Swath ???

[Matt.D]

Awesome!!! I want one! That will stop some of the Riv owners thinking they own the broadwater!!!

[Squidly-Diddly]

this thing has been sitting in a lot off hwy 101 in Redwood City, CA forever.

one of those "more questions than answers" jobs.

Originally Posted by MatthewDS

Just wanted to contribute three pics of an icebreaking SWATH nearing completion.

Thanks Matthew,

but that is neither a SWATH nor a Icebreaker.

By the builders definition, it is a catamaran with some SWATH features when ballasted. Hence a "hybrid" craft.
It may be icegoing to some extend, but not icebreaking. By the very nature, a Icebreaker needs to deploy his weight above the ice surface to break it. A SWATH has its weight BELOW the surface.

Regards
Richard

[BMcF]

Originally Posted by HReeve

As I said, the multi-strut variants are called SLICE's.

That is quite incorrect. the SLICE variant of SWATH design has the submerged hulls broken in to two sections, fore/aft. So they have two starboard hulls and two port hulls. Of course that is also why they have multiple struts...but there have been conventional SWATH with multiple struts too,

[Ad Hoc]

Originally Posted by apex1

By the very nature, a Icebreaker needs to deploy his weight above the ice surface to break it. A SWATH has its weight BELOW the surface.

Exactly.

Icebreakers ride up and over the ice, and use their weight to crush the ice. A SWATH (true SWATH) can't do this, as the buoyancy (hulls) is below the lwl not above!

[MatthewDS]

Regarding the icebreaking capabilities and SWATH nature of the ship I posted, this is what the builder has to say: (http://www.akship.net/pages/news.html)

"The vessel will have three distinct modes of operation: a catamaran mode for high speeds; a small-water-area-twin-hull (SWATH) mode for stability in high sea states; and a shallow-draft landing-craft mode that provides substantial buoyancy for maneuvering in shallow water. In addition, the Susitna will be the world´s first ice-breaking twin-hulled vessel."

Richard points out correctly that it is not purely a SWATH, however, it operates as a SWATH in one of it's three modes, and I felt that was enough to make it relevant to this thread.

Additionally, while I agree that typically an icebreaker operates by riding up on the ice and breaking it from above, the reality is that the hulls on the Susitna are designed to break ice from below. If this means that it isn't really an icebreaker that's fine, but it is designed to break ice, and is not simply reinforced to withstand ice.

Originally Posted by MatthewDS

Regarding the icebreaking capabilities and SWATH nature of the ship I posted, this is what the builder has to say: (http://www.akship.net/pages/news.html)

"The vessel will have three distinct modes of operation: a catamaran mode for high speeds; a small-water-area-twin-hull (SWATH) mode for stability in high sea states; and a shallow-draft landing-craft mode that provides substantial buoyancy for maneuvering in shallow water. In addition, the Susitna will be the world´s first ice-breaking twin-hulled vessel."

Richard points out correctly that it is not purely a SWATH, however, it operates as a SWATH in one of it's three modes, and I felt that was enough to make it relevant to this thread.

Additionally, while I agree that typically an icebreaker operates by riding up on the ice and breaking it from above, the reality is that the hulls on the Susitna are designed to break ice from below. If this means that it isn't really an icebreaker that's fine, but it is designed to break ice, and is not simply reinforced to withstand ice.

Regardless of the manufacturers claims, that is NOT a icebreaker, and it will not break ice! Ice cream maybe........but lemon only.
By the very nature of the hulls, that is just not possible, no matter how strong they are made. And that was said by one who operated icebreakers for many years, me.
This hull shape gets immediately stuck in real ice conditions, and it will not break free again, the shape is too sharp.
Retards have designed that craft, it is the worst of all worlds, a real goat.

Regards
Richard

[MatthewDS]

Richard, I see your point. Regardless of whether or not it was designed as an icebreaker, you contend that the hull form will not work as intended. Fair enough, time will tell.

I have attached a picture of the waterbody that the ferry is designed for, which has ice pans, but no solid ice. I should also note, that I am not associated with the designer or the builder, in case anybody thought that.

[HReeve]

Originally Posted by BMcF

That is quite incorrect. the SLICE variant of SWATH design has the submerged hulls broken in to two sections, fore/aft. So they have two starboard hulls and two port hulls. Of course that is also why they have multiple struts...but there have been conventional SWATH with multiple struts too,

I stand corrected.

[sdowney717]

E-craft also has considerable arctic abilities, able to sail through 2 feet of ice.

2 feet of loose pack ice pans or 2 feet of solid ice??
Maybe that center hull can lower down and crush the ice under it, but unlikely.
must just be loose ice.