2007 December 6
November 2007


The TP 52 class has been a tremendous success. The box rule approach to big boat racing lets boats race on a one-design basis while allowing room for designers to experiment with design features. By using a "box within a box" type rule that sets minimum and maximum dimensions boats are almost ensured of similar boat speeds. But while the TP 52 class continues to grow there are a small group of owners who want bigger boats. Rosebud from the Farr design office is the first of the new Storm Trysail-Transpac 65 rule boats. Once again Bill Lee of Santa Cruz was called on to work with a group of designers to formulate the new rule. Roger Sturgeon, owner of Rosebud, along with his project manager, Malcolm Park, also was very involved with the creation of the rule. Westerly Marine of Santa Ana, California, built the new boat.

One of the keys to the STP 65 rule was that it would create a boat that could also compete under the IRC and ORR rules. This would help minimize obsolescence. The box sets limits of 65 feet, 7 inches for LOA; displacement between 28,600 and 29,480 pounds; beam from 14 feet, 9 inches to 15 feet, 9 inches; a lifting keel drawing a maximum of 15 feet, 9 inches; and a large rig. The lifting keel will be fixed in the down position while racing but can retract to a draft of 10 feet, 10 inches for entering the harbor or doing some gunkholing. The D/L of Rosebud is 54.8 and the L/B is 4.18, making this a very light and quite narrow boat. Note in the profile how the hull flattens out right around the base of the keel fin. The Farr office does this in order to attenuate the "bump" in the longitudinal distribution of volume caused by the additional volume of the keel. Jet fighters do this too.

I don't have a set of lines for this boat but I'm going to guess that the half angle of entry, indicating just how fine the bow is, is about the same as the half angle of the deck. In this case it is 12 degrees. The knifelike rudder is pushed forward on the hull so that it will stay immersed at the top when the boat heels to 22 degrees. In order for the rudder to maintain its grip in the water it has to stay immersed, and this can be a problem at high heel angles. Rosebud is designed to sail upwind at 23 to 24 degrees of heel. The sheerline appears dead straight to my eye and I'm sure the freeboards are designed to fit the rule minimums. In IRC configuration 700 kilograms will be added to the bulb, as the IRC does not penalize vertical center of gravity for a given displacement. Note that the bulb is a beavertail type with a chine that begins at about the 50-percent chord position and continues aft. This chine on the bulb will further lower the VCG.

Belowdecks Rosebud is all business. There are pipe berths for the crew. These begin about 6 feet aft of the mast and extend aft beyond the rudderstock, indicating the importance of keeping weight aft while racing this yacht. Forward of the berths there is a small galley to starboard and a head to port. Forward of the mast is all devoted to sail stowage. The engine is connected to the retractable prop unit by a short shaft for optimal weight distribution. The nav station is nestled under the cockpit sole between the engine and the drive unit.

The rig is big, as you would expect with an SA/D of 40.15. The bowsprit is fixed and could prove vulnerable in tight starting maneuvers. The triple spreaders are swept 20 degrees. And no running backstays are indicated. The small bullet-shaped cabintrunk has been pulled aft to avoid conflict with tight jib sheeting angles, which can be as close as six degrees. On a typical mom and pop cruiser you'd be happy with a sheeting angle twice that big. Just for mom, there are three pedestal winches in the cockpit so she should be able to crank that jib in by herself in all but the strongest breezes. "Come on, dear. The main has to come in too!" Halyards and other control lines are led under the deck, through the cabintrunk, to banks of stoppers set into divots taken out of the aft corners of the cabintrunk.

At this time there are two other STP 65s under construction. Rosebud has one regatta win to her credit and a not-so-notable Transpac race finish due to tactical decisions. I'm certain we will see Rosebud's name at the top by the end of this sailing season.