Electric Launch Design optimized for semi-displacement speeds

What I fail to understand is why you find mischaracterizing what I've said so endlessly fascinating. If you want a truism, a new design is more current than an old design. I didn't say it was better, shinier, or anything except representative of someone's relatively current thinking. The Z11 is considerably more conventional than recent hydrofoil offerings, for example.
 
Stephen Ditmore said:
What I fail to understand is why you find mischaracterizing what I've said so endlessly fascinating. ...
Click to expand...

There is no mischaracterisation at all.
You fail to understand that you, fail to understand, that is all.

Stephen Ditmore said:
... If you want a truism, a new design is more current than an old design....
Click to expand...

Again, you fail to understand.
A truism, is something that is self-evident. Thus, you're point being?? (again).

Stephen Ditmore said:
... I didn't say it was better, shinier, or anything except representative of someone's relatively current thinking. ...
Click to expand...

Current thinking of what?...have you spoken to the designer about what they are currently thinking?

Stephen Ditmore said:
....The Z11 is considerably more conventional than recent hydrofoil offerings, for example.
Click to expand...

Again, im shocked at this endless misdirection and conflating one with the other.
Ergo, you are attracted to all things bright and shinny....to have a narrative of "something"...of what, no idea.
 
What you claim I don't understand, I do understand. What you claim are facts are truisms that are too obvious to be considered a useful contribution to this thread. This part of BoatDesign.net is supposed to be a space for collaborative design projects. If you don't like my ideas, please propose something better. If it's not relevant to semi-displacement electric launches, please take it to a different thread (a link to which you may post here if you want).
 
I'm somewhat loathed to continue,.....and yet....

Stephen Ditmore said:
... What you claim are facts are truisms that are too obvious to be considered a useful contribution to this thread. ...
Click to expand...

It is you that constantly introduces these non-sequitur "truisms", no one else....and what do they contribute...nothing, just pointless misdirection at a bright shinny thing.

Stephen Ditmore said:
...This part of BoatDesign.net is supposed to be a space for collaborative design projects. ...
Click to expand...

Says who?

Stephen Ditmore said:
... If you don't like my ideas, please propose something better....
Click to expand...

Why should I propose something?...is it a rule of the forum?
I am merely replying to posts that I read and asking for clarification upon the Ops claims, or request...or where Ops seeks information.

Stephen Ditmore said:
...If it's not relevant to semi-displacement electric launches, please take it to a different thread...
Click to expand...

Oh the irony.
You fail to grasp the endless misdirections on this thread are introduced by...er...umm....let me think!! :rolleyes::eek:





 

Attachments

Stephen Ditmore,
I'm still waiting for my question in post 180.
JS
 
Looking for a boatbuilder / sponsor willing to offer the winner prize money. In return for accepting the prize money, the recipient would license the sponsoring builder to build the boat. In my view, the builder should also offer the recipient per-hull royalties.
 
This is finally taking shape. It doesn't seem easy to find such an altruistic person. In any case, whoever pays for the design should participate in selecting the winner. They might even want to be the sole judge of the competition, or even set the rules themselves. And, naturally, such an "exceptional" design should be worthy of an "exceptional" award.
 
8mLaunch_in_container.jpg
8mLaunch_in_container2.jpg

A 40-foot high cube shipping container typically has interior dimensions of approximately 39 feet 5 inches (11.99 meters) long, 7 feet 8 inches (2.34 meters) wide, and 8 feet 10 inches (2.69 meters) high. My way or resolving whether catamarans are eligible is to require all contestants to be:
  • Fully functional as a club launch
  • Fit inside a high cube shipping container
This may be achieved by demounting (simple disassembly), so long as it can be done with a minimum of steps and fuss.
It may be achieved by turning the boat on its side (as required in the case of my monohull design), or by orienting it in any other way for which a support cradle can be designed.

This and other requirements may change if a sponsor is found for the contest, at the sponsor's discretion.
 
I think that the premise that a launch optimized for semi-displacement speeds would be different if it is electric powered than diesel power is misguided. A launch designed for a minimum range at semi-displacement speeds would be a relevant discussion if electric power is specified. However, semi-displacement has to be defined, which already takes many threads of endless discussions. A target speed must be chosen for the discussion to be relevant.
 
gonzo said:
I think that the premise that a launch optimized for semi-displacement speeds would be different if it is electric powered than diesel power is misguided. A launch designed for a minimum range at semi-displacement speeds would be a relevant discussion if electric power is specified. However, semi-displacement has to be defined, which already takes many threads of endless discussions. A target speed must be chosen for the discussion to be relevant.
Click to expand...

I agree entirely. It may have been a mistake to give top speeds (different for differet loadings) a significant place in my original "Parting Shot". I think the more central point for optimization should be the specified range/time relationship:
70 nautical miles in 8 hours or less in the half-load condition (weight of persons on board: 350 kg (772 lbs)).​
This implies an average speed of 8.75 knots, a speed/length ratio of 1.716 (length Fn=0.515) on a 26' (8m) waterline.

Concerning the matter of optimization, I've found these interesting reading:
The Electric Launch Fusion and the Component Waveform Theory | WoodenBoat https://www.woodenboat.com/online-exclusives/electric-launch-fusion-and-component-waveform-theory
https://mcgowanmarinedesign.com/mcgowanmarinedesign.com/Home_files/Hull Speed_ 2017.pdf

Concerning who I see as the market for such a launch:
Mediterranean’s first zero-emissions sailing club forms in Balearic Islands https://www.ibinews.com/news/mediterraneans-first-zero-emissions-sailing-club-forms-in-balearic-islands/53579.article
 
9-knots with a 26' waterline?

That calls for a catamaran.

( Or a stabilized monohull. )
 
Excluding me, the other two Americans who espressed interest wanted to enter catamarans.

Having said that, it's interesting that Nigel Irens, best known for his multihulls, designed the Clara 8m monohull for semi-displacement performance.
Hull Design for Propulsion in Small Craft - Clara Boat Company by Nigel Irens https://claraboat.co.uk/hull-design-for-propulsion-in-small-craft/
I agree that the Clara's shortcoming is inadequate stability to carry 8 passengers and an operator under ISO 12217 Cat. C.
A bouyancy tube all 'round, making it a RIB, might be sufficient to cure that problem. With that modification, I think a Clara would be a worthy entry.
 
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