[CaptEvan]

I came across this interesting review on the merits of axe bow design and the enlarged ship concept. It was performed by Damen, parent company of Amels, and Delft University, with the results shared in a yacht design symposium last November in Amsterdam. Lars, you were likely in attendance.

http://hiswasymposium.com/pdf/2006/J.%20Gelling.pdf

The improved efficiencies and enhanced sea-keeping are quite impressive. I understand Damen has delivered at least 4 axe bow fast patrol and supply vessels, and hint at the yacht market. While they state a prospective yacht owner would need to be enthusiastic about the modern design, it is also an invitation for rebirth of some classic profiles.

Also of note, was their aborted tests on a wave-piercing model.

This brings to mind the "mystery bow" of the gorgeous subject of a prior thread shown below.
http://www.yachtforums.com/forums/ge...-way-work.html



Would love to hear your thoughts.

Evan

[KCook]

Interesting figures from the studies. But the concepts are hardly novel ....

http://www.formedia.co.uk/newsdetail.asp?articleID=96

Kelly

[Codger]

I tried pulling this file a couple of times but it seems to hang up. Anyone else?
http://hiswasymposium.com/pdf/2006/J.%20Gelling.pdf

[AMG]

The file loaded fine for me. Interesting, but nothing new really. Axbows, at least looking like such, has been around for a hundred years and sailing boats have been fitted with similar styled bows for at least a decade now.

They say it is for those who wants a "modern" yacht, but I would like to call it a styling fashion. There are benefits and there are disadvantages and I am thinking of the spray as the worst, positioning of anchors as well and you will get a longer yacht with less usable space.

I think it will fit best for low powered and economical propulsions where low resistance is essential for speed and range. Just as 100 years ago.

I wonder if the new Katana will have an axe bow or a wave piercing perhaps...?

[Codger]

AMG
Thanks for the precis.
If there are advantages couldn't they simply be incorporated for the most part below the waterline leaving the designer to utilise a more traditional bow with it's advantages above the waterline? More of a "best of both worlds" hybrid approach.

[AMG]

Originally Posted by Codger

More of a "best of both worlds" hybrid approach.

I think this is possible and a bulbous bow is doing the job already. I made a design where the bow has two shapes, one for less pitching and one for deflecting spray and reduce the risk of nose-diving. This is a fast boat, on a slower the bow can sit deeper. But eventually you are back to a more traditional bow which after all is more appealing to most people and not bad if the boat is just long enough.

http://www.yachtforums.com/forums/6059-post63.html

[CaptEvan]

The point was not that the axe bow was anything radically new, as I understand the Vikings built them a few years ago.

They are interesting test results for fast patrol and supply boats especially in built seas. The numbers are significant improvements over conventional hulls.

I thought this might be applicable to some expeditions and trawlers, that tend to be out in the nasties.

Codger, if you'd like to try that link by email, I will send it to you.

[AMG]

I don´t know where the borderline between axe and wave-piercer bows goes really, but it will be interesting to see how the Feadship above and the project Sigma will perform when they are launched. Having a luxury yacht where salt water is sprayed all over it may not make the crew (or owner) happy at the end of the day..?

[Codger]

My reference point, is of course Anemone at 80metre so that is the application that has me going Hmmmm. What works at 30 metre or 150 metre doesn't necessarily translate to 80M. Bulbs make me nervous when it comes to ice.
The Phoenicians used a bow some time ago that was a recurve. WAG, perhaps a wave piercer down low with a flare higher up to add buoyancy?

CaptEvan. Thanks. Called the office and they got it for me. VPN in to some hotels can be wierd sometimes.

[AMG]

Perhaps this integrated bulb would work in ice..? Not the perfect icebreaker but there are ice classed boats with bulbs and for ice where you are using a luxury yacht, I guess my solution will survive...
http://www.yachtforums.com/forums/6042-post55.html

[Codger]

Makes a lot of sense. Could be built to be much less susceptible to off axis impact damage than the typical forward extending structure.

[Codger]

Phoenicians. Take a look at this.
http://www.cedarland.org/ships.html

Since nobody is around now that actually saw these vessels I'm wondering if the waterline is as depicted or could have been higher on the one dated 850BC.

This adherence to linear time is frustrating. Should be able to just pop around and take a look first hand. Physicists need a good smack up the side so that they get the impediments out of the way. Oops, management style program needs a reboot.

[MaxResolution]

Clearly these Phoenicians were on to something. Just think, as we keep seeing our jobs going offshore, and resulting defaults in the sub-prime sector, maybe 117 oarsmen per side wouldn't be such a bad idea, as a sort of 'alternative power' for the Feardship above. And speaking of low-tech; any one of us could have taken out the entire Corinthian fleet with a simple modern flare-gun. ...Didn't they know about flaming arrows?

I think this beauty definately needs sharks teeth painted across the bow.

[Codger]

Max
You don't thread drift, you take a tidal wave to them.
The Phoenicians did use fire ships.
234 oarsmen sure wouldn't have a weight problem for long so that may be a solution to another problem that has nothing to do with Axe bows.

There do seem to be many bow shapes and structures that have been played with over the past couple thousand years. Beauty of it is that as materials, maunfacturing processes and requirements change the shapes get revisited and modified. Who knows what is yet to come.

[MaxResolution]

Ooops, sorry, I never was much at team sports, in fact I can't name a single Miami Dolphin. On the other hand, Coach, who could pass up such a graphic opportunity?