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Featherlight, design and engineering


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I had to look at the site and found it quite interesting. FEATHERLIGHT - Royal Huisman - The spirit of individuality

 

-----FEATHERLIGHT TM is a design and engineering  methodology aimed at providing a lightweight  aluminium construction from the outset. Its result isn’t  a conventional superyacht relying on compromises to  achieve a degree of weight reduction, but a purpose- driven effort to make the yacht truly as light as possible,  and recapture any vantage that composite hulls might  have, whilst benefiting from using aluminium.----------

If it is a good way to keep big boats light as possible, would it would on smaller boats? and how small would it be efficient?

While looking at their other projects page I came across this. TAKING A DIFFERENT TACK - Royal Huisman - The spirit of individuality

Seems this is a real forward looking company and not just about getting wet.

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Please. Aluminum boats are well proven but this is nothing really new or revolutionary.

It doesn't matter once you've built the hull and the interior designer insists marble countertops everywhere and your weight savings go to shit.

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24 minutes ago, Zonker said:

Please. Aluminum boats are well proven.

This^^.  I love surveying aluminium (and aluminum for that matter).  Defects are predictable and easy to find when present.  Certainly cannot say the same of FRP or Composite boats.

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For an aluminum hull the design & composition of the appendages would seem to be key; to prevent electrolysis the keel would seem to need to be 100% composite with a lead bulb and the rudder composite as well 

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2 hours ago, Parma said:

For an aluminum hull the design & composition of the appendages would seem to be key; to prevent electrolysis the keel would seem to need to be 100% composite with a lead bulb and the rudder composite as well 

Yeah right, make that Super light out of carbon fiber, and sell the boat within a year or two.

 

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2 hours ago, Parma said:

For an aluminum hull the design & composition of the appendages would seem to be key; to prevent electrolysis the keel would seem to need to be 100% composite with a lead bulb and the rudder composite as well 

That's a load of rubbish.

The boat in my avatar was launched in 88. Is Aluminium and since 1995 had a lifting steel fin with 3 tonne of T on the bottom.

Prep the aluminium properly and have enough anodes around and the boat was good as new.

Only corrosion was from when a battery was dropped in the bilge, and a coin but due to regular maintenance (and drying the bilge after rain) they were both found without issue. 

 

Use the right aluminium and treat it properly and you will have a good strong boat for a long time. 

 

 

 

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2 hours ago, Schnappi said:

They should make a giga press that stamps out aluminium super yachts that are affordable to the masses.

Back in the 80's or there abouts they tried something like that using explosives in a water filled mould to push the aluminum into shape.

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Pretty lame.


They need to contact the kiwi design team from the '87 Americas Cup.  Story as I understand it, was they were told they couldn't build their composite boats lighter than an approved aluminium equivalent.  So they submitted plans for an aluminium 12m which was rule compliant, but in practice would only be possible to build by milling out of a single block. 

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6 hours ago, SCARECROW said:

Pretty lame.


They need to contact the kiwi design team from the '87 Americas Cup.  Story as I understand it, was they were told they couldn't build their composite boats lighter than an approved aluminium equivalent.  So they submitted plans for an aluminium 12m which was rule compliant, but in practice would only be possible to build by milling out of a single block. 

The story I heard was that typically aluminium boats contained pounds of filler, mainly because of welding distortion, so Russ Bowler put forward the proposition that if one took sufficient care it ought to be possible to build a boat fair without the filler.
Obviously such a boat would be unreasonably expensive, but that wasn't mentioned in the rule.

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Two things fuck up the weight savings of alimimum in superyachts.

1. Bog. Too much fucking pink stuff. Composites need almost none when built properly.

2. Structural fire protection

Note that #2 is also a probkem for composites.

Steel only needs it to meet time class (A60, B30 etc). But Al and FRP need it even to achieve A0 or BO. The weight savings are significantly affected if you use standard materials (which of course if budget is there, you can use otjer stuff)

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9 hours ago, Rambler said:
11 hours ago, Schnappi said:

They should make a giga press that stamps out aluminium super yachts that are affordable to the masses.

Back in the 80's or there abouts they tried something like that using explosives in a water filled mould to push the aluminum into shape.

 

The issue was the same one as the origami boats: the hull is the biggest component of a boat but it isn't the biggest cost driver of a boat.

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5 minutes ago, IStream said:

 

The issue was the same one as the origami boats: the hull is the biggest component of a boat but it isn't the biggest cost driver of a boat.

That even applies to dinghies. Look at ehat a brand new carbom 505 hull costs vs fully fitted grp 505

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Large format 3D printers squirting out composite materials have the potential to completely re-make the economics of boatbuilding with highly integrated hull/structure/cabinetry designs but it's going to take a decade or two to get there. 

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16 hours ago, Swanno said:

That's a load of rubbish.

The boat in my avatar was launched in 88. Is Aluminium and since 1995 had a lifting steel fin with 3 tonne of T on the bottom.

Prep the aluminium properly and have enough anodes around and the boat was good as new.

Only corrosion was from when a battery was dropped in the bilge, and a coin but due to regular maintenance (and drying the bilge after rain) they were both found without issue. 

 

Use the right aluminium and treat it properly and you will have a good strong boat for a long time. 

 

 

 

I'm not doubting you and you are obviously comfortable with what you've got but that steel fin sounds scary to me

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11 hours ago, Parma said:

I'm not doubting you and you are obviously comfortable with what you've got but that steel fin sounds scary to me

Curious as to why a steel fin is scary?

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8 hours ago, Swanno said:

Curious as to why a steel fin is scary?

It just seems to me that the opportunities for electrolysis are much higher for a cast iron or steel fin in conjunction with an aluminum hull than for a glass/laminate hull.

I have cast iron in conjunction with a glass laminate hull and the fin does show rust at some spots. Granted that's after 15 years, but hauled every 2 years. I suspect that if the hull was aluminum I'd be seeing more "opportunities" for electrolysis around the sail drive, through hulls, rudder & mast step let alone the deck hardware.

 

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6 hours ago, Parma said:

It just seems to me that the opportunities for electrolysis are much higher for a cast iron or steel fin in conjunction with an aluminum hull than for a glass/laminate hull.

I have cast iron in conjunction with a glass laminate hull and the fin does show rust at some spots. Granted that's after 15 years, but hauled every 2 years. I suspect that if the hull was aluminum I'd be seeing more "opportunities" for electrolysis around the sail drive, through hulls, rudder & mast step let alone the deck hardware.

 

Electrolysis is the compositional change of water when passing An electrical current through water.  Useful in such things such as hair removal.

Electro chemical corrosion is the compositional change of metals immersed in an electrolyte when an electrical current is passed through the electrolyte.  I.e. zinc vs steel alloy in sea water.

I am somewhat over simplifying and maybe being overly nerdy, but these are two very different chemical actions/reactions that are often confused and mis interpreted in the boating industry.

Carry on.

 

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On the aluminium hulls I've worked on there is usually a meter tied into the bonded zinc system. Biggest issues I saw was corrosion under the faring.

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And a good time time to bring up the story of Sea Call.

 

"...Despite the triumph of the schooner Atlantic’s record setting passage across the Atlantic, it would be over 10 years before her designer would receive a commission to design a yacht to rival her. But when he did, William Gardner created one of yachting’s greatest schooners and one of yachting’s greatest lost opportunities.

Having tank tested Sea Call against the smaller Atlantic and the stretched version of her, Gardner was satisfied that he had created a faster vessel. In her construction he specified a combination of vanadium steel and monel metal. This experimentation resulted in violent electrolysis and within three weeks of her first trial the decision was taken to scrap her..."

 

Sea-Call-Profile-schooner-blueprint-e1435842395521.thumb.jpg.c216e6975137de5d62b97228054af8b4.jpg

Pix courtesy of G. L. Watson

 

Here is the contemporary story from the NYT:

1619259120_SeaCallNYT.thumb.PNG.36c8ebcf87fedd6c7227140095f5b8c5.PNG

However, G. L. Watson will build you a replica today out of more compatible alloys.

https://www.glwatson.com/projects/to-build/sea-call/

Checkbooks out anyone?

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Ooops

On 9/16/2021 at 3:37 PM, Parma said:

For an aluminum hull the design & composition of the appendages would seem to be key; to prevent electrolysis the keel would seem to need to be 100% composite with a lead bulb and the rudder composite as well 

No, you build the rudder of aluminum plate with a s.s. or aluminum rudder stock.

The keel can be aluminum with poured lead inside. Or bolt on lead external keel.

These are all well proven solutions.

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On 9/18/2021 at 4:58 PM, Zonker said:

Ooops

No, you build the rudder of aluminum plate with a s.s. or aluminum rudder stock.

The keel can be aluminum with poured lead inside. Or bolt on lead external keel.

These are all well proven solutions.

In fact, isn't contact between carbon fiber and aluminum in spars a big problem? If so, it would seem to be even moreso if the two were immersed in sea water, no?

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Yes, it is. If you built a carbon fin you'd have to isolate it from the aluminum hull. That's not hard to do. You just can't have them in physical contact.

But I would go with a high alloy steel keel way before a carbon fin. If you are building in aluminum you are not getting the lightest boat (carbon gets you there). So then in the keel, where a bit more weight is generally OK, a steel fin can be perfectly acceptable and a lot more damage tolerant.

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On 9/17/2021 at 6:11 AM, fastyacht said:

Two things fuck up the weight savings of alimimum in superyachts.

1. Bog. Too much fucking pink stuff. Composites need almost none when built properly.

...

A sales rep for a global leading composite company told me the cost of filler and paint for an aluminum build is greater than the complete cost of the composite bill of materials for a carbon yacht. This is to finish to yacht standards.

Sure, you can leave an aluminum boat unpainted, and sure, it will be ugly as a commercial barge. And sure, you can live very inexpensively in Los Angeles by pitching a tent on a sidewalk. Many people make these choices: you can save money if you make such choices.

But if you want a yacht finish, you will pay money. No escaping that.

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11 minutes ago, carcrash said:

A sales rep for a global leading composite company told me the cost of filler and paint for an aluminum build is greater than the complete cost of the composite bill of materials for a carbon yacht. This is to finish to yacht standards.

Sure, you can leave an aluminum boat unpainted, and sure, it will be ugly as a commercial barge. And sure, you can live very inexpensively in Los Angeles by pitching a tent on a sidewalk. Many people make these choices: you can save money if you make such choices.

But if you want a yacht finish, you will pay money. No escaping that.

That is nearly verbatim, Vectorworks, 2008.

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On 9/18/2021 at 10:57 PM, Parma said:

It just seems to me that the opportunities for electrolysis are much higher for a cast iron or steel fin in conjunction with an aluminum hull than for a glass/laminate hull.

I have cast iron in conjunction with a glass laminate hull and the fin does show rust at some spots. Granted that's after 15 years, but hauled every 2 years. I suspect that if the hull was aluminum I'd be seeing more "opportunities" for electrolysis around the sail drive, through hulls, rudder & mast step let alone the deck hardware.

 

I am far from a metallurgist though we had no such issue after 15 years though the fin was bituminised and then coated in red oxide then bogged then anti fouled. There were poly slides on the top of the fin where it sat in the hull with aluminium chocks with stainless steel bolts locking it all in place. The head of the fin rusted in one spot where someone stuffed up (me) where a new weld was required but overall, it was in very good condition.

Perhaps the anodes and surface prep insulated us.

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Aluminum is ok 

oil canning and keeping the paint on it are a challenge 

there  is a huge amount of  volume  consuming internal structure on a metal boat 

metal boats  must have a layer of thermal insulation on the inside skin 

also during the life of the boat electricity must be kept off the hull

metal is  only suitable  for large yachts 

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On 9/18/2021 at 5:28 PM, Hitchhiker said:

Electrolysis is the compositional change of water when passing An electrical current through water.  Useful in such things such as hair removal.

Electro chemical corrosion is the compositional change of metals immersed in an electrolyte when an electrical current is passed through the electrolyte.  I.e. zinc vs steel alloy in sea water.

I am somewhat over simplifying and maybe being overly nerdy, but these are two very different chemical actions/reactions that are often confused and mis interpreted in the boating industry.

Carry on.

 

Offs.

It is galvanic corrosion anyway :D

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40 minutes ago, Hitchhiker said:

How does that relate to corrosion of metals in a marine environment?  Go Cats.

It doesn't I'm just not sure I like your definition of electrolysis, so trying to understand your pet peeve.

I think the more important distinction is the source of the current not whether its the chemistry of the electrolyte vs the chemistry of the metal that's changing.... that just seemed like a weird distinction.

Its all electro-chemistry, you have to understand both the redox reaction and the current loop.

 

Galvanic corrosion always follow the electrochemical potential of the materials, (i.e. zinc corrodes before steel) but if I hook up battery wrong I can make the steel corrode though electrolytic corrosion.

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On 9/20/2021 at 12:41 PM, carcrash said:

A sales rep for a global leading composite company told me the cost of filler and paint for an aluminum build is greater than the complete cost of the composite bill of materials for a carbon yacht

Maybe he was somewhat biased maybe!? I don't agree with the statement. In a one off composite build on a male plug you still have to fair it. Primers will be different but not much. Topcoat will be the same. So not much difference in paint.

It really depends on the level of skill of the aluminum builder. I wrote a spec where the amount of bog allowed was a maximum of 1 paperclip thickness (0.8mm / 0.032") over a 1m span. In 10 gauge (0.1" / 2.6mm) plate superstructure where weight was all important. We put a meter stick on the un-bogged superstructure to check. A very well built composite one-off would be lucky to have that level of fairness before bogging.

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1 hour ago, JohnMB said:

It doesn't I'm just not sure I like your definition of electrolysis, so trying to understand your pet peeve.

I think the more important distinction is the source of the current not whether its the chemistry of the electrolyte vs the chemistry of the metal that's changing.... that just seemed like a weird distinction.

Its all electro-chemistry, you have to understand both the redox reaction and the current loop.

Apologies for the thread drift.

 It is not my definition, rather it is the industry standard definition. You are missing the basic point and difference between "Electrolysis" and "Electrochemical corrosion"  The first effects water, the latter effects metals immersed in the water.  It is also note worthy that "Galvanic" corrosion is a type of "Electrochemical corrosion".

I was specifically referring to Parma's mis-use of the term of "Electrolysis" as it was being used to reference a type of corrosion that occurs to underwater metals.

There are various forms of "Electrochemical corrosion", which can include Galvanic or Stray current.  Any time that a disparate enough voltage potential  exists there will be "Electrochemical corrosion". 

Even on the same metal! Example being a Stainless Steel alloy shaft that has suffered crevice corrosion.  Once the passivated layer is eroded, there is now a voltage difference between the passivated layer and the exposed alloy creating "Galvanic" corrosion which is a form of "Electrochemical corrosion", but is not "Electrolysis".

A classic example of Stray current corrosion occurred on a friends Saildrive due to a DC current leak from the stereo. This was also a form of "Electrochemical corrosion". Again, this was not "Electrolysis".

Here is a link that will provide various examples on this subject https://www.sciencedirect.com/topics/engineering/electrochemical-corrosion

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On 9/20/2021 at 9:41 PM, carcrash said:

A sales rep for a global leading composite company told me the cost of filler and paint for an aluminum build is greater than the complete cost of the composite bill of materials for a carbon yacht. This is to finish to yacht standards.

He forgets to mention the cost of moulding, good sales man.
Huisman and Bloemsma build smooth alu hulls.
https://bloemsma-holland.com/en/

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2 hours ago, LeoV said:

He forgets to mention the cost of moulding, good sales man.
Huisman and Bloemsma build smooth alu hulls.
https://bloemsma-holland.com/en/

Well, vectorworks included it in their numbers. For 1 offs they dodnt build expensive moulds. A big 5 axis system makes all sorts of things plssible imcluding 1 off female moulds straight from cutterhead.

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On 9/16/2021 at 2:40 PM, Zonker said:

Please. Aluminum boats are well proven but this is nothing really new or revolutionary.

It doesn't matter once you've built the hull and the interior designer insists marble countertops everywhere and your weight savings go to shit.

Yes, but it permits bigger marble countertops and more of them!

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On 9/17/2021 at 7:40 AM, Zonker said:

Please. Aluminum boats are well proven but this is nothing really new or revolutionary.

It doesn't matter once you've built the hull and the interior designer insists marble countertops everywhere and your weight savings go to shit.

As far as I can tell interior designers get paid per kg and more often than not more than the Naval Architects and engineers in charge of making it work.

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Carl Eichenlaub, who built a lot of one off boats in San Diego, told me when he first elected to build in aluminum neither he nor is work force had much experience so he hired some aircraft workers from the nearby Naval Air Rework Facility at NAS North Island. He was shocked at the time those workers took to get perfectly fair work and realized labor costs and delayed deliveries were going to eat him alive. When he judged his boatyard workers were enough up to speed with metal working he fired the aircraft workers and went with good enough is good enough, using fairing compound to correct the irregularities.

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5 hours ago, kinardly said:

Carl Eichenlaub, who built a lot of one off boats in San Diego, told me when he first elected to build in aluminum neither he nor is work force had much experience so he hired some aircraft workers from the nearby Naval Air Rework Facility at NAS North Island. He was shocked at the time those workers took to get perfectly fair work and realized labor costs and delayed deliveries were going to eat him alive. When he judged his boatyard workers were enough up to speed with metal working he fired the aircraft workers and went with good enough is good enough, using fairing compound to correct the irregularities.

.

I wonder how the aircraft builders adjusted their technique, going from .080 and rivets, to .188, .250 amd .313 and welds?

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