SIG45 #001 progressing well

The work of assembling the composite elements of the SIG45 will soon come to a close. The construction of the SIG45 is highly detailed, with a variety of elements contributing to the integrity of the structure.

Depending on the loads experienced by the various parts of the boat (determined by Finite Element Analysis), skin thicknesses, panel sizes and reinforcements can be varied. For example, the area supporting the mast has a thicker carbon skin that areas with lesser loads such as the roof. Stringers (also known as omegas) serve to break up large side panels into smaller, more rigid ones. The floors and even bed panels are part of the structure, serving to strengthen the platform in the same way as the stringers.

Finally, various types of carbon are used locally for reinforcement, serving to provide additional strength and to distribute loads around the structure. For example, the main beam alone, which carries the loads of the mast, has several layers of biaxial carbon, followed by a total of 84 unidirectional carbon strips, all meticulously laid by hand on top of the basic 5 layer laminate!

In case you were wondering why the bows are so blunt, it is because the crash boxes still have to be mounted! The next steps will be to fit out the interior systems and furnishings – you will be kept up to date!

SIG45 #001’s Sails

North Sails in Connecticut has developed and built a beautiful set of sails for the SIG45. Their extensive experience of high performance multihulls, including ORMA 60s, Volvo 40s and the SIG45s little sister, the Lightspeed 32, has contributed to the proper geometry and shaping of the sails.

When designing the sails, the polars generated by the VPP (Velocity Prediction Programme) are used to determine the apparent wind speed and direction at different sailing angles. This gives the angle of attack of the leading edge of each of the sails, and allows the shape of the sail to be optimised.

The high aspect ratio, square top mainsail will be powerful and efficient, and with the leading edge of the sail designed to work perfectly with the rotating mast. The sails on the SIG45 will be somewhat fuller than those on the VX40 (the SIG45 is heavier), but will have similar twist characteristics as both boats are fast.

The jib and mainsail have been constructed using 3DL, North’s proprietary technology in which sails are thermo-moulded as a unitary membrane on a full-sized 3-dimensional mould. Compared to a traditional sail assembled from panels of flat sailcloth, a 3DL sail stretches less for its weight, holds its shape over a wider wind range and retains its designed shape longer. Using 3DL for the mainsail alone saves as much as 40kg (88lb) relative to a set of Dacron cruising sails!

The boat has five headsails. The masthead asymmetric spinnaker will be flown from the end of the bowsprit and hoisted with a 2:1 halyard. It is a fairly flat sail, as the boat will usually have the apparent wind forward of 90 degrees even when running. The storm jib will be hoisted using the 2:1 halyard of the staysail.

The staysail, self tacking jib and fractional gennaker will all be operated using Karver furlers. The staysail and the fractional gennaker will be hoisted on 2:1 halyards, while the head of the jib will be held in place by a lashing. The fractional gennaker can be used to achieve very high reaching speeds, and can also be used for running when wind speeds are too high for the larger asymmetric. The Gennaker uses a low stretch laminate fabric with Kevlar yarns for reinforcement.

In combination with the triple reefing points of the mainsail, this set of headsails provides options for a wide range of wind angles and weather conditions.

I look forward to sending you pictures of the sails actually hoisted on the mast in just a few short months.

Kind regards,

Hugo Le Breton

Le Breton Yachts
Lombokstraat 8, 1094 AL Amsterdam, Netherlands, Telephone: +31(0)20 692 8930 or +31(0)6 5583 8060
hugo@lebreton-yachts.com | www.lebreton-yachts.com