Yacht propulsion systems are the heart of the boat either you have sailing yacht or super yacht so to speak motor yacht. Whatever the system in the boat is, there is always source of energy and the equipment to convert this energy to mechanical energy for motion. In between these two separate parts of propulsion system, there is always another system, which supports each other or connects each other like shaft.
Energy source is generally marine diesel engine to produce power for the boat. Engine systems are designed by technology and installed in engine room which is in the hull to provide efficient power which drives the yachts with the cooperation of other connected systems on board.
Hull design brings most of the limitations applied on the speed but another very important issue is the budget that we have. Besides the budget, size of the boat and capacity of the fuel storage are other factors which we need to consider in details. Let us look at the existing propulsion systems.
Conventional propulsion systems:
In conventional propulsion systems on board the yachts mostly adapted by sailing yachts which are composed of diesel engine as a power source, shaft systems as a connector and propellers as converter to convert this mechanical energy to motion. Single hull sailing boats or yachts mostly have single propeller, since catamarans have two systems on board due to the nature of the design, which is multi hull. Because of the nature of design, they have two propellers, one installed on the center line of starboard hull, the other one is on the center line of port hull.
On the other hand, motor yachts could have more than one propeller depending on the speeds required. Sometimes they have equipped three propellers, one in the center line, the other two as like two-propeller motor yachts, are symmetrical on the both starboard and port side of the hull.
The only handicap is the alignment problem of whole system, which is engine, shaft and the propeller have to be inline altogether. This basic requirement affects the design of the boat. The picture above is the only solution of conventional systems, which is called sail drive. Diesel with the shaft and propeller attached each other in a compact manner.
Modern propulsion systems:
In modern propulsion systems are created to replace or reduce handicaps which conventional system creates. Sometimes the energy sources for modern systems are also changes from diesel engine to gas turbine. Other source for energy could be electrical in nature.
Electric propulsion system is widely used in river and canal boating circles. Electric motor retrieved the energy from batteries virtually noiseless, have no smell of fuel and produce no pollution emission. In other words we call them reliable ?green? systems, which protect nature.
Electric propulsion system can also be combined hybrid installation which allowing either electric or diesel propulsion. Electric motor driven by the diesel engine will then function as dynamo, charging the batteries for the next round of electric propulsion. This system is called diesel electric system as well, which is used in submarines widely which they use this system when they are not on the surface.
Electric propulsion often involves heavy discharge of batteries and it is strongly recommended a battery that can sustain such treatment and has a long life span. Electric consumption gauge is recommended to use additionally as one of the components.
This system could facilitate fantastic design availabilities due to the connectors used, which are cables. This means that power source, battery banks or diesel electric generators could be anywhere of the boat and propeller powered by the electrical motor is connected with wires with the convenience of the other equipment installment. A wide variety of range could be thought of. Look at the picture on the left.
Hydraulic propulsion system can be used in many cases when may be preferred generating energy to the vehicle and vessels to the propeller shaft by means of hydraulic motor instead of using conventional set up of engine and gear box.
In this technical performance a hydraulic wane pump is mounted instead of the gearbox. Wane pump makes the sail boat, luxury super yacht, ships, and crafts moving backward and forward depends on the direction of hydraulic flow, which can be completely controlled by the direction control valve.
Direction control valve progressed to control the direction of flow or turn the propeller and the volume of hydraulic which corresponded speed. Definitely there is an engine but can be build in different location. Hydraulic pipe system claims that the energy transfer units in this system. Take a look at the picture on the left.
Some hydraulic products which are developing from the engine can be used for light weight solutions found additionally in the market in bow and back thruster and anchor winches as a wide coverage solution in the world. Hydraulic propeller system can also be used as an auxiliary propeller system attached to the mechanical shaft with belt system. When the belts are tightened, hydraulic motor generated turn will engage with the propeller shaft. Look at the picture on your left.
You realize that all modern systems either electrical or hydraulic there is always diesel engine for the energy source, but the only difference between the conventional system is the location of the diesel engine and linking systems.
Another propulsion system mostly adaptable with motor yachts is the waterjet systems. High pressurized turbine system compresses the sea water and ejects from the back of the yacht and provides forward push for the yacht. These types of system application create advantages in operation but bring maintenance problems together with it. Mostly marine diesel engine or gas turbine is part of energy source since there is no propeller but diametrically adjustable nozzles which 360 degrees rotatable. ?The running thrust of the boat could be increased by making nozzle mechanism diameter smaller than the previous speed requirement.
In these high efficient propulsion systems the only problem is the fuel control. These systems are also built and combined with wide range hydraulic units and parts due to the heavy duty requirements. Waterjet system could be used long range commercial cruise applications but limitations are the necessity of having auxiliary propeller needed which is sometimes required for maneuvering purposes while in the port or marina.
Whatever the budget we have we need to concentrate on the simplicity of the systems. There is an old saying, the simpler the system it is the easier to control as well as easier to maintain. We shouldn?t forget this all the time. Nice to have now but if you can?t manage the maintenance it could be liability in the future.
Manufacturers reserved their own concept in planning safety in their own construction which is guided by experience alternative combination of systems comes up. Results are fast, integral, effective and greatly common in community of naval environment. New systems are registered and replaced old systems based on the origin of needs.