Building a 46ft performance/cruising Catamaran

[Slainte Mhaith]

Test fitting the dummy board (real foils will be made from carbon fibre).

Making sure of the correct position before cutting holes in the hull and and laminati g the cases.

That photo looks all sleek and performance, awesome.

 

[Takashi]

I would guess they are planning on having lets say 4 strings of 750W each 3kW in total.

You have some shaded spots on one string you lose effectivity on only that string and not the whole system.

Eish. Short but loaded sentence there. Can cause expectations which are not met.

If you have significant shade on a part of a panel the diodes can bypass that section and nothing an mppt can do to recover the loss.
The mppt will use to remainder of the output wisely or at max efficiency.

PS With masts and stuff you are going to have constant shades on panels thus make sure the supplier don't blame future panel failures on shading issues (diodes sometimes fail). They must approve the application.

 

[Ratel]

I would guess they are planning on having lets say 4 strings of 750W each 3kW in total.

You have some shaded spots on one string you lose effectivity on only that string and not the whole system.

That's what I meant, thanks

 

[Slainte Mhaith]

I would guess they are planning on having lets say 4 strings of 750W each 3kW in total.

You have some shaded spots on one string you lose effectivity on only that string and not the whole system.

Thanks, get it now. The statement made it sound that using MPPT chargers will make things better but actually it is the number of strings (and thus more mppts) that make it better.

 

[Ratel]

Received a few packages this morning...
2 electric motors and 6 lithium batteries and a 5000w inverter/charger.

Getting real now.

 

[Ratel]

So our "composting" heads arrived from OGO today.

OGO™ Compost Toilet

OGO™ Compost Toilet is one-of-a-kind. It is the smallest product on the market, waterless and proud to be made by hand in the USA.

ogotoilet.com

No stinky marine heads with their associated blacktanks and raw sewage on this boat. We decided to go with these units from OGO. The only other competition was from a company called Compoost in the UK.

In the end the footprint of the OGO was a much better fit.

 

[Ratel]

The spider frame mould is being readied for the lamination process where carbon fibre will be used to save weight.

All interior bulkheads have been laminated and the guys are busy gelcoating all interior surfaces. We are not using any paneling, again to save weight, but also much easier to keep clean.

The aft cockpit piece is ready to be lifted onto the boat.

 

[NoRush]

Permission to aboard Captain ? I do love water but in my swimming pool and love
stable ground. Your thread has just ignited my own dreams I thought was long dead. I will be following this epic build.

 

[whitedelight]

Interesting build. Looks similar to a HH catamaran. I really like the aggressive hull design. Is there enough strength in the design to fly a hull?

 

[Ratel]

Interesting build. Looks similar to a HH catamaran. I really like the aggressive hull design. Is there enough strength in the design to fly a hull?

She is going to be very stiff, carbon fibre stringers across the hull deck. Whether one really want to fly a hull is a completely different question, hahaaa.


The leeward foil will counteract any hull lifting on the windward side by lifting the leeward hull some.

 

[Ratel]

And just like that we are out of the mould!

 

[Ratel]

 

[whitedelight]

Awesome . That frontend looks so mean. Probably posted before but what is the beam?

 

[silberfuchs]

Once more I am impressed with your project.
I hope everythings works as you intended to.

My stupid question today is: Why does the design have inverted bows?

Greetings, G.

 

[Ratel]

Once more I am impressed with your project.
I hope everythings works as you intended to.

My stupid question today is: Why does the design have inverted bows?

Greetings, G.

Very good question actually.

I also asked the builder this question. The main function of reverse bows/wave piercing bows is to reduce pitching. Not only is it uncomfortable but it also negatively affects the performance of the sails.

There is also less deceleration as the bows "slice" through the water.

Disadvantages are that it is more difficult to fend off the bows in tight marina spaces, there is a risk of stuffing the bow (on this boat we have curved lifting foils that reduces that problem) and less volume in sail lockers up front.

So in summary it has everything to do with increasing sailing performance. I'm not complaining about the looks either!

 

[Ratel]

Awesome . That frontend looks so mean. Probably posted before but what is the beam?

The beam is 7.5 meters.

Seaquest Catamarans | SQ46

Seaquest Catamarans offers a new exciting sailing experience. Combining state-of-the-art materials, advanced yacht design, sophisticated styling and comfortable, lightweight interior results in a ground-breaking performance cruising yacht.

seaquestcatamarans.com

 

[roxenz]

Very good question actually.

I also asked the builder this question. The main function of reverse bows/wave piercing bows is to reduce pitching. Not only is it uncomfortable but it also negatively affects the performance of the sails.

There is also less deceleration as the bows "slice" through the water.

Disadvantages are that it is more difficult to fend off the bows in tight marina spaces, there is a risk of stuffing the bow (on this boat we have curved lifting foils that reduces that problem) and less volume in sail lockers up front.

So in summary it has everything to do with increasing sailing performance. I'm not complaining about the looks either!

An Norwegian guy came up with a sort of inverted bow for ship (google X-box Ulstein). While not as aesthetically pleasing as your yacht's design, it is apparently very effective.

 

[silberfuchs]

Very good question actually.

I also asked the builder this question. The main function of reverse bows/wave piercing bows is to reduce pitching. Not only is it uncomfortable but it also negatively affects the performance of the sails.

There is also less deceleration as the bows "slice" through the water.

Disadvantages are that it is more difficult to fend off the bows in tight marina spaces, there is a risk of stuffing the bow (on this boat we have curved lifting foils that reduces that problem) and less volume in sail lockers up front.

So in summary it has everything to do with increasing sailing performance. I'm not complaining about the looks either!

Hello Ratel,

Thanks for your answer.
Being a monohull guy (I did mention that earlier) I am principally worried about the lack of reserve buoancy on multihulls.
I saw some rather interesting video footage and read some remarks of crew members on these big 60 foot plus "hurry-around-the-world" racing machines - monohulls n.b. - about what happens when they are surfing down the one wave and dig into the one in front at speeds of 25 knots or higher.
In my younger years I had the chance of crewing on a tornado cat. At much lower speed I assure you we dug the leward hull in and I used the whole length of the trapeze cable not to fly too far off the then capsized boat.

I am fully aware, that these designers have experience and will have tried out a few things before they really build a speed machine like yours.

Over and above all I hope your dream comes true and everything works out well.

Best wishes and greetings, G.

 

[subie]

Also waterline length is king. Like cubic inches are for horsepower

 

[subie]

Hello Ratel,

Thanks for your answer.
Being a monohull guy (I did mention that earlier) I am principally worried about the lack of reserve buoancy on multihulls.
I saw some rather interesting video footage and read some remarks of crew members on these big 60 foot plus "hurry-around-the-world" racing machines - monohulls n.b. - about what happens when they are surfing down the one wave and dig into the one in front at speeds of 25 knots or higher.
In my younger years I had the chance of crewing on a tornado cat. At much lower speed I assure you we dug the leward hull in and I used the whole length of the trapeze cable not to fly too far off the then capsized boat.

I am fully aware, that these designers have experience and will have tried out a few things before they really build a speed machine like yours.

Over and above all I hope your dream comes true and everything works out well.

Best wishes and greetings, G.

Dont go there
After sailing on a heavy Catamarran like a leopard 40 on a one week trip in deep ocean I am very pro modern cats. Racing ,like with mono hulls, is a different ball game. Things break at sea mono or multihulls. With modern navigation and weather info there is no need to go test yourself and boat in the ultimate storm conditions anymore. This is going to be a wonderfull fast and seaworthy boat