BD Yachts 56 more about engines and other details

BD Yachts – following the January 2016 presentation of the innovative BD56 project, TiàSimó, Naval Architect and Managing Partner at BYDGROUP – naval architect and designers ofBD56 – provides us with more details and further clarifications based on the questions received over these last few months.

BD56 ENGINES

Being a very unique boat, the BD56 (designed and engineered by BYDGROUP) has very specificneeds in terms of propulsion that conventional sailing yachts and conventional motor yachtshave  not.  Whiledeveloping  the  project,  the  BYDGROUP  team  found  that  the  inboardpropulsion systems available were inefficient for the BD56’s particular design. For a high speeddesign,  high  thrust  propellers  are  required,  but  they  are  unavailable  in  a  folding  version,necessary to reduce drag when sailing. Retractable propellers were another possible solution,but they are technically complicated and have reliability issues, as well as being very costly dueto necessary customization.

With  this  specific  yacht  BYDGROUP  needed  the  most  efficient  and  convenient  propulsionsystem available on the market, requiring reliability, ease of use and maintenance, a sufficientpower  to  weight  ratio,  and  very  importantly,  a  way  to  reduce  drag  from  submersedappendages: shafts, struts and propellers. The result was unexpected – outboard engines!With  thrust  at  a  0º  angle  to  the  DWL  with  an  outboard  engine,  the  drive  applied  by  thepropeller is equivalent to the drive applied by a conventional shaft at a 10º angle. In addition,the possibility of changing the thrust line angle provides for even greater efficiency.

Given the low weight of the outboards, the position of the CoG in balancing the hull with driveapplied from the stern is equivalent to that of a conventional inboard configuration.

The engines are hidden in the transom of the boat below the deck, well ventilated and withsufficient space to be lifted out of the water when sailing.

The power available for this boat is either one 200 hp engine (11,5 Knots Max) or two 350 hpengines (21 Knots Max).          

Why?

-Easy to install and maintain

-Fantastic maneuverability by joystick

-High global reliability

-Parts & maintenance available worldwide

-Easy to lift the engines out of the water, thus removing any added resistance

-Reduced weight

-Weight to power ratio of the whole propulsion system is apx. one HP per kilogram.

-No need for a complex engine room

-Electronic control systems for docking the boa

Although  Mercury  motors  are  proposed  by  the  yard  for  the  initial  release,  one  of  theadvantages that currently offered by BD Yachts is that the owner can choose any leading motorbrand available globally: Yamaha, Honda, Suzuki Marine, Evinrude, or Seven Marine.

TESTS OF CFD, RESULTS, RELIABILITY, EXCELLENT PERFORMANCE…

In  order  to  validate  such  a  unique  design,  BYDGROUP  and  BD  Yachts  invested  time  andresources in the most advanced calculation and prediction technology – CFD  (computationalFluid Dynamics) – to analyze the performance of the boat, both when motoring and under sail.

The naval architects TiàSimó and Raul Gonzalo designed more than 20 different hull modelsand  configurations  that  were  tested  in  a  virtual  Towing  Tank,  where  real  conditions  weresimulated. For the calculations BYDGROUP worked with a specialized team with Volvo OceanRace  and  America’s Cup  experience, Cape Horn  Engineering: the  accuracy  of the  results  iswithin 5% of the theoretical design data. Their experience in the optimization and analysis ofplaning sailing yachts is a warranty for success. With the help of CHE, BYDGROUP developedan optimal design giving the best performance both under sail and under power.

PRICES AND DELIVERY

The  BD56  is  a  tailor  made  product,  built  considering  the  needs  of  their  future  owners  inmultiple configurations, colors and finish qualities, to meet the demands of the most demandingyachtsman, and therefore yard does not have an exact price.

A full option BD 56 with a five (5) year warranty & maintenance service has an estimatedprice of 2.2 million euros. Delivery time for the first unit is 15 months.