another idiot with mad ideas, new boat build

Those Seateks look a bit tasty.
Far too much engine for my needs though. That may get me about fourty knots with those beuties fitted.

Cummins uk have said the 5.9l qsb is no longer available new, but also looking in to bringing a pair over from the states.

Slowly getting there. I think i have had the designer pulling his hair out :)
 
Robg71 said:
Those Seateks look a bit tasty.
Far too much engine for my needs though. That may get me about fourty knots with those beuties fitted.

Cummins uk have said the 5.9l qsb is no longer available new, but also looking in to bringing a pair over from the states.

Slowly getting there. I think i have had the designer pulling his hair out :)
Click to expand...

As far as I know you can buy factory reconditioned units direct from Cummins, at at massive discount in comparison to brand new units.

They're going to be as good as new engines IMO. I used to own a light aircraft, and factory overhauled engines were the norm....nobody but nobody fitted new units. Ok so they were petrol, but the principle transfers across to diesels.

In fact diesels lend themselves to reconditioning more than petrol engines, because of the heavy duty construction, with liners etc etc.....

Just a thought.....
 
rustybarge said:
As far as I know you can buy factory reconditioned units direct from Cummins, at at massive discount in comparison to brand new units.

They're going to be as good as new engines IMO. I used to own a light aircraft, and factory overhauled engines were the norm....nobody but nobody fitted new units. Ok so they were petrol, but the principle transfers across to diesels.

In fact diesels lend themselves to reconditioning more than petrol engines, because of the heavy duty construction, with liners etc etc.....

Just a thought.....
Click to expand...


Indeed you can. I have a price from Cummins uk, and a supplier in the US. I have no issue against factory recons, am also looking to see what other prices from volvo and cat.
 
I think latestarter of this forum can supply those. Might worth an ask. He knows a little something about engines!!!!! :)
 
the latest...
am in Holland. had a good day. the two boat builders are with me and suitably impressed.
tomorrow we go and look at another new build and a completed for sale boat.

steel weight.
14 tons
allowance for engines 2 tons
we should be able to keep it under 20 tons if we are careful.
aluminium structure is out, as cost versus weight saving is not in our favour.

For top speed:
20 ton , wl 13.43 mtr. , 26 kn needs 764 HP
22 ton , wl 13.47 mtr. , 26 kn needs 838 HP

for cruising speed:
22 ton , wl 13.47 mtr , 20 kn needs 532 HP
24.5 ton , wl 13.53 mtr. , 20 kn needs 560 HP

24 ton is for absolute max calcs for stability etc.
all stability calcs come in very nicely and pass for rcd offshore cat 4 metre seas.

getting there...
Steel cutting in two weeks
steel delivered end of month....
 
Robg71 said:
all stability calcs come in very nicely and pass for rcd offshore cat 4 metre seas.
Click to expand...
Rob, just a thought: that's B category, according to RCD classification.
Nothing wrong with that, but I would have expected a boat like the one you're going to build to meet also the A category requirements.
I mean, I've seen similarly sized plastic boats rated as CE A (and I'm not talking of Nordhavns and the likes, just normal planing boats), so I can't see any reason why yours shouldn't tick the same boxes.
Worth asking the builders, imho.
Not because you'll do anything different with the very same boat if she'll be cat A or B, but it's a nice to have feature, also for future resale, and shouldn't add much to the cost - if anything at all.
 
Robg71 said:
the latest...
am in Holland. had a good day. the two boat builders are with me and suitably impressed.
tomorrow we go and look at another new build and a completed for sale boat.

steel weight.
14 tons
allowance for engines 2 tons
we should be able to keep it under 20 tons if we are careful.
aluminium structure is out, as cost versus weight saving is not in our favour.

For top speed:
20 ton , wl 13.43 mtr. , 26 kn needs 764 HP
22 ton , wl 13.47 mtr. , 26 kn needs 838 HP

for cruising speed:
22 ton , wl 13.47 mtr , 20 kn needs 532 HP
24.5 ton , wl 13.53 mtr. , 20 kn needs 560 HP

24 ton is for absolute max calcs for stability etc.
all stability calcs come in very nicely and pass for rcd offshore cat 4 metre seas.

getting there...
Steel cutting in two weeks
steel delivered end of month....
Click to expand...

Are those actual hp prop. requirements for those speeds, or the size of the engines you're going to fit?
 
Robg71 said:
Those are actually prop requirements.
I will check ref cat A, but its also built to Lyods spec.
Click to expand...

On the stabilisation issue, here's some interesting stuff, also the spec's and plans for a high tech/ low drag paravane. ( can you afford £90k for hydaulic stab's?)

NACA Foil Shaped Low Drag Aluminum Paravanes

Please see our Roll Attenuation article for more information on Paravanes for Motor Yachts.

LARGE NACA FOIL ALUMINUM PARAVANES

Plan square area is 383 square inches for the wings, not counting the bulb.
Weight is 79 lb., of which approx. 19.5 lb. is lead in the nose of the bulb.
Appropriate for boats up to approximately 50 to 65' on deck by 15' of beam,
depending on displacement.
* Design and Specification: $200


MEDIUM NACA FOIL ALUMINUM PARAVANES

Plan square area is 233 square inches for the wings, not counting the bulb.
Weight is approximately 40 lb., of which approx. 10 lb. is lead in the nose of the bulb.
Appropriate for boats up to approximately 35 to 50' on deck by 12' of beam,
depending on displacement.
* Design and Specification: $175


SMALL NACA FOIL ALUMINUM PARAVANES

Plan square area is 138 square inches for the wings, not counting the bulb.
Weight is 17.5 lb., of which approx. 4.25 lb. is lead in the nose of the bulb.
Appropriate for boats up to approximately 35' on deck by 10' of beam
depending on displacement.
* Design and Specification: $150



25' Boojum - Click for Larger Image
These low-drag paravanes make use of NACA foil shaped surfaces combined with a lead ballasted NACA foil shaped bulb. They are designed to be machined out of marine grade aluminum plate and rod so that they can be shaped, and so they are lighter for a given wing area than steel paravanes would be.

The sizes given above are conservatively rated. In other words each size can be used on a larger vessel than is indicated. It is all a matter of degree. The roll attenuation will simply be more or it will be less, as compared to that of a larger or smaller wing area.

Effectiveness is a function of wing area and pole length vs. your vessel’s righting moment. With a larger the vessel the poles can be made longer, achieving greater leverage, therefore a greater effect for the same size paravane.

These paravanes are balanced and are adjustable for different speeds. For more information, please inquire.

http://www.kastenmarine.com/roll_attenuation.htm
Click to expand...
 
boat Calcs are for CAt A RCD, as its no extra just a few stiffeners.
biggest difference is in safety gear.
HAd a cracking couple of days, lots of good ideas bounced about and a few issues settled.
still head scratching over motors.
Designers engine guru has said 6.7l 450hp iveco nef... (He sells them)
i said 480 5.9 qsb...
at the moment we are looking at options still....

my prefered is the 5.9, as factory recons are way way cheaper than anything else. but only if its the right engine for the job.
we need to keep weight down, so moving up in capacity will instantly add half a ton. (C7 ACERT and volvos all heavier

looked at a finished 46 footer, the finish is stunning. you would be hard pressed to tell it from plastic boat....
some of the design ideas and use of space are really good.
also had a look at a mid build 50ft aft cabin. kits go together very easy.
well impressed

the steel should be delivered end of month.
some design details to sort then we cut....

photos to follow
 
Last edited:
Robg71 said:
boat Calcs are for CAt A RCD, as its no extra just a few stiffeners.
biggest difference is in safety gear.
HAd a cracking couple of days, lots of good ideas bounced about and a few issues settled.
still head scratching over motors.
Designers engine guru has said 6.7l 450hp iveco nef... (He sells them)
i said 480 5.9 qsb...
at the moment we are looking at options still....

my prefered is the 5.9, as factory recons are way way cheaper than anything else. but only if its the right engine for the job.
we need to keep weight down, so moving up in capacity will instantly add half a ton.

looked at a finished 46 footer, the finish is stunning. you would be hard pressed to tell it from plastic boat....
some of the design ideas and use of space are really good.
also had a look at a mid build 50ft aft cabin. kits go together very easy.
well impressed

the steel should be delivered end of month.
some design details to sort then we cut....

photos to follow
Click to expand...

Just out of interest how much more does it cost for the profile cutting, in addition to the basic cost of the steel?
 
Robg71 said:
boat Calcs are for CAt A RCD, as its no extra just a few stiffeners.
biggest difference is in safety gear.
HAd a cracking couple of days, lots of good ideas bounced about and a few issues settled.
still head scratching over motors.
Designers engine guru has said 6.7l 450hp iveco nef... (He sells them)
i said 480 5.9 qsb...
at the moment we are looking at options still....

my prefered is the 5.9, as factory recons are way way cheaper than anything else. but only if its the right engine for the job.
we need to keep weight down, so moving up in capacity will instantly add half a ton. (C7 ACERT and volvos all heavier

looked at a finished 46 footer, the finish is stunning. you would be hard pressed to tell it from plastic boat....
some of the design ideas and use of space are really good.
also had a look at a mid build 50ft aft cabin. kits go together very easy.
well impressed

the steel should be delivered end of month.
some design details to sort then we cut....

photos to follow
Click to expand...
The guru, Latestarter, really likes the QSB, quote, these are the best marine engines.
 
rafiki_ said:
The guru, Latestarter, really likes the QSB, quote, these are the best marine engines.
Click to expand...

Yes, I have been in touch with Latestarter
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the window framing has changed. we are going for a flush fit, glued in style.
the attention to detail is superb.
had a walk around a marina full of steel boats. they outnumbered plastic by ten to one in there, and youy can struggle to tell them apart at times.
dutch boat builders certainly know there stuff
 
Untitled_zps41624498.jpg


Thanks Karl.
I cant wait for the steel to turn up now. one month to go....
by christmas is our plan to have the hull welded and ready for fitting out.
still lots to do though.

the photos above are a 46 footer, the 50 has the extra length in the accommodation and the cockpit area. also slightly wider.
am struggling with storage for a dinghy at the moment. we could keep it on the flybridge, its strong enough, but I am looking for another solution for the aft. Im looking at some Opacmare gear,
any other solutions for tender storage very welcome.
we dont have the depth at the arse for a tender garage. as it would mean serious work chopping in to the seating arrangements etc, and unsuitable for an opening hatch large enough.
 
Given your current cruising grounds I would suggest a small Rib tender / dive tender on fly bridge with crane and a second small dinghy with wheels or light to carry.

my one bug bear locally is carrying dinghy / outboard over rocks or any distance!

I have a 1.8 m can carry easy but fits 2 adults at a push and no engine but probably my favourite dinghy out the 5 I currently own !!!

Maybe a kayak would suit you in these instances ???
 
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