Chebacco News 54

 

Altus Trip – Richard Spelling

So I’m pulling Schroedinger to Altus; traveling on 40 west of OKC. Around mile marker 70 I start to see big huge windmills in the distance. As I get closer there are more and more, then a whole farm of them – maybe a hundred. I start thinking, “Hey, these weren’t here the last time I was through this way.” Then I get to trying to figure when the last time I actually WAS through here was – on 40 west of OKC. Seems it was while I was in the Marines going to El Toro, driving a friends Volkswagen van, with four bald tires, in the middle of a huge winter ice storm. Back in…. 1984. Time flies when you are having fun. I think I need to get out more..So I’m pulling Schroedinger to Altus; traveling on 40 west of OKC. Around mile marker 70 I start to see big huge windmills in the distance. As I get closer there are more and more, then a whole farm of them – maybe a hundred. I start thinking, “Hey, these weren’t here the last time I was through this way.” Then I get to trying to figure when the last time I actually WAS through here was – on 40 west of OKC. Seems it was while I was in the Marines going to El Toro, driving a friends Volkswagen van, with four bald tires, in the middle of a huge winter ice storm. Back in…. 1984. Time flies when you are having fun. I think I need to get out more… <grin>

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With the “mountain” in site, on a two lane road, I have a blowout. With only a couple thousand miles on these tires and with the weight of the trailer well within the weight rating. Last time I buy tires at Pep Boys. Second blowout, actually, but the first one was caused by a roto-tiller hidden in the grass, so I can’t hold that against them.

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Go to jack up trailer and scissors jack won’t fit under axle. Pull forward to a more level spot and it will then fit under axle but it won’t even begin to lift up the trailer. Break out truck jack and use it on frame of trailer to take some of the weight, then use scissors jack to lift axle up enough to get wheel off. Need to weld me up one of those funny looking “stick under axle and pull forward” trailer jacks.

Go to put on my spare (which is brand new, from previous blowout) and guess what. It doesn’t fit on the hub. The center of the hub (which I replaced years ago because the bearing races were loose in the hub) is just slightly too large for the rim.

And I’m in the middle of BFE so, of course, my cell phone doesn’t work. With fortuitous foresight I had tossed a 3lb hammer and 1-1/8″ thick piece of round stock in the bed of the truck instead of putting them up properly before I left. I bent over the new wheel and pounded on the hub center in a circular motion for about 10 minutes till I “persuaded” it to be a little bigger.

Nice wind for sailing when I get there but I just came off a night shift and a long drive, so I sleep

Next day the wind is real light but we go out anyway. Decent sail.

dadboatlakealtus

I pack up and head back, trip is uneventful.

***

Chebacco Lily Catchpole – Howard Sharp

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It was a beautiful day and we managed to navigate without damage to boat or egos.

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Some construction photos. Turning day; easily done by two and the slight slope outside the garage.

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The cockpit construction, with bridge deck. I built in two battery boxes for the not too far off day when we will all be using electric motors (at the moment she’s propelled adequately at 5kts by a 5hp Nissan). Lily has navigation lights, and one of the battery boxes is taken up by a 1/2 size 12v battery recharged by a solar panel.

I’m keeping the boat on a trailer, launching it every time I sail, and motoring away from a crowded dock. I chose to lock off the motor dead center and use a remote throttle from the cockpit rather than reach back over the motor well. Rapid last minute changes of direction are not possible, but in my view the convenience of having throttle control right under my hand (or foot) is a worthwhile trade off. I’ve also found that I need to keep the centerboard down for better directional control, especially when in reverse.

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Two weeks after launch, I took the boat to the boat to the WoodenBoat show at Mystic, CT, as part of the Phil Bolger tribute. Chebaccos were well represented,as you can see. From the left, Ben Ho’s raised deck version, with a lot of useable space in an enlarged cabin, and a self-draining cockpit, “Lily Catchpole”, and David? Robichaux’s “Grey Cat”.

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We got to meet PB himself – Ben Ho with PB:

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Here he is asking me to conduct experiments to see what effect raising the centerboard has on weather helm:

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And on Saturday “Lily C.” and I were delighted with an honorable mention in the Concourse D’elegance owner-built category:

I’ve sailed bigger yawls in the past, but the Chebacco has reminded me just how useful the mizzen can be for a single-handed sailor. Even under motor, the sail can be used to reliably steer the boat for minutes on end, while I go about clearing things up for docking, navigating, or preparing for night. “Lily Catchpole” will easily sail at 5kts, and with 15kts of wind has reached 6.5kts under one reef – pretty good for a boat of this size. We’re planning a circumnavigation of Manhattan, and hope to bring you a report.

Howard.

***

That Trip – Nick Hughes

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Dear Richard here is an account of our first journey in Sylvester the Chebacco we bought from Richard Elkan in London in May. My girl friend Sally and I left Greenwich , London at 5:10 a lovely calm morn with the promise of force 5/6 gusting 7 later in the day.

We decided to motor with our trusty lil’ Honda BF5 as we wanted to complete the trip of about 25 miles in one day as quick as possible. We passed quickly through the Thames Barrier, the old Docks , and wharfs and kept a weather eye open. We had decided that if the weather had taken a turn for the worse by the time we reached Gravesend we would overnight there but as it happened there was a N.Easterly blowing making for a nasty chop but nothing terrible, so we decided to press on.

However once we were in the mouth of the Thames Estuary the awful combination of a N.easterly now picking up in strength on an ebb tide made for a rough passage. The area is notorious for being rough in a North Easterly but we reckoned we had just enough of a window to get through. We then followed the Isle of Grain coastline at a very healthy distance as it dries out for about a mile and we watched as surf formed on the far shore. and so we headed for to the River Medway Estuary about 4 miles away.

And so it went… the wind now reaching the promised 5/6 and gusting more at times, not the most pleasant of journeys. the next two hours were bloody rough, the waves up to 7- 8 feet high. Sylvester’s bow rose up and up then we slide down or rather pounded down before the next one rose before us. After an hour we had not come to any grief and were impressed by Sylvester’s strength and ability in such a sea and motored on. We took on only little water as we were head on to the wind .. again most impressive.

Keeping well clear of the dreaded lee shore on the Grain shallows we literally ploughed on!! then as we approached the mouth of the River Medway we saw a small yacht run aground on the Grain shore, surf was breaking over her and it was frightening to watch. No one could get near because of the lack of water/ surf etc and she sent out a Mayday. Soon enough the police rib came out followed by the Sheerness lifeboat. In the meantime she had somehow found enough water to get free… a lucky man!

We then had the pleasure of entering the Medway with the N.E wind building up huge waves astern which were actually breaking .It was hard work to keep from broaching … surf down the waves …. yaw.. get ready and off we went again!! … even some big modern motor cruisers were struggling as they ran for shelter. Finally after about half an hour we were in more sheltered waters and could relax for the next two hours until we reached home.

We finally got back to our barge at 13.30, cold wet but very very confident in Sylvester’s abilities. We live on a 1926 Dutch barge and spent 26 hours bringing her back from North Holland to England but that was nothing compared to our first journey in Sylvester.. Thanks Phil Bolger to designing such a stunning little boat and credit to Bill Sampson who built her..Hopefully we shall be able to go for a sail soon.. but thats another story yet untold.
regards Nick & Sally

***

Inspector Clouseau a cold moulded Chebacco – John TumaRichard,

I am sending along some pictures of my modified Chebacco, “Inspector Clouseau.” Two weeks before the launch date, I discovered the boat was covered with pink overspray. It’s a mystery where it came from, hence the reference to the Pink Panther.

My boat is a combination of cedar strip and cold molded construction to the lines of the lap-plank Chebacco 20. However, I adapted the full keel from the glass house Chebacco for this boat. By eliminating the centerboard trunk, I was able to open up both the cockpit and the cabin. The boat carries 200 pounds of scrap steel and concrete ballast.

Inspector Clouseau sails to weather remarkably well, though how is a bit of a mystery, but off the wind this boat really shines.

The pictures show me out sailing in the Oakland-Alameda Estuary, and also out on San Francisco Bay.

If anyone is interested in knowing more, they can reach me at j_tuma (at sign) comcast (period) net.

John Tuma

 

PS: Thanks for putting the Chebacco News together. I really enjoy

seeing what other Chebacco enthusiasts are up to.

 

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Chebacco News 26

Chebacco News

Number 26, May 1999

kangaroo

GINA – on Kangaroo Island, Australia

GINA

Colin Hunt, of Victoria, Australia, sent me this picture of GINA – Clive Colenso’s lapstrake Chebacco. He reports a good, dry boat which has been surveyed for charter hire. The waters around Kangaroo Island can get pretty rough. GINA has the cockpit modified to be self-draining with approximately ½ cubic meter of underfloor stowage for outboard, anchor etc.

Colin asks if anyone has the offsets for any version of Chebacco on a computer file in .DXF format? This might lend itself to CNC routing, to allow mass production of Chebaccos!

Chebacco –25 . . .

Simon Jones (also in Australia) reports:

I’m building directly onto the bulkheads which I have moved to new stations , I am intending to rig her with a jib and a small bowsprit to accommodate anchors and larger foresails ( reachers etc, ) the interior has been enlarged to give full sitting headroom and quarter berths as well as a big double forard , taking out the centreboard has allowed me to cut the keel down to a flat keelson reducing draft and giving me a nice companionway to stand in with the hatch open , ( I’m just running thru all the alterations I can think of here ). I have closed in the cockpit at the stern to give me a large lazarette for storage, the cockpit is still 7′ long so plenty of day room … I have jumped up the deck height 6″ all round and instead of a flushdeck style cabin I have changed to the standard box cabin as in the 20 with a 5″ side deck (just enough for one foot, the other using the cabintop) while this is pretty thin its enough to go forard if necessary, however I hope to use

my forard hatch for most foredeck work . I’m keeping the mizzen as I have always found them to be worth every penny.

I’m currently epoxying everything as its obviously easier than doing it after construction, and I hope to have her in the water before the end of the year as I have the luxury of being able to work on her pretty much full time.

Your idea of having a Chebacco meet sound great! … I’d love to fly over to Canada and be in it…. That’s one fantastic cruising ground they have there and a chance to sail there should never be missed (falling in the water however is a one off!…. your firth would be warm by comparison) ok …I wont bash your ear about it all any more … I’ll be sure to get piccies to you when I have them.

Cheers Simon.

Well! This’ll be one interesting boat. As far as I know, it’ll be the very first Chebacco-25 to be launched. Watch this space!

Plywood – your views –

Tim Fatchen – yet another Australian, writes:

[WBS in Chebacco News #25
“So – Write to me about your ideas on plywood. I’ll fess up first – I
used pretty cheap Far-Eastern ply labeled BS1088, though it was
clearly nothing of the kind. It has frog-hair thin outer veneers, and
thickish inner ones. On the other hand the glue is certainly
waterproof and there are few if any voids in the inner veneers. My
theory is that glass/epoxy sheathing would make it acceptable, and
so far I’ve had no problems (3 years after launching). Let’s hear your
stories!”]

Bill, you clearly took the road favoured by the elite. From your
description of the plies, we fairly clearly used the same source for
Flying Tadpole in 1991, except ours was a grade down and didn’t try to
pretend to BS1088 (unless the BS stamp was added later to boost sales).

Nevertheless, still good waterproof glue and very few voids despite the
froghairthin outer plies. After seven years of abuse in Flying Tadpole,
the only problems which have arisen are two or three spots where
checking of the top ply has occurred (a series of slits about 1/2 inch
long, look like razor nicks) and we haven’t bothered doing more than
give them a lick of paint. Longevity was helped by through epoxy
encapsulation.

Our Nymph, even older (1989), was made from the same ply. Even more
abuse, sits for months at a time under the oak tree, gets roughly hurled
onto decks of houseboats occasionally, always makes landfall on sharp
stones lurking in the mud…Various nicks, dings and scratches in the
bottom, brutally neglected, but still absolutely sound (and originally 3
coats of epoxy inside and out, but no fibreglass).

In both cases, the ply was very heavy, though – I suspect mangrove wood
as the inner plies. Only real objection to it is that it’s a dog to work
compared with gaboon – splinters. I’m reminded of this as we’re still
using odd leftovers of 1/2 inch (not as good as the 1/4 inch was for
voids) as backing plates for deck hardware, battery boxes etc.

So that’s seven and ten years respectively of both use and neglect, the
latter being harder on boats…

Tim & Flying Tadpole

A few notes on the Chebacco’s properties

By Giuseppe ‘Pippo’ Bianco

Like most of the CN readers, I’m particularly intrigued by Phil Bolger’s designs and I have purchased plans for the Micro, Long Micro and Chebacco. The latter is very close to what I need: the most boat which conjugates sheet plywood construction, easy transportation, launching and hauling with a trailer, comfort and safety. I’ve not been able to find any data like righting moments and seaworthiness index for the Chebacco, so I decided to try to compute them by myself. After all, I’m a scientist by profession, so, I said to myself, this shouldn’t be too difficult… Well, that is true only in part. A complete analytical description of the interaction between a sailboat, the wind and the sea waves is almost impossible, and probably the only way to get comprehensive and reliable results would be building the boat, stuff her with instrument (like inclinometers, accelerometers, strain meters), sail it in a variety of conditions while recording the data, analyze them and draw the proper conclusions. I’m pretty sure that nobody carries out such measurements except maybe large, well funded designing companies working on super racers involved in world class competitions. So, in the amateur’s world, one is forced to use a mixture of common sense and a few empirical formulas.

A few basic numbers are needed to make a first assessment. Carl Adler (early readers of the Common Sense Design’s Newsletter will recall him as the Micro prototype builder) runs a great interactive sail calculator on the WWW which allows direct comparisons between any pair of sailboats listed in his database, recently integrated by myself with the relevant data for the Micro, the Long Micro and the Chebacco. The URL of his page is http://www.image-ination.com/sailcalc.html.

The parameters one needs to know for each boat are the length at water level (LWL), length out all (LOA), the beam, the displacement and the sail area. For the Chebacco those numbers read as follows (in metrics, yeah):

LOA=5.99 m; LWL=5.04 m; Beam=2.26 m; Displacement=789 kg; Sail area = 16.35m2.

The sail calculator crunches those numbers and rapidly comes out with the following sentences for our boat (compared hereafter with the corresponding data for the Micro and Long Micro):

Category: racer. Carl classifies the boats into four categories: racer, racer/cruiser, cruiser/racer and cruiser, in descending order of performance. Micro classifies as racer/cruiser, while Long Micro gets a cruiser score.

Capsize Ratio: 2.5. This number is an indicator of a boat’s ability to resist to the capsize: a value lesser than 2 is considered good; the higher the number, the more vulnerable is the boat. Micro gets 2.0, Long Micro 1.8, so both are stiffer than the Chebacco.

Hull speed: 5.5 knots . This figure depends only on the LWL. Micro 4.7, Long Micro 5.3.

Sail area displacement ratio: 19.5 . This is an indication of how powerful a sail plan is with respect to the vessel’s displacement. Values around 18 and higher indicate high performance boats. Micro gets 17.5, Long Micro 23.5.

Displacement length ratio: 170 (light). Micro sports a huge 411 (heavy), Long Micro an average 274 (moderate).

Length to beam ratio: 2.24. Micro gets 2.21, Long Micro 2.63. A value of 2.7 is considered average; 2.2 is low.

Motion comfort: 10.6. This numbers depends on a complex way from displacement, length and beam: the higher the number, the more comfortable is the boat. Micro gets 17.8, Long Micro boosts a 20.1.

Be warned that sometimes the ratios above are not plain ratios, but rather complex expressions involving odd powers of the parameters. A good description of the formulas used to compute the above parameters is given in  http://home.att.net/~hcyoung/formulas.htm

Well, the empirical formulas above confirm what the Chebacco sailors know already about her being spirited. Her capsize ratio is apparently not so good, such as the motion comfort index which is worse than the Micros’.

Not content yet with these numbers, my next step involved some more in-depth analysis. There are two ways to do that. The first is the old-fashioned one: grab a (modern) scientific calculator and a ruler, make measurements on the plans and compute the sought-for parameters, following algorithms commonly found in books on boat design. The second consists in modeling the boat in a dedicated computer program, which in turn will do all the number crunching. Commercial hull design programs are very expensive and barely worth the expense by an amateur: the free demo versions are, in my opinion, almost useless. Luckily enough, however, there are a few nice complete programs around, available free of charge on the WWW. The ones that I know better are Carene40 and Carene50 by Robert Lainé, Hulls by Gregg Carlson and Hullform 6S by Blue Peter Marine Systems. The Carene family is nice and robust, but it’s a bit lacking when one needs to compute the static properties of a boat. Hulls is great, with the only possible exception being the limited number of sections allowed to model a hull. Hullform 6S is probably the best and most complex, yet relatively easy to use, but unfortunately it doesn’t perform the plate development as the first two. On the other end, it’s not limited to hard chine hulls, and comes with a nice user’s manual.

I decided to use Hullform 6S to do my analyses. The first step has been to input all the sections as described in the table of offsets of the Chebacco’s plans. This is quite straightforward. I did that using the 42″ water level as baseline: the end elevation view of the resulting hull is shown in the figure below, where on the right half is the forward view and the left half is the aft view. The scale is in meters. This is very close to the drawings on the original plans, even if admittedly not perfectly fair. I didn’t consider the keel to keep things simple.

chebend (2)

Now, in order to perform the static analysis, one has first to balance the hull. I found that my synthetic hull balances very well (i.e. the pitch angle is very small) using the center of buoyancy positions given in the plans, with a few cm tolerance. Using a nominal displacement of 789 kg (1740 lbs.), the plans indicate a bottom draft of 0.193 m, while I find a bottom draft of 0.205 m. This is a difference of 12 mm. Alternatively, to sink the boat at the nominal draft, the displacement would have to be 710 kg (1565 lbs.). I don’t know which one is the correct number. Please note that this is the bottom draft (canoe body draft), not the keel draft.

The nice thing with Hullform is than one can compute the righting moment as well as other parameters for any heel angle. Let me warn you however that my analysis is oversimplified. It doesn’t take into account the combined effect of masts, sails, crew position, wave effects, and so on.

Another warning here: the righting moment computation requires knowledge of the position of the center of mass of a boat, around which the boat rotates when heeling. Longitudinally it has to be in the same position of the center of buoyancy, but the unknown here is its vertical position. This is tough to compute and actually, in the real world, it moves together with the crew and all the stuff on the boat. I first set the center of mass of the Chebacco on the waterline plane, but I’m not sure whether this is true or not. According to Bill Samson, this is a bit too optimistic, so, following his suggestions, I’ve performed the same calculations two more times, respectively lifting the center of mass by 0.1 and 0.2 meters.

Last warning: apparently Hullform treats any hull as if it was completely decked at the sheer level, even if there is no mention of this in the user’s manual. The Chebacco is not decked for a good part, so my results are optimistic.

Nevertheless, after 111 runs of the program, here are the plots of the computed righting moments with respect to the heel angle for three different vertical positions of the center of mass, referred to as VCG (vertical center of gravity).

Image6 (3)

My first (VCG=0.0 m) synthetic hull gets the sheer into the water at about 35 degrees of heel. It is apparently self righting up to about 115 degrees, but over that angle it goes all the way down to settle upside down. Looking at the numbers, there is no chance to right it back by pulling on the centerboard… Note also how the curves move downwards when VCG increases, indicating the well known effect of worsening stability. For VCG=0.1 m, the sheer at midships gets submerged at an heel angle of about 40 degrees, and the righting moment vanishes at about  degrees. Finally, for VCG=0.2 m, the sheer gets under water about 45 degrees and the boat is self righting up to about 95 degrees of heel.

An important number used to assess the stability of an hull is the ratio between the area under the curve with positive righting moments to the area over the curve where the moments are negative. In our first case (VCG=0.0 m), this ratio is about 2.7, reasonably good, but it goes down to 1.9 for VCG=0.1 m and to 1.3 for VCG = 0.2 m. After having computed these and several more parameters (actually Hullform does everything), one opens “Principles of yacht design” by L. Larsson and R. E. Eliasson at page 54, enters those numbers in the equations therein and computes a magic number, called the Dynamic Stability Factor (DSF). The Chebacco’s parameters for VCG=0.0 yield DSF=11, placing our beloved boat among the “inshore” vessels. This classification, endorsed by the International Standard Organization, classifies vessels into 4 categories following the water conditions they’re qualified for: sheltered (DSF<10), inshore (10<DSF<25), offshore (25<DSF<40) and ocean (DSF>40). The most penalizing for the Chebacco is the so-called Beam Displacement Factor, which apparently indicates that the beam of the Chebacco is too wide with respect to her typical displacement. However, increasing the displacement is not that effective in getting better figures for the DSF, and this apparently confirms that Phil Bolger and Brad Story are right (surprised?) when they say that additional ballast would be useless in the Chebacco. On the other hand, a slightly narrower beam (e.g. 2.0 m instead of 2.2 m) would have boosted the DSF to much more seaworthy values. The situation obviously worsens for VCG=0.1 (DSF=9), and for VCG=0.2 m (DSF=7). Hence, based on the above criteria, the 20′ sheet ply Chebacco is marginally qualified for inshore waters.

It needs to be said however that this flaming of the wide beamed boats came after the infamous Fastnet disaster in 1979, in particular because those boats are more easily capsized due to the action of big (b-i-g) and breaking waves and, when capsized, are more stable upside down. I don’t think that any Chebacco sailor would ever try to test his boat in really bad seas, so watch the weather forecasts… In any case, like Bill Samson said elsewhere in the CN, this reasoning is academic because there’s no notice yet of a Chebacco having been capsized.

Given the flared sections of the Chebacco’s hull, I tend to think that the computed DSF values are a bit underestimated, and I would conclude by saying that those boats “…are very good in rough water and forgiving in squalls and with prudent and skilled handling and not exceptionally bad luck would get over the North Sea, or the ocean for that matter; but by present day standards they are inshore and fair-weather boats”.

P.S.: for those who didn’t catch it yet, the last sentence is Phil Bolger’s opinion on his Chebaccos. I’m by no means an expert in boat design, and my speculation should only be considered as the result of a few pleasant hours of work of an amateur boat builder during a rainy week-end. Nevertheless, I would love to hear PCB’s opinion on this “paper”…

Bibliography

Lars Larsson and Rolf E. Eliasson 1994. Principles of Yacht Design. Camden, Maine: International Marine

Howard I. Chapelle 1936, 1994. Yacht Designing and Planning. 2nd Edition. New York, London: Norton

Philip C. Bolger 1994. Boats with an Open Mind. Camden, Maine: International Marine

Tabernacle and Bowsprit

David Neder writes

I am located in the city of Waukesha, Wisconsin. About 90 miles NNW of Chicago
or twenty miles due west of Milwaukee/Lake Michigan.
I am attaching photos of the “Anna C”.

Agf00001
Bow with tabernacle and short sprit.

Since the boat will be trailered and I am too long in the tooth to wrestle with a mast, I added the tabernacle. Its section modulus in both the x and y axis is twice that of the mast at the pivot
point.


Materials: 1/2 Fir Marine Plywood, Ribbon strip mahogany plywood, mahogany, red oak, West Epoxy, Fiberglass. Two part poly-urethane paint on the exterior. Interior is paint with Acrylic paint with a fungicide. Construction is taped seam.

David J. Neder

And finally

David sent some other images, too, but there’s no more room in this issue. Neither is there room here for all the plywood-related comments, so they’ll have to be held over as well.

Please send your contributions to me, Bill Samson, 88 Grove Road, Broughty Ferry, Dundee, DD5 1LB, Scotland. wbs@sol.co.uk

Chebacco News 04

Chebacco News

June, 1995 Another couple of months have come and gone and progress continues on the Chebacco-building front around the World. Here, in the Northern hemisphere, temperatures are getting into the epoxy setting range. Scotland has been particularly lucky, with temperatures getting into the 80s during the first week in May (though they did fall back into the high 40s later in the month).

Can you help?

I had a letter from Mark Raymer of South Bend, Indiana, who has been considering building a Chebacco-25. He wants to be sure that a Chebacco will point high and tack through no more than 90 degrees, as windward performance is important to him. Unfortunately, having had no first hand experience of sailing a Chebacco, I was unable to help him. If anyone has had such experience, or knows anyone who has, it would be great to hear from them. As I explained to Mark, most of us are amateurs who are building, or contemplating building a Chebacco. As far as I am aware, none of us amateurs has actually completed one yet, and, so far, I’ve been unable to establish contact with Chebacco owners with a lot of sailing experience under their belts.

Establishing contact

Bill Parkes from Mechanicsburg, Pennsylvania, who is just plucking up the courage to start on his own lapstrake Chebacco hull, tells me he got together with Gil Fitzhugh so he could see the techniques used, at first hand. Gil tells me that within a couple of years he has gone from the stage of ‘floundering’ to that of having his experience sought out. Plank shapes Once again, thanks to those of you who have made financial donations to help this newsletter to continue and also to those who have written or eMailed me with Chebacco-oriented chat or gossip. Anselmo Lastra was particularly interested in Gil Fitzhugh’s use of a mylar spiling ‘batten’ to determine the shapes of planks. He wonders if it would be possible to predetermine these shapes so that the fitting of individual planks could be avoided. Does anyone know if this is possible? He also suggested that the newsletter should appear on the World-Wide-Web in order to extend its readership. I’m going to try that soon! Stripper Chebacco gets underway You’ll recall that Fraser Howell, of Nova Scotia, was planning to build a round bilged Chebacco-20 using 1/2″ pine strip planking overlaid with 1/8″ ash. Fraser emailed me the other day: : I’m finally underway. All of my ash and pine have arrived. I commenced cutting the keel pieces out of 1 1/2″ ash. They are dry-fit together in my driveway. They put a real perspective to this project. Alas I am differing from the plan already; I extended the cheek pieces 18″ aft to increase the overlap. I can’t foresee that this will cause any problem, can you? The next step is to shape the cheeks then tie all four pieces together, bedded in Sikaflex and through-bolted. . . . Lapstrake Chebacco-20 News continues to come in from readers. Once again, there’s lots of progress reported by Gil Fitzhugh, of Morristown New Jersey. As far as I can tell, Gil is the furthest advanced amateur builder of a lapstrake Chebacco. You’ll recall that Gil is using the method described by Tom Hill in his book ‘Ultralight Boatbuilding’. This involves setting up temporary moulds (UK spelling!) with battens defining the shape of the plank lands. As you can see from the photos below, this method has resulted in beautifully fair curves. We are fortunate, indeed, that Gil has agreed to make available the table of offsets he obtained from a full size lofting of the lapstrake Chebacco lines. You’ll notice that these differ hardly at all from the offsets provided by Phil Bolger, but include, in addition, offsets for the plank lands as well as a couple of diagonals (for those who understand these things!). The table is appended at the end of the Newsletter. Gil writes: . . . I also erected two diagonals. D1 goes from waterline 48″ at the certerline, to the intersection of waterline 12″ with buttock 24″. D2 goes from waterline 42″ at the centerline, to the intersection of waterline 24″ and buttock 36″. These diagonals cross the stations at sharper angles than the buttocks and waterlines, and will give an easier time drawing station molds. I’m also enclosing the offsets for where my planks cross the stations. this seems to be a great black hole. The plans never show you how to do it. . . .[ Gil then goes on to point out the following caveats:] 1. I kept to Phil’s 6 planks to a side, but I don’t think that number is inscribed in gold tablets. It could be 5 or 7 planks. . . . 2. I did not try to duplicate the plank lines in Phil’s drawing . . . [here we have some philosophy of the aesthetics of plank seams. In short, Gil’s plank line ‘sheers’ tend to get more pronounced as you move up from the keel to the sheerline, whereas Phil’s tend to get less pronounced] A builder who prefers to have his boat look like that [Phil’s drawing] should not use these offsets. 3. My sheerstrake will come out too wide. I did it that way on purpose because I intend to put rubbing strakes both at the top and at the bottom of the sheerstrake, possibly in contrasting wood. That will make the sheerstrake appear narrower, I hope by an eye-pleasing amount. . . . If someone wanted to use these offsets for a boat with no rubbing strakes, I’d suggest narrowing the sheerstrake by about one and a half inches for starters, adding 1″ to the strake below and a half inch to the one below that. 4. This is all a convoluted way of saying these offsets represent the personal thoughts of someone who has never done it before and has no assurance it will work. You’re free to follow me into the swamp, but don’t assume I’ve cleaned out all the alligators. I’ve lettered the planks A through F, where A is the garboard plank and F is the sheerstrake. The offsets locate the intersection of two planks on the station, as follows: Of course, to get from the offsets to the molds, you have to subtract plank thickness, plus ribbands if you’re using temporary ones à la Tom Hill, as I am. Gil Fitzhugh’s lapstrake Chebacco hull has been assembled dry, with screws. He will take it apart and coat the strakes with epoxy prior to final assembly. Another view of Gil’s hull. A view of Gil’s hull from the transom end. -ooOoo- Sheet ply Chebacco-20 I’ve had a mixed winter with my Chebacco project. In February we had a storm that shredded the (admittedly old) polyethylene tent that I’m building under. Tarpaulins had to be pressed into service until I could locate a supply of sufficiently wide polyethylene. I’m happy to say that all’s well again, and as I write the hull has now received: 3 coats of WEST epoxy (over 6 ounce glass) 2 coats of white Veneziani Plastolite epoxy paint 3 coats of white Veneziani Gel Gloss (a 2-pack linear polyurethane paint) I’ve experimented with roller and paintbrush and found that the epoxies go on best with a roller, and the gloss with a brush. This painting has taken far longer than I anticipated, what with sanding, filling, painting, more sanding, more filling, more painting, . . . Anyway, she’s beginning to look pretty good (from 5 or more feet away, at any rate). I’ve made the mast from reclaimed pine floor joists – two of them, 2 1/2″ thick, epoxied together. I didn’t have very many big cramps, so I filled the spaces between them with cable straps; tightened with pliers. Bill Samson’s sheet ply Chebacco hull after the February storm that shredded his tent. The deck and cuddy have now been painted, too. The mooring cleat (Jonesport style) on Bill’s boat. Detail of the hatch of Bill’s Boat. . . . and finally Please send me your news, thoughts, dreams, problems, . . . Bill Samson, 88 Grove Road, West Ferry, Dundee, DD5 1LB, Scotland. e-mail: w.b.samson@tay.ac.uk Phone: +44 1382 776744 (The ‘+’ should be replaced with your code for UK) The following pages contain Gil Fitzhugh’s offsets for his lapstrake Chebacco, and the names and addresses on the Chebacco News mailing list (note that not all of these people are actually building Chebaccos). Bill Samson

Chebacco News 01

Chebacco News

Number 1, September 1994

This is the first ( and possibly the only) CHEBACCO newsletter. The response to my intial mailshot was wonderful in quality, but rather underwhelming in quantity! My mailing list currently stands at eight and covers the globe very satifactorily – including Australia and New Caledonia as well as the US (NY and NJ). I fear I am Europe’s only representative in the Chebacco community.

The future of this newsletter depends on you, the readers. As you can see, it is made up of contributions I received in response to my mailshot, as well as my personal news. The possibility of more issues depends on whether you write to me telling me what you are up to; what may seem trivial to you could be of great interest to the rest of us, so don’t be shy! For example, let us know if you are currently building , or just dreaming over the plans. What version of Chebacco are you working on – hard chine, lapstrake or Chebacco-25? As you know , the drawings don’t come with a building key, so tell us how you are to build her. What materials are you using? Have you strayed from the plans in any way?

Send future contributions to me:

Bill Samson,
88 Grove Road,
West Ferry,
Dundee,
DD5 1LB,
Scotland,
U.K.

As you know, this newsletter is not a money-making scheme, so please feel free to copy it to anyone who might be interested – it’ll save my postage costs!

The next newsletter will appear as soon as I have enough material to make it worthwhile.

Turning Over a Chebacco Hull (almost) Single Handed

A couple of months ago I arrived at the stage where my hard-chined Chebacco hull was complete and ready for turning over for fitting out. She had been built in my bcak yard with a tree to one side and a hedge to the other. The hull had been built on stocks of reclaimed timber, about a foot off the ground.

One approach to this problem is to get half a dozen gorillas (or their nearest human equivalent) to support the hull while you crawl underneath, knocking away the stocks and dragging them out from under – hoping that the gorillas don’t get tired or bored meantime and drop everything on top of you. Once the stocks are away the team might be persuaded to flip the hull over without dropping it on its thin sheerstrake – although this can be tricky as handholds are not plentiful on the outside of the hull. The main expense of such a technique is a keg of beer to reward your patient strongmen.

This method sounded a bit nerve-racking to me, besides which it isn’t always possible to get all the gorillas you need at a mutually convenient time. I decided to try to do the job myself by rigging up a scaffold (gallows?) from which to suspend the boat while the stocks are removed ad ropes to pull which will turn the boat over.
The scaffold consists of two arches, or portals, which are placed over the hull, about 5 feet from each end. Each portal has two pulley sheaves let into its cross member (top) through which a long rope loop is threaded, going around the hull.

Because Chebacco’s hull is very beamy, I had to raise it , stocks and all, by about a foot, so that the sheerstrake would clear the ground when the hull had rotated through 90 degrees. I did this by levering one side of the stocks off the ground using a 12-foot length of 2 by 4 as a lever, and while it was raised, my long-suffering next-door neighbour inserted concrete blocks under the legs. I repeated this operation on both sides until the hull was sufficiently high.

The next step was to complete the rope loops around the hull and through the sheaves on the scaffolds. I used three eighths inch diameter polypropylene rope for the loops and knotted them using a carrick bend, which is less likely to slip or come apart than a reef knot or bowline. The knots have to be placed so that they will not pass through the sheaves as the hull turns over.

Trestles were placed under the stem and transom in order to prevent the hull crashing down if the rope loops gave out when the stocks were knocked away. The stocks were knocked away and dragged out from under the hull without mishap, leaving the hull hanging upside down under the scaffold.

I pulled gently down on the rope loops, which obediently ran through the sheaves. After about 80 degrees of rotation, gravity took over and the hull swing (too) quickly over into its right-way-up position; about a ccouple of feet off the ground. The 2 by 4 lever and heaps of old car tyres were brought into play to allow the knots to be undone and the hull lowered, one end at a time, to its final resting place on wooden blocks.

News from Builders

Gil Fitzhugh, of Morristown NJ, is building a lapstrake Chebacco-20. His chosen method is to build a mould from temporary bulkheads and ribbands placed where the strakes will overlap. In this way he is able to ensure that the lands will form fair and even curves before starting to cut out the strakes. The method is described in Tom Hill’s book, “Ultralight Boatbuilding”. The main snag with this method is that the permanent bulkheads need to be fitted after the hull is lifted from the mould and turned over.

Another good idea from Gil is the way he built his (inner) stem. It is laminated from mahogany and includes the mast step. In other words, it extends all the way back to bulkhead #1. Gil’s keel, too, is laminated; the front and rear sections from (I think) 3/4 inch thick fir, and the cheeks either side of the centreboard from 3/4 inch oak. The laminations are horizontal.

Gil writes:
The wood’s expensive, but it’s available locally . . . Epoxy has made it possible for Klutzes like me, who aren’t in a hurry, and who aren’t building in quantity, to make a good boat out of wood that Nat Herreshoff or Colin Archer wouldn’t have bothered cutting up for the fireplace.”

I must add though, that Gil’s photos of the keel and mould show that his workmanship is anything but “klutz”-like.

I understand that Gil is to use sapele marine ply for the hull. I guess the result will be a real gold-plater when it hits the water.

Peter Gray of Queensland, Australia is well advanced on the construction of a hard-chine Chebacco. When he wrote to me in June, the Hull had just been finished and he hopes to finish the boat around Christmas this year – a good time to launch in Australia, I should think.

Peter is using exterior grade ply, WEST system epoxy and stainless steel screws and bolts. He’s also scouring second hand boatyards for authentic fittings.

Allan Bell of Fairport NY is currently dreaming over plans for a lapstrake Chebacco which he plans to start constructing in a year or so. I hope he will find Gil Fitzhugh’s experiences (see above) helpful when the sawdust starts flying.

My own Chebacco is a hard-chine one. She’s built from Far Eastern marine ply. This is pretty inexpensive (about $30 a sheet if you buy it in quantity) and has alarmingly thin outer veneers. I used the same stuff for a skiff I built 6 years ago and, coated with WEST epoxy and 2-part paint, it has been entirely satisfactory and hasn’t needed repainting in all that time (apart from the odd ding). For tree wood I’m using reclaimed red deal (a fairly resinous pine/fir) which is reasonably durable when it is coated with epoxy – and pitch pine (longleaf yellow pine) for floors. I’m using copper boat nails for almost all my fastenings. I have built the hull strictly according to Phil Bolger’s plans, right down to the hollow keel. I finished the outside of the hull with one layer of 6 ounce glass cloth in three coats of epoxy and 2-part paint on top. Under the waterline I used standard antifouling paint applied directly on top of the epoxy.

The fitting out of the hull is almost complete now. One snag I came across was that the half inch ply for the cabin top was tough to bend and resulted in some sagging of the framing. If I was to do it again I’d probably laminate the roof from two layers of quarter inch ply.

One final point – I used 22 sheets of ply for the entire boat. Brad Story does it with 15 but he makes the keel and floorboards out of tree wood and, on his gold platers, the coamings and cabin sides are made of solid mahogany (about 3/4 inch thick, I think).