Ice Band ?

Discussion in 'Boat Design' started by Polarity, Jun 14, 2002.

  1. Polarity
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    Polarity Senior Member

    As part of the construction of my steel sailing yacht I am considering the addition of an "ice band" (for why see my site ) I have heard that it should be welded insite the hull with one third above the dwl and two thirds below. Does anyone have any more/different information on this?

    Help greatly appreciated

    Cheers

    Paul
     
  2. james_r
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    james_r Junior Member

    Hi Paul:

    From your post I understand that you're thinking of welding additional plating inside the hull. To me it makes more sense to just increase the plating thickness at the DWL. Don't forget the bow area - sooner or later during your trip through the Nortwest Passage you'll have to punch through some ice. You may also consider beefing up the skeg, rudder stock and protecting the prop in some way.

    If Ted Brewer can't help you try contacting one of the classification societies (ABS, Lloyd's or Norske Veritas). One of them may have developed scantling rules for yachts operating in ice.

    By the way, great site. It almost makes me want to attempt the same thing but we're finally starting to get some warm weather in my neck of the woods so I'll just stay where I am for now.
     
  3. Polarity
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    Polarity Senior Member

    Thanks James

    I am not sure what construction issues there would be having a seperate thickness of plate to weld in at the waterline, but it's certainly an idea. I am looking at the weight implications of the other reinforcements now.

    Anyone out there done this to a yacht??

    Paul
     
  4. Steve Gray
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    Steve Gray Junior Member

    Hi, again, Paul.

    Did you ever resolve this matter? As far as I can see, and having read stuff by people who've been silly enough to play in the ice before, there are two kinds of strengthening that tend to be used. The first is transverse stiffening to help protect the boat if it gets nipped by ice, which is partially to do with thickness of the 'armour', but more to do with actual bracing, and I suspect that this is already an integral part of your boat's design. The second is direct protection against impact and abrasion, which is what the ice band is all about, I guess.

    Putting a steel band on the inside of the WL (and down the inside of the stem?) may help the overall stiffening and add more armour but won't protect the bits of the boat that are under direct attack. Can I suggest a technique that I've read of that was used in the past? Along the areas of the hull that are likely to be in direct contact with the ice (i.e. WL and the stem), mount sacrificial armour that can take impact and be replaced reasonably easily. This could be steel plates or wooden beams ('shingles'?) that can be abused, removed, patched, replaced or discarded more ready than the hull itself. Accounts of brash and growler ice chewing into even steel hulls would encourage me find a solution to this problem. The sections of this external band could perhaps be set into flanges that are attached to the hull, although they'll need to be faired to deny the ice anything to get a grip onto. Weight distribution is obviously the biggest concern.

    Another thing that I've been made to consider in this context is that the outboard parts of the steering and drive gear should be easily removable in the event of threatened nipping (and take plugs in case you need to pull the drive shaft!) ;o).

    However, I notice that this was hot news back in June, so you're probably sorted by now!
     
  5. Polarity
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    Polarity Senior Member

    Hi Steve
    There was a lot of discussion on this over at the metal Boat society forum.
    This link should take you to the thread...

    Interesting idea about the sacrificial armour though.

    Construction we due to start this year but due to various reasons (lots of them of the green and folding variety!) will probably not be until next. The removal issue is an interesting one as I am currently looking at a skeg hung rudder,so not sure how I would get around it...

    Cheers!

    PAul
     
  6. gonzo
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    gonzo Senior Member

    Have you considered a sacrificial plating of a polymer? Some plastics have more abrasion resistance than steel. Airboats have been using this materials for more than fifteen years with great success.
     
  7. Polarity
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    Polarity Senior Member

    I hadn't - what kind of material did you have in mind?
     
  8. Mike D
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    Mike D Senior Member

    Polarity

    Maybe you don’t need an ice belt :D

    From a weekend newspaper but originally in the L.A. Times


    RESOLUTE BAY, NUNAVUT - For 500 years, explorers nudged their ships through these Arctic; waters, fruitlessly seeking a shortcut to the riches of the East. The Northwest Passage, a deadly maze of sea ice, narrow straits and misshapen islands, still holds the traces of those who failed.

    There are feeble cairns, skeletons lying face down where explorers fell, makeshift camps piled high with cannibalised bones and, on one rocky, a trio of wind-scoured tombstones. Whole expeditions, hundreds of men and entire ships, are missing to this day The first explorer to survive a crossing, in 1906 spent several winters trapped by ice.

    Despite that -, or maybe because of it – Canadian Mountie Ken Burton wanted nothing more than to join the pantheon of polar explorers who had threaded their ships through the passage's narrow ice leads and around its shimmering blue-green icebergs.

    In the summer of 2000, Burton gingerly nosed a 20 metre aluminum patrol boat into the heart of the Northwest Passage, Ice floes could crumple the boat like paper. Even the smallest iceberg, a growler, could rip apart its delicate hull.

    But there were no bergs. No growlers. No thin cakes of pancake ice To his surprise, Burton found no ice at all. A mere 1,450 kilometres south of the North Pole, where previous explorers had faced sheets of punishing pack ice, desperation and finally death. Burton cruised past emerald=d lagoons and long sandy beaches. Crew members stripped and went swimming. Burton whipped through the passage, “not hurrying”, in a mere 21 days.

    “We should not, by any measure, have been able to drive an aluminum boat through the Arctic,” said Burton, still astonished and just slightly disappointed. “It was surreal.”

    It was also a glimpse of the future. For several summers now, vast stretches of the Northwest Passage have been free of ice, open to uneventful crossings by the flimsiest of boats. Climate experts now blandly predict what once was unimaginable. In 50 years or less, the passage will be free of ice throughout the summer, a prospect that could transform the region and attract a flotilla of cruise ships, oil supertankers and even US warships.

    “It’s something that no one would have dreamed up for our lifetime,” said Lawson Brigham, deputy director of U.S. Arctic Research Commission and former captain of the U.S. coastal icebreaker Polar Sea, which made it through the passage in 1994.

    The parting of the ice is the product of natural, long-term atmospheric patterns that have warmed the Arctic in recent decades and, to a lesser extent, the gradual heating of the planet by green house gases.

    The planet’s temperature has risen by just over half a degree over the last century. In the Arctic, temperatures have risen 1.5 to 2.2 degrees. In these northern seas, at the boundary between water and ice, that small difference has changed the landscape for thousands of kilometres.

    "The image Of the Arctic was always one of an ice-locked, forbidden spot," said James Delgado, director of the Vancouver Maritime Museum and author of Across the Top of the World: The Quest for the Northwest Passage. "If we as a species have wrought this change, it's humbling; given its history as such a terror-filled place."

    The receding ice is throwing open a gateway to Far North, a region long defined by its isolation, sparse population and stark, simple beauty. Ship traffic could carry with it a rush of civilization and commerce.

    "It's not just about transport; it's about the whole development of the Arctic frontier," said Lynn Rosentrater, a climate-change officer with the World Wildlife Fund in Norway. "It's going to happen, so we need to plan for it."

    The once-deadly route has been rechristened "Panama Canal North" by shippers eager to shave nearly 8,000 kilometres off the trip from Europe to Asia/ Already, a. parade of strange shlps and faces is streaming through the passage. Canadian transit officials who monitor the route dub the newcomers "UFOs," for "unaccustomed floating objects." These have included, in the last few years, a Russian tug that dragged a five-storey floating dry dock through the passage, adventurers skimming through in sleek sailboats and a boatload of Chinese sailors that arrived unannounced in the Arctic village of Tuktoyaktuk, disembarked to take photographs and left when a Mountie arrived.

    This summer, the Canadian navy sent warships north of the Arctic Circle for the first time since the end of the Cold War. And U.S. naval officers are circulating a report called Naval Operations in an Ice-Free Arctic that discusses, among other things, the need for a new class of ice-strengthened warship to patrol newly opening Arctic waters.

    With each summer warmer than the last. and with species such as dragonflies and moose showing up for the first time, many here are bracing for a stranger warmer world. Unlikely as it seems in a town where residents still skin and dry seals in their front yards, some of those taking a long-range view hail this remote outpost as the next Singapore.

    “If it's handled correctly, you sit on an international Strait. take a proactive stand and profit nicely," said Rob Huebert. the associate director ~f the Centre for Military and Strategic Studies at the University Qf Calgary.

    The passage wasn't traversed until 1906, when legendary polar explorer Roald Amundsen completed the trip in three years. The feat was not accomplished again until Canadian Mountie Henry Larsen took a schooner with a hull made of 60 centimetre-thick Douglas fir through the passage and then back again in the 1940s.

    Although common sense mandated that the passage could never be practically used, the siren call of the shortcut has never been silenced. The first contemporary test of the passage for commerce was prompted by the modern-day equivalent of spice: crude oil. In 1969, Humble Oil & Refining Co. sent through a mammoth 114,000-ton supertanker. Double-hulled and ice-strengthened, the Manhattan became the world's biggest icebreaker.
    The 43,000-horsepower monster easily cruised through 4.5-metre-thick piles of ice and would reverse, gather steam and try to plow through 12 metre ridges of ice. But it ground to a halt several times and broke free only with the help of a Canadian icebreaker. The ship eventually reached Prudhoe Bay with several holes in its hull.

    "When all was said and done, economically, it didn't make sense," Huebert said.

    That was before the ice started its retreat.

    The Canadian Ice Service reports that Arctic ice has disappeared at a rate of about 3 per cent each decade since the 1970s. It is getting thinner as well Ice sheets that used to be 3 metres thick are now less than 2 metres from top to bottom. Last month, scientists at the National Snow and Ice Data Centre in Boulder, Colo., announced that Arctic sea ice had reached a record low since satellite measurements started 24 years ago.

    "In some years now, you can do the Northwest Passage almost in a rowboat," said the Canadian Ice Service's Lionel Hache.

    The passage remains notoriously unpredictable from year to year, and even from week to week. Last August, it was clogged with some of the thickest ice seen this decade, said J.P. Lehnert the officer in charge of the Canadian Coast Guard station in Iqaluit.

    To those who have been watching the passage, ir seems only a matter of time before all manner of ships, from supertankers to sailboats, start transiting these once formidable waters.

    There are no traffic jams yet. But shipping companies in Europe and Asia are quietly sniffing out opportunlties.

    '"The incentive is there," Huebert said. "You cut a huge amount of travel time and in international time is time is money."

    The largest. supertankers, which don't fit through the Panama Canal and must go around South Amenca, would save even more time.

    The discovery of mineral resources in the far north, like the diamond strikes of the Northwest Territories, could spur efforts to export such riches by ship. Canada's vast stores of fresh water may one day be valuable enough to export

    The most northerly human settlement on the passage and in all of Canada, is Grise Fiord about 1,500 kilometres from the North Pole. The Inuit call
    the town Aujuittuq, for "place that never thaws. Out." Even the Inuit have standards when it comes, to suffering. These bleak shores were not settled voluntarily.

    During the Co1d War, the Canadian government decided to relocate a handful of Inuit families from the relative warmth and good hunting grounds of Northern Quebec to the country’s northern reaches: the bleak rocky shores of Ellesmere and Resolute Bay on Cornwallis Islands where there is little to hunt and even less to gather.

    So many US military personnel had flooded into the Arctic to monitor Russian threats by air and sea from stations at Eureka and Alert that the Canadians feared losing control of their northern flank. The Inuit were human flagpoles, dispatched north to establish Canadian sovereignty.

    Since then, Canada has considered the frozen archipelago of ocean, ice and islands to be their land and the Northwest Passage to be their internal waterway. With an open passage, all that has the potential to change. “Our sovereignty.” said passage expert Huebert, “Is on thinning ice.”

    Since an open passage would link two oceans, US State Department Officials argue that it should be treated as international waters, open to all. “It’s one of those issues on which we’ve agreed to disagree,” said an official at the US embassy in Ottawa.

    With the waters open to new traffic, Canadians are taking a renewed interest in their Arctic backyard.

    “I never imagined I’d be this far north, but these are our waters and we should know what’s going on in them,” said Lt, Cmdr. Chris Ross as his warship, the Goose Bay, stood anchored in Frobisher Bay outside Iqualuit, the first warship to pass this far north in 14 years.

    A prominent concern is illegal fishing. As ice recedes, rogue vessels have been moving into the area, lured by the rich Arctic seas, which are almost wholly unregulated.

    “They’re just scooping the shrimp up. They’re scooping the turbot up,” said Lt. Cmdr. Scott Healey, a Canadian navy officer who spent 10 years aboard coastal patrol vessels out of Halifax and watched the once-rich North Atlantic fishery collapse.

    International waters elsewhere have been plagued with modern piracy and frontier lawlessness. “You become a magnet for smuggling humans, diamonds, guns, drugs,” said Huebert. “We’re blind if we think that just because we’re Canadian it’s not going to happen.”

    How best to patrol the passage remains a question. It all depends on how quickly the ice melts and how brave interlopers are. “I don’t want to scream, “The sky is falling and we have to build a nuclear powered icebreaker in the next 18 months,” McLeod said, “But we don’t want to get behind the eight ball.”

    U.S. navy officials are worried about falling behind as well. Their new report on the challenges of an ice-free Arctic cites the potential need for a new class of Navy ships – icebreakers and a new focus on a harsh part of the globe the military has been able ignore since the Soviet Union broke up.

    If the ships come, so will the infrastructure: hotels, bars and even stoplights.

    The vision is almost unimaginable to the Inuit who are still reeling from the first wave of change: the trickle of explorers, whalers and soldiers who penetrated the realm and altered it forever.

    "We didn't know what a cold was or what measles were until the whalers came. And we had no problems with alcohol; until 1940,” said Dinos Tikivik, a 39 year old corrections officer who serves with the Canadian Rangers, an Inuit and Indian force that patrols Canada’s remote regions.









    Another article.


    Environment threat

    LOS ANGELES TIMES

    RESOLUTE BAY Experts on the Arctic’s environment worry that shipping could hurt, but also say there will be no way to keep the traffic out. Dave Cline, a consultant in Alaska, and expert on northern shipping, fears ships could disrupt polar bears and bow-head whales and could jeopardize huge rafts of eider ducks that congregate by the thousands in open water areas within ice sheets.

    He's also concerned about smuggling of polar-bear hides and walrus tusks and about the trash that would be left by tourists. The biggest concern is an oil spill in places more pristine and harder to reach than Alaska's Prince William Sound, an area-only now recovering from the 41 million litres of oil spilled by the Exxon Valdez in 1989.

    The person whose phone will ring in the middle of the night if there is such a spill is Earl Badalco, Nunavut's director of environmental protection services. He's worried enough about it that he keeps track of what be calls “the incidents" - recent traverses of the passage by ships.

    "Five vessels went through in 2000; only two requested permission," he said, scrolling through a list on the computer in his office in Iqaluit.

    Although Canada has stringent shipping rules for its northern waters, compliance is voluntary.

    In 1996, the tourist vessel Hanseatic ran aground on a sandbar in the passage. The weather was good, those aboard were evacuated safely and very little fuel leaked into the passage. Many fear the next grounding may not end so happily.





    No comment other than please don't leave your garbage in my back yard :)

    Michael
     

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  9. yipster
    Joined: Oct 2002
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    yipster designer

    north east passage

    Henk de Velde is another ice loving sailor but doing the never done before north east siberia passage and has finally, as i understood, russian permission to do so. meanwhile he's hanging out in haway has a site and a forum where you can reach him about ice bands and more i asume. http://www.henkdevelde.nl/go/

    :) yipster
     

  10. gonzo
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    gonzo Senior Member

    The polymer they use on snowmobiles is a polypropilene. If you are going to weld extra plates, they would be better on the outside. This way they can get easily repaired or repaired, particularly if you tack weld the panels. Also exterior plates bridge over the framinging instead of getting welded in between so the job is much easier.
     
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