Sprit Rig Virtues and Details

Of my published designs, two of the most popular (Phoenix III and First Mate) make use of a sprit rig with a small jib set flying. You can read some of my comments about the rig in this post from May 2012.

Phoenix III showing-off her sprit rig and flying jib

Despite the simplicity and effectiveness of this rig, I receive a large number of enquiries about the details of setting and reefing, and it appears to me that many people are unsure of how to benefit from its virtues. This is a real pity, because the sprit rig can set a very large sail area from a very short mast, and is a rig which is ideally suited to small boat cruising. In addition, if set properly, it is a good sail for windward work.

Phoenix III tacking away from a Pooduck Skiff in a battle to get up-wind

For me, one of the great joys associated with small craft is experimentation with rig variations, and learning how to make rigs which use an absolute minimum of store-bought fittings. There are plenty of old books about traditional seamanship around, and time spent learning is a good investment.

Below is an except from Phil Bolgers book, 100 Small Boat Rigs (Copyright 1984 International Marine Publishing ISBN 0-87742-182-X)

Back to the 17th century. What Ive said about spritsails in Rig 23 ap­plies. By adding a jib to the basic boomless spritsail, some extra area is added in an efficient form, without any multiplication or lengthening of the few short spars. The jib is a good airfoil in its own right, and the draft off it improves the drive of the mainsail. The position of the jib is perfect for a leading-edge device. The spritsail is prone to twist on ac­count of the difficulty of keeping the peak up tight. But the jib compen­sates for the twist to some extent. Taking the jib off doesnt affect the balance of the rig as much as might be thought. If its sheeted correctly, 10 or 12 degrees out from the centerline, the pull of the sheet tends to swing the bow into the wind. The forward position of the sail has a sur­prisingly small tendency to knock her bow off the wind. By the same token, if you want to make a boat weathercock downwind, as in a broken-down powerboat that wont steer if she gets broadside to the wind, a loose-footed staysail is not the best sail to make her do it.

This is one of the few sloop rigs that can be weatherly without backstays or standing rigging of any sort. The spritsails mast is so short that it can be built very stiff without its weight overpowering the boat. With the sloop rig the mast is stepped farther aft than in a cat, so the weight of a heavy mast does still less harm.

Moreover, the head of a spritsail is in tension, even when it isnt set up as hard as it should be, and that holds the masthead. The peak halyard of a gaff sail has the same effect, but its not as powerful because theres less trouble keeping a gaff sail properly peaked: the angle of the halyard to the top of the taller mast of the gaff sail works at a better mechanical advantage. The halyard is also slipping on a sheave, with the vector of its force dividing the angle of the standing part and the fall, while the throat of a spritsail can be lashed, or even shackled, solidly in place.

Of course any cantilevered mast has some give. A big boat with this rig would need something by way of a backstay to get the most drive out of the close-hauled jib. In the 15-footer cartooned, with a 13 1/2-foot mast and sprit, and a jib of 18 square feet, the backstay isnt crucial. The rig is auxiliary to the oars, and since it is a spritsail, the spars can not only be stowed in the boat, but stowed out to the sides to be out of the way of the oarsmen. This is the most powerful and weatherly rig that can meet that specification. The fact that its a cheap rig, easily built, strong and reliable, easy to maintain, and readily repaired with makeshift material, is an incidental bonus.

For those of you who would like to learn more about the rigging and versatility of a spritsail, there are three exceptionally good illustrated articles available in back issues of Woodenboat Magazine  #89 and #165.  The magazines are available as instant digital downloads for only a few dollars each, and I recommend them to you. Here are links to both issues: -

http://www.woodenboatstore.com/product/WoodenBoat_magazine_Issue_89_DIGITAL

http://www.woodenboatstore.com/product/WoodenBoat_magazine_Issue_165_DIGITAL

Read More..

Maine BoatBuilders Show Links

The final verdict is still out, but I feel it was a good show. The weather was too nice on Saturday so attendance was low. Today compensated for this with a steady stream of people and a higher than normal attendance. Friday and today were the best days.

Here are some pictures care of Maine Boats Homes and Harbors.

Read More..

Boat Kits Boat Kits Boat Kits

There is a lot of work happening in the world of kitting boats in the shop. The Goat Island Skiff kits have been done for a week now and are going to make some beautiful boats. The Deblois Street Dory, Hull #1 is being planked by a customer here in Portland, and plans are being finished up by Eric Risch for a new, 149" rowing skiff called Caravela, which will be built for customers in Marthas Vineyard and will be available as a CNC cut kit by the end of June. As if that was not enough, we are excited to soon announce a new collaboration with a fabulous designer in Europe who is known for his beautiful sail-and-oar boats. A press release will be forthcoming. Enjoy some images of the boats we are kitting.



Goat Island Skiff (designed by Michael Storer) built by Richard Harvey in the UK with a beautiful sail by John MacNamera.



Deblois Street Dory (designed by Clint Chase) being built by Shane Hall in Portland, Maine.



Echo Bay Dory Skiff (designed by Eric Risch) being kitted for CNC by Clint Chase, available in late March

Read More..

Beneteau 423 First Impressions

We took possession of our new 423 last weekend and renamed it Finisterra. Yesterday we went for our first sail and finally had an opportunity to try the boat on all points of sail under power and under working sails. Here is a brief summary of what we discovered.

We left the slip in the downtown marina and took advantage of the flat water and light air in the turning basin to see how the boat maneuvers in forward and reverse. Finisterra is equipped with a Slipstream 3 bladed folding prop. We found that it operates smoothly when going from neutral into forward or reverse and provides plenty of thrust in forward. Outside the marina we saw 7 knots with the Yanmar diesel running at 2,200 RPM. Since its a folding prop, it takes some throttle to get the boat moving when backing down, but overall performance is good. We had a three blade feathering prop on our last boat and it would occasionally snag some seaweed, so I think this prop is a good compromise for our purposes.

Sailing conditions were excellent with about 12 knots of breeze that built to about 16 in the afternoon. I unfurled the mainsail and I have to admit that its awfully easy to operate the in-mast furling system. We puttered around under the mainsail only for half an hour. Its a tiny thing with a hollow leach and no battens but it has fairly good shape and pushed the boat along at about 5 knots in 15 knots of wind on a beam reach. I was pleased to see that it is in nearly new condition. With the 140% jib set, the boat came alive and we drove upwind with the apparent wind angle at about 40 degrees and about 7.5 knots of speed. Later, as we bore off to a close reach, the speed increased to about 8. Easing sheets a bit more, we put the boat on a beam reach and saw 8.5 on the knotmeter. Bearing off further brought the wind on the port quarter and our speed dropped as we expected. At all times the helm was light and well balanced, and perfectly responsive. Sailing back toward the marina the wind fell to about 5 knots as we approached the marina entrance and the boat ghosted along very nicely. I rolled up the jib and fired up the engine, then furled the mainsail just before entering the marina. All almost too easy. Our berth is near the head of the gangway and the fairway is narrow so its a tight turn into our downwind slip but the boat maneuvered easily and we made our first landfall perfectly.

Having designed, built and sailed a number of racing yachts, I expect my boats to perform well. There is no need for a cruising boat to be a slug in terms of performance or handling and the B423 meets my expectations. I struggle with the idea of in-mast furling. I prefer the strength and simplicity of a full battened main and slab reefing and will likely convert this rig. Other than that, were very pleased with the boat.

Read More..

Arcona 410 Review

Arcona is a name we seldom see in the USA, which is unfortunate because this Swedish company builds a line of nice looking and fast boats that I think could do well in this country. All of their current products were designed by Stefan Qviberg, another name that is pretty much unknown in the USA but I must say his firms work is impressive. The 410 is the latest collaboration between Qviberg and Arcona.

Simplicity and balance are main elements of the Arcona 410 design

As I studied the drawings and photos of the 410, the theme that came to mind was simplicity and balance efficiently combined. In the profile view above, notice the delicately sprung sheer and balanced bow and stern profiles. The cabin trunk is low and blends perfectly with the subtly sprung sheerline. Simple designs are often the most difficult to execute well.

The 410 is fitted with a tall fractional rig with non-overlapping headsails. Notice the oversize spinnaker pole.
This boat will be a serious competitor on the race course.

The Arcona 410 is intended as a racer/cruiser and I would place it on the racier end of that spectrum. With a displacement of 17,200 pounds on a 36.75 waterline, it has a displacement/length ratio of 155 and a sail area/displacement ratio of 22.0. These numbers are indicative of a light and fairly powerful sailing yacht. By comparison, my Beneteau 423 has a D/L of 152 and a SA/D of 16.0. While the two boats have similar D/L ratios, the Arcona has roughly 33% more power in the rig. Its going to be a lot quicker in light air, and have higher speed potential in a breeze. The Arcona will be a the more interesting boat to sail. 

Wide side decks, non overlapping jibs and an Admirals Cup style mainsheet system show the 410s emphasis on performance.

I like the distribution of volume in the plan view below. The overall beam is 11.48 feet and the bow is relatively fine. Notice that the stern is not as wide as you find on some other recently designed cruiser/racers. There has been a faddish trend toward extremely wide sterns on this type of boat in recent years, and while that hullform has obvious advantages when a boat is in planing mode, I think a more balanced hullform offers better handling characteristics in a seaway.

The decks of the 410 are wide and uncluttered, perfect for racing. The cockpit is a good compromise for both racing and cruising, with big seats and plenty of space for working the boat or lounging. The open transom and twin helms are convenient for boarding from the dinghy and enable the helmsman to sit well outboard.

Notice that there is no provision for anchor storage on the bow. This is great for racing but youll want to order your 410 with a bow roller and windlass if you plan to anchor. I like the recess for the dodger that is molded into the cabin top. The way we cruise, there is never a time when we want the dodger put away, but if you race as much as you cruise, a fold-away dodger makes a lot of sense.

Notice the recesses for sheet and halyard tails, and the mainsheet traveler mounted on the sole. Another nice feature is the block and tackle backstay adjuster, which is lighter and faster than a hydraulic unit would be. This boat has teak toe rails that are smaller than I would like for cruising.

Near perfect accommodations plan.

Arcona offers the 410 in two and three cabin layouts, and I could live with either, but the two cabin version would be ideal for a cruising couple. The aft stateroom incorporates a huge berth, a large hanging/stowage locker and plenty of shelf space.  

The small deadlight in the hull will provide a surprising amount of light in the aft stateroom. 

The aft head is just large enough to incorporate a shower. The three cabin version of the 410 offers a single head, located aft, while the two cabin includes an additional small head in the forecabin. In the main salon you find a large galley to port, with lots of counter space. Notice that the lockers above the stove are raised a few inches above the counter. This cuts into locker space a bit but creates more counter space.

Scandinavian styling: simple lines and high quality woodwork.

The arrangement of the galley wouldnt be very convenient to work in when the boat is under sail. This is probably a reasonable compromise if you dont do a lot of cooking at sea. Once in the slip or on the anchor, I think the cook would like this wide open arrangement. the nav station, opposite the galley would be a nice place to work anytime. The chart table is an ample size and there is plenty of storage space.

 The main salon includes a large dropleaf table and plenty of seating space, but the settee to starboard doesnt look quite long enough to be a good sea berth. We have the same basic arrangement aboard Finisterra and I added a lee board in the quarterberth to convert it to a usable sea berth when were underway.

The forward cabin includes the aforementioned head, a large v-berth and smallish hanging locker. The accommodations plan shows that the berth has been pushed aft a bit to allow for storage room aft of the anchor locker but I dont see an access hatch in the photo below. Aside from that, the forward cabin looks bright and airy.

V-berth in the 3 cabin version of the 410

The styling of the interior of the Arcona 410 fits nicely with the overall theme of clean, simple lines. While some might appreciate fancier design elements in the accommodations, I think this approach will wear well over time. The corners and edges are softer than we see in the latest designs from competitors like Beneteau and Hanse, yet it is a thoroughly modern looking interior. I like it a lot.

Overall I give this boat high marks for design and it should be a worthy competitor in the marketplace as well as on the race course. Add a few amenities such as lazy jacks and an anchor windlass and youll have a fine cruising yacht. I encourage you to visit the Arcona web site, which is where I found the information on this boat: www.arconayachts.se.

Read More..

Workshop News

It is about time I said a little bit about what is going on in the workshop. Being a one-man-band is very satisfying, but it means that just a few concurrent jobs take up all of my time. I like writing and designing, but at the moment Im definitely burning the candle at both ends!

Annapolis Wherry Tandem

In late 2012 I reported on the construction of a CLC Annapolis Wherry Tandem in this post  and showed some photos of the finished boat in this one. After completion the Annapolis Wherry Tandem sat for a number of months under shelter beside my workshop because the owner was overseas doing post-graduate studies. 

Well, the day finally came for a test row and the boat went very well indeed. The only problem was a slight bow-down trim, but that was sorted out on the second outing, and turned out to have simply been caused by having the foot stretcher set too far forward. With that adjusted the trim is now perfect. The following photos were taken on the initial outing, so you may just detect the trim I mentioned. Despite that the boat went fine, and on the second outing a few weeks later she was perfect.

That is the owner, Dr McArthur, looking on as I make preparations for the initial launching.  Dr McArthur is a very experienced oarsman, having rowed for 55 years of his long life.

Just getting the feel of the boat about two minutes after the launching.  You can see how we have the excellent  Piantedosi Row Wing adjusted for a "left-over-right" rigging.

A "turtles eye view" as Dr McArthur  becomes more familiar with the boat. 

Even though we had the foot stretcher too far forward, the boat is still trimmed  reasonably, and she certainly ran nicely, with excellent directional stability.

The boat proved to be stable and fast. Subsequent outings have been  longer, and weve  explored more of the performance envelope. She is a practical and enjoyable package.

Jim Michalak Scram Pram

In this post I mentioned that I had been given the job of finishing off the construction of a Jim Michalak Scram Pram. 

My part in the project is nearing completion, with just some detail work around the hull, initial coating work on the spars, and setting up the running rigging and sail to go. The owner will pick-up the boat and do the remainder of the painting and varnishing. However, I hope that he and I will be able to fit in a day or two of sea-trials prior to her departure (by road) for her home waters. Here are just a few pictures: -

View from the helmsmans position, port side, looking forward. You can see what an enormously roomy vessel she is for a light fifteen footer. It is easy to see that if the boat suffered a knock-down, the windows (not yet installed) and the raised deck on either side of the centre walkway would keep the boat dry and buoyant.

Forward/port window dry-installed with Pencil Cedar surrounds.  Window and internal framing held in with silicon bronze screws throughout. See the aft/port window loosely fitted and waiting for the surrounds to be fabricated.

Close-up of internal framing showing how I have stamped markings at the top/right to identify the components after disassembly. The window installation was a much more difficult and time-consuming process that I had anticipated, as each window is  slightly different from its fellows, and there were a number of lurking "tricks for young players".

Windows from the outside. The protective film and paper will be left in place as long as possible. Fore and aft decks will be screwed down onto flexible bedding compount to allow future removal for maintenance. When I did it, it took 93  #8 x 1-1/4" silicon bronze screws! However, it is a very good idea.

Filling/draining bungs for the three water ballast tanks were sourced from Duckworks. They come as a brass tube (see longest tube in the photo) and an expanding rubber or plastic plug. When the lever is pushed down the plug expands and grips the inside of the tube. My problem was that the bottom of the boat is only 9mm/3/8" thick and the tube would protrude. I worked out the shortest length that the tube could be and still allow the plug a full-depth grip, and cut the tube (see cut tube in foreground). I then fabricated some blocks so that the tube protruded only 9mm/3/8" below the block. When set in the tanks on the bottom of the hull, the brass tube and plug fit neatly without extending past the outer surface of the hull. Note how I cut holes in the blocks and the brass tube to allow water to drain right down to the bottom of the tank.

Bung set into the bottom of the tank, positioned below the inspection port to allow opening and closing.  The block was very thoroughly sealed with about four full coats of epoxy prior to installation, and the tube and block were set in polyurethane bedding compound during installation. This was done so that the expansion and contraction of the brass would be taken up by the bedding compound - an epoxy joint would surely show hair-line cracks before long.

Mast partner is held to the forward bulkhead by four 5/16" bolts - two of them are silicon bronze and two (which you can see) extend through the aft face of the partner and act also as attachment and pivot for the mast gate, which I made from 8mm alloy plate. These two bolts are from 316 stainless steel, and if I can locate the required plate, I may replace the alloy with 316 stainless.

1-1/2" thick laminated mast step sitting upside-down on the bench prior to installation in the hull. Note the groove to act as a drain to prevent water accumulating in the step, and also the very thorough sealing of the internal surfaces with epoxy. This was done ahead of installation because access is difficult after. The rounded-over edge at the rear of the step (as it sits in the photo) is to allow it to sit neatly against the glass fillet between the forward bulkhead and the floor of the cabin (which is also the top of one of the water-ballast tanks).

More about jobs, both in the workshop and coming up, and also some progress reports on stock designs such as Whimbrel and Fleet in a day or so. I need to go to bed!

Read More..

Weighing a keel bulb while attached to a boat

The Star 45 R/C Model Sail Boat - Builders Journal: Weighing a keel while attached to a boat

Weighing a keel while attached to a boat
From "Larry Ludwig"

"Weighing a keel while attached to a boat can be done with a high degree of accuracy. You can test this out on a boat with a removeable keel. Lay the boat on its side with the keelbulb on the scale with the keel parallel to the table. Then take the keel off and weight it and you will be amazed that they are nearly the same, as in within 95% or better."

Read More..