J8 Topaz
The design of the hull lines of J8 was originally from the legendary boards of Frank C. Paine. Paine is famous for his 1930 J-class yacht Yankee that was modified and updated in 1934 and the only J that could compete against the considerably longer waterline Super Js'. The lines plan shows that Paine designed J8 with an 88 ft original waterline length, a foot longer than any other J ever designed. He intended to accept a penalty on sail area for waterline length, which was quite radical in those days. The handicap system that is used nowadays is totally different but history has proven that waterline length is crucial in these designs.
The hull lines of J8 proved to be very fast in an extensive research project that our office undertook. All Js from the past that could possibly be built today were examined with a specifically developed Velocity Prediction Program for yachts with long keels and long overhangs. The five designs identified as best in this research were also analysed with Computational Fluid Dynamics software. The lines of J8 came out as one of the three best performing lines, very fast in light airs and downwind in all conditions. This design has the lowest wetted surface and highest keel aspect ratio of all Js.
The design was then extensively optimised to perform under the J-class Association handicap system. Mast position, stability, sail area and hull stiffness were extensively researched. The hull structure was designed and augmented to take very high runner loads in order to reduce head stay sag.
The design has a double cockpit, double deckhouse layout with the helm station amidships just in front of the aft deckhouse. During racing the aft cockpit is the runner cockpit, the mid cockpit the sail storage and helm position is amidships in-between the aft deckhouse and main cockpit. The primary winches, and the mainsheet winches are close to the helmsman: this creates short communication lines and facilitates trimming and helming without the use of headsets. This concept has already proved to be very efficient on the J-class Lionheart, also from our boards. In cruising condition the aft cockpit is for the owners and directly connected to the master deckhouse and cabin, creating privacy. The 'art deco' interior is also designed by our office, a styling concept that fits the time period of the Js very well and will be unique in look and feel.
The hull of J8 was built at Bloemsma Alumiuniumbouw, already responsible for two other aluminium Js (Lionheart and Rainbow). The yacht is finished by Holland Jachtbouw to a very high quality standard and launched in 2015 and has a similar hybrid propulsion installation to Rainbow. The yacht will benefit from the experience of Hoek Design and HJB with the J construction projects.
42.7 m
27.8 m
6.75 m
4.72 m
Holland Jachtbouw
2015