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Minggu, 26 Juni 2016

Different Rigs on the Same Boat

Most of my published sailing boat plans come complete with a number of different rig options.What makes mine different from most other offerings on the market is that I try to arrange the various rigs so that the original mast can be used for several different rigs, and that the original mast steps and mast partners can be used. By that I mean that a builder can choose one rig at the time of building, and at a later date, rig the boat differently by simply ordering some new sails and, maybe, making a few different yards, or gaffs etc. But no structural changes need to be made to the boat herself, and the rigs can be changed at will.

Each photo below is of Paul Hernes Phoenix III named Willy Wagtail.  Even though she is sporting a green sheer strake in the first, second and fourth photos, and is looking nicer with a more plain colour scheme in the other two, she is the same boat, and nothing has been changed other than the sailing rig.


Phoenix III with her sprit rig set without a boom. This can only be done on boats which have had the correct sheeting geometry designed-in from the beginning.

Here is the very same boat, but with a boom fitted. The boom makes the boat slightly easier to handle, and allows more options for sheet locations, but the boomless rig is more seaworthy, as there is no boom to drag in the water if the boat is over-pressed - a situation which often prevents the helmsman from being able to ease the mainsail and can lead to any boat sailing herself over into a capsise 

Showing off with her new paint job, Willy Wagtail has been rigged with the balance lug sail. The mast is the original, the mast step is original, and the mast partner is original. All Paul did was use a different sail. Some days, he starts off using the larger sprit rig (which can be sailed with or without the jib) and changes to the smaller balance lugsail if the wind comes up, or if he starts to feel lazy.

This shows the boat sailing under mainsail alone


In this photo, Willy Wagtail is carrying the flying jib from the sprit rig, and a standing lugsail taken from a Joel White-designed Poohduck Skiff - which by coincidence is a design which can also be sailed with or without her jib.

The matter of hull/sail balance is frequently brought up, and one cant just put any rig on any boat and expect the boat to perform properly. The rigs have to be proportioned in such a way the hull balance is maintained within certain limits, otherwise you will end up with excess weather-helm or, even worse, lee-helm. At the design stage I put a lot of time into proportioning the various sail plans so that they will balance. However, you can see from the last photo above that there is a lot more tolerance for centre-of-area and centre-of-lateral resistance changes than the theorists will admit (I limit my comments here to small centreboard and leeboard dinghies - and even then, the rudder and centreboard proportions, area, and location must be taken into consideration when following this line of thought).


This is Periwinkle with her Periauger or Cat-Ketch rig as designed...

...and here she is with the mizzen removed altogether, and the main mast moved back to a third mast partner and step. This step was designed-in to allow just this procedure.

Another shot of Periwinkle moving well with the mast and mainsail in the third location. This arrangement changes the sail area from 155 sq.ft to 104 sq.ft without the need to reef both the mizzen and the main.

Here, the crew of Periwinkle were anticipating tricky conditions outside the cove and had not only used the mainsail and mast in the third location, but had tied in a reef as well.

In this photo, owner John Shrapnel has moved the main mast to the third location, and has set the mizzen sail only. In this configuration, the boat is only carrying 52 sq.ft of sail, but she is under good control and is moving fast. John mentioned eight knots by GPS with the boat very lightly loaded - but anyway, she is going well.
This is another shot from the same day (52 sq.ft mizzen sail only) and I am told by a person who I trust (no names) that Periwinkle was actually overtaking the boat in the background.
Another Periwinkle but this one has been rigged with the gaff-headed cat rig (details supplied with the plans in addition to the cat-ketch rig). The mast is exactly the same as the main mast on the cat-ketch rig, and is stepped in the standard forward location. This rig can also set a small jib not shown here.
John Shrapnel is the most experienced Periwinkle owner at the moment, and he has tried a number of different rigs, and configurations, and is currently using the standard balance lug mainsail (the one from the standard cat-ketch rig), but with the mast set in the forward location (normally balanced by a mizzen mast and sail). One would think that this arrangement would induce lee-helm - something to be avoided at all costs. However, John has pulled the forward end of the boom aft to the mast, therefore moving the centre-of-area of the sail aft enough to prevent lee-helm, and in the process the aft end of the boom has cocked up high above any vulnerable heads. The result is that the rig is now a 104 sq.ft Standing Lug.

See in this youtube clip just how well the boat goes when being sailed by a light crew - in this case one person.




The old-fashioned rigs have got a tremendous amount going for them if you know what you are doing, and if you are prepared to be patient with your development. All basically cordage, wood, leather, and cloth.
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Rabu, 22 Juni 2016

Oars and Oarmaking Different Strokes for Different Folks


Oars are a delight to make and we are trying to make something new for the market. A prototype for a Carbon Fiber blade-Spruce oar has been completed for a customer here in Portland to be use for his new sculling boat, an Annapolis Wherry, being built by him from a Chesapeake Light Craft kit.

The main prototype effort here were the blades, an infused laminate of carbon fiber with a light core material in the middle.


The core adds stiffness with negligible additional weight. Infusion is incredibly tricky to get right and much time was spent in making it work to make a perfect blade.


The looms are Sitka Spruce for these oars (and can be done in native Northern White Spruce) and they are specially designed such that they counterbalance perfectly with the carbon blades. The blades will lay on the top of the water and without any pressure from the hands.


This balance means less fatigue for the rower, a better feel, and greater speed because the rowers kinetic energy is not wasted in moving a blade-heavy oar forward and backwards as the blade exits at the release and enters at the catch. Another design element to Clints oars is in their flexibility. Oars should flex a little, especially in fixed seat boat, but also in sliding seat boats (the amount will differ depending on the rower). The faster the boat goes and the faster the rower wants to go, the stiffer they may want their oar to be made. But for recreational sculling and pleasure rowing in fixed seat boats, you want an oar with an amount of flexibility. It means less fatigue, a gentler stroke at the beginning and end, and better endurance for the rower. How much flex is very subjective and based on experience on the water as well as intuition. When Clint makes oars, youll often see him shaping the loom then taking it to the floor and springing it. Then the shaping continues based on the feedback from the wood.

Every board, each species, and different length oars will all feel different. What is right is based on our customers needs, rowing style, their goals, the waters and conditions the rower is in most of the time, and of course it depends on the boat itself.

Youll notice that the oar blades are quite different between these two oars.

The blade area and the shape are key factors in how much "Slip" the oar has in the water. Slip is a term for how much grab the blade has on the water, how much water the blade holds. Thus, a large, wide blade slips less in the water and can potentially produce more drive for the boat. There are other factors of course. But for the sake of this post, looking at these two different oars, the spruce spoon blade oars are specifically made for open water conditions where feathering is not completely necessary. The carbon blades will need to be feathered especially when the water is choppy. The blade area is also more outboard making these more efficient oars for flat water conditions or when there is a slight chop, for feathering. Other differences between these oars are in the oar leathers.


The carbon blade oars have a plastic sleeve that makes feathering easy. The all spruce oars have traditionally stitched leathers with a custom button that we produce on a lathe with nylon.


The split buttons are seized to the leathers with nylon twine and epoxy (and elbow grease). Another big difference between these oars are the upper looms. We laminated spanish cedar to the upper looms of the carbon blade oars to help counterweight the oars and make the looms a little more durable (and it looks snazzy!). The result is very nice and no lead counterweights were needed in the handle. The oars are sensationally light for 96" sculls.



I will update the post when I have a proper scale to take weights. The spruce spoons are counterweighted with 2lbs of lead (see lead insert sticking out of handle, boring hole for other insert).

The balance point for both oars is just below the leathers and the result is a very comfortable oar on the water that is effortless to bring through the stroke cycle, from recovery to catch, the blades have little perceptible weight to them. Careful varnishing follows construction. We use a fabulous product called Le Tonkinois, a linseed varnish that makes a durable finish that is very easy and pleasurable to maintain.


A parting shot shows what makes me as excited about this new kind of oar as much as the performance benefits it is the aesthetics that make them special. The contrast of Spruce wood and Carbon Fiber to me represents the yin and yang of oarmaking -- balance. We are trying to make rowing more fun with balanced, high-quality, beautiful oars made with passion.

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Selasa, 07 Juni 2016

Fleet Videos of performance with Two Different Motors

As some of you already know, Fleet is a planing-hull derivative of my very successful Flint design. For some background you can look at this post and at this post.

Fleet awaiting more trial runs
Fleet was designed from the outset to perform well in the very speed/length ratio spectrum in which normal planing hulls are at their worst. By that I mean the so-called "semi-displacement" or "semi-planing" range - widely thought to be in the S/L ratio range of 1.5 to 2.5.

Speed/Length ratio is basically the speed of a boat (expressed in knots), divided by the square root of the waterline-length (expressed in feet) of the boat. So let us take Fleet as an example: -

  • LWL (length on the waterline) equals 14 feet
  • Assume S/L ratio of 2.5
  • Speed divided by 2.5 equals 3.74 (i.e. square root of 14 ft LWL)
  • Therefore, Speed in knots equals 2.5 times 3.74
  • Speed equals 9.35 knots (10.8 mph, or 17.3kph)
Now those speeds sound modest, but for a small boat like Fleet it represents a very satisfying speed indeed. More importantly, because this hull has been proportioned to operate within this S/L ratio, the boat trims well, instead of pointing her bow in the air like the standard planing hulls, which chew fuel at a high rate just to pull a large wake.

So far Ive been able to carry out several test runs in Fleet using both a 9.8hp Tohatsu two-stroke and a 2hp Honda four-stroke. The 9.8hp Tohatsu is based on the powerhead from the 6hp and 8hp models, so is suitable for this light-weight boat. My next test will be using a 4hp motor, which I think is about the optimum size from an efficiency perspective. In my part of Australia, 4hp (2.9kW) is the largest motor allowed without boat registration.

Here are two Youtube clips - firstly using the 2hp Honda, with which I achieved a consistent 7.9 knots measured by GPS with my weight aboard, and 7.1 knots with my wife joining me (she only weighs 60kg/132lbs. The 9.8 Tohatsu gave 15.5 knots (17.8 mph or 28.6 kph) with two heavy men aboard plus gear.




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Senin, 30 Mei 2016

Fitting Different Rigs to an Existing Boat

One of the great joys of owning and/or building a small wooden sailing boat is that there is plenty of opportunity for experimentation. For some reason it doesnt seem right to go shifting things around on a glass production hull, but wooden boats lend themselves to modification. With high-quality epoxy and fastenings, the end result should be as good, or better, than the original work.

Ive mentioned previously that rig modification was something which interested me from before I left school. I had been brought up sailing racing boats at the local club, all of which had modern, deck-stepped rigs with lots of stainless-steel fittings and sails full of batten pockets. Although I loved the sailing, I felt the urge to cruise alone in a boat fitted with a more simple, traditional rig such as a standing lugsail.

Phoenix at about age 20 with her original rig
For me, the first real experiment came when I converted the cruising dinghy my Dad had designed and built. She had been constructed with a deck-stepped Bermudan rig just like all of the racing boats Id sailed. She was (and still is) a fine boat, but I got it into my head that Id re-rig her with a Chinese Lugsail (a.k.a. Chinese Junk Rig). I spent a long time on the calculations - far too long, I believe - but that was because I didnt really know how accurate I had to be with all of the proportions, and I was particularly concerned about the location of the centre-of-area of the sail in relation to the centre-of-lateral resistance of the boat.
Phoenix showing how well she could get to windward with her Junk Rig. A nice day in tropical North Queensland.


Accelerating out of the tack and heading off hard on the wind. This rig was exceptionally easy to handle, reef, and furl, and has been one of my all-time favourite rigs. I will be making another one sometime...

After the Chinese Lug rig, I fitted the same hull with about four or five other sail configurations, finally settling on the Balance Lug which she currently carries.

When I designed boats such as Phoenix III, First Mate, and Periwinkle (and some others which have not yet been published), I decided from the outset that I would arrange the rig proportions so that several different rigs could be used on the same mast(s) and/or using the same mast step and partners. This results in boats which can be rigged in a number of different ways without having to make any physical alterations to the structure of the boat. I have already spoken about this a little in my post about Phoenix III and the Perfect Customer 

Here are some more photos to illustrate what I mean.
John Shrapnels Periwinkle showing her standard Cat Ketch (Periauger) rig. Crew weight is a little far aft, but she is going nicely. This boat is very fine up forard, and needs to have weight kept out of the bow when pressed.
Same boat, but with the mizzen removed and the mainmast and mainsail moved aft to another mast step and partner. The rig is still perfectly well balanced, even though the 51sq ft mizzen has been removed entirely.
Here she is with just the mainsail up, stepped in the middle location, but with a substantial reef tied in. It may look calm in the little bay, but it was blowing outside on the more open water.
When it really starts to blow, or when the crew weight is low, you can set the mizzen in the central location. Once again the hull balance is fine, but the rig has been reduced to a snug 51 sq.ft. Even so, when this picture was taken, the boat was doing 8 knots by GPS! If you needed to , even this sail can be reefed.
This shows you the rig combinations on paper. Note how well the centres-of-area cluster near the centre-of-lateral resistance of the hull in all combinations. The key to this was careful proportioning of the sails and the mast locations.
This is another rig which can be used on the boat. The little flying jib is optional, but will help her a lot and will stand ok without shrouds or backstays. The gaff-headed cat rig is set on exactly the same mainmast as in the standard rig, so there is no alteration required to any part of the boat. This print is of an early sketch and some elements are not shown.
...and her you can see Graham Faulkners Periwinkle with the Gaff-Cat rig, beachcruising on Fraser Island, Queensland, Australia (this was the second boat built, and Graham even made his own sail!)
This shows the three mast locations - the mainmast partners in the lower/left of the photo, the central position through the main thwart, and the mizzen partner through the stern sheets (aft thwart)
All of that thinking made me very tired! Actually, that is just me showing the comfortable sleeping position on either side of the centreboard case.
Build yourself a wooden boat, and then try some rig experiments - it is great fun.
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