Constant deep V deadrise. Powering up angle.

Well we got through that one rather gracefully and now the original question:

"I am hopefull that it will lift up almost level at all power & speed settings."

Depends what you mean by almost level. With trim tabs and lots of speed the angle of attack could be less than 5 degrees. An aircraft wing achieves an optimum lift to drag ratio at an angle of attack of about 10 degrees depending on the airfoil used and the wing loading. Water is very much more dense and if one is going 50 knots and falls overboard the water feels more like a concrete road than water so at 50 knots a planing boat's angle of attack can be extremely small create enough lift to support the boat even if it's fairly heavy but one needs to keep the majority of the keel out of the water to prevent a very high skin friction from slowing the boat down. So the answer is yes and no. At 50 or 60 knots an angle of attack is required but very little is needed to support the boat. But at 20-25 knots and trim tabs extended one may actually be able to run at 0 degrees angle of attack or level w the water surface. The reason for running at very low angles of attack usually is to ride smoother on small bothersome short waves usually called chop. But a deep, Deep V hull will typically run smooth on a chop anyway and more efficiently at considerable angles of attack so running "level" is not desirable anyway. So Cyplops2 how fast do you plan on running your boat?. And is my english ok?

 

All those steps bring back memories of a WW II Elco PTB that installed 5 steps under a boat to increase speed. Worked well. Raised the WOT from + or - 42 knots to 55 knots. That was a significant increase in fuel efficiency for a overloaded boat in combat conditions back then.

 

The "shingles" that run cross-direction to the "strakes"?

Odd full circle experience - I asked what these did near the bow back in February and didn't know the correct term to use
http://www.boatdesign.net/forums/powerboats/what-do-these-steps-near-bow-do-36823.html

 

Sorry I don't get the question. Strakes are the long, edgy bumps running longitudinally, shingles and steps are transversal to strakes.

 

Is m3mm0s talking about strakes or the shingle-steps?
All my boats have had strakes since the 70s. The shingle-steps coming back is new to me.

 

I'm affraid nobody has managed so far to understand what is m3mm0s actually talking about. It is not his fault, we clearly have a language barrier (or a google translator) at work here.
I hope he will soon get back to clarify his thoughts.

 

Is "shingle" instead of "step" the best term to refer to this type of "shingle"?
A step as I know it runs from keel thru chine.
Are they "shingles" if they are staggered?

 

OK friends. The correct word is strakes

 

The picture shows ventilated forward strakes, on a two step monohedron hull form.

 

PAR I see in your profile what profession I want your opinion. How do you see my model could be walking in the U.S. market;

 

Post a 3 view set of lines for your hull, general scantlings, weight estimates, preformance expectations and it's SOR and I'll have a look.

 

r9

The length of the vessel is 9.00m in width without tubes 1.60 and 0.65 height. The degrees in front of the keel 52 is in the middle 32 and the transom 25. The weight will be about 1000 kg. With a motor 300 horses under the theoretical speed is calculated at 72 knots with two to 85. The shipbuilding Milestone out of 4 is 3.81

 

You don't honestly think this is enough information, to make any type of design assessment do you?

 

Certainly not but these I can give for now

 

PAR, it is a RIB 9 m long and around 2 mt wide with tubes, with a deep-vee hull. Kind of an off-shore raceboat type. The top speed sounds a bit too optimistic with just 300 HP. Around 50-55 kts would imho be more reasonable, but I'll leave that to your designers evaluation. I believe the concept does have a market if done with proper (nothing less than excellent) quality. RIBs appear to gain popularity at a very high pace.

From the aesthetic point of view, it looks good imho. I like the idea of mirror-metal varnish. But the underwater hull is the invisible part of the boat. You'll play your odds with the deck and console design, and with the handling qualities.

Cheers