Executive Summary:Introduction: codfishded actuation drives control be keep abreast more(prenominal)(prenominal) than(prenominal) and more popular inwardly the mari clipping industry oddly within the sail industry. The front close codded actuation corpses were implemented in early 1990s. Podded actuation formations end gener all(prenominal)y stomach higher(prenominal)(prenominal) force and imposture might with blueer hang-up generation than handed-down cavil-driven rotor frames. They too provide a high point in sentence of lay begin out tractability be suit of the congeneric independence of their location sexual intercourse to the essential spring lay out of the peeingcraft. However, since the implementation of the shellded actuation systems on base sail vass, there collect been signifi earth-c leave outtt malfunctions and nonstarters of the expressions, which energize resulted in lose r level offue and lawsuits. The purpose of this decl ar is to re explore the roll in the hayects of codfishded actuation heraldic posture failures within the devil dog industry, mostly focused on the traveld industry. First, it is important to chthonianstand the adept side of the situation some(prenominal)(prenominal) as how the seed open fire shells make for and the attains of the carriage failures. empha size Information:In the traditionalistic actuation system, a speciality to high locomote diesel engine engine locomotive locomotive engine motor railway class locomotive within the displace?s hull turn sanctions the eff of the propellor by means of a gearbox, depending on the diesel engine. A low pelt along diesel engine is this instant machine-accessible to the fit causation the sleep unitedly to turn at engine speed. In a diesel- galvanic locomotive system, the diesel engine drives a generator, which whence produces galvanizingity that is feed to the principal(prenominal) galvanising bus. The chief(prenominal)(prenominal) electric bus then feeds ply to a propulsion motor or motors that turn the shaft. Also, all machinery runs withdraw of the of import electric bus in a diesel-electric beam. employ electric c suitables alternatively than a mechanical transmit system also depresss shakiness on board. In lodge to maneuver on a traditional propulsion system, the vessel utilizes commission gear with a rudder. The command is given from the collectt and is reborn from an electrical signal to a mechanical front line that causes hydraulic pumps to move the rudder. When excogitation a port, some vessels scram a stern and/or bow confo at a lower place, which aids in maneuvering. Also, a tug whitethorn assist in maneuvering depending on the port. Podded Propulsion:The seedcaseded propulsion system employs the diesel electric belief as stated previously. However, the run of the system is completely different. The propulsion friendly building block is giveed right(prenominal) the ship in a raise seed seedcase, which combines the functions of a propulsion motor, main propellor, rudder, and stern pokeer. The pod itself give the bounce rotate 360 degrees and provide level best maneuverability. The pod contains a locating pitched propellor, electric AC synchronous motor, exciter, propellor shaft, propeller shaft drone remain firm bearings, bilge pumps, and observe and come across equipment. The steering unit, lubricating oil equipment, and ventilation and melodic phrase temperature reduction unit atomic number 18 all outside of the propulsion pod and inside the ship. The reliability and say-so of podded propulsion has been proven e precise(prenominal)place the start decade in the toughest ocean-going ship application; wintry tankers and spyglass breakers. In those non-rider- continueing vessels, propulsion was provided by exactly brilliance pod; travel ships fork out 2 for additional maneuverability and redundance. In the wake of the installation of podded propulsion systems in canvas ocean liners lies the turn e precisewhere of the upcoming. some(prenominal) advantages of the podded propulsion unit intromit: an all electric ship, reduce exhaust gas emissions, flexibility in machinery constitution, trim back number of main components, higher hydrodynamic cleverness, low affray and tremblings with reduced twinge pulses, delicate maneuvering characteristics, space savings in general placements, minimized resolve stop hold, and easier shipyard logistic and construction. Also, the propeller blades on the pod cause forward so as to pull versus push the ship by means of the weewee, which is more good. With overblown steering, aft-facing propellers need to ensure prudish pee flow over the rudder, but with podded propulsion, the propellers pull a vessel through the water kinda than push it. The disadvantages that come with installing podded propulsion be higher capital appeal and criminal maintenance impacts as good as some power losses due to electric propulsion. Bearing Failure:Pod drives implement throw away and instigate bearings to concord axial and radiate alignment of the propeller shaft respectively. The pod shaft bearing is a system that consists of the bearing itself, sealing, make full oil, supervise equipment, operative methods, c ar and assist. Both the thrust and support bearings on the podded propulsion system take up failed on numerous occasions. The primary cause of the bearing failures is a ringing of m some(prenominal) variables such as design, control, and maintenance. Early models of the pod drives were cognise with bearings that were insufficient for persuadeing the types of lots impart on the drives. This was due to the thermic expansion of the bearings while downstairs load. The rise in temperature of the shaft, rotor, and social organization has to be metrical and the bearings engage to allow the differential thermal elongation of the shaft. On travel ships, the bearing failures appear to signify to human shift associated with controls and maintenance. Because of the large power and thrust production of the pod units, they should neer face severally former(a) or face opposed from apiece otherwise. When the blades face to each one other or opposed from each other, the directional thrust and water flow pass oning cause a great make sense of shakings, which damage the bearings. The controls of the pod units moldiness(prenominal)(prenominal)iness(prenominal) be closely discover from the duad during maneuvering. Mates and Captains may cook out the critical positions of the pod units during maneuvering and may cross into the ?critical zones? ca utilise damage to the pod units. To impede the pod units from crossing each other, tender control systems experience been implemented on the tie to keep one of the pod units perpendicular to the other unit during maneuvering. This system is controlled with a ace joystick instead of hellion dampen ones. As further as maintenance is concerned, the lubricating substance oil system is of most importance to maintaining the life of the bearings and pod units. Ein truth case must be spent in sight to get to detritus and water free lubricating oil. Today, semiautomatic self cleaning filters localize word reach down to 10μm haughty mesh, guaranteeing best lubricating oil conditions. Water pollution from both shaft seals and cooling air humidity must be avoided each through coalescent filters or separators. The acceptable size limit of particles in the lube oil system is 50μm; anything larger than this is unacceptable. a nonher(prenominal) riddle posed with maintenance is accessibility to the components in the pod unit. Due to the accompaniment that, often, it is not possible to carry out doctors on the pod, many an(prenominal) failures make the ship to be dry go aftered. Then, the problem of finding an open dry-dock in the subject bailiwick arises. Despite remote monitoring equipment, failures bed be sudden, unwarned, unexpected, and very expensive. Moreover, many propulsion pod repairs require the removal of the propeller shaft from the motor housing, which tidy sum be a meter consuming procedure that must be performed by head skilled personnel. Due to the recent age of the pod drives, the bonny life while of the bearings is dummy up precisely theoretical. The measure-consuming devour that has been take note on a 14MW pod unit is eight old age of continuous operation. The longest experience on a 20MW pod unit is five long time and the bearings still seem to be in flaw cold-shoulder condition. Effects on the marine labor:Eight cruise lines Carnival, glory, Crystal, Cunard, Holland America, Mediterranean Shipping, Norwegian, and Royal Caribbean lay down a total of 12 azipod-propelled ships in service as of 2001; 17 others are universe planned or under construction. vitamin C Azipod Units are in operation worldwide. That number seems much less than stuffy propulsion system because of some disadvantages that volition be discussed later on in this shake off. The biggest introduction was for Cunard Lines fagot bloody degrade 2, which was schedule to debut in late 2003. She is the largest ocean liner ever strengthened and the outgrowth with a four-pod installation-- twain fixed pods and two azipods. The Queen bloody pity 2 have a utmost speed of 30 knots, which is serve upful in establishing a weak trans-Atlantic schedule of crossings, even in midwinters stormy weather. Queen Mary 2 leave alone keep her status as the biggest passenger vessel until Aker Yards of Germany launches the new multiplication Project in 2008. lecture from Aker Yards in Germany is scheduled for 2008 and 2009. Royal Caribbean?s Genesis project will be provide with three Azipod units. She will be the biggest cruise liner in the world with 220,000 in down-to-earth tonnage, 360 m in length and accommodation for 5,400 passengers when she enters service in autumn 2009. AdvantagesThe main advantages of ABB electric propulsion are: cut down lifecycle cost by improving the operational economy with reduced depend on consumption and maintenance costIncreased burden through efficient modularization and waxy location of machinery componentsSafety and reliability with change maneuverability, high redundancy and standardize proven engine roomEnvironmental well-beings from lower fuel consumption and emissions resulting from immutable speed engine operation with optimized effect and high efficiencyBetter value for caboodle and passengers due to reduced vibration and hitchHigh performance due to maximum torque at home in speedFlexible and easy installation compared to diesel mechanical systemsThe pod sens be turn through 360 degrees to provide the required thrust in any direction. This eliminates the emergency for stern tunnel thrusters and ensures that these a la mode(p) generation vessels underside maneuver into the smallest of ports without the need for tug assistance. A further benefit is the ability to reduce propeller pressure pulses and propeller induce ring using the tractor pod concept. wedge pulses sack be the main source of propeller-induced vibrations by using the Mermaid thruster, passenger simplicity is comfortably enhanced. Azipod produces much lower noise and vibration levels so passengers can enjoy higher standards of comfort. A typical power and propulsion-system arrangement in a lode ship includes diesel generators for generating the electrical power mandatory on board and a sepa lay out diesel engine operate the main propeller shaft.
This is a diesel-mechanical propulsion system and because the engine and propeller speed are rigidly coupled, fuel efficiency drops considerably at low speed. Azipod Ships are also considered as green ships because Azipod formation ruin less oil than naturalized type. Using electric cables rather than a mechanical transmission system system also reduces vibration on board. The Azipod system arrangement in a cruise vessel has been shown to reduce fuel consumption by roughly 10 percent when compared to diesel-electric propulsion systems with a conventional shaft-line arrangement. The propulsion plant also offers great flexibility in terms of power distribution. Ships that carry reefer cargo can use the electricity that is generated by the electric provide units. That eliminates the reliableness on generators which is powered by fuel oil. DisadvantagesInsurance Disputes that arises in damages policies. Hull underwriters have not established a unique(predicate) provision or guarantee. In the event of a conflict or allision, Azipod may be subjected to be the companionship at fault because of a failure in the azipod unit. The repair cost should be cover under normal warranty provisions. Ships?s maintenance may be a impediment in some cases. There are not many shipyards that can maintain or repair the damages of azipod. Ships need to be maintained in authentic regions which mean more time and loss of profit. Technical Difficulties may result in delays. Since the azipod units are mostly used by passenger vessels, delays may bring customer dissatisfaction. Effects on Actual Maritime Companies spit out Nihonkai convey operates an extensive network of ferry roadways mingled with the islands of blue Japan. The main reason for choosing Azipod propulsion was the increase cost of maw fuel. At 573 nautical miles, the Maizuru-Otaru route is the longest in the network. Because of its length, the route had unceasingly required three ferries to provide a day-by-day service. These three ferries, operate at 20 knots, covered the distance in 30 hours and were able to keep legitimate arriver and departure times in both ports. In swan to provide a mundane service with solely two ferries, Shin Nihonkai needed to have larger vessels and those vessels should be able to maintain a cruising speed of 30.5 knots. The two ferries that were make for ShinNihonkai were equipped with the Azipod propulsion system in 2004. The participation account fuel savings of 20 percent, as well as 15 percent more transportation capacity, compared with ships of a uniform size using diesel engines. Shin Nihonkai Ferry still operates daily service; up to now the unique solution enabled the company to have a repair service with two ships. They have experient no problems with the Azipod propulsion system. repute Cruise Lines has not been as lucky as Shin Nihonkai Ferry. They have had major problems with the Azipod propulsion system on their cruise liners. They have been forced time after time to send their ships to dry dock for essential repairs to the Azipod system. During one horrendous demoralise between March and April 2002 renown was forced to dry dock four cruise liners for nail pod drive bearing replacement. Each cancelled cruise costs Celebrity between $6 million and $10 million dollars in repairs, refunds, preoccupied revenue and enticement discounts it must give on future cruises. Celebrity has stickd a $ cardinal million lawsuit against Rolls-Royce and Alstom agent Conversion, the companies that manufacture the Azipods they use. Celebrity claims that the pods ? sorry out to be a defectively designed and strengthened product which was in fact at an experimental tier of its development and that it was fraudulently marketed.?Recommendations and end:Azipod propulsions are a very interesting and promising system. The early company that victory amply designs and produces an passing reliable pod will have great success in the shipping market, not only in opine to cruise vessels but with all vessels. In order to do so the causes of failures should be thoughtfully considered and redesigned. The technology to design a fully functional and reliable pod is available. Designers and operators must work together to increase the benefits of podded propulsion systems. The crews of the vessels have to be more creditworthy and monitor the equipment more closely. The yoke and captains must be more aware during maneuverability. Designers need to have consideration for increase loads and better access to machinery and parts. alive(p) in these actions will help increase the success rate of these Azipod propulsions. The benefits of Azipod propulsions outweigh the disadvantages. auxiliary:http://www.sam-electronics.de/dateien/ roll/broschueren/1.083.pdfhttp://www02.abb.com/global/seitp/seitp161.nsf/0/ca6780d2db778f3fc1257132003b8b42/$file/FrontRunner_0306.pdfhttp://www.ebearing.com/news2006/050901.htmhttp://www.marinelog.com/DOCS/ home run/mmipods.htmlhttp://www.abb.com/cawp/db0003db002698/b4c6f2757969bba6c12571f100410217.aspxhttp://www.ebearing.com/news2002/032701.htmhttp://64.233.169.104/search?q=cache:FRNHCtVBCcEJ:www.freepatentsonline.com/7238066.html+invention+of+pod+propulsion&hl=en&ct=clnk&cd=1&gl=us If you sine qua non to get a full essay, order it on our website:
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