Recently Norsepower, the makers of an innovative spinning sail for ships, installed the first tiltable versions of its product. This helps vessels that must travel under bridges be able to still take advantage of the technology without needless destruction of public property and the occasional electrocution.
Before we get into the specifics of this install, let’s review how the technology works:
Instead of relying on large cloth sails like an ancient sailing ship, the ship has rotating cylinders. The rotation takes advantage of the Magnus effect, and allows wind coming from different directions to still help push the ship forward. This takes some of the work off the ships’ giant bunker fuel-burning engines.
While most ship’s engines aren’t this huge, they’re all still pretty big. Even saving a few percent of the fuel makes a big difference.
It does take some energy to rotate the Rotorsails, so conditions will not always be right to get a net gain out of the system. To make sure the system only runs when it would actually help the ship, and not waste energy, the system is run by computers. They do the math, and automatically turn the system on and off. That way, when they run, they lower fuel consumption.
Norsepower has been able to demonstrate savings of 5-20%, depending on conditions, with more recent studies showing improvements of up to 25%. The International Maritime Organization (IMO), a United Nations agency, is pushing for a 50% reduction in carbon emissions from shipping by 2050, with smaller targets by 2030. By retrofitting existing ships, they can remain in service for longer without needing to be replaced because they can’t meet future standards. For new ships, it makes a lot of sense to “future proof” the ship with Rotorsail technology so it can have a longer design life.
There’s just one big problem. The things are tall. Really tall. For ships that only sail the oceans, the Rotorsail made a lot of sense so far, because the sky’s the limit on how tall things attached to the ship can be. For ships that must use canals and intracoastal waterways, having those big sails can be rather problematic. The biggest problem? Bridges.
Sure, drawbridges tilt up and out of the way (providing an opportunity for suicidal daredevils to jump their cars), but many bridges don’t tilt up like that, so a ship has to either fit under the bridge or not go at all. We all like to watch videos of the Canopener Bridge, but multimillion dollar ships just can’t afford that kind of fun the way U-Haul renters and RV owners in Durham, North Carolina seem to be able to.
In addition to bridges, powerlines often cross the channels and rivers that cargo ships may navigate. I don’t know about you, dear readers, but playing with high voltage like Marv in Home Alone 2 doesn’t seem like a good time, and apparently the owners of big ships agree.
To avoid the needless destruction of the Rotorsails and possibly hundreds of millions of dollars of valuable international cargo, but still be able to use the Rotorsail, Norsepower came up with a good solution:
By making a tilting mechanism, the ship can save fuel while crossing oceans, but put the things away when it’s time to go under the bridges. While the idea might seem obvious, keep in mind just how big the ship and the Rotorsails are. It takes quite a bit of engineering work to make big hinges, the hydraulics needed to tilt them safely, and the electronic controls to make sure they go down instead of taking the proverbial Louisville Slugger to a country’s infrastructure.
And the people of Norway, the Netherlands, Denmark, Sweden, and Poland will all be thankful that the SC Connector will be the first ship to have these tilting mechanisms under their Rotorsails, as it’s going to be safely going under bridges and powerlines in their countries.
“The Rotor Sail technology has been proven in the market for a while, but the size is unique for our project. The sails are far more efficient than conventional sails of the same size and the tilting function is essential to our voyage routes,” said Ole Sævild, Managing Director, SEA-CARGO, the owner of the ship. “Given the estimated emissions savings, we will use our experience of this full scale project, and proceed to develop it further for other vessels in our fleet.”
Obviously nobody would have seriously considered running them without the tilting mechanisms, but the fact that they’re now available makes it a workable option for a much greater number of ships. We can all appreciate the fact that ships will be making less emissions, especially of greenhouse gases. That is something people the world over can seriously appreciate.