A reduction gear box ZF 3050 will be provided for each engine. Reduction ratio determined on relation to the propeller design and propulsion. Two skewed propellers, 6 blades, diameter about 1.3m, designed to obtain high efficiency and low noise will be provided. They will be made by nickel- aluminium-bronze (NiBrAl). Each propeller will be statically and dynamically balanced. Manufacturing tolerances will be according to ISO 484/2
Two spade rudders with drive by wire steering control will be provided. The blade size will be determined to ensure good manoeuvring capabilities; the rudder will be properly transversally off-set from shaft line axis in order to remove the screw shaft without dismounting the blade. The rudders construction material will be AISI 316L. Rudder holes will be in stainless steel, rudder stock will be made of Marinox 17 or equivalent, welded to the rudder blade and sized according to the Classification Rules.
The steering system will be of electrohydraulic type. A drive by wire steering wheel will be fitted in the wheelhouse, while one joystick will be installed on each side wing. On the dashboard a control panel will show the main info (mode, alarm status, rudder angle) of the steering system. The hydraulic system will be made of one power pack (oil reservoir with a 400Vac/50Hz/3ph pump) and 2 hydraulic cylinders (one for each rudder).
A bow thruster unit hydraulically driven (85hp) will be installed in a dedicated space. The propeller will have fixed blades and will be fitted in a 20in tunnel. The installation will be executed strictly according to Manufacturer instructions and specifications. Grids on bow thruster tunnel will not be provided in order to maximize the thrust performance. Control Joystick will be installed on the main helm station in wheelhouse and on the wing control stations.
Two units, one for each side, will be installed on the transom edge actuated by servo units connected with control units. The system will be governed by a control panel placed in the wheelhouse.
Safety and Security
BILGE AND FIRE SYSTEM
BILGE AND FIRE SYSTEM
Each watertight compartment will have a separate bilge suction, with foot valve, connected through the main bilge manifold to the bilge pump. Water from the bilge will be discharged overboard through an overboard connection located in the engine room. Main engines cooling pumps can be used to draw water from the engine room bilge in case of emergency. A second bilge suction will be installed on each watertight compartment, with foot valve, connected through the emergency bilge manifold, to the emergency bilge/fire pump and discharging overboard through a three way valve. The emergency bilge manifold will be installed out of the engine room. Where drainage is not necessary, the arrangements may be omitted provided that yacht safety will not be impaired. The chain locker will be self draining, additionally one bilge suction connected to a dedicated hand pump will be provided. A bilge alarm system, connected to the alarm and monitoring system, will be installed in all compartments served by the bilge system. The bilge pumps can be started and stopped from the control panel. Bilge lines will be flexible hoses fire resistance (ISO 7840) inside machinery spaces while fire resistant (ISO-13363) hoses outside machinery spaces; the manifolds will be made in AISI 316 stainless steel. The fire figthing system will have its own pump placed in engine room, and will be connected to the bilge system through the main manifold in such a way that the bilge and fire-figthing pumps may serve as bilge pumps and vice-versa. The emergency bilge/fire manifold placed out of the engine room will allow to use the diesel motor pump for feeding the fire fighting system too, by suctioning from a dedicated sea chest. Fire hydrant valves, with fire hoses and nozzles will be fitted.