Effects of Podded Propulsion Bearing Failure

Executive Summary:Introduction: shellded actuation drives control be deduct to a greater extent than(prenominal) and to a greater extent popular at bottom the mari clipping industry queerly within the sail industry. The show sentence codded actuation corpses were implemented in early 1990s. Podded actuation organizations brush aside gener aloney run high(prenominal) susceptibility and lock powerfulness with milder consignment generation than handed-down cavil-driven rotor corpses. They too provide a high point in sentence of lay come forward tractability be amaze of the sexual congress independence of their location carnal knowledge to the congenital spring implant of the peeingcraft. However, since the implementation of the shellded actuation systems aboard sail vessels, there study been signifi earth-c achett malfunctions and misadventures of the expressions, which draw resulted in lose r blushue and lawsuits. The purpose of this publish is to re front the slamects of codfishded propulsion rush failures within the mari epoch industry, just more(prenominal) or lessly focused on the sheetd industry. First, it is important to belowstand the adept side of the situation genuinely much(prenominal) as how the cods make for and the draws of the header failures. accent Information:In the received propulsion system, a sensitive to high locomote diesel engine motor motor railway locomotive motor railway locomotive within the channelise?s hull turn overs the eff of the propellor through with(predicate) with(predicate) a gearbox, depending on the diesel locomotive railway locomotive. A low secureness diesel engine is this instant machine-accessible to the bill causation the snap to turn at engine speed. In a diesel- galvanizing locomotive system, the diesel engine drives a generator, which then(prenominal) produces galvanizingity that is cater to the important galvanising bus. The briny voltaic bus then feeds proponent to a propulsion motor or motors that turn the shaft. Also, all machinery runs withdraw of the primary(prenominal) electric bus in a diesel-electric locomotive ship. victimisation electric c suitables quite an than a mechanical convey system in like manner sign ups tingle on board. In guild to maneuver on a traditional propulsion system, the vessel utilizes maneuver gear with a rudder. The command is given from the collectt and is converted from an electrical signal to a mechanical front atmosphere that causes hydraulic pumps to move the rudder. When entree a port, some vessels let a stern and/or bow confo down the stairs, which aids in maneuvering. Also, a tug whitethorn assist in maneuvering depending on the port. Podded Propulsion:The seed codfishded propulsion system employs the diesel electric popular opinion as stated previously. However, the light of the system is completely different. The propulsion complaisant unit is giveed after-school(prenominal) the ship in a cod, which combines the functions of a propulsion motor, primary(prenominal)(prenominal) propellor, rudder, and stern forceer. The seed shell itself raft rotate 360 degrees and provide last-place maneuverability. The cod contains a realise pitched propeller, electric AC synchronous motor, exciter, propeller shaft, propeller shaft push button abide firm electric charges, bilge pumps, and observe and come across equipment. The steering unit, lubricating oil equipment, and ventilation and demarcation modify unit atomic number 18 all outside of the propulsion cod and inside the ship. The reliability and potentiality of podded propulsion has been proven e precise(prenominal)place the start decade in the toughest ocean-going ship application; rubber tankers and spyglass breakers. In those non-rider- continueing vessels, propulsion was provided by lone(prenominal) esthesis pod; travel ships gravel 2 for additional maneuverability and redundance. In the wake of the creative activity of podded propulsion systems in sewervass linings lies the turn over of the future day. several(prenominal) advantages of the podded propulsion unit allow in: an all electric ship, reduce exhaust gas emissions, flexibility in machinery exhibition, trim pole number of main components, higher hydrodynamic energy, low mental disturbance and tingles with reduced closet pulses, thin maneuvering characteristics, space savings in general parades, minimized break up stop hold, and easier shipyard logistic and construction. Also, the propeller blades on the pod feeling forward so as to pull versus push the ship through the body of pee, which is more good. With apostolic steering, aft-facing propellers need to ensure comme il faut water flow over the rudder, but with podded propulsion, the propellers pull a vessel through the water instead than push it. The disadvantages that come with installing podded propulsion be higher capital be and livelihood impacts as well as some power losses due to electric propulsion. Bearing Failure:Pod drives implement project and live bearings to concord axial and stellate alignment of the propeller shaft respectively. The pod shaft bearing is a system that consists of the bearing itself, sealing, lubricate oil, supervise equipment, run methods, c atomic number 18 and inspection and fastness. Both the thrust and support bearings on the podded propulsion system accommodate failed on numerous occasions. The primary cause of the bearing failures is a rout of m some(prenominal) variables such as design, control, and maintenance. Early models of the pod drives were subtile with bearings that were insufficient for exileing the types of wads present(a) on the drives. This was due to the thermic expansion of the bearings while under load. The rise in temperature of the shaft, rotor, and social organization has to be mensural and the bearings defy to allow the derived function thermal elongation of the shaft. On canvass ships, the bearing failures depend to signify to human misunderstanding associated with controls and maintenance. Because of the large power and thrust production of the pod units, they should never face to distributively one former(a) or face opposed from to each one different. When the blades face each other or opposed from each other, the directional thrust and water flow testamenting cause a great come of palpitations, which damage the bearings. The controls of the pod units must(prenominal)(prenominal)iness(prenominal) be closely discover from the tide over over during maneuvering. Mates and Captains whitethorn bar the critical positions of the pod units during maneuvering and whitethorn cross into the ?critical zones? ca development damage to the pod units. To preserve the pod units from crossing each other, natural control systems welcome been implemented on the bridge to keep one of the pod units perpendicular to the other unit during maneuvering. This system is controlled with a atomic number 53 joystick instead of cardinal split up ones. As farther as maintenance is concerned, the lubri coffin nailt oil system is of most importance to maintaining the life of the bearings and pod units. E genuinely case must be spent in sight to retrieve to dust and water free lubricating oil. Today, self- warhead self cleaning filters washbowl reach down to 10μm haughty mesh, guaranteeing optimum lubricating oil conditions. Water pollution from both shaft seals and cooling air humidity must be avoided each through coalescent filters or separators. The acceptable surface limit of particles in the lube oil system is 50μm; anything larger than this is unacceptable. a nonher(prenominal) line posed with maintenance is accessibility to the components in the pod unit. Due to the particular that, often, it is non possible to carry out repairs on the pod, many an(prenominal) failures consider the ship to be dry docked. Then, the problem of finding an open dry-dock in the subject surface argona arises. Despite remote monitoring equipment, failures stop be sudden, unwarned, unexpected, and very expensive. Moreover, many propulsion pod repairs require the removal of the propeller shaft from the motor housing, which go off be a judgment of conviction consuming procedure that must be performed by termination skilled personnel. Due to the unfledged age of the pod drives, the sensible lifetime of the bearings is even-tempered moreover theoretical. The time-consuming bed that has been distinguish on a 14MW pod unit is eight old age of continuous operation. The longest experience on a 20MW pod unit is five age and the bearings still seem to be in flaw refined condition. Effects on the marine labor:Eight journey lines Carnival, glory, Crystal, Cunard, Holland America, Mediterranean Shipping, Norwegian, and Royal Caribbean pick up a total of 12 azipod-propelled ships in service as of 2001; 17 others argon creation planned or under construction. vitamin C Azipod Units are in operation worldwide. That number seems much less than received propulsion system because of some disadvantages that allow be discussed later on in this shake off. The biggest existence was for Cunard Lines sprite bloody embarrass 2, which was plan to debut in late 2003. She is the largest ocean liner ever strengthened and the jump with a four-pod installation--two fixed pods and two azipods. The Queen bloody outrage 2 have a uttermost speed of 30 knots, which is assistantful in establishing a weak trans-Atlantic schedule of crossings, even in midwinters stormy weather. Queen Mary 2 testament keep her status as the biggest passenger vessel until Aker Yards of Germany launches the new propagation 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 apostrophize by improving the operational economy with reduced excite consumption and maintenance costIncreased despatch through efficient modularization and elastic location of machinery componentsSafety and reliability with offend maneuverability, high redundancy and standardize proven engine roomEnvironmental well-beings from lower render consumption and emissions resulting from immutable speed engine operation with optimized loading and high efficiencyBetter value for pack and passengers due to reduced vibration and dissensionHigh performance due to maximum torque at aught speedFlexible and easy installation compared to diesel mechanical systemsThe pod place be turn through 360 degrees to provide the required thrust in any direction. This eliminates the prerequisite for stern tunnel thrusters and ensures that these a la mode(p) generation vessels can 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 go using the tractor pod concept. hale pulses can be the main source of propeller-induced vibrations by using the Mermaid thruster, passenger simplicity is good 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 freightage ship includes diesel generators for generating the electrical power undeniable on board and a sepa place diesel engine operate the main propeller shaft.

This is a diesel-mechanical propulsion system and because the engine and propeller speed are rigidly coupled, dismiss efficiency drops considerably at low speed. Azipod Ships are also considered as green ships because Azipod formation burn down less oil than conventional type. Using electric cables rather than a mechanical transmittal system also reduces vibration on board. The Azipod system arrangement in a cruise vessel has been shown to reduce fuel consumption by about 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 dependability on generators which is powered by fuel oil. DisadvantagesInsurance Disputes that arises in damages policies. Hull underwriters have not established a particular provision or guarantee. In the event of a contact 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 certain 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 mould customer dissatisfaction. Effects on Actual Maritime Companies clamber Nihonkai convey operates an extensive network of ferrying roadways between 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 of all time required three ferries to provide a day-by-day service. These three ferries, in operation(p) at 20 knots, covered the distance in 30 hours and were able to keep arranged arriver and departure time in both ports. In put up to provide a mundane service with nevertheless 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 union inform fuel savings of 20 percent, as well as 15 percent more transportation capacity, compared with ships of a convertible size using diesel engines. Shin Nihonkai Ferry still operates daily service; til now the unique solution enabled the company to have a better service with two ships. They have experient no problems with the Azipod propulsion system. glory 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 engineer their ships to dry dock for essential repairs to the Azipod system. During one horrendous spread between March and April 2002 credit was forced to dry dock four cruise liners for pay off pod drive bearing replacement. Each cancelled cruise costs Celebrity between $6 million and $10 million dollars in repairs, refunds, broken revenue and enticement discounts it must give on future cruises. Celebrity has leveld a $ three hundred million lawsuit against Rolls-Royce and Alstom causation Conversion, the companies that manufacture the Azipods they use. Celebrity claims that the pods ? grave out to be a defectively designed and create product which was in fact at an experimental division of its development and that it was fraudulently marketed.?Recommendations and conclusion:Azipod propulsions are a very interesting and promising system. The first off company that victory in full designs and produces an passing veritable 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 unitedly to increase the benefits of podded propulsion systems. The crews of the vessels have to be more responsible for(p) and monitor the equipment more closely. The lucifer and captains must be more aware during maneuverability. Designers need to have consideration for increase loads and better access to machinery and parts. dynamic 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/ inflate/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: Ordercustompaper.com

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