Damen Marine Components (DMC), part of Damen Shipyards Group, has smashed its propeller nozzle world record by 33 percent downwards.
This downsizing to an inside diameter of 665 millimetres only – from the previous 1,000 mm ‘entry level model’ – marks a new milestone for DMC’s Optima Nozzle series.
Already one-third smaller than the previous one metre (1,000mm) Benjamins, the new 65 centimetre nozzles are, however, dwarfed altogether by the biggest models in the Optima series. With their 8 metre inside diameter, these exceed the two 65 centimetre ones twelvefold.
The two record-breaking 665mm nozzles weigh 188 kilos each and are quite extraordinary, since they were built for one 50 foot (15m) yacht. “ By specific orders from the customer, DMC Optima propeller nozzles had to be installed. In addition, the owner wanted his 11-knot yacht to have two propellers. Clearly, he is somebody who knows his business, considering this explicit and uncompromising choice which also included a stainless steel inside ring. Definitely an insider, ” said Aart Vogelaar, Sales Manager DMC.
DMC’s Optima propeller nozzle is recognized throughout the industry for its proven characteristics of combining reduced noise and vibration with propelling performance. “ Its profile was designed towards an optimum ratio between engine output, fewer revolutions and thrust, both forward and reverse, ” added Vogelaar.
This model – with the matching propeller pitch – is widely deployed in inland waterway vessels, Stan Tugs, push boats and hopper dredgers. Its noise/vibration/thrust performance mixture is the Optima’s trademark.
For dredgers, Stan Tugs or inland waterway vessels, DMC’s Optima nozzles usually have an L/D 0.5 ratio (length = 0.5 x diameter). For push boats the L/D is 0.6. The two world’s smallest nozzles feature L/D 0.4 in order to still safeguard ‘crew comfort’ at the river yacht somewhat higher 11 knot speed.
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Press Release, July 18, 2014