[Stephen]

For those of you who haven't seen this new wave-piercer motoryacht yet, you may find this interesting.

http://www.nwbs.com.au/sup_yac.html

http://www.shipspotting.com/mo...59520

Stephen.

[YachtForums]

I received some images on White Rabbit, although this is a tri-maran. I haven't seen the hull under the waterline, but I'm pretty sure this isn't a wave-piercer. We were thinking about doing a review on White Rabbit...

[jonstinton]

Well, according to Boat International June 05 edition, it is called E-Motion, and there is a great rear photo of it in the magazine, but i'm not sure if i'm allowed to scan it in. Could you answer that question Carl?

[AMG]

Hi Jon,

On this website you´ll find all about her; http://www.yachts.nwbs.com.au/

Probably a design we will see more of in the future, eventhough it will have the same problems as catamarans to be widely accepted..?

[Kevin]

White Rabbit is reviewed in the July issue of Yachts and while I haven't read the entire article, it seems to have come out on top in terms of proving that a trimaran is a viable alternative to a conventional hull.

[KCook]

Originally Posted by AMG

Hi Jon,

On this website you´ll find all about her; http://www.yachts.nwbs.com.au/

Probably a design we will see more of in the future, eventhough it will have the same problems as catamarans to be widely accepted..?

Dunno Lars. To me that wave-piercer tri is much more attractive than any cat I have seen.

Kelly Cook

[AMG]

Originally Posted by KCook

Dunno Lars. To me that wave-piercer tri is much more attractive than any cat I have seen.

Kelly Cook

As I have seen trimarans of this kind since I was a kid and they have still not made it, I dunno either...

Btw, it is not a wave-piercer but has four active foils between the hulls.

What will help the development of trimarans might be the rocketing fuel prices. And combined with sails they might be the best option in the future?

[YachtForums]

I read the article in Yachts too, but it really didn't answer many questions. For example...

1. There's no doubt that White Rabbit (and the trimaran concept) is inherently stabile, both at speed and at rest. This configuration is further enhanced with an active foil system. According to the Y.I. article, it's a VT Maritime Dynamics system and there are four foils, each with 50 sq. ft. of surface area. It's pretty safe to assume they're using horizontal foils that span the distance between the center hull section and the sponsons (two on each side, fore & aft). Between this stabilization and the narrow cross section of the center hull and sponsons, I'd have to expect a dramatic decrease in pitch and roll momentum.

2. Before I looked at the article, I kept wondering about its engine room config. Obviously the propulsion systems aren't located in the outriggers! BUT... the center section is SO narrow, it had me wondering. According to the specs, the engines are staggered, front to rear. Clearly, there isn't enough space for the engines to placed side-by-side. Although this is rather unconventional for a yacht, it's actually a GOOD thing, because it further enhances stability. Quite simply, it keeps the engine weight closer to the longitudinal centerline of the hull.

3. The article tends to emphasize the above deck space. Probably with good reason... White Rabbit has a 50 foot beam! But of course, they didn't say much about below deck space. I think it's reasonable to assume, given this hull configuration... the below deck space won't match a comparable a mono-hull.

4. This hull has many benefits, BUT... I have to wonder how maneuverable it is? I understand it has a fixed bow thruster and a deployable stern thruster. I would imagine this was mandatory, because there is very little space between the props to create any leverage against the hull for maneuvering/pivoting AND you've got two rather large outriggers that are effectively acting like long rudders. This would create an opposing force against turning.

5. The article also indicated that wave slap was considerable reduced. I can understand this, due to the sharp bow entry and the narrow cross section of the center hull and outriggers, BUT... in my experience, wave slap can become more pronounced when water CAN'T be displaced and is forced to travel under exposed sections of an inner hull. In studying the pics of White Wabbit ( ) it's clear the tunnels have sufficient vertical height to allow most wave-chop to pass uneventfully. But when the seas get big... I dunno!

Wisdom is welcome!

[KCook]

I think your comments are right on target Carl. I've never run a tri (except a dottering deckboat). But guys with "tunnel hull" performance boats report essentially the same limitations. At least with regard to wave slap. These little tunnel hull speeders are of course, in a different realm from the big wave-piercers. But, they report that all is well as long as they are able to run fast enough to lift the hull high enough for the tunnel roof to clear wave tops. However, when wave height does reach the top of the tunnel, the slap is a killer. They are then forced to slow wwaaayyyyy down and limp on in displacement mode. Also, could "piercing" equal "broaching" in extreme swell?

Kelly

[YachtForums]

Originally Posted by KCook

Also, could "piercing" equal "broaching" in extreme swell?

You've raised a good question. White Rabbit is not a wave-piercer, but the narrow cross section of the forward center hull raises some questions. You could say White Rabbit is a "wave-piercer" buy the definition of the word, not the actual hull design.

Lady Lola (seen in the picture below) is a conventional mono-hull. Here she is seen encountering large swells. White Rabbit will not have the same forward bouyancy of a traditional mono-hull. It will have a tendency to "pierce" the wave, as opposed to going over it.

This is only conjecture, because I haven't been onboard anything like White Rabbit, especially in big seas, but theoretically... this would be my concern.

[Kevin]

That pic was on the ladylolaandshadow.com website... awesome shot really. Although I think it's a little more to do with angles and perspective than that yacht actually submarining.

[brian eiland]

Originally Posted by YachtForums

....Lady Lola (seen in the picture below) is a conventional mono-hull. Here she is seen encountering large swells. White Rabbit will not have the same forward bouyancy of a traditional mono-hull. It will have a tendency to "pierce" the wave, as opposed to going over it.

That is an interesting photo. I can't seem to pick out that large of a swell??

[jonstinton]

Here you go Brian. I thought that picture on the other website was not particularly clear either, so here is my version.... hope this helps.

[jonstinton]

Looking at the two photos together, it seems to look like a pot hole in the water!

But if you follow the direction of the swell it does make a little more sense!

[jonstinton]

And that was my 100th post

[the sad individual then cowers back in the corner, awaiting its next feed]