Electric Launch Design optimized for semi-displacement speeds

From https://www.rselectricboats.com/faqs/

What is the weight of the Pulse 63 electric RIB?

815kg (including the batteries).​

From Coding & LCA - RS Electric Boats https://www.rselectricboats.com/coding-lca/

Design CAT C

Capacity 6 Persons​

From Eco-Friendly and Sustainable Electric RIB from RS Electric Boats https://www.rselectricboats.com/eco-sustainability/

PET Core
Natural Flax Fibre
Recycled Carbon Fiber (presumably chopped rather than continuous)​

We're going for a capacity of 8 or 9 persons on an 8m waterline boat with the same motor and about the same range.
Seems on target to me; steady as she goes.

 

While I believe these to be displacement speed launches, I thought I'd share what I've learned of them.
This is a Doug Zurn design with which Boston Boatworks and the late Mark Lindsay were involved: An Island and an Engineer: The Inspiring Story Behind Three Mile Island’s New Electric Boat https://www.outdoors.org/resources/amc-outdoors/features/the-inspiring-story-behind-three-mile-islands-new-electric-boat/
Attached as a PDF is information on the L-33 by Rob Ladd.
On Labor Day I took a (slow) cruise on the Dave Gerr designed Solaris: Category: Solaris https://www.hrmm.org/news/category/solaris. Solaris gets all her power from the onboard solar panels; no shore-side charging.

 

The entry packet is ready! (attached)

 

Concerning a simplified approach to power prediction, Appendix A from Robert Beebe's Voyaging Under Power, 4th Edition, is attached.

“Wyman’s Formula” was published in Professional Boatbuilder #94:

Wyman, David B., author: “Wyman’s Formula,” 54:96, 57:7
Professional BoatBuilder #94 Apr/May 2005 https://www.woodenboatstore.com/products/94-pbb-apr-may-2005?srsltid=AfmBOopgS5Bz6PchkmEx-0AzA8PIVwCZu1EfmC9UU2UQdYrJEAJjSMt1
​

There's more discussion of power prediction at Power predition formula https://www.boatdesign.net/threads/power-predition-formula.45639/page-2#post-963483

 

Correction: Issue 54 August/September 1998, pp 96-97 Free download: Issue Library - Professional BoatBuilder Magazine https://www.proboat.com/issue-library/#issue-number-54/98
Professional BoatBuilder issues 1 through 196 can (as of 2024-11-09) be viewed and downloaded for free at Issue Library - Professional BoatBuilder Magazine https://www.proboat.com/issue-library/

 

Thank you DCockey.

Who is going to METSTRADE and would print & hand out eLDC Entry Packets?

Any other ideas for how to promote the contest?

• Should we seek an affiliation or relationship with a show or magazine? How should I go about that? Should it be IBI? Electric Hybrid Marine Technology? The new owners of Professional BoatBuilder (no longer WoodenBoat)? Someone else?
• How about a school or some other player in the electric boat world?
• Do we need to modify our due dates?
• Other thoughts / possibilities?

I'd like to welcome naval architect Winn Willard of Ray Hunt Design (New Bedford, MA, United States) to our panel of judges. While Ray Hunt Design is best known for monohedral deep vee planing hulls, Winn indicates he is interested in semi-displacement forms. Thank you, Winn, for joining us.

Entry information can be downloaded from this thread post #168.

 

PBB would be a natural fit but is there a new owner? I have not seen or heard anything about a new owner, and the website has not been updated.

 

Yes, it happened before IBEX. Aaron Porter resigned, but then was reinstated.

This contest, as you may know, was the Parting Shot in the August/September issue at Aaron Porter's invitation. He said they would not be adopting it as their "design challenge", though, as the last one caused friction with the WoodenBoat staff.

Ar IBEX the rumor was there might not be a Dec/Jan issue. I expect we'll know soon.

 

Aaron was announced as editorial director of IBEX (new position) just before the IBEX show. While it's logical to assume that means IBEX will be publishing PBB in the future there is nothing in the announcement about IBEX taking over PBB. IBEX Hires Aaron Porter as Editorial Director - IBEX Show https://www.ibexshow.com/ibex365/news/ibex-hires-aaron-porter-as-editorial-director/

If PBB resumes publication under IBEX or a other new owner then friction with WB would not be an issue.

 

That's my hope, too - but my sense is there are parties still feeling each other out, and that the transition is going to be a slow process.
I don't think the new owners and the IBEX show people are one and the same. What I heard is that it's a group led by someone involved in the original creation of PBB.

 

I've provided additional comments on the relationship between intact stability and capacity per ISO 12217 at The ISO 12217 Stability Series is currently under revision https://www.boatdesign.net/threads/the-iso-12217-stability-series-is-currently-under-revision.69718

 

Here's one of the Phil Bolger powerboats that presaged the modern America's Cup hydrofoil sailboat hulls.

 

A handsome large launch at Indiantown Marina, Indiantown, FL.

 

We do not have enough entries to proceed with this project as a design contest. I'm about to write those who have contacted me to discuss whether there's a way forward, some change we should make, or if involving a sponsor would help (and who to approach).

I invite suggestions here. In the coming days I'll post what I've drawn, and others are invited to do likewise.

 

There is no free lunch.
You have to pay for what it costs to design and build a boat to your specifications.
How much are you willing to pay?
There is no free launch.
JS