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.
Press Release, July 18, 2014