Ice and Roller Furlers

[DoubleWhisky]

Originally Posted by thinwater

So, for those that sail in the north country, is it all hank-on sails? It's really not that hard to build ice on a furler, and I can see that a frozen drum and a frozen luff groove on a frozen bow could make for a real problem.

I personally believe in the hank-on sails in the north.
Arctic sailing is quite popular there and most boats go north with hank-on sails only.
You can use some chemistry on lines, sails and roller itself, but some days of rough weather - common in high latitudes will wash everything.
Built-up of ice can be really dangerous, I think.

The boat featured in this thread:
http://www.cruisersforum.com/forums/...tml#post579365
carried furling genoa.

Nobody knows now, but I think there is possibility, that built up of ice there could somehow add to the forces responsible for losing the mast. Of course - it is only a POSSIBILITY and pure speculation.

Anyway, I think that rollers are dangerous far north and far south...

[hummingway]

I've read accounts of ice having a serious effect on a boats waterline to the extent that that constant chipping was required ... not in waters I'd sail in though. Ice weighs about 60 pounds a square foot I think.

[boatman61]

Brrrrr........ only times I ever go Nth of 40 is to work or to buy.... its cold enough here tonite in Portugal at -1c.... Cheech gonna have to move further Sth next year

[thinwater]

Originally Posted by hummingway

I've read accounts of ice having a serious effect on a boats waterline to the extent that that constant chipping was required ... not in waters I'd sail in though. Ice weighs about 60 pounds a square foot I think.

"A pint's a pound, the world around", or just a wee hair more.

[thinwater]

Originally Posted by hummingway

Depends on the temperature. Salt slows the rate of freezing and thereby lowers the freezing temperature until about -20C or -4F and then it makes no difference.

This is a good point, Hummingway.

No question, the less salt the more severe the issue. Saltwater ice, in temperatures not too far below freezing, is not quite as tenacious as freshwater ice, because the salt prevents the formation of strong crystals. It is actually a mixture of ice and salt water solution, but it can still be quite solid.

Colligative properties of water

With seawater, freezing will begin at about 29F but not be very strong until 20F or so.

Lake sailors aren't going to sail through the winter; the water tends to get hard. Few ocean sailors are going to see the really cold temperatures required for strong ice, even though the docks may remain ice-free. Perhaps the Chesapeake in early season (before the Bay can freeze) offers some of the best conditions for freezing a furler.

Still, I would like to hear from some real arctic warriors. One of my other habits is winter mountaineering (ice climbing); I've learned a lot of cold and wet coping strategies. Just another puzzle to work through, and a whole different game from summer sailing.

[cal40john]

Originally Posted by thinwater

"A pint's a pound, the world around", or just a wee hair more.

or a wee hair less if it's ice (ice floats)

John

[thinwater]

Originally Posted by cal40john

or a wee hair less if it's ice (ice floats)

John

Right you are.

[capngeo]

All I have to say Is I'm damn glad that those hardy souls LIKE to go where its cold, as it leaves more room down here for those of us who don't!

[GordMay]

Originally Posted by hummingway

... Ice weighs about 60 pounds a square cubic foot I think.

Solid Ice has a specific gravity of about 0.92, and weighs about 57.4 pounds per cubic foot.
Sea Water has an SG of about 1.03, and weighs 64.08 Lb/Cu Ft

[capngeo]

Originally Posted by GordMay

Solid Ice has a specific gravity of about 0.92, and weighs about 57.4 pounds per cubic foot.
Sea Water has an SG of about 1.03, and weighs 64.08 Lb/Cu Ft

Salt water ice or fresh water ice?

[mrohr]

[QUOTE=Hiracer;578749]The problem I see with hanked on sails is that you can't do a head sail change until after you turn off the cabin heat and your stack has cooled down, otherwise if there is any wind at all you are almost certainly going to melt a hole in your headsail.

OTOH, when a wall of wind comes in, the time to depower your sails is NOW, not when the stack has cooled. So, points there for furling gear.

Well,doesn't burning a hole in your sail depower your rig? Problem solved!

[DoubleWhisky]

Originally Posted by thinwater

No question, the less salt the more severe the issue. Saltwater ice, in temperatures not too far below freezing, is not quite as tenacious as freshwater ice, because the salt prevents the formation of strong crystals. It is actually a mixture of ice and salt water solution, but it can still be quite solid.

You are absolutely right, thinwater.
The real problem is freshwater, as a freshwater is the material for the ice built-up. And there is abundance of freshwater around when temperature near sea level is between 15 and 32 F: rain, wet snow, mist, fog...
And the built-up can be frighteningly fast. Saw it once and... SABENA (not for the late Belgian Airlines, but for Such A B....y Experience Never Again).
Try imagine, how much of ice built up You can have on the rolled foresail on 60 - footer. 3000 pounds? 4000 pounds? Probably something like this...
And You have not means to get rid of this... Once the ice is settled, You can not even unroll the thing just to remove the ice by flapping the sail. And the wet coming from up is is washing salt down - so You get the ice built-up also down the furler...