For once, agree with our Norwegian brothers on ship design

having been on too many DP vessels with sterns like a huge slab, somebody realizes that holding station with ass to weather requires a stern with is faired like a bow! SIMPLE GENIUS!

[B]Ulstein introduces the X-Stern[/B]

//youtu.be/11W-xM0coHY

AUGUST 26, 2014 — The Ulstein Group is introducing the X-Stern, a design feature that brings the X-Bow effect to the aft ship, along with additional ice operation capabilities, increasing operability through positive effects on station keeping, wave response, comfort and safety in harsh conditions.

Ulstein Group introduced the X-Bow to the market in 2005 as a design feature that increases crew comfort while giving the opportunity to keep up speed in foul weather or the option of reduced fuel consumption. Currently, close to 100 X-Bow vessels are being constructed or have been delivered from shipyards world-wide.

Ulstein says that the X-Stern takes a new step in increasing vessel operability even more.

Several marine operations would benefit from the opportunity to position the ship stern towards the waves, wind and current. Having this choice increases the operational window.

The X-Stern is a sloping and higher stern, allowing for a sharp stern shape in which the transom plate is replaced by a pointed aft.

The X-Stern is a gentle displacer, resulting in lower pitch and reduced wave drift forces, and has ice operation capabilities.

For vessels where the best possible motion characteristics are vital, the Captain’s first choice will be to place the X-Stern towards the weather instead of the bow.

When placing the stern towards the weather, the X-Stern has a major effect on the vessel’s capabilities and flexibility. The aft working sector increases. Stern first, the vessel will be less influenced by weather, and wave drift is reduced.

The work deck aft is enclosed, with no sea on deck or ice build-up and increased safety for crew, cargo and equipment.

“An innovation process is a long process, in which we work strategically in order to come up with safer, smarter and greener solutions,” says Tore Ulstein, deputy CEO and Head of Markets & Innovations in Ulstein. “We discuss operational challenges with our customers, and work on how to transfer these challenges into technical solutions which can be turned into commercial products. The X-Stern is patent-pending in several countries, including the U.S.A .and in the EU.”

Definitely not a new concept. Picture didnt download but ill keep trying.

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X-stern is just a new term for the old canoe stern.

[QUOTE=c.captain;142979]having been on too many DP vessels with sterns like a huge slab, somebody realizes that holding station with stern to requires a stern with is faired like a bow! SIMPLE GENIUS![/QUOTE]

Old concept that has come full circle.

It would be interesting to know how that kind of stern improves the vessel’s ice operation capabilities.

Surprised it took them this long. Double ended sailboats have been around for ages and ride like a dream in heavy seas. The bottom where the z-drives are mounted is still pretty flat. Slappage reduced significantly from the transom, but still possible?


The Vik Sandvik 493 is a better solution, x-stern would add to much length on the vessel.

I love the look of those ships

Who thinks a few of these would be perfect for the long run from Dutch up to the Chukchi sea? And really anywhere else as well since the days of needing to stern up to anything are long gone. Better ride and the wheelhouse windows are further from the breaking waves.

]
The Vik Sandvik 493 is a better solution, x-stern would add to much length on the vessel.[/QUOTE]

I have always wondered why a design like that has not caught on especially after the Centerline and Strongline have proven to be successful in the gulf.

http://hornbeckoffshore.com/fleet/vessels/hos-centerline

Fuck them we did it first…

When HOS build that?
Is it lng fuel cell powered as well?

[QUOTE=powerabout;143053]When HOS build that?
Is it lng fuel cell powered as well?[/QUOTE]

http://www.marinelog.com/DOCS/NEWSMMIX/2010jan00050.html

[QUOTE=Fraqrat;143012]http://hornbeckoffshore.com/fleet/vessels/hos-centerline

Fuck them we did it first…[/QUOTE]

VS 493: 2004
HOS 370: 2009

Nope, too slow.

The company bought and had the idea around that time. It sat tied up a for a few years before the conversion started. That vessel is older that 04 so nope not to slow.

[QUOTE=Fraqrat;143069]The company bought and had the idea around that time. It sat tied up a for a few years before the conversion started. That vessel is older that 04 so nope not to slow.[/QUOTE]

The age of the hull is of no value when comparing the implementation of the design.

Yeah you right but the thought and intent was there first that’s why they were bought. Economics played it’s part in implementation. Either way it’s a very good idea and they DP like a wet dream when properly powered.

There is a lot to said for being able to watch the deck activity while looking forward. Also it’s better to keep the pointy end into the weather and the propellers properly immersed at the leeward end of the boat.

This concept has been around for a very long time. Just look at any of the “eastern rig” (house aft) trawlers. I suspect that the primary reason that mud boats are built with the house forward is that the first designs were based on shrimp boats.

Arthur Blount of Rhode Island built one of the first forward wheel house supply boats, in part because I think he felt that was what the companies would buy based on what the converted stuff they had been using. I saw some scans if some old seacor/sea bulk ad type stuff that showed drawings of an aft wheelhouse supply boat from a ways back.

Personally I’d love to see them become more common, though with the advances in hull and wheelhouse design I see it becoming less likely to catch hold.

Glasscock Drilling had 2 boats I remember with the houses aft. The GAIL STORM and PARI PASSU built in the late '40s or so. The PARI PASSU was working out of Sabine in '70.