New Super Yacht - inverted bow section?

[billy backstay]

floats like this ....

Ship is very light now, no masts, spars or rigging, Probably minimal interior yet?

I would imagine the boot stripe is going to have to be moved by a meter or two, when she floats with her finished livery, and multiple heavy toys, installed and deployed.

 

[Tanton Y_M]

Seems to make sense. Maximum waterline. Bow projection above to keep dry. A good looking approach.

Or on my #153, to extend the bow for anchorage purposes.

 

[Rawhide]

Why would you bother putting sails on it?

 

[SloopJonB]

And the most distorted.

Possibly the single most distorted IOR boat ever. Even the cabintop has a kink in it. The only fair line I can see on that pig is the outline of the big portlight.

Your views on Jones designs are well known on these forums. I appreciate what he was trying to do to circumvent the rule. Jim Young constructed a similar bow on his OT Heatwave back in 1977

I sometimes think I should have bought the Oyster SJ30 on Saltspring just to see your reaction when I sailed by.

I would have been very polite and congratulatory in person then I'd have come on here and trashed it.

Actually I can't find a pic of that boat - I know he drew some good looking boats.

 

[DA-WOODY]

Following her unveiling last week, Dutch shipyard Oceanco has launched its largest yacht near Rotterdam today as the 106-metre sailing yacht Project Y712 is lowered into the water for the first time today. The mysterious bow cover was removed revealing a radical wave-slicing stem.

Becoming more common every day

 

[12 metre]

And the most distorted.

Possibly the single most distorted IOR boat ever. Even the cabintop has a kink in it. The only fair line I can see on that pig is the outline of the big portlight.

Your views on Jones designs are well known on these forums. I appreciate what he was trying to do to circumvent the rule. Jim Young constructed a similar bow on his OT Heatwave back in 1977

I sometimes think I should have bought the Oyster SJ30 on Saltspring just to see your reaction when I sailed by.

I would have been very polite and congratulatory in person then I'd have come on here and trashed it.

Zing!

 

[Two Tone]

The story of the bow is unusual, but not to be told I am afraid.

She will float on her lines when completed, no problem...

For all the doubters out there - just think of what 100m of waterline gives for a hull speed... With 3 Dyna rigs fully wicked up...

 

[SloopJonB]

About 25 knots - I doubt she'll plane or surf.

 

[Gissie]

Following her unveiling last week, Dutch shipyard Oceanco has launched its largest yacht near Rotterdam today as the 106-metre sailing yacht Project Y712 is lowered into the water for the first time today. The mysterious bow cover was removed revealing a radical wave-slicing stem.

Becoming more common every day

Bugger, hot coffee hurts when it comes out the nose.

 

[ModernViking]

Elvstrøm Coronet 38

 

[DA-WOODY]

Elvstrøm Coronet 38

In DAGO that would be an ICE Kelp Breaker B)

 

[Autonomous]

Elvstrøm Coronet 38

Is that a... boner?

 

[Lark]

Elvstrøm Coronet 38

Is that a... boner?

And love handles.

 

[ModernViking]

More "potent" on this picture.
They are still around here, and quite popular, but Elvstrøm /Kjaerulff never tried the idea with a bulb again. I get that .. h34r:

 

[DA-WOODY]

That was Brilliant but too far ahead of its time

As the 300 HP Verado would not be invented till many years later

 

[SloopJonB]

I remember when Elvstrom was doing that. They didn't take it further because it didn't work.

Apparently bulbs only work in a narrow speed range - in effect they have to be "tuned" to a desired speed. Not so good for sailing vessels.

 

[billy backstay]

I remember when Elvstrom was doing that. They didn't take it further because it didn't work.

Apparently bulbs only work in a narrow speed range - in effect they have to be "tuned" to a desired speed. Not so good for sailing vessels.

My understanding is that the principle is about creating a slipprier bow wave, but that only works in flatter water, and at optimum speed, as you state. Wouldn't any serious sea state negate the bow wave effect?

 

[12 metre]

The theory is a bulbed bow creates a secondary wave system such that at a certain speed, the trough of this wave system coincides with crest of the vessels wave system (and vice versa), effectively cancelling each other out. Primarily effective at cancelling or reducing the bow wave.

On a commercial vessel, you can see that the crest of the bulb wave occurs well in font of the bow, and where you would expect the trough to be is where you would expect the crest of the bow wave to be.

As SJB, says, they are "tuned" to a certain S/L ratio, but can be effective outside that exact S/L ratio, but less so the further you deviate from that

IIRC, the 6 mR Prince Alfred allegedly had good pace offwind, but suffered upwind., which makes sense. I imagine the bulb would generate significant added resistance upwind especially in any sort of seaway, and it looks like the bulb would add a fair amount of wetted surface which would be detrimental in the light stuff.

So, they kind of work offwind in a breeze, but in the bigger picture, overall performance suffers.

Of course, there has been a lot of development in bulb bow design since the time of Prince Alfred, and it's possible a newer design may work on a heavier vessel where wavemaking drag is significant.

 

[longy]

Vertical motion was the biggest problem putting bulbs on small hulls. You can see Elvstrom tried to taper the bulb vertically, but that did not do enuff. Too much taper, you don't form the wave. Bulb location is designed for a certain depth range, than for speed range.

 

[DA-WOODY]

Bad boat to be the FLOSS guy in a SoCal race