Modern Take on Old Ideas (Fluyt Ship)

[philSweet]

It will require a paid crew of about 10, two or three of which will want to be year round salaried in the six figure range.

Rough metrics suggest a construction cost of 10 million USD. Start collecting ballast - you're going to need a lot of it - 80 tons or so. If done as a fore-aft rig, same sail performance at maybe 40 tons less displacement. Yours should draft about 10 feet - sometimes it's difficult to find a slip for that.

You should go take a look at Earl of Pembroke (tall ship) - Wikipedia https://en.wikipedia.org/wiki/Earl_of_Pembroke_(tall_ship)

Nevermind - she was scrapped a year ago - bummer.

 

[BlueBell]

Even were it previously suggestible to me to have backed away from building such a ship as I've envisioned, the biting tone of your admonition puts me in the peculiar position of having no choice but resisting what you say and appearing arrogant and foolhardy. What alternative is there? Should I accept your criticism as true that I'm incapable of novel ideas and that some man I've never heard of has created something infinitely better than I can even conceive? In any event, thank you for taking time to contribute, though I found the style of your contribution to be unwarranted and demeaning.

Skip,

Take what you can from bajansailor's input. He means well and is in the know.
To put his constructive criticism into perspective,
I believe what you are undertaking is 20 - 50 times more than what you expect it to be, from a time, effort, money standpoint.
And that's giving you the benefit of doubt; it could be much higher.

How many people will live on the boat?

 

[Skipper]

I'm in a bit of a rush, so I'll have to put off replying to the unanswered posters for just now. However, I wanted to post my current concept for the general fairness of my ship at water line:


190 x 465
171 x 378
153 x 300
136 x 231
120 x 171
105 x 120

These numbers represent the length and width of overlapping ovals and should be divided by 23 to acquire metered measures. The first number is bowmost and the last aftmost. The spacing between the centroid of each is such: 105, 91, 78, 66, 55.

Ultimately, it renders a shape similar to an air-foil, but wider as it approaches aftward. Here are some images illustrating it:

As such, the ship's hull ratio is 69:19. If it should be 36 meters long, it will have a breadth of just under 10 meters.


In abscissae and ordinate terms where the axis is from the bow to the stern and the ordinate is from the axis to one side and assuming a ship with a length of 30 meters:

(Abscissae, Ordinate)
(10.1087, 4.1304)
(14.6738, 3.7174)
(18.6303, 3.3261)
(22.0216, 2.9565)
(24.8912, 2.6087)
(27.2825, 2.2826)

 

[bajansailor]

Skipper, you have lost me there totally, with your newfangled way of designing a hull.

Coincidentally, I saw this link to Sao Gabriel, Vasco da Gama's flagship on Facebook earlier -
(13) Facebook

And here is the photo in the link, for those who are not on FB -

 

[Skipper]

The math is leading me to a structure such as this (ignore the keel as I haven't read enough on the subject to as yet have any idea what is proper. Also, the bottom image isn't mathematical, just a guess of what it seems to be. I'll need to go over the numbers before I am able to provide the actual longitudinal axis. Some research seems to suggest this general shape to be a "trawler hull". Upon looking at this, I realize that, were I to construct the hull as such, I'd need to redesign the weight load on the top of the ship substantially by moving it forward. However, I have just started reading of how to calculate weight distribution so will need considerable time before I am able to plan for the aforementioned.

 

[Skipper]

Aluminium conducts electricity fairly well, and so has a pretty good chance at safely conducting a lightning strike into the sea, especially in the thicknesses you would need for a vessel this size. Lightning has punched through fibreglass.

Consider that aircraft get hit by lightning:

In the very first paragraph of an article on how composite aircraft cope (https://www.compositesworld.com/articles/lightning-strike-protection-strategies-for-composite-aircraft), I found this:


So if lightning is part of the motivation for mixing those materials, I think you are better off with an all aluminium hull.

Before you mix the materials as you outlined, check how they move, both when a load is applied and when temperature changes. Expansion at different rates will put a stress on the joint.

If the glass fibre hull is just built inside the aluminium parts, such that they are only held together mechanically, they will move against each other and erode. If you want to bond them together, here is one source on what to do with the aluminium first: A Beginner’s Guide to Using Aluminum Epoxy https://www.hotmelt.com/blogs/blog/a-beginner-s-guide-to-using-aluminum-epoxy



The above are the reasons I can think of. There may be more.



It will be your boat, this is a valid point, and enough people care about how their boat looks that there is even a name for this: the row away factor. Do you like what you see when you row away from it? But how informed your decision is as to how much weight you should give that row away factor compared to other considerations, such as building cost, running cost, and how the vessel sails, that depends on how much experience you have with sailing vessels resembling what you drew, and other vessels that may give you similar accommodations. You have not said how much experience you have.

How many people will live on the boat?

Robert, your input is more than I could have hoped for. Yes, I see now that I will need to consider carefully and mathematically how the different expansion rates will coexist without failure if I am to keep the current concept. Also, thank you for the link and information about the epoxy; I hadn't yet come across such a quality solution for connecting them. As for experience, I have only ridden upon ships but never sailed myself. I'll enroll in a course before undertaking as much for sure. Again, thank you so much for your response.

It will require a paid crew of about 10, two or three of which will want to be year round salaried in the six figure range.

Rough metrics suggest a construction cost of 10 million USD. Start collecting ballast - you're going to need a lot of it - 80 tons or so. If done as a fore-aft rig, same sail performance at maybe 40 tons less displacement. Yours should draft about 10 feet - sometimes it's difficult to find a slip for that.

You should go take a look at Earl of Pembroke (tall ship) - Wikipedia https://en.wikipedia.org/wiki/Earl_of_Pembroke_(tall_ship)

Nevermind - she was scrapped a year ago - bummer.

Phil, hello. I'll avoid writing too much of my own estimation to avoid embarrassing myself, but my numbers were substantially different from your own. I'll be needing to go back and reconsider them before I'm able to offer an informed response.

Skip,

Take what you can from bajansailor's input. He means well and is in the know.
To put his constructive criticism into perspective,
I believe what you are undertaking is 20 - 50 times more than what you expect it to be, from a time, effort, money standpoint.
And that's giving you the benefit of doubt; it could be much higher.

How many people will live on the boat?

Yes, I might have been a bit neurotic in interpreting his comments as I did. As for how many will be on the boat, I'm planning for my wife and four children plus any more which we may have in the following years.

Skipper, you have lost me there totally, with your newfangled way of designing a hull.

Coincidentally, I saw this link to Sao Gabriel, Vasco da Gama's flagship on Facebook earlier -
(13) Facebook

And here is the photo in the link, for those who are not on FB -

View attachment 192543

Sorry for that, I've been reading a book on shipwrightery and it mentioned some ideas that got me thinking. I'll definitely convert any abnormal means of mensuration to common forms before I start building anything. As for the photos, they are quite interesting. That boat is definitely stout.

 

[gonzo]

Gonzo,
When you say the building method, is your meaning the idea of fiber-glass locked into aluminum? The idea was that the aluminum could better absorb any impacts with coral while having the inner fiber-glass hull lock into it such that I would be free from worry should lightning strike one of the masts. I also have a few other ideas of how it might be of profit, but they are vague and not yet thought through. As for the top heaviness, I too see it and am looking to remedy the concept once I am better educated to do so. The old brigs and fluyts had this design and they seem to have been capable of traversing the sea, but I'm not sure what the key is that makes the design justified. Perhaps the large cargo load acted as additional ballast to such a strong degree that it corrected its trim and changed it from an upsetting couple to a righting couple. I'm still reading and hope to be better informed before I set about making sketches and plans. In any case, thank you for your input and know it has been warmly welcomed and will weigh on my future planning.

Aluminum and polyester resin are not compatible materials. It would take a lot more than a post to be able to explain the mechanics of materials and chemical interaction, but you can do some research and take some courses on it.
Lightning protection is a complicated issue that does not have a simple solution. To start with, avoiding hitting coral is largely a matter of good seamanship. Further, EMP from lightning strikes can completely destroy all your electronics and usually does.
The old brigs and fluyts had staggering loss of life at sea that would be unacceptable today.
Cargo ships only sail well when loaded. Cargo ships converted to pleasure usually behave badly and have structural issues like hogging.
You probably will get better informed by going out sailing in rough weather. It may be that the dream of sailing around the world is not for you. Sadly for many dreamers, the discomfort and lack of sleep that are a reality of cruising across oceans often destroy the dreams.

 

[Skipper]

So, here I have the general shape of the ship. The hull below the water-line was arrived at mathematically and is the shape I'll likely move forward with. The part of the ship above the water-line is drawn based very loosely upon my original concept art and without mathematical reckoning.

 

[Skipper]

I wish to ask for some assistance in my pricing calculations. If the boat were to be 33 meters in length, 9 in breadth, and, also, 9 in heighth, I have considered two ways of generating a rough estimate of the external surface.

A cuboid: 1350 m2
A cylinder: 1057 m2

So, it would seem to have an external surface of a bit over 1000m2. If I were to construct the hull at 3cm thickness, the hull would be ~30+ cubic meters of material. If the epoxy resin and fiber-glass are to be in equal quantities, this means I'd need 15 cubic meters of epoxy, or 15,000 liters. Assuming the epoxy to cost about 2.25 USD per liter, I could expect to spend, upwardly estimated to compensate, something around 35,000 USD.

Does all of this seem correct? I am assuming the fiber-glass and resin to be of the same weight above which must be incorrect. Might anyone be bothered to help correct my estimations? I'd be eternally grateful.

 

[bajansailor]

Does all of this seem correct?

Ummm, no, it will cost a lot more than this.
And the structure of the hull is going to be a lot more complicated than your basic assumption above.
You will also need a mould (either male or female) if you want to build in fibreglass.

5 gallons (say 20 litres) of epoxy from Lewis Marine is approx US$600, so the cost per litre is approx US$30.
LMS Catalog - Bridge https://www.lewismarine.com/catalog/#p=439
It should be possible to buy epoxy by the barrel, which will bring down the cost, but even so, you are easily looking at a million dollars in basic materials for the hull.
And maybe half that again for the mould and other costs (at a very rough estimate)

Then there is the labour cost - ok, in China this is very low, but it will still be a factor.
And you can roughly estimate that the cost of the hull will be (at most) 10% of the total, so you will easily be up around US$10 million before you know it.

Do you have US$ 10 million to throw at this houseboat project?

Even if you use polyester resin rather than epoxy the cost is still going to be millions.

 

[Skipper]

Ummm, no, it will cost a lot more than this.
And the structure of the hull is going to be a lot more complicated than your basic assumption above.
You will also need a mould (either male or female) if you want to build in fibreglass.

5 gallons (say 20 litres) of epoxy from Lewis Marine is approx US$600, so the cost per litre is approx US$30.
LMS Catalog - Bridge https://www.lewismarine.com/catalog/#p=439
It should be possible to buy epoxy by the barrel, which will bring down the cost, but even so, you are easily looking at a million dollars in basic materials for the hull.
And maybe half that again for the mould and other costs (at a very rough estimate)

Then there is the labour cost - ok, in China this is very low, but it will still be a factor.
And you can roughly estimate that the cost of the hull will be (at most) 10% of the total, so you will easily be up around US$10 million before you know it.

Do you have US$ 10 million to throw at this houseboat project?

Even if you use polyester resin rather than epoxy the cost is still going to be millions.

No, I do not have 10 million USD to throw at anything. Hopefully, that will not be a barrier which stops my progress. It is my estimation that most materials are infinitely cheaper in China than the West as this is the manufacturing epicenter of the world. I can source sundry formulations of epoxy resin with hardener for 400rmb per 25 liters and 3500rmb per 250 liters. Were I to contact the supplier and wish to buy it in even more bulk, I imagine the price could be lowered even further. As for moulding, I have devised a concept to avoid needing as much and will test it tomorrow. Finally, for labour, I am planning to construct it myself. I keep seeing numbers in the millions thrown about, but anyone can readily go on Taobao and find prices far lower. In any event, please do not take my apology as an offense. I am very grateful for your proffered help, but am more of need of a review of my calculations in regard to the area than in my assessment of the price of materials. Again, please do not take my apology as an indignation.

 

[Skipper]

Aluminum and polyester resin are not compatible materials. It would take a lot more than a post to be able to explain the mechanics of materials and chemical interaction, but you can do some research and take some courses on it.
Lightning protection is a complicated issue that does not have a simple solution. To start with, avoiding hitting coral is largely a matter of good seamanship. Further, EMP from lightning strikes can completely destroy all your electronics and usually does.
The old brigs and fluyts had staggering loss of life at sea that would be unacceptable today.
Cargo ships only sail well when loaded. Cargo ships converted to pleasure usually behave badly and have structural issues like hogging.
You probably will get better informed by going out sailing in rough weather. It may be that the dream of sailing around the world is not for you. Sadly for many dreamers, the discomfort and lack of sleep that are a reality of cruising across oceans often destroy the dreams.

Well, in my defense, I have been through a hurricane in a long-lining vessel in the middle of the Gulf of Mexico on a boat of not 20 meters with only myself, the captain, and his dog where the engine was unable to return us to shore such that we were sucked back out to sea and through the eye of the storm during which time, which is to say the time in the storm and not in the safety of the eye, I was forced to crawl across the bow and right the rope that attached his parachute anchor as best I could to a metal post meant to hold it that had been fully bent over from the power of the storm and, afterward, spending the entirety of the night listening and being shaken in horror as the hull of the ship was lifted several meters into the air and smacked down upon the water over and over and over again. Whereas, on good trips, we would be out for two to four weeks waking before dawn and fishing past dusk. However, it may be that I am not able to fully grasp this great discomfort of cruising on a sail boat of which you mention.

On to your other points, I will take them into consideration and continue my reading to better inform myself of these mechanics of materials and chemical interactions which preclude the dual use of aluminum and ester of which you speak. Thank you for your advice and concern and forgive my above tone. Being dissuaded from something one wishes to do by men who refuse to even justify their critiques quickly grows irksome.

 

[bajansailor]

OK Skip, re post #26, how many millions DO you have?
Because even if you build it in China it will still cost you millions.

I am planning to construct it myself.

A polite suggestion - try building a little dinghy first for your ship, and see how long that takes you. Yes really, please do something like this first. Buy a set of plans for $50 for a boat that you like - some plans are even free. There are many available on the internet.
There is absolutely no way that you can build a 33 metre vessel by yourself.
Even a well equipped yacht building yard with a skilled workforce and at least 10 - 15 people working on the boat full time would probably easily take a year to build a one off vessel like this.
Not to mention how you first need to produce all of the design and construction drawings - are you going to produce perhaps a hundred detailed drawings yourself as well?

 

[Rumars]

So, it would seem to have an external surface of a bit over 1000m2. If I were to construct the hull at 3cm thickness, the hull would be ~30+ cubic meters of material. If the epoxy resin and fiber-glass are to be in equal quantities, this means I'd need 15 cubic meters of epoxy, or 15,000 liters. Assuming the epoxy to cost about 2.25 USD per liter, I could expect to spend, upwardly estimated to compensate, something around 35,000 USD.

Does all of this seem correct? I am assuming the fiber-glass and resin to be of the same weight above which must be incorrect. Might anyone be bothered to help correct my estimations? I'd be eternally grateful.

Rule of thumb, per sqm, 1kg glass + 1kg resin = 1mm thickness (actual numbers vary by glass content and production technology). 30mm needs 30kg mixed resin, x 1000 = 30000kg. Epoxy resin density varies between 1.2 and 1.3 t/cubic meter, so you need 23-25 cubic meters of epoxy. That's 51-56k USD at your quoted price.

In reality 100k for materials is to low of an estimate, you haven't even considered stiffeners, fairing and paint.

I'm curious about what you have devised for economising on molding, since that's another horse that was beaten to death by now.

Be advised that in larger sizes one off construction economics tend to favor metal or cored builds, not monolithic glass.

 

[BlueBell]

Skip,

Your material cost estimates seem reasonable.
You're not getting a lot of direct responses to your questions because they are so far out there.
We are not trying to rain on your parade.

If your thread is failing to "float your boat" then I would suggest hiring a Naval Architect.

Cheers, all the best, and good luck.