ode to Joy

Ode to Joy:
Trudeau J-Class

Summary:
The new J-Class continues the Trudeau tradition of classic sailboats that combine the remarkable artisanship and advanced scripting that are the Trudeau trademark. Although J-Class is the largest of the current Trudeau releases, it sports the nimble handling of a dedicated ocean racer. The boat is powered by  a sloop-rigged mainsail and jib. In addition to its two primary sails,  J-Class introduces the Trudeau Spinnaker, giving skippers yet one more option to boost downwind performance.
 The boat responds to apparent wind and has notably rapid upwind acceleration, consistent with the J-Class sail plan and boat design.  Lap performance testing so far gives the boat a PHRF Handicap of 0.93, placing it squarely in the middle of the pack, but notably slower than several other large race boats on the market.  Like it’s predecessors in the Trudeau fleet,  J-Class offers a wide range of handling options and racing effects, including an updated wind shadow system  that’s appropriately tuned for the size of the boat, and a single reef-point in the main.   There’s room for a skipper and three crew members, and all can share sailing and racing responsibilities through a newly upgraded version of the Trudeau HUD.
 In summary, this is an impressive release that dramatically updates the Trudeau racing line  that dates back to the original Defender. With J-Class, Trudeau Yachts  comes back to the race circuit with a roar, tossing his hat in the ring and throwing a gauntlet down in a market already crowded by other, faster boats, including the ACA33, VOJ, and RC44. 

 J-Boats
On April 26 Trudeau Classic Yachts launched its long-awaited J-Class.

The J-Classin SL was inspired by a  handful of truly majestic boats that competed for the America’s Cup during the 1930’s under the “J-rule.” Their brief reign was brought to a sad close when war broke out at decade’s end. Only 10 J-Class vessels were finished, and only three (Shamrock V, Enterprise, and Velsheda) remain in service today. The boats were long and sleek (the new Svea under construction has an LOA of 41.5m with beam only 6.40m!). These were extreme but classic vessels built for speed, sporting an enormous sail plan that conformed to a “Bermuda rig” sloop design (a triangular mainsail at a large triangular jib).

Velsheda

Although J-Class was the cup standard for only a decade and very few were ever built, their majestic size and sharp racing lines captured the imagination of all who witnessed them, and J-Class still today serves as a striking icon that exemplifies the spirit and adventure of everything we call Sailing.

The task of adapting  the spirit and substance of such a legendary vessel  to the waters of Second Life was without doubt a daunting goal. However, it  proved a natural fit for the Trudeau Yacht Yard, whose knowledge and experience measured up to the task.  The Trudeau production line includes a prolific series of classic boats that combine both detailed artisanship and careful attention to realistic sail performance for either racing or cruising. 

TCY is certainly no stranger to America’s Cup racing, either. Trudeau’s Defender I recreation of the 1895 America’s Cup classic won “Best of Show” at the 2006 Sanchon Boat Show, and scant  months later TYC launched Defender II, an upgrade fully adapted for SL racing. Defender II’s the boat that gave the name to “Big Boat Racing” in Second Life, and transformed sailboat racing along the way (“Leave that little Tako at home… tonight you can sail with the big boats!”).  

Never one to rest on its laurels, TYC next provided the physics engine that powered the ACA32 racers across the course  in the landmark America’s Cup-SL  Competition two years ago.  And what’s an AC race without sailors? Lorinda Cordeaux of TruCor provided the classic animations that breathed life into the helm and crew positions.

 But time passes, and with age comes the wisdom and experience to meet new opportunity. A few months ago I wrote an article saying, with I hope gentle humor that “I want a new gun.” The sailors of Second Life  had kept the  promise initially set out in Surfwidow Beaumont’s video; they were knowledgeable, focused and highly dedicated. They needed and deserved a boat as cutting edge as they were, something that took advantage of current technology and pushed the limits hard.

Since I wrote that little article, Mothgirl Dibou launched the Fizz3, a perfect answer for one-design dinghy racing.  With the release of J-Class we may be on the way to the big-boat answer, the next-generation replacement for the Defender II/ Trucordia Yawl, and all that those great boats represented.

Beta Crash Test Team

Before going any further, let me give a big shout out for the Beta Crash Test Team. This is the group of people who spent several months trying out various versions of the boat, making suggestions, offering feedback, and trying hard to find the last few venomous bugs that were overlooked hiding in the bilge. The test team includes racers and cruisers with both RL and SL knowledge and experience; they hail from from many yacht clubs, and all corners of the grid. Remarkably, even though only three J-Class boats are actively sailing today, several of the beta testers knew J-Class well and  even had first-had experience watching them compete under sail.

Here’s my listof beta testers, and please let me know if I missed your name so I can add it to the credits: Arrekusu Miromachi, Rikk Lovell, Chaos Mandelbrot, Manul Rotaru, Julia Ceres, kentrock messmer, Taku raymaker, M1sha Dallin, Liv leigh, Bea Woodgett, disisme misfit, Jane fossett, Francois Jacques, Epicurus Emmons, ahjep Kattun, Rikk Lovell, Armchair binder, Gemma Vickovic, Blackbird Latte, Bunnie Mills, and Oliphant Ming.

   

J-Class at Westland Marina Yacht Club

  The Boat

I have a number of topics I’d like to discuss about J-Class, so I’ll only hit some of the high points today. We’ll cover more details next time.

Hull and Rig:like other recent Trudeau releases, J-Class is a “rideable.” In other words it’s a real boat, a boat you can get up and walk around on… It’s not an attachment clipped to your pelvis.

Although it weighs in at only 28 prim, it’s fashioned with the remarkable and relentless attention to detail that’s a Trudeau hallmark. How it all fits in 28 prim is nothing short of miraculous. The hull color is easily adjustable by voice commands, and if you’d like to name the boat or personalize the hull, you can download the postscript texture files from the Trudeau website.

Bunnie Mills designed the sails; contact her in Second Life if you want custom sails; if you want custom work done on the hull and rigging, you may  find a boatwright here.  The physical size of the boat is impressive, with a 26m LOA, 4m beam, and 3.23m draft. While this adds to the boat’s regal demenor,  the boat’s dimensions can present significant, unexpected problems.Ffor example, it’s easily possible to run aground in some standard cruising areas, including  parts of Blake Sea.

On a reach both the jib and main boom will clip the top of racebuoys in Blake

I’ve run aground in both Gallilee and even in Atlantic sims, so keep a watchful eye on the depth gauge even in open water.  keep an eye on the towering mast too. It rises a full 30 m over the water line, but the functional height of the mast is even greater; I’d recommend observers and judges stay at a minimum altitude of 60m  to avoid interference with racing boats.

Having said that, there are also a number of positive advantages to the size and proportions of this wonderful boat.  For example , as you round a mark on a run the boom is high enough to clear most buoys, giving an experienced race skipper a decided tactical advantage. Of course you’ll strike those same buoys when heeling on a reach (as shown in the figure on the right).

Sailplan:The boat has a standard Trudeau sloop design with a mainsail and jib, but it also comes with a wonderful surprise: an enormous spinnaker fashioned from sculpted megaprim. Even at maximum draw distance, this huge parachute makes J-Class an attention-grabber and unmistakable.

Crew:The boat has room for a skipper plus three crew. If you’re not an average height or shape, never fear: J-Class comes with easily editable sit positions to ensure the owner is at home with the wheel. In addition, the helm and crew are wonderfully animated by Larinda Cordeaux, and crew members will even appropriately move to sit on the windward rail as the boat starts to heel. As with other Trudeau boats, the crew can share huds with the skipper, adjusting all sail parameters so the captain can focus on the helm. Future versions of the boat will even turn hiking control over to the crew, allowing them to shift weight and balance the boat. An unbalanced boat will pay a penalty with a reduction in lift, just as occurs in real life. So hey, that crew? They aren’t just deck ornaments anymore!

Large and Economy sized

  Performance

 How does J-Class compare to other Trudeau boats on the water?   That’s actually a difficult question to answer, since all the boats in the fleet prior to the Trudeau Twenty were predominantly attachables that used a Tako- style real wind algorithm to power the boat. Beginning with T20,  the Trudeau designs favored ridable boats fashioned from sculpted prims and the sails were powered by an apparent wind algorithm  replete with new RL features such as mainsail reefing and wind shadow.

 The J-Class continues that legacy, and the figure below shows in red where the new boat fits by comparison with the Leetle Cat (green) , the Twenty (yellow), and the Knockabout (blue). The curve for each boat plots the boat speed (speed over ground) for different apparent wind headings. Only the mainsail and jib were raised, and a real wind speed of 5 m/s  was used throughout to simplify the testing since reefing would not be a factor.

The red curve for J-class below shows that a nearly fourfold increase in speed over ground occurs as the boat’s heading falls off from 30 and 40 degrees apparent. Under these conditions, the boat’s maximum velocityoccurs at an approximate apparent wind angle of 50°. Beyond that there is aparabolic decay in thrust that becomes a slower, virtually linear decay and performance over approximately 110°.

The response curve for the J-Class appears similar to the other three boats plotted below. The Trudeau 20 is the slowest of the group,achieving a maximum upwind speed that is significantly less than half the real wind velocity. The knockabout is approximately 10% faster on upwind point-of-sail, and the Leetle Cat is roughly 15% faster still.

The J-Class shines going to wind; the results below show a major performance boost at headings of 40 – 80 apparent when compared to any of the other boats.

with just the mainsail and jib flying ,  on downwind points of sail the three boats give fairly similar performance results, and all four curves overlap.

 

 Of interest, the diagram below also charts (in pink) the knockabout boat speed on a downwind run with the jib winged. Winging enhances the boat’s forward speed beginning at approximately 140° apparent. This extra thrust grows larger at higher downwind angles, and at 170° winged sails can give an approximate speed boost of 30% in the T20, LCat, or KA.   However, please note: The J-Class is the only boat of the current Trudeau group that does not respond to winging, and any attempt to enhanced performance by flipping the sails traveling downwind will result in a fairly hefty loss of forward momentum.

 

J-Class main+jib performance compared to 3 earlier Trudeaus

 

 The kind of graphs shown above do not tell the whole story, however;  they only show the maximum steady-state speed at any particular apparent wind direction for the given sheet settings.  They don’t reveal how quickly the boat responds or how rapidly it reaches maximum velocity on a new course heading.  A boat of the size and inertia of the Trudeau Tradewind, for example,  responds to a new tack sluggishly and often takes considerable time to reach a new steady-state speed.   However, despite its size J-Class was one of the most nimble and responsive Trudeau boats of the fleet.   In most cases it took only a few seconds for the boat to adjust to changes in heading. That should make the boat considerably quicker on the race course than the graphs above might otherwise indicate.

The above graphs also fail to consider factors that impact performance, such as reefing.   With increasingly strong wind velocity a close-hauled boat  will heel, losing power as the sails become less effective. Reefing, or shortening the sail, is a simple way to keep the boat in a more upright, and efficient position.

  How far a boat heels depends on the apparent wind velocity and the boat’s heading.  Skippers in RL and SL often disagree about when to set a reef point or shake it out. the graphs below may answer the question for J-Class, at least for the heading of 40° apparent.

For the chart below, the J-Class sailed on a continuous heading of 40° apparent while the wind intensity (boat wind) varied.  The blue curve indicates the boat speed without reefing. The pink curve shows the same response with the first reef point set. the point where the pink curve crosses the blue one  indicates the apparent wind speed when reefing becomes an effective boost. For J-Class, the time to read iswhen apparent wind reaches  11.0 m/s.

 

 

 We will discuss spinnaker effects an upcoming article, so I’ll save most of that discussion until later. I did want to share, however the graph that showsThe shape and size of the spinnaker affect when maximally adjusted.

  The blue curve below is the boat speed with just a mainsail plus the jib.  The red curve is identical, except the jib drops at a heading of 90 and  the spinnaker goes up.I’ve indicated the optimum spinnaker settings below. The graph demonstrates that the spinnaker offers a significantly greater downwind boost compared to the jib. (Grin… perhaps that’s no surprise). we’ll talk more about the shape of that curve next time.