How do container ships antifoul?

[Polly1]

Does anyone know the answer to this as I have been wondering? I know that part of the answer is the rise and fall with unloading will kill the weed on the sides but I saw the bottom on one yesterday due to an imbalanced load and it was not fouled.
Cheers
Guy

 

[savageseadog]

Tri Butyl Tin

 

[Jamesuk]

Dry dock

 

[achwilan]

Jotun Seaforce
I tried it in april 2011: impressive, I just had to sponge the hull in july...

 

[achwilan]

Antifouling

Jotun Seaforce
I tried it in april 2011: impressive, I just had to sponge the hull in july...

July 2012 of course

 

[sailorman]

Tri Butyl Tin

Its far too dangerous for us yachties to use, i mean we use 3 1/2 lts a year

 

[martyn78]

How do container ships antifoul?

With a VERY big brush/roller.

 

[Twister_Ken]

25 knots.

 

[epervier]

How do container ships antifoul?

With a VERY big brush/roller.

Wrong

Airless spray, using proper poisons, xylene, dicopper oxide, zinc oxide, Solvent naphtha, ethylbenzene, iron oxide, plus a few more ingredients.


which of course you can't buy at your local chandlers, because it says on the tin,

wait for it........

Dangerous to the environment

 

[penfold]

Tri Butyl Tin

What he said; the IMO is a better lobby group than the RYA.

 

[LittleSister]

What he said; the IMO is a better lobby group than the RYA.

... and also container ships don't tend to cluster in large numbers sitting stationary in lots of sheltered fragile river and bay environments. There's a lot more poison from container ships, but it's generally much more dispersed.

 

[Pasarell]

Wrong

Airless spray, using proper poisons, xylene, dicopper oxide, zinc oxide, Solvent naphtha, ethylbenzene, iron oxide, plus a few more ingredients.


which of course you can't buy at your local chandlers, because it says on the tin,

wait for it........

Dangerous to the environment

I assume this is all tongue in cheek?
Just in case:
Airless spray: The "big roller". Nothing to stop you using on a 30 footer except you would use a lot more paint and make a big mess
Xylene. Thinners No 3 from your local chandler. The main solvent used for antifoulings
Dicopper Oxide. The main biocide used in pretty much every antifouling for the last 25 years
Zinc oxide. Minor biocide used in pretty much every antifouling
Solvent Naptha. Slower solvent than xylene and constituent of most antifoulings and other paints you buy. Also known as Shellsol 100A if you want to buy at your local chemicals supplier.
Ethylbenzene. Usually in the blend of thinners No3
Iron Oxide. Also known as rust. Usually removed from container ships before antifouling

TBT hasn't been allowed on any ships, anywhere, for many years now - although I've no doubt there are still a few around parts of Asia!

Most container ships have switched to a completely non toxic and long lasting fouling control system such as Intersleek from International, but even if still using a conventional antifouling very similar to what most yachts use then the consistent high speed and little time in port means you can design the polishing rate very accurately and avoid any fouling.

 

[sailorman]

... and also container ships don't tend to cluster in large numbers sitting stationary in lots of sheltered fragile river and bay environments. There's a lot more poison from container ships, but it's generally much more dispersed.

Felixstowe on the Orwell estuary springs to mind

 

[Koeketiene]

Does anyone know the answer to this as I have been wondering? I know that part of the answer is the rise and fall with unloading will kill the weed on the sides but I saw the bottom on one yesterday due to an imbalanced load and it was not fouled.
Cheers
Guy

When in dry dock every couple of years.

They're constantly on the move at considerable speed, so far less chance for fouling to occur.

 

[Robg71]

We dry dock every year for a maintenance period and remove around three hundred tons of mussels etc etc....
But there again, we sit on DP for most of the time, and generally stooge about at 15 knots....
I dont have a photo to hand, but google images, dsv seven atlantic

 

[Ianhampshire]

Container ships, like all other deepsea vessels, use an environmentally safe anti-fouling paint system. International and Jotun, amongst others, manufacture such commercial anti-fouling paint systems designed to last a minimum period (normally 3 or 5 years).

The vessels classification society requires the vessel to undergo a hull inspection twice in every 5 year period. The intermediate inspection may be undertaken by approved divers but the 5 yearly inspection must be carried out in dry-dock. During these dockings, the hull is blasted to remove weed and shell growth etc after which a new 3 or 5 year anti-fouling paint system is applied.

No anti-fouling paint system is completely effective, and obviosuly less so over time, so if you did see a very clean hull then it is possible that the ship had been recently dry-docked and repainted

 

[nigel1]

Or, the hull was recently scrubbed in water. Major operators monitor vessels performance, speed against fuel consumption,and can predict when it is economical to scrub the hull.

 

[flipper]

When I worked for this lot 20 years ago:

http://www.umc-int.com/underwater-maintenance/

we used to do a lot of hull cleaning, prop polishing and anode replacement in the Torbay anchorage.

The picture in the link is a hydraulic pamper which you can 'drive' upside down under a container ship. We'd be in for hours as it's shallow work.