JEFF GILBERT DESIGN
Q&A

Answers to Queries re: Scarper Flo (SF), 9.5m Gaff Cutter

I've received a gratifying amount of mail on this newish tilt at an oldish concept. I'm answering all the queries that came via the list here in a single posting. SF is a Blue water live-aboard Gaff Cutter for a couple to grab their dog and leave for good!. SF is both affordable (WLL<30) & owner-buildable (Ply on ply/ring frames, single hard chine.) NB. Query #1 covers plan acquisition & my general philosophy in this area.

Query #1
>From Mike Stockstill, 
mkstocks@bellsouth.net  ...
> https://mkstocks.tripod.com
> March 31, 2000
>Do you have any study plans available?

A: Study Plans are available for $25 US... the cost is mainly in A3 Color Photocopies and US Airmail.   If interested air mail a money order to

                   Jeff Gilbert Design,
                    9 Birbai Place, Waramanga,
                    ACT 2611, Australia.

I'll send your package the same day.  You'll get some real nice pictures for your wall, even if you don't build.  You may be better off buying the full set of 30 pages of offsets and plans for $US 50.  Included are full 3-D offsets and full 2-D developed panels, all at 82 centers, so that you can position bulkheads to suit yourself.  The warning, and reason for the lowish price is this...
you are buying plans which will ultimately produce a good craft, but only with a fair bit of input from you.....
I draw and computer run plans to the stage where an experienced builder could proceed, a competent back yarder too. Even had I the time, I wouldn't have the inclination to go the whole hog and write step-by-step manuals, as these construction techniques, sequences and details have been written plentifully and so much better by others.  For example, for this kind of construction, I'd recommend Buehler's Backyard Boatbuilding:

https://www.georgebuehler.com/books.html

Other useful building books:-

https://www.boatdesign.net/books/boatbuilding.htm

Query #2
>From: Peter & Polly Vanderwaart <pvanderw@optonline.net>
>March 29, 2000
> I want to ask you about the hull shape. Offhand, I don't remember
>seeing a v-bottom boat so deep forward and so shallow aft. The effect
>is somewhat exaggerated by the extended "mackerel's tail" run. What
>is your thinking, and how did you develop the shape?

A: My brother also picked this up. I think there is a bit of a tendency to superimpose a Bristol CC over this design. In fact there are more differences than similarities.  Scarper carries a large spread of sail, with the mast fairly forward, out of the full head-room area of the accommodations..  Consequently  I wanted a lot of forward flotation, and went for it with the deeper forefoot. The forr'd 2/3 beneath the V-berth is dedicated to this (about 30 cubic ft).  I'm 6'3" tall and wanted galley headroom while retaining an elegant sheer, low and upswept into a longish bowsprit. The only way to achieve this is to go deep, in this case it shows up in the forefoot. Another reason is that the narrow beam/fine entry -this gives the headroom (& adds speed) without a huge displacement penalty. This kicks out a lot of lift at the bow..again the deep fore-foot compensates.   The long aft run...(incredibly, given the extent of accoms, this design works at 27' 6" i.e. nearly 4ft cut off aft) I was after speed. and lowish wet area CF a conventional long keeled cutter. The ballast (40% inside, u/floor) is taken care of in the center third of the boat, & with the drop/ bilge  keel combo taking over the whole nature of the ship,  the long keel is replaced by a much atrophied version, which assists directional stability & protects both motor & rudder.  On the "Mackerel" tail, take a look at Zoe, by Daniel Z Bombighter, a veritable Hot-Rod of a Gaff Cutter, and  IMHO the "Classic Design of the Century for Extremely Short Persons"! (see p.91 Aug 1999 Classic Boat Mag).

>The L-shaped board is also the first that I can remember where the
>foot of the 'L' is allowed out of the centerboard case. I would worry
>that there could be trouble guiding it back into place, especially
>with a side load.

A: If its hard to haul up because of lateral forces, it will be because you are hard on the wind and hence it might be prudent to leave it down!(accidental fail-safe design!!?). Actually the boat is heavily ballasted at 50%, of with the board only 10% of overall.  There is no need to deploy it in shoal areas, or be pulling it up and down like the Keystone Cops. There IS a mistake in the dwg..the haul up cable should protrude from the tip not go through it from the side. When hauling it up (use a long-handled crank onto drum) this will guide the tip into the slot and she'll scrape on in after that.

The slot could have a couple of 45deg lip guide plates to help it in.  The tip itself would be ground to a rocket nose cone shape.  Both board & entry slot are heavily beveled, so that at worst it would scrape along in like tight scissors.  I'm happy to redraw the Drop Keel Profile...this is, after all, an appendage. The plate profile from tip to aft upper semi-circle about the axle could be changed to a constant inside curve which equalizes the problem. Again, reshaping the board as a triangle with a tangent from the tip to the upper semicircle about the axle would work fine but make access to one side of the Dinette a real clamber.  Another option is go rectangular..whack the tip off with oxy, then throw more lift weights in the bilge (NB boards on Zoe).

Question # 3
>From: Sidney L. Patin  <sidney@s...>
>Mar 27, 2000 (message 404 BCC Archive)
>How much would she cost to build in a yard ....

A:  These boats are conventionally carvel on steamed frames, and so are very expensive. Chuck Paine's Rockport 30, whilst an extraordinary boat in all respects, will set you back $450,000 US.
   ..............  https://www.chuckpaine.com/z30western.html
Because of the much simpler techniques in Scarper, (Stitch and Glue Ply on frames) you may be able to have it built for under $100,000 US. sailaway. There are 30 footers on the Market for less.  But you know and I know, the only way to get a bargain here is to avoid the huge Labor component you'll pay a yard.  I.E.  roll up your sleeves and leave them that way for a long time!

>.....and can you tell me who has already built your design (email
>addresses?)

A: In round figures, the number built is zero. The level of interest is moderate, but steady.

>How much are the plans?

Cheap, with reason. Please refer to Question 1 above.

>is there a way to build the boat with a bit more beam than 8'4'' (that
>would be kind of skinny for a live aboard IMHO)?  For something that
>length, I would be looking for a beam of about 10' or so, so my wife
>would have room for her grand piano. Ha ha.

A: Fair enough. I have seen a custom cat design with a music room .. a Shuttleworth I think. You'll find most Pilot Cutters are in fact 10ft wide.  (On the other hand some Sydney,  Australia inner city Terrace houses are, incredibly, 8 feet wide. But they don't even float!)  Lyle Hess' definitive BCC has a 10' 1" beam on a LOD of  28' 3'' which gives a relatively Tardis-like ratio of 2.8 to Scraper's slender 3.8.  In Scarper I deliberately sacrificed beam for gains in speed, stability, elegance and land transportability, in that order. So naturally you can have ten foot beam, but you will add considerable displacement due to the constraints forced on the design by the simplicity of the single chine construction. You  could control the displacement by cutting  the deadrise (and adversely affecting motion comfort). You would gain some form stability. Like all design exercises, no changes are without consequence. Ask your wife to replace her piano with a flute! Very peaceful, too.

I hope the above is of assistance. I would be delighted to answer any further queries if you can handle the delay!
Yours Sincerely
Jeff Gilbert
jgilbert@dynamite.com.au

 

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