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Synthetic Sebum Makes Slippery Sailboats
sonnejw0 writes "Sea-faring vessels are a major contributor of greenhouse gas production due to a deficit in international laws and inherent inefficiencies at sea, such as barnacle build-up on hulls. Many marine animals avoid the build-up of drag-inducing barnacles through secreting oily residues from their pores or through the nano-molecular arrangement of their skin. Sailors regularly defoul their hulls, removing the barnacles at dry-dock, which requires them to reduce the amount of time they have at sea. Some synthetic chemicals in paints have been used to prevent barnacle build-up but have been found to be toxic to marine animals and thus outlawed by several nations. Now, engineers are trying to replicate the skin of marine animals to produce a slippery hull to which marine bacteria cannot attach, saving fuel costs and improving speeds."
The image of a smegma producing sail yacht is now stuck in my head!
Where's the brain bleach when you need it!
A surface that inhibits barnacles is only a start, for there are other things one can do to make a ship more eco-friendly
One if obviously a more fuel efficient engine
The other is to improve the design of the propeller to make it more efficient while lessen the drag
Then there is the need for a much lighter material for the construction of the ships
Last but not least, new designs of ships are also needed.
Muchas Gracias, Señor Edward Snowden !
Genetically engineered whales with a built in cargo hold. You just have to train them well, and take advantage of their natural migration patterns..
... stopped reading after the headline...
...and no, you don't grow out of it.
Any further discussion would be TMI.
Maybe we can line fire hoses with this amazingly slippery material?
-kgj
The glue that barnacles produce will stick to Teflon.
Here is an old 2005 article similar to this concept that talks about using a "skin" similar to shark skin to combat the barnacles.
LOAD "SIG",8,1
LOADING...
READY.
RUN
We did it once upon a time.
Apparently Supertankers and Cargo ships have cut their speeds down to 10 knots to save fuel, some of the greatest Cargo ships of the Age of Sail managed 13 knots no dinosaur juice needed.
And everything one of the other posters cited about better materials and new designs still applies.
Flettner Rotors are more efficient than conventional sails, they failed because Diesel was just too cheap.
http://en.wikipedia.org/wiki/Rotor_ship
Enercon a Wind Turbine company built a Rotor Assisted ship to ship its Wind Turbines and cut fuel cost 30%
http://en.wikipedia.org/wiki/Enercon
http://www.treehugger.com/files/2008/08/flettner-rotors-cut-fuel-use.php
America's cup boats typically are hauled out of the water after every days racing. There is little opportunity for stuff to stick to them because they are always moving, and anything that does stick is washed off. Furthermore there is a ton of work done at low reynolds numbers and boundary layers to ensure the boat bottoms are as efficient as possible - including micro-grooving the bottom material. I am not sure about America's cup, but in many racing series it is against the rules to add any shedding coatings other than anti-foul paint. America's cup boats do not use anti-foul.
This post brought to you by your friendly neighborhood MBA.
So why the hell is a third- or tenth-order minor benefit listed described as the prime reason behind this research?
If you can make ships more efficient in the water, making ships that run on renewable sources becomes more possible. Steam- and diesel-powered vessels were invented to improve speed (and capacity) in the water. The more you can improve the efficiency, the more speed you can get out of less and less energy. Which makes things like wind power (sails) or solar power (electricity) more and more of a possibility.
True, but that's still a second-order benefit at best because shipowners ALREADY wanted more efficient ships long before any environmental concerns ever arose because such ships have always been cheaper to run.
Look at the changes in ships between 1850 and 1950. Do you really think environmental concerns drove those changes? Do you really think the owners of Liberian-flagged and Filipino-and-others-crewed vessels really care one whit about the environment? Yet even those ships have become more efficient and therefore more environment-friendly over the decades.
And that's only because when large ocean-going vessels are involved, the profit motive aligns pretty nicely with environmental concerns.
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Sea-faring vessels are a major contributor of greenhouse gas production due to a deficit in international laws and inherent inefficiencies at sea, such as barnacle build-up on hulls.
Sea-faring vessels are the single most efficient way of transporting goods we have. The reason they're a big contributor of greenhouse gas production is that our global economy requires that a lot of goods are transported around the world. Try transporting thousands of containers across thousands of miles by truck (please, don't actually try this, it's bad for the environment).
The IMO (wikipedia) is one of the most widely acknowledged international authorities on anything. They've made a lot of internationally respected laws, improving sea transport on many levels, including the environmental effects.
It's true that hull fouling is a problem for ships. It's also true that many (especially large) ships burn Heavy Fuel Oil (HFO), which contains a lot of pollutants (like sulfur) and isn't as clean as, say, diesel oil. It's also true that ships burn a lot of HFO, and it's true that ships further pollute the seas by dumping garbage overboard.
However, while the amounts of HFO burned by, say, the Emma Maersk, are enormous (about 300 metric tonnes per day at full operation), this is almost nothing when compared to trucks. Assuming 300mt/day at a cruise speed of 25 knots (over 45km/h), that equates to roughly 30 tonnes per 100 km. A semi-trailer truck pulling two TEU containers runs at around 30 liter per 100 km (that's around 8 mpg, anyone that can confirm this number?). This means the Emma Maersk, carrying 14000 TEU, uses 1000 times as much fuel as a truck carrying 2 TEU, which makes this ship about 7 times as fuel efficient as trucks.
And another thing: with HFO costing 300-400 dollars per metric ton, the Emma Maersk burns up about 100,000 dollars per day when running at full capacity (this almost never happens, especially now with the economic crisis, but bear with me). That's about 3 million dollars a month in fuel. The Emma Maersk is crewed by a minimum of 13 seafarers, but let's take 20 for easier calculations, since it's probably closer to reality anyway. Suppose each of those 20 people earn 10,000 dollars a month (which is a lot - maybe the Captain, Chief Officer and Chief Engineer make this much... just maybe). That means total crewing costs for this ship would be 200,000 dollars a month, with fuel costs 15 times higher. What I'm trying to say here is this: it's in the companies' best interest to improve their fuel economy. A 7% increase in fuel efficiency would save them more money than not having to pay the crew. I'm fairly certain there are no cheap and easy ways to drastically reduce fuel usage, or they would have thought of it by now.
All of this is not to say that there isn't room for improvement in the maritime transportation business, far from it. This research and other research like it can and will do great things for the shipping industry and the environment. I just didn't like how the summary made the industry the bad guy here.
P.S. If you want to read more about the IMO's actions on air pollution: go nuts.
I'd rather you rationally disagree than irrationally agree.
Has anyone tried adding the well-known Microban additives to marine paints?
TFA states that barnacle infestation begins with filming of bacteria on the hull, followed by algea eating the bacteria, then barnacles feeding on the algea.
Some Microban additives puncture bacteria and hence kill them. They are used in kitchen and medical equipment and institutional wall paints. Why not attack the root of the food chain rather than the top rung?
We could just keelhaul more people. They'll scrape all the crap right off the bottom of your ship. Or they'll get stuck down there and create a bigger problem. Either way, it's entertainment. Yar.
I guess good news travels slowly. ;-)
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For pleasure yacht sailors this is a big topic.
It is a constant battle against marine life which wants to live on any part of the hull in the water.
The main antifouling up to now which has been very effective is hard bottom paints containing Tributyltin. wiki: http://en.wikipedia.org/wiki/Tributyltin
This has unfortunately been proven to be fairly toxic to marine life and has consequently been banned worldwide for all craft under a certain length. Not sure of the length but large shipping vessels and somewhat the navy etc are still using it as it really is the only proven way to do a good job keeping that bottom clean.
All modern antifoulings for pleasure yachts are now based one of two things. One is a copper (copper oxide) mixed with various biocides. This is a hard type paint, often merely ground copper mixed with epoxy. This will give you a very smooth finish, and it depends on the copper (which most marine life doesn't like) and the biocides to keep the hull fairly clean. You have to dive under once in a while and scrub the hull down. Small price to pay for sailing around paradise!
The other type used is called an 'ablative' paint which may or may not contain copper/biocides but is meant to flake off itself as the marine life grows on it. This does not work for boats that live more at marinas with little sailing time, and requires bottom-jobs on the boat more often. The upside is that it is much easier to apply and does not require as much hull cleaning.
It all comes down to..if they could invent something that did not require frequent haulouts and kept your hull clean and smooth, they could easily charge $500 per gallon of the stuff and people would be lining up to pay for it.
It's easier to fight for one's principles than to live up to them.
Not and option for sailing racing boats - International Sailing Federation Racing Rules of Sailing prohibit this kind of solution: "53 SKIN FRICTION A boat shall not eject or release a substance, such as a polymer, or have specially textured surfaces that could improve the character of the flow of water inside the boundary layer."