Engineering - Royal Australian Navy

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Naval Engineering Bulletin • June 2001 comings caused by this were solved by the introduction, principally by the United States Navy (USN). The USN produced a paper based maintenance system, which required the semi-trained maintainer to religiously follow a set of instructions, mainly for what we would call today “servicing”, but also for some longer term maintenance routines. After the war, with the increasing complexity of marine propulsion equipment, this process recommended itself for development into a true maintenance system. The British Royal Navy (RN) pioneered this approach and the planned maintenance system was born. It was introduced fleet wide in 1953. It was based on the operational cycle of the ship (refit to refit) and consisted of a card based system in which maintenance routines were specified to be carried out at by three month intervals and planned by class of ship under the control of shore based Class Authorities. Generally the system was a success not least in that it allowed operating authorities to be aware of the mechanical state of their ships for the first time. The Navy was considered to lead the world in design and operation of preventative maintenance management systems. There were, however, drawbacks. No instructions as to job content were available, nor was, a simple and effective planning procedure. Further, the tendency was to err on the side of caution, over-maintenance was considered acceptable in the search for increased reliability, and hence availability, and the system was very manpower intensive. Indeed, the introduction of a formal system, with a requirement for a disciplined approach to maintenance, actually led to an increase in workload and manpower requirements. This necessitated the introduction of fleet maintenance units to undertake the work that the hard-pressed ship’s staffs of frigates, destroyers and small ships could not manage. Availability could not be shown to have increased noticeably - indeed the amount of down-time was arguably greater through a combination of time required for maintenance tasks and the increased corrective maintenance required through maintenance induced defects. Over a period of 25 years the system evolved steadily and improved markedly. The basic interval was increased gradually from three to six months (significantly reducing workload and increasing availability), the number of mandatory items were reduced, and the ships’ engineers were given more authority to determine the maintenance to be undertaken and when. Job Information Cards (JIC) were produced giving explicit instructions as to the work content and listing the tools, and spare gear required. A muchimproved planning system was introduced and better control of the history of plant and machinery became available. The end result was the maintenance management system, which is still in use today. Despite the fact that the maintenance management system was probably the best preventative maintenance system available many problems still existed. Not least was the difficulty in modifying the system in the light of experience. When setting up a given routine it is natural for all concerned to proceed with caution. The design authority must depend initially on the advice of the manufacturer who will have designed, or modified, his product to suit naval requirements, and will thus propose a shorter period in which major maintenance procedures are carried out to protect his guarantee liabilities. He will also be interested in increasing his spares supply possibilities. The design authority itself will build in a safety factor in the belief that experience will allow it to reduce periodicity as reliability is proved. The maintenance authority, which produces the JIC, will also add in “belts and braces”. All of this is entirely natural and occurs throughout the maintenance field worldwide. The problem occurs when expertise suggests that there is scope for increasing periodicities. Almost inevitably inertia and caution, coupled frequently with a lack of verifiable information, will cause the decision to be delayed or deferred indefinitely. Nowhere in the system was a place for the reporting of availability, reliability and maintainability data to help in the process of reduction in maintenance effort. Several attempts to rectify this deficiency foundered, generally on the increase in workload imposed on ship’s staff. With the advent of the gas turbine frigate in 1977, with a much-reduced complement and high availability requirements, depended on simpler, more dependable electrical auxiliaries. Coupled with the first perception of the need to reduce operating costs if the service was to maintain its fleet in being, combined to force a review of maintenance policy in the late 1970’s. 61
Naval Engineering Bulletin • June 2001 The Implications of Revised MARPOL Regulations on RAN Tankers By Lieutenant R.M. GISHUBL, RAN Due to increasing worldwide environmental awareness the international community has been tightening regulations for the protection of the environment. On 6 March 1992 the International Maritime Organisation adopted new amendments to its Marine Pollution (MARPOL) regulations. These regulations are designed to limit the amount of oil that could be released in the event of collision or grounding of oil tankers. These regulations apply to all new tankers ordered after 6 July 1993 and existing tankers from 25 years after delivery. This article examines the impact of the MARPOL amendments on the Royal Australian Navy’s two tankers, HMA Ships SUCCESS and WESTRALIA. It will also look at the options available to the Royal Australian Navy and once the options have been outlined they will be compared using the squash ladder method to find which would give the most effective solution to the fleet. a double hull so if the outer hull is damaged the cargo tanks will remain intact preventing the escape of oil 1 . Other regulations limit the size and configuration of tanks and specify damage standards so that even if an oil tank is breached the outflow of oil is limited 2 . Due to the high cost of implementing these improvements smaller existing tankers are exempt from the requirement to have double hulls while larger tankers, above 30,000 deadweight tons 3 , have 25 or 30 years from delivery depending on existing cargo tank protection 4 . Ships effected by these regulations that are over five years from delivery are subjected to increased regime of inspections to ensure the structural integrity of the ship. As SUCCESS is much smaller than the implementation deadweight, having a full load displacement of only 17,933 tons, this ship is not effected. WESTRALIA is larger with deadweight of 33,595 tons and so falls under the regulations. Regrettably, due to the time and research limitations, the design or costing of options will not be examined. For the purpose of this article it is assumed that the Navy will continue with the two oceans Navy policy and every effort will be made to comply with the Royal Australian Navy Environment Policy. The aim is to determine impact of MARPOL 4 amendments on the Royal Australian Navy’s tankers. Implications of MARPOL In order to prevent the escape of large quantities of oil escaping from tankers in the event of grounding or collision, with the consequent environmental damage such as the Exon Valdez incident in Alaska, stricter construction regulations have come into force. These requirements are contained in MARPOL Annex II and require oil tankers to have As WESTRALIA’s segregated ballast tanks are external wing tanks they protect the cargo tanks and as they extend the full depth of hull WESTRALIA qualifies has having partially protected cargo tanks 5 . Thus WESTRALIA has, at the latest, 30 years from delivery to comply with these requirements. It is not clear when WESTRALIA was first delivered as meant by the MARPOL regulations, at the earliest it would be the date the ship was launched or any time up to commissioning in the RFA. In order to understand the difficulty in determining the delivery date an outline of the history of WESTRALIA will be useful. WESTRALIA was a merchant products tanker laid down in 1974 by Cammell Laird shipbuilders of England as part of an order of four for the Hudson Fuel and Shipping Co. The 1. MARPOL 73/78 Annex I regulation 13F 2. MARPOL 73/78 Annex I regulations 22-25 3. “Deadweight” (DW) means the difference in metric tons between the displacement of a ship in water of a specific gravity of 1.025 at the load waterline corresponding to the assigned summer freeboard (ie full load displacement) and the lightweight of the ship. ‘Lightweight’ means the displacement of a ship in metric tons without cargo, fuel, lubricating oil, ballast water, fresh water and feed water in tanks, consumable stores, and passengers and crew and their effects. 4. MARPOL 73/78 Annex I regulation 13G 5. See HMAS WESTRALIA Arrangement of Tanks 62
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Engineering - Royal Australian Navy

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