small icebreak boat

[Eric Zhu]

hello everyone , im a new member in the forums,
now i have two potential project , one is solar power field(offshore), they need a small ice break boat , width less than 3 meters is better , length no more than 12 meters ,
the other is in a lake , they need a small icebreak boat , small one ,
so how to make a solution for it , if you have good suggestion , pls share your idea ,
or by email :zhuwj@sinostsc.com
whatsApp:+8615165209832
thank you every one

 

[TANSL]

I sent you an email but the recipient's email provider rejected my message. Could I use another email address?

 

[gonzo]

First, what is the thickness of the ice?

 

[Eric Zhu]

I sent you an email but the recipient's email provider rejected my message. Could I use another email address?

zhuwj@sinostsc.com this is no problem
(this email belong to Shandong Taibang Shipbuilding Co.,Ltd)
if cant use , pls send email to ericcx@163.com (pls CC to zhuwj@sinostsc.com)
thank you

 

[Eric Zhu]

First, what is the thickness of the ice?

one place Max. thickness : 30 cm
the other no more than 10 cm
thank you

 

[gonzo]

The main issue is that icebreakers are usually big and heavy to be able to break the ice. They don't just break the ice, but need to have enough power to move it too. There are several methods or designs. In general they can all ram the ice to open a path when it is not too thick. The classical design, when the ice is too thick to break by pushing, gets rammed into the ice and goes over it. The weight of the ship breaks the ice and it move a short distance, then repeats the operation. The size you want is simply too small. As a comparison the recommended thickness of ice, with a significant margin of safety, is about 35 cm for a 40 ton truck.

 

[Squidly-Diddly]

I've been thinking of a new way to cut path through ice and shove the resulting blocks under the shelf.
The idea would be that it should take much less energy and heavy boat to saw two narrow cuts than to pulverize the entire path width's worth of ice.
Also that a truly clear path should stay open much longer than a slurry of crushed ice. I'm guessing a slurry of jagged crushed ice will re-freeze very fast because the jagged ice chunks will have much more exposure to the sub-freezing air.
Finally, it would be hoped that a row of blocks shoved under the ice shelf would create turbulence from whatever water flow exists, and thus bring up warmer water and keep path open longer.
Exact nature of this device is unknown, but will probably be barge that could be assembled from small road or rail transportable parts. Thus it could be used in remote locations where its not possible to bring in a full size ship.

 

[Barry]

For a few years we sold both Scat ( probably out of business now) as well as Hovertechnic hovercrafts. The common small units were the 10 1/2' Hoverjet GT and the 12 1/2' Hoverstar GT powered with about 60- 80 hp and with dry weights of 550 and 625 pounds respectively. Hovertechnics now does not build these recreational units but have larger more powerful models.
A unique feature is that when running on ice, quite often depending on thickness, the ice would break either underneath it or a bit ahead.
A hovercraft produces a shallow concave dimple underneath it with a bit of a wave on the perimeter of the dimple. Air also gets entrained under the ice.

Below is a link that shows the Canadian Coastguard using this attribute to break ice and in the video they mention breaking thickness up to 3 feet (90cm) mind you a lot bigger units than the ones that I noted above

How a hovercraft helps Canada combat spring flooding | Canadian Coast Guard hovercrafts are providing a unique solution to keeping river ice moving, to prevent jams and spring flooding | By The Weather NetworkFacebook https://www.facebook.com/watch/?v=482176242982222


Additional notes:
1) If you are mainly moving personal or lighter payloads, a hovercraft may be more practical and faster
2) There are still other hovercraft builders in the market. In the smaller sizes that I mentioned above, there was a single engine -single fan with a splitter in the duct. Some air went into the center plenum and skirts and the rest of the fan air provided thrust.
Larger hovercraft will normally have one or more engines dedicated to lift and one or more engines dedicated to thrust

I would imagine that an Airboat may also also work and be more cost effective

 

[BlueBell]

Great suggestion Barry!
Although it hugely exceeds the 3m beam limit mentioned in the original post.
Canadian Coast Guard recently sold one of their old hovercraft.
A collector bought it.
Nothing wrong with 50 knot cruising speed.
There is a small plaque at the helm recognizing the top speed of 65 knots,
but warns operation above 50 knots is considered dangerous.
It is a very noisy machine, I've been on it.

 

[Robert Biegler]

I've been thinking of a new way to cut path through ice and shove the resulting blocks under the shelf.

About 45 years ago, I read an article describing a concept for doing exactly that. I have not seen an example of it since.

The vessel approximated a scow with a somewhat hollow, concave V section at the bow, like a Hickman Seasled. The vessel was supposed to be driven up the ice with only the outer edges of the hull making contact and cutting the ice (I imagine fitting big chainsaws there would help, but that was not part of the concept as presented in the article). A large excentric weight would make the vessel roll and alternately hammer down each side, helping to break the ice. Then when the vessel drove further up the ice, the cross section changed from a concave V to a convex V, which was supposed to break the ice into two large pieces and push it under the solid ice. That way, it would leave a clear path behind it, instead of a path filled with icy slush.

I don't know whether even a prototype was ever built, or whether it was all vapourware. And I don't remember what name it was given.

I would imagine that an Airboat may also also work and be more cost effective

I expect if the ice is too thick to break, it would just go over, though that would not help any vessel that may be supposed to follow.

 

[Barry]

About 45 years ago, I read an article describing a concept for doing exactly that. I have not seen an example of it since.
I expect if the ice is too thick to break, it would just go over, though that would not help any vessel that may be supposed to follow.

I had said "I would imagine that an Airboat may also also work and be more cost effective"

I did not mean to suggest that it would be an ice breaker but rather the method to get men and supplies to the projects.

A hovercraft might do both functions, 1) break the ice for a boat to follow behind or 2) skim over the ice carrying men and supplies.

 

[HJS]

Ice Breaker https://www.mobimar.com/commercial-vessels/trimaran-concept/ice-breaker
JS

 

[Squidly-Diddly]

The vessel approximated a scow with a somewhat hollow, concave V section at the bow, like a Hickman Seasled. The vessel was supposed to be driven up the ice with only the outer edges of the hull making contact and cutting the ice (I imagine fitting big chainsaws there would help, but that was not part of the concept as presented in the article). A large excentric weight would make the vessel roll and alternately hammer down each side, helping to break the ice. Then when the vessel drove further up the ice, the cross section changed from a concave V to a convex V, which was supposed to break the ice into two large pieces and push it under the solid ice. That way, it would leave a clear path behind it, instead of a path filled with icy slush.

I don't know whether even a prototype was ever built, or whether it was all vapourware. And I don't remember what name it was given.


I expect if the ice is too thick to break, it would just go over, though that would not help any vessel that may be supposed to follow.

Very interesting, but sounds like a lot would need to go Just Right for it to work. I'm thinking of something with quite a few Moving Parts and yes probably chain saws or big circular saws, and then shallow cut saw on a guide flying back and forth, from gunnel to gunnel, to score the sheets enough for something else to crack them into large block-rafts, then something else to shove them under the shelf.
Idea is to remove ice using minimal energy, but also a system that could handle any thickness of ice.

One issue with keeping a path open is that Ice Sheets will drift to close any path, and sheets tend to want to expand.

 

[Eric Zhu]

thank you for everyone suggestions, so far , not have one have an effective solution, Please continue to give us advice

 

[Rumars]

What exactly do you expect us to say? You already have the lenght and beam limitations, and whatever other parameters your clients have given. Icebreaker underwater hull shapes are known as is the force needed to break ice. So you design the heaviest boat you can given the parameters and check if the force per area is sufficient to break the intended ice thickness. If it's not you add some additional equipment to the boat to achieve this goal. That could be a mechanical device like the sliding hammer a pile driver uses, or something more exotic like a drone laying out explosive cord in front of the boat.
All you have to do is break out the books and know the intended average operating conditions.