• Sponsored By:

How does the Torpedo do it?

Ask questions before buying our plans or request a new design. Anybody can post here

Moderator: bateau-webmaster

How does the Torpedo do it?

Postby Spokaloo » Fri Nov 30, 2007 8:16 pm

Alright designer-guys, Im here to learn.

How is it that the Frost Torpedo, as redesigned by some shops in Maine and built at Rumery's, can do 32 mph? It isnt a planing hull by any stretch, it has waaay too much slope in the aft sections (no monohedron), its soft chined, and has a VERY sharp entry. They estimated 15-18 kts, but it ran wildly past expectations.

38' LOA, 9' beam, round bilged, and driven with 315 hp. One of the builders is quoted at being able to get 6gph at 30mph. THATS 5 MPG! Pretty far stretch from the 1-3 most boats get.

Id love to know how it works, because I think itd be an interesting boat to develop in this technique, as it could be an extremely efficient commuter, or with a sailboat-esque trunk, could have vast accomodations.

http://www.rumerys.com/T38%201%20folder/T38.6

http://www.rumerys.com/Torpedo38/T38.1%20header.500

(couldn't get the images to post to the forum without loading elsewhere)

I know it has similar proportions to the FL26, but It looks to be a very different boat as far as running characteristics, even exceeding a certain commuter by another designer.

E
Spokaloo
* Bateau Builder - Expert *
* Bateau Builder - Expert *
 
Posts: 4013
Joined: Tue Aug 22, 2006 5:29 pm
Location: Spokane, Wa
Location: Spokane, Wa

Sponsored By:


Register to see less of these.

Postby Dukydo » Fri Nov 30, 2007 10:43 pm

A different looking boat to say the least. I'm no expert by any means. Far from it. But I find the thing fascinating. It is squat and has more hull above the water than below. From the wheel back it is all above waterline.
duke
User avatar
Dukydo
Active Poster
Active Poster
 
Posts: 473
Joined: Mon Mar 14, 2005 3:07 pm
Location: Janesville, Wisconsin

Postby D2Maine » Fri Nov 30, 2007 11:14 pm

nm
Last edited by D2Maine on Thu Feb 16, 2012 10:25 pm, edited 1 time in total.
D2Maine
Very Active Poster
Very Active Poster
 
Posts: 596
Joined: Tue Nov 27, 2007 4:01 pm

Postby pete44 » Fri Nov 30, 2007 11:51 pm

Looks like one of my favorite Eastern Shore workboats — a Chesapeake Bay Hooper Island draketail.

Image

“The "Hooper's Island Draketail" was named after the small island located in the lower half of the Chesapeake Bay on Maryland's Eastern shore. In the early 1900's, when the internal combustion engine first appeared, watermen were trading the sailing rigs for the engines and the local boat builders were looking for new ways to build better and more efficient workboats. One such builder noticed the torpedo boat destroyers pass by his home, and he thought that the hull design would be good for a workboat. He copied the hull design and built a boat with a V-bottom. The boat was fast, good looking and because of the narrow beam and sleek lines, it was relatively inexpensive to build.

The design caught on and the boats sprang up everywhere. The boat acquired the name "draketail" because the stern resembled the back of a duck's tail. A few years later, a new box stern type became popular, and the draketail became old fashioned. Eventually, the full name was shortened and now most people only know them by the name "ducktail". Today, not many of these beautiful boats exist. But through the passage of time, the boat has become a classic.â€
pete44
Frequent Poster
Frequent Poster
 
Posts: 79
Joined: Thu Jan 25, 2007 11:11 pm
Location: Maryland

Postby Spokaloo » Sat Dec 01, 2007 1:27 am

D2, good call on the Leonard W (which happens to still be in the back shed at Rumery's). From what I heard, the Lowell boys saw the hull during its construction and said it was pretty bastardized from an original Frost. Apparently they built in some of the hog it had developed over the years and didn't get some of the lines right. Sounded like the sheer was off and the buttock lines were different than initially intended.

Frost's boats were fast, but were they as fast as the Torpedo ended up? I wonder if the draketail really made a big difference.

Pete, Ive always liked the downeast workboat look, almost (but not quite!) as well as the PNW salmon trollers. Frost was supposedly the godfather of the modern lobsterboat, and thats pretty obvious in the photo you posted. Thanks for the short history.

It just seems like that boat gets through the water so stinkin efficiently, I want to see how it applies to a smaller boat. That 38 would be a blast as well, or something similar (34' is such a nice size for near-shore waters).

E
Spokaloo
* Bateau Builder - Expert *
* Bateau Builder - Expert *
 
Posts: 4013
Joined: Tue Aug 22, 2006 5:29 pm
Location: Spokane, Wa
Location: Spokane, Wa

Postby Vman777 » Sat Dec 01, 2007 2:33 am

I love the Hooper Island Draketail. Wish somebody had plans or somebody would do one, say in a 25'-30' range.

Right now the only plans I know of for a draketail are from Kaufman Design. http://www.kaufmandesign.com/stockpln.html

The 20' Hooper Island Lauch
Image

David
Vman777
Active Poster
Active Poster
 
Posts: 425
Joined: Sun Sep 25, 2005 11:37 pm
Location: Orlando, FL

Postby jacquesmm » Sat Dec 01, 2007 10:34 am

It is easy to design such a boat and get the same performance (minus the hype).
To keep it brief, last month, Joel and I participated in a seminar given by Nigel Irens. He explained the theory, nothing new but well applied by him to his Range Boat. Read about it here:
http://www.hiswasymposium.com/pdf/2004/ ... 0Irens.pdf

The most interesting part is not in that paper but was discussed with him after wards: why do those boats and plans not sell?
(Range boats sold 2 or 3 units in 4 years!!!!)
Because they have limits that people do not accept (or understand), because marinas charge docking fee by length and because of misconceptions.

People do not accept that those boats must be light and narrow.
See all the questions about the Nina (LB22): can I raise the freeboard, add a cabin, widen the boat?
They often reason that if they have a 26' boat, it must have the same double cabin, galley and shower than in the Bayliner they saw at the dealer.
They buy the Bayliner but since a Sunday afternoon trip cost $ 200.00 in fuel, they stay at the dock with it. In the mean time the Range Boat owner is cruising and cruising and cruising.
They don't cruise but at least they have headroom in the shower.
:doh:

VSLH are a great concept but a commercial fiasco.
I already designed the LB22, the FL26 is coming soon and if it works, you will see more.
There is no magic in the design. I have many lines plans and specs of those hulls including the Hooper Island Launch and probably the Torpedo. The design is not the problem, the problem is with the choices made by the builder/owner.

There is hope on the horizon: crude oil is going up and we may not be able to afford gas guzzlers anymore.
Jacques Mertens - Designer
http://bateau.com
User avatar
jacquesmm
Site Admin
Site Admin
 
Posts: 20178
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA

Postby pete44 » Sat Dec 01, 2007 12:27 pm

Vman777 wrote:I love the Hooper Island Draketail. Wish somebody had plans or somebody would do one, say in a 25'-30' range.


The Chesapeake Bay Maritime Museum store has plans for “Martha,â€
pete44
Frequent Poster
Frequent Poster
 
Posts: 79
Joined: Thu Jan 25, 2007 11:11 pm
Location: Maryland

Postby Spokaloo » Sat Dec 01, 2007 1:04 pm

See, we need a section of the forum where the designers can post some of those essays and documents on design. Not only does it help make sense of what our boats are doing (and is incredibly interesting to someone like myself who wants to learn as much as he can), but can also better explain why you design something a certain way and may reduce the number of people who want incongruent changes. When a question pops up, just shoot them a link like that.

How about this?

28-32'
deep, narrow forefoot
speeds similar to those of the other drakes, cruise at 12-20, top around 30ish
sleeping for 2+2 ( +2 may be out in an open wheelhouse with canvas)
Soft boot-type enclosure that pops out of the cabin top for a full height shower ( :o remember, 6'3)
head
Small stove to make some food on

Too much? Not looking for a trawler, but getting the most out of her limited load-carrying ability.

P.S.; SWMBO just gave this the go-ahead, she likes it.

E
Spokaloo
* Bateau Builder - Expert *
* Bateau Builder - Expert *
 
Posts: 4013
Joined: Tue Aug 22, 2006 5:29 pm
Location: Spokane, Wa
Location: Spokane, Wa

Postby jacquesmm » Sat Dec 01, 2007 2:53 pm

The FL26 is a minimal version of what you just described.
It could have a vee hull and be longer but the philosophy of the boat is identical.
Jacques Mertens - Designer
http://bateau.com
User avatar
jacquesmm
Site Admin
Site Admin
 
Posts: 20178
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA

Next

Return to Questions before purchasing the plans and announcements..

Who is online

Users browsing this forum: Google [Bot] and 1 guest