Maritime Technology and Innovation - Essay Example

?Maritime Technology 508560) Introduction Ships that transport cargo in containers by a method called containerization are called Container ships. Container ships are fast replacing the cargo ships of the eighties that used to transport all material other than crude oil by the process of stocking up its holds with the cargo. Break cargo items were lashed on securely and each item was unloaded at the destination port individually. Replacing these break cargo ships with container ships minimized cost and reduced the time of unloading drastically leading to huge margins for ship owners. Development of Container Ships Container ships are usually defined in terms of TEU or twenty foot equivalent units. An 8500 TEU for example can transport 8500; twenty foot equivalent units of containers between two ports. With time being a critical factor for most globalized operations and fuel costs increasing by the day it has become inevitable for the shipping owners to transport maximum number of containers possible in one single voyage. This has lead to a continuous research and study into the development of new designs of increased capacity that would be capable of withstanding the rigours at sea. At the time, it should also be able to navigate easily through different canals and seas offering varying degrees of drafts. (Container Ship Types, 2000) Source: 4250 TEU Container ship, (Container Ship Focus, June 2006) Technical Requirements Purchasing of 18000 TEU ships is a matter of great achievement for any company and it is said that only Maersk which is the leader in Container ship transportation have ventured into buying 10 number of ships from Daewoo. The increased container capacity poses lot of technical queries, which need to be taken care of. 1. To account for the increased number of containers the length and width of the ship would be needed to be increased proportionately. This increase would again pose problems to the ships manovereability. It is known that ships have to navigate through various canals that exist between high seas to cross across continents. The PanaMax of size 4100 TEU’s delivered in 1980 was the largest to be delivered in those times and was named by its ability to pass through the Panama Canal. There was however no major change in the next twelve years and the size hovered around 4500-5500 TEU’s. Ships of length 294.1m, width 32.3m and draft of 12m was the maximum dimension of a ship capable of passing the Panama Canal. An accident leading to the slippage of 4 containers containing lethal arsenic oxide into the sea in 1992 near New Jersey lead to the International Maritime Organization (IMO) adopting the guidelines on safe securing of cargoes and became part of the International Convention for Safety of life at sea, 1974. (SOLAS) This required the ship must have a Cargo securing manual approved by the Flag State.( Container Ship Types, 2000) Most container ships built thereafter were an offshoot of the PanaMax category with increased TEU. The Post-PanaMax built in 1996 had a capacity of 6400TEU. By 1999 this size had increased to 9000 TEU’s. These ships have cell guides which enable better arrangement of container cargo above deck. However five cargo holds were unprotected from rain and rough seas which made it very critical to have an efficient bilge or waste water disposal system. The Suez-Max Large container ships (ULCS) built thereafter were capable of carrying 12000 TEU’s. The Post-Suez-Max ships are classified as those ships which can carry capacities upto 18000 TEU. This would require a ship breadth of 60m with a maximum draft of 21m. The Suez Canal is being revamped to accommodate these increased sizes of ships in the current years. Ships of 18000TEU are classified as Malacca Max since the Malacca strait offers a draft of 21m. The harbours of Singapore and Rotterdam are the other ports that offer such drafts. (Container Ship Types, 2000). Therefore it is inevitable that while placing orders for such large container ships of 18000 TEU’s the owner has to very sure about the cargo he intends to transport and the destinations of travel. This is because of the draft limit these ships pose and the degree of expert manovereability required in navigating such huge ships. Ships sailing between ports without full load capacity would also prove quite costly for the company. 2. The other main concern apart from accommodation of such huge sizes and its navigation through crowded ports is the technical requirement of hull design. Ships of such large lengths need to be checked for the various kinds of extreme sea loads using a number of engineering analyses. (Pamela the Great, 2005) These include (i) Dynamic Loading Approach (DLA) finite element analysis. (ii) Spectral Fatigue analysis (iii) Bow Fare slamming analysis (iv) Springing analysis (v) Whipping analysis (vi) Green Water analysis (vii) Vibration analysis Source: Forces on Ship’s Hull, ABS, 2005 3. Ships for such huge lengths need to tested for torsional responses at 0.4 x L where L is the length of the ship. The torsional moments generated should be used to calculate the maximum stresses developed in the steel members at these sections and whether these areas have been adequately reinforced. (ABS Refines Rules for Large Containerships, 2005) 4. A great degree of cyclic stress is generated in the side hull portion of the ship due to the repeated impact from the waves. The hull structures are therefore strengthened to resist fatigue failure and also prevent failure by shear buckling. Proper designing of the ship’s hull is important to prevent it from tear. 5. These containerships to minimize the amount of drag on the hull, usually take a unique shape of a large bulbous bow with a large overhanging rear end. This tends to create non-linear loads in the ship which needs to be accounted into the improved design calculations. (ABS Refines Rules for Large Containerships, 2005) 6. 18000 TEU ships require increased breadth of ships to accommodate the higher quantity of containers. This places immense loads on the double bottom floors that are primarily used as ballast tanks. Vibration analysis needs to be carried out in these sections 7. Apart from the design features that have been elaborated above, the next critical requirement of these ships is conformance to the requirements of SOLAS (Safety of Life at Sea). The position of the deckhouse is very critical since it should be located at such a position which ensures proper visibility for the navigator on the bridge. Therefore this would require the deckhouse to be placed near midship or at a forward location of the ship. However torsional design checks emphasize the deckhouse to be allocated further to the rear of the ship. Therefore a balance needs to be attained for optimum deck stationing. Source: American Institute of Marine Underwriters Technical Services Committee, Improper container loading on the MSC Napoli, 2007 The International maritime Organization on January 1, 1996 brought in a new regulation 22 which contained guidelines for upgrading the visibility from the bridge. (Container Ship Focus, June 2006) Although the radar is an effective instrument for detecting obstructions in front of ships, it is human visibility that is most reliable since there have been instances where small boats and dhows have not been registered on the radar. These new designs for improving ship visibility have been finally adopted in the Maersk variant which involved separation of the deckhouse from the engine room. The deckhouse located in the forward area of the ship is also prevented from any visibility problems due to containers. This increases the ship capacity as more number of containers can be stocked. The fuel tanks are placed in safe area below the deckhouse. This design modification also reduces bending moments generated on the hull. (Container Ship Focus, June 2006) 8. One of the prime concerns of handling such large container carriers is the time the ship would actually take in transporting cargo from one port and unload it at its destination port. Although the unloading process can be improved and speeded up with effective cranes, it is the speed of the ship that poses a degree of uncertainty on the ships voyage. Since the time taken to unload cargo at a port cannot be reduced drastically one could increase the speed of these ships to account for this delay. It has been calculated that an optimum value of 25 knots would be ideal for such huge ships. Further, the conventional single main engine poses certain problems. The fourteen cylinder engine cannot produce a speed of 25 knots and the 16 cylinder engine is inefficient due to the large space and weight required. The risk of cavitation causing pitting cracks on the surface of the propeller blades is also worrisome since this would further reduce speeds due to increased drag on these surfaces. Shaft power required for rotation is also high. Therefore to attain such speeds with greater mechanical efficiency it would be wiser to go for twin-engines coupled with two propellers. (Container Ship Speed Matters, 1998) Source: Predicted suction side cavitation, Container Ship Focus, 2006 9. The other requirement of such huge container ships is the robustness of the steering system. If for any particular reason, like the flooding of the steering room the steering system fails; the ship could pose a great degree of threat to other ships in its vicinity since these ships would keep changing direction with the direction of sea current. A failure of both the engines failing simultaneously is a highly unlikely situation. Therefore in the event of failure of one engine, the other engine should be capable of navigating the ship and reach its destination port safely. 10. Like the SOLAS the other critical item that needs to be satisfied are the MARPOL (marine pollution) requirements. Greenhouse gas emission indexing is a method introduced by the IMO to ascertain the units of CO2 (carbon dioxide) released per unit container carried per unit distance. CO2 emissions in ship are actually a result of fuel consumption. Following these guidelines is an important facet of container ship development. However, adherence to such strict guidelines has prompted many developing countries to back out of this commitment stating that they are not required to follow such measures since they were originally not part of the ‘Kyoto Protocol’.( Container Ship Types, 2000) However adherence to these norms is a moral responsibility of the seafarer. 11. Arrangement of cargo in the holds of 18000TEU ship is another area of concern since minimum time is to be taken for the unloading of the same. The standard boxes of height 8’6” are currently being replaced with a size of 9’6”. (Container Ship Focus, 2006) 12. Reducing delay in transport of cargo is the primary requirement of all shipping companies. However with the new security concerns that have come up post Sptember 9/11, it has become very difficult to access coastal shoes due to large arrangement of multi layer of security. The ships exit and entry points should be such that it prevents easy access of terrorists and stowaways. Case Study Maersk, the leader in container transportation has placed an order for 10 numbers, 18000 TEU ship from Daewoo Shipbuilding & marine Engineering Co ltd, Korea. Source: Twin Propulsion, Maritime Propulsion, 2011 The delivery date is on 2015 after which an additional order of 20 ships would be placed. These have been named as the ‘Malaccamax’ series with twin propeller design. This huge container ship is to be called as the Triple-E which try to emphasize their three principles Economy, Energy efficiency and Environment conformance. The ship has 16% higher more container capacity than the Emma Maersk ‘PS Class”. The dimension of the ship is in the range of 400mm in length, 59m height and 73height. (Container Ship Types, 2000) The data obtained after analysis with regard to carbon dioxide emissions and waste heat recovery systems show the Triple-E producing 20% lesser CO2 per container than the Emma Maersk. Conclusion The market for container ships keeps growing at a frenetic pace. It has been tabulated that in 2005, 74.6 million tonnes of cargo were transported which was equivalent to 78% of all cargo shipments transported during the year. The shipping industry and especially the container segment is in a state of perennial boom since no other form of transport offer the capacities that can be loaded in a single ship voyage. 18000 TEU’s is the current maximum limit of size that has been developed by the ship building industry. To accommodate such large sizes more and more ports are undergoing a revamp since a vibrant port directly manifests itself in the growth of the state’s economy. However the only point of caution is to ascertain how far the design and other technical requirements that have been briefly stated above have been conformed with, to achieve a stable ship. Reference Lists 1. ABS Refines Rules for Large Containerships, 2005, ABS, Available at http://eagle.org, [Accessed on 15th March 2011] 2. Container Ship Focus, June 2006, Container Ship Focus, Lloyd’s Register. 3. Container Ship Development-Pamela the Great, 2005, Germanischer Lloyd Non Stop 4. Container Ship Types, 2000, Military, Available at http://globalsecurity.org, [Accessed on 15th March 2011] 5. Container Ship Speed Matters, 1998, Available at http://marinetalk.com, [Accessed on 15th March 2011] 6. Propulsion details of the Maersk Triple-E Class 18000 TEU Container ships, 2011, Maritime Propulsion, Available at http://maritimepropulsion.com, [Accessed on 15th March 2011] Read More