, I'd love to see them iterate at smaller scale before trying to go full scale.
[1] Chapter 7, RESISTANCE AND POWERING OF SHIPS U.S. Naval Academy:
https://www.usna.edu/NAOE/_files/documents/Courses/EN400/02....
I had some downtime while living on a marina for a bit, so I read a bunch of the research literature. Freestanding wingsails that can fully rotate like this have the neat property that they can "weathervane" with very little drag. In fact a bare mast on a traditional sailboat with the sail down generates a lot more drag than the wing, due to turbulence vs laminar flow.
It's not clear from these renders, and I'm not motivated enough to dig into it, but most designs I read about in this category are self trimming. Saildrone is a good example, where it uses a 2nd smaller wing on a boom to control the overall angle of attack of the wing. Change the setting on the "tail" to change the angle of attack. The wing will follow the direction of the wind no matter how it shifts. So controlling these boils down to a small electric actuator, which is easy to make controllable via a screen, software, or what have you.
In fact one of the motivations for people experimenting with this stuff at more modest scale is it could be huge for adaptive sailors, because it makes sail handling so trivial.
On top of that, a modern wing sail is much more efficient than the sails used in the old cargo ships and of course, the modern ship comes with an engine. Bad or no wind will cause more engine use, but not the ship getting stuck in one place.
Amazing beauties, shame there's only a few of them left.
> He said that once they failed to pass Cape Horn for 100 consecutive days.
IIRC those Flying P-Liners were used a lot on the Chilean guano trade. So they had to go round Cape Horn against the prevailing winds on the way out. And with a square rigged ship not being the best for beating against the wind, it sounds believable.
And there could be a premium for the service. I could see Tesla paying extra to ship electric cars with burning bunker fuel. As a customer I’d pay extra for that.
(but I'm an idealist, for sure :-))
Airfoil sails "Wingsails" [0] have some proven history and these folks have the advantage of 60 years of CFD software dev! [1] (wow on that last part)
Just curious, what makes this design in OP even worse from your point of view?
[0] https://en.wikipedia.org/wiki/Wingsail
[1] https://en.wikipedia.org/wiki/Computational_fluid_dynamics
Biplanes worked great for most of the history of aviation, but we can do better now with math.
The hull shape of a steel hulled windjammer is not vastly different from a modern container ship of similar size. Very similar length/beam/draft ratios, both have pretty "boxy" hull shape midships. The big difference is the bulbous bow, which doesn't make much of a difference at the lower speeds a sailing ship spends the vast majority of its time, and of course the stern with the propeller.
> Biplanes worked great for most of the history of aviation
To nitpick, if we consider the age of flight to start with the 1903 Wright flyer, biplanes were mostly obsolete by the mid-1930'ies. So about 30 years out of a so far total of 118 years.
Remember, that it is not just those who say "this is new, therefore good" who are fools but also those who say "this is old, therefore good".
Old sailboat designs are old, but no longer competitive.
Old communication media (printed text, for instance) are old, but very competitive.
Wallenius Wilhelmsen seems to be a joint venture of Wallenius Lines of Sweden and Wilh. Wilhelmsen of Norway.
Under Cargo it simply says it is capable of carrying 7,000 cars in the cargo hold. It doesn't appear to be set up for shipping container cargo. It is possible that top-loaded shipping containers don't work well with the sails/airfoil that need to be above the ship.