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JS Shirase

Posted: Tue Nov 14, 2017 5:35 am
by JK
The ship is very light going by the picture. Water lubrication for the hull.
I am very curious about how this operates in colder temperatures. They would need a huge seabay to provide enough water, heat it somehow, and a big pump.


Icebreaker.jpg

Re: JS Shirase

Posted: Tue Nov 14, 2017 6:52 am
by Merlyn
Weird machine, lubing water with water?
Or water with over the ice as a cutting liquid?
Seems to be spraying too far away from the hull re the contact/ cutting point?

Re: JS Shirase

Posted: Thu Nov 30, 2017 3:46 am
by JK
He Merlyn, its water lubrication for the hull to make passage though the ice easier. The ship is up on a ridge of ice, trimmed by the stern, or light. Not sure. A lot of breakers use air lubrication.

Re: JS Shirase

Posted: Thu Nov 30, 2017 4:42 am
by Merlyn
Interesting, I can see now it's virtually at the top of its stroke it would appear.
So it's a continuous flow then and not adjusted by the rise and fall of the bow then?
So a lot of squirting wasted then?
Air models have lower ejector points perhaps?
Wonder what psi?

Re: JS Shirase

Posted: Thu Nov 30, 2017 9:49 am
by JK
I would expect it is low pressure, high volume.
when I worked in the Arctic, you were running pretty well on full recirc, with the returns either going back to the seachest or seabay depending on temp settings. My preferece was to run seabay temperatures up around 24*C to stop alarms. The emergency pump seabays could get problematic unless there was a warm water feed to keep it from icing up.
This looks like a significent amount of water. In the right conditions I expect it would ice up at the discharge. I wonder how it is set up to prevent problems.