The VG-GP42

Project Detail

Specifications:
LOA 12.80 m (42′ 0″)
LWL 12.34 m (40′ 6″)
Max Beam 3.65 m (12′ 0″)
Draft 2.60 m (8′ 6″)
DSPL 4200 kgs (9260 lbs)
Ballast 2310 kgs (5093 lbs)
SA (up) 108 m2 (1163 ft2)
SA (dn) 246 m2 (2.648 ft2)

Performance Ratios:

(40′ 6″) (sailing condition)
(12′ 0″) DSPLl/length – 70
(8′ 6″) SA/DSPL – 37

OCR_grand_prix_1The Offshore Racing Congress, after only eight months of intensive work, is now unveiling the “ORC Level Rule”. This is a BOX RULE expressly studied and designed for three different sizes of boats: 26, 33 and 42 feet. The target focus has been to promote the conception and construction of boats that are fun to sail, that are seaworthy and have considerable longevity. The development of the rules included significant contributions from many of the most famous design offices in the world, for which the ORC is extremely grateful. The ORC is now proud to present these new Grand Prix Rules to the market, believing that they will deliver the highest level of yacht racing to the general market place.

In brief, the rules are designed to create level rating, one-off custom race boats within a tight but simple box. They will allow owners to maintain some design freedom with the opportunity for them to select their own designers and builders. The principle characteristics of the ORC Level Rules are a light displacement, a simple fractional rig with non-overlapping jibs, no runners, and large sail areas producing boats with great performances for a relatively affordable cost. This rule will allow owners and sailors to compete on a level basis using only elapsed time.

One of the most commonly asked questions I get, with regards to a boat designed to a box rule, is “how do you know which corner of the box to design to?” In order to answer that, one needs to understand what a box rule is. Essentially it is a set of parameters, designated by the rule, with minimum and maximum dimensions describing the geometry of the boat. Unlike a formula driven rule, these parameters are non-dependant (e.g. changing displacement doesn’t change sail area and visa-versa) and they encourage the “type forming” of boats within a class. It’s then up to the designer to make the correct assumptions in order to optimize their flavor of boat to achieve the best performance. That’s where experience and understanding of the rule comes into play. In 2004 VGYD was asked to consult in the formulation of the ORC Grand Prix Rules, and is now in the unique situation to combine their experience and knowledge of the rule with the speed potential of their proven race boat designs.

The VG-GP42 is the first of the ORC “box rule” boats to be designed by Van Gorkom Yacht Design. This powerful and easily driven hull form, combined with a vast sail area and a generous righting moment, will rival the performance of many modern day 50 footers. The canoe body has a fine entrance angle at the bow with narrow “U” sections forward, and a gentle rocker running aft. The philosophy of having a narrow waterline beam, a low wetted surface, and a moderate prismatic of 0.532, produces a boat that will dominate the competition in light to moderate wind ranges. While in bigger breezes, as the residual resistance on a hull increases proportionally with the speed of the boat, a LWL/BWL ratio of 5.0 and a displacement/length ratio of 70 indicates a relative reduction in wave making drag and the potential for both a strong windward performance and the ability to readily plane.

The sail area/displacement ratio can be thought of as a measure of power to weight. That said, the VG-GP42 will have and a projected upwind SA/DSPL of 37 indicating a great upwind performance. The downwind SA/DSPL of 85 will have this boat breaking out and popping up onto waves very quickly. The all carbon rig will be fractional with masthead kites. The carbon spreaders will have a 15 degree sweep, and the permanent backstay will be adjustable with a cascade and magic box system.

A pre-preg carbon fiber and foam core laminate would be the ultimate construction process for the VG-GP42. However, a wet-preg carbon fiber/Kevlar and a foam core layup, vacuum bagged in an epoxy resin, is also an option for a minimal percentage loss of righting moment and a significant cost advantage. Carbon fiber uni-directional material is used in areas of high loading such as the keel grid, chainplates, and in critical transverse framing and bulkheads.

The GP42 box rule creates a well conceived working platform for both round-the-cans and offshore racing. The large open cockpit of the VG-GP42 will allow the helmsman and trimmers to do their jobs without the hassle of traffic jams. The helm can be configured for either wheel or tiller steering. The cabintop and bridge deck add to the aesthetic value of the boat as well as being a functional base of operations for the pitman.

The spacious interior of the VG-GP42 has a very functional and clean finish, well attuned to round-the-buoys racing or the riggers of offshore regattas. There are six fixed berths 2m in length. The galley, forward and to port, has a sink, and a two-burner stove. To starboard there is a cooler, the top forming the navigation table. Aft of the companionway is the engine box housing an inboard Yanmar 29hp diesel with Saildrive. The appendage package features a fixed keel with a draft of 2.60m. The keel has a state-of-the-art, low center of gravity, high-lift foil and dolphin T-bulb configuration. The rudder blade, also with the same successful high-lift foil section, and stock are fabricated entirely of carbon fiber.

In addition to the VG-GP42, Van Gorkom Yacht Design is in the process of designing a GP33 and GP26. Please contact us for more information on these designs.