Green Machine

A company called Sly Yachts had a design contest "aimed at singling out the best ideas and most innovative designers in the boating sector" and here is the winner – the Green Cruiser 50. Designed by Davide Tagliapietra (from Schickler Tagliapietra Yacht Engineering). Not sure if we’ve seen that particular keel combo, (and check out the rudder) but it is a good looking cruiser with some innovative thinking behind it. Here’s what Tagliapietra had to say about the boat:

The high technological content of this boat is aimed not only to increase comfort and performances, but moreover to open up new horizons for a potential environmental sustainability.
A composite of bamboo fibre/epoxy resin was chosen as the main material of construction due to the benefit in the net balance of CO2 emissions. The availability of the natural fibre on a large scale, similar techniques in manufacture and good mechanical properties make it possible to replace traditional glass fibre almost completely and without affecting the total boat displacement. Oil and wax are applied to the interior panels and other treatments with low environmental impact are selected for working surfaces. On deck and on the mast tube photovoltaic paint in conjunction with high efficiency solar panels contribute to create a little power plant enabling the production of 5.5 Kw during the day.

The hybrid diesel-electric propulsion system can take advantage of the renewable energy captured and exploiting an extended range or allowing the yacht going inside protected areas in fully electric mode.

Diesel generators are positioned in a more suitable position at mid boat allowing  the two aft cabins becoming generous and, importantly, allowing a reduction in actual noise level.  Sailing performance improvements have been carefully taken into consideration and successfully achieved. An innovative keel system which has been specially thought through, developed and now patented, allows the boat to have a translating bulb mounted on a fixed winged keel. The advantages of a ‘traditional’ canting keel come along without the typical drawbacks. Draft is limited to 2 meters. The keel attachment to the hull  is completely standard and the wings prevent the need for daggerboards. As a consequence nothing is affecting the interior space.

Because numbers are what matter; the new appendage configuration has been investigated with CFD codes and a comparative VPP study, incorporating the whole yacht. Considering  the same boat equipped with a fixed keel, the same draft and the same righting moment, similar performance is evident in the range of TWS 0-10 knots. Over 10 kts a large performance advantage is visible, especially beam reaching.

More details are available here (www.styacht.com)