Maintenance Management

Introduction
Shipping is a business enterprise conducted within the realm of maritime transport. As such it should be able to sustain itself economically, to pay for its own expenses and to build up the necessary resources to renew itself. It is a most dynamic business, change in the rule rather than the exception, and probably more so than ever. Shipping industry is governed by multitude of statutory regulations that support ship safety and pollution prevention efforts by national and international level. The nature of shipping business allows companies to carry the flag of the country which best fits to the company objectives. While some of the flag states pay utmost intention to improve the quality and performance of its registered vessels, while other flag states, it’s just a matter of business, which is being called flag of convenience. The maintenance free ship has not yet been constructed, even if it were technically feasible, the procurement of such a ship would be of astronomic cost. Therefore, ships are built to be maintained and sometimes repaired to keep the ship serviceability and to preserve its value with a view to its future sales price. The overall condition of a ship is directly related to the standard of maintenance. Properly managed maintenance activities assist compliance with regulatory requirements and minimize the risk of problems arising from Port State Control inspections, International Safety Management Code (ISM) Code audits or inspections by bodies such as charterers or Protection &amp; Indemnity clubs.

Maintenance Methodology
Maintenance is categorized into three types:


 * 1) Preventive Maintenance: It is a set of activities performed on plant equipment, machinery, and systems before the occurrence of a failure to protect them and to prevent or eliminate any degradation in their operating conditions.
 * 2) Corrective Maintenance: In this type, actions such as repair, replacement, or restore will be performed after the occurrence of a failure to eliminate the source of this failure or reduce the frequency of its occurrence.
 * 3) Predictive Maintenance: It is a set of activities that detects changes in the physical condition of equipment (signs of failure) to conduct the appropriate maintenance work to maximize the service life of the equipment without increasing the risk of failure.

Proper maintenance is not merely a question of finding out what to do and when to do it. It is a question of planning the rational available man power resources and procurement of spares and requisites in time.

The four maintenance situations is described as follows:

The desirablesituation is when there is a reasonable balance between the work that is to be done and the manpower there is to do it. The first warningis a situation where there is not quite enough manpower to keep pace with the maintenance plan and one begins to push back jobs to a later time. The criticalsituation, this is when the quantity of maintenance jobs are lagging continues to build up, and the moment of serious breakdown somewhere on ship is approaching. The time of collapse, nobody can foresee the full extent of the misery. The ship comes off-hire, drifting at sea or lying idle in port, extensive and costly repairs result.

The recent trend is to put increased emphasis on analysis and planning, taking into account various operational constraints. This added emphasis is due to the high cost of maintenance work and the serious consequences of breakdowns.

Maintenance Cycle
Looking ahead, classification societies are taking an active interest in condition monitoring, which shows promise as a substitute for dismantling many machinery components for visual inspection. Condition monitoring or measuring the physical properties of a component or system, is a technique being used to check the deterioration with use of component or a system, and to check the critical parameters of component or system operation, when choosing condition monitoring methods and parameters it is necessary to have knowledge of the different types of failure and their causes, and how these may be predicted or detected.

Condition monitoring can be divided in two mainstreams:


 * It can be performed just before a planned stop of a complete plant. During this session, all machines which are part of the maintenance plan are measured. This gives a rough impression of the need for maintenance of the machines. The basis for the vibration levels being international standards such as ISO, or comparison with earlier measurements or similar installations. Before the measurement, an overview of possible fault frequencies is made on the basis of the types of bearing, number of gear tooth, couplings, and etcetera. This method gives a brief impression of the state of the installations. It is sufficient for less critical components only, since the most important tool for condition monitoring, the development of wear, or fault-frequencies, in time is missing, and there is no actual monitoring of the machines. Typical examples for such actions are plants, just before a summer or winter stop, or larger ships, which base the order of maintenance for pumps, generator, winches and so on, on the results of the measurements.
 * The other method of condition monitoring is based on periodical measurement, with the period being determined on the basis of importance of the machines in question, and the type of operation. The deviation of the frequency pattern in time, and especially the development of frequencies related to typical components such as bearings, gears, rotor bars and other, is the basis for judging the machines need for survey. This means the installation is only stopped and opened when it is determined necessary. This lowers, in some cases dramatically, the maintenance cost per engine. Furthermore, and not less important, the number of failures will drop, since a number of failure will be established in an early stage. Condition parameters and functional performance are relative factors. They may give a quantitative measures of a component ability to perform its function relative to its performance in an as new condition. The functional performance of a component may be expressed in two different ways:


 * 1) By a simple, measurable, physical dimensions, such as the quantity delivered by a pump;
 * 2) By a computation of several measurable, physical properties, such as efficiency.

The functional performance of a system will be dependent on the performance of each individual component in a system. A system normally consist of several different types of component, and the performance of each may not have the same influence on the performance of the system. The present value of system performance is a measure of present technical condition. It thus provides valuable information to those responsible for the operation of the system. A graph plotting system performance values against time will reveal the changes in technical condition, and it is possible to get fair indication of when the limiting value will be reached. Maintenance may thus be decided accordingly. The sudden changes in performance caused by as incidents tell us: - How serious the different types of failure are; and - How different the maintenance work has been, and what action should be given highest priority.

Condition monitoring is suitable for keeping track of performances which deteriorate over a period of time. Another area where condition monitoring is being applied is the surveillance of rotating machinery. The most common methods used here are :


 * Impulse measurements; and
 * Vibration measurements

The key to this is periodical measurements of a number of machinery parameters, of which vibration measurements is the most important one. In standard maintenance, the machines are inspected at fixed intervals. These intervals are usually determined on the basis of experience with other equal machines, or based on the manufacturer’s guidelines. These are often on the safe side, resulting in shorter interval terms than actually necessary, due to a very conservative safety margin. Exceeding this period, means risking a critical failure, and you will not be willing to take such a risk. This means, you will have to stop and open the machine once its time has come. The advantage: easy planning of maintenance, since a schedule can be made far ahead. The disadvantage: not all machines follow this schedule, and minor errors in, for instance, alignment, mounting conditions, balancing of components, and so on, may cause the installation to fail within its expected "maintenance free" period. Vibration monitoring makes it possible to have better control over the actual need for maintenance of the installation. In most cases, this means a lowering of total maintenance costs, and a decrease in maintenance costs per machine. Non destructive testing is another area of condition monitoring, where inspection parts for cracks and integrity is an example for, to avoid any failure in the future of the machinery or a system. A special area of condition monitoring relates to the underwater hull and propeller. The increase in the cost of fuel has meant that attention is now being devoted to the prevention of the growth of and the conservation of hull smoothness. However, there are so many factors influencing both measurements and actual hull resistance that special care has to be taken to reveal change at early stage.

Once the techniques have been sufficiently refined and proven, this is expected to be a development which all owners will welcome. A variation of condition monitoring has already been adopted by some societies for examination of tail shafts with oil lubricated bearings, where checking of wear down and analysis of the oil has let us extend considerably the intervals between tail shaft withdrawals. Hull surveillance is another field in which classification societies are taking an interest, At present hull surveillance is directed toward measuring and recording loads imposed on the hull girder and in the slamming area over a period of time, but it is conceivable that the techniques could be used to assess the overall strength of the hull, perhaps more accurately than is now done by taking gauging. In a ship equipped with a conventional alarm system, the alarms are usually triggered when a single operating parameter is exceeded, for simple cause/consequence relationships it is not necessary to perform any analysis to determine the cause of failure. For machinery systems of a more complex nature some failures may be detected only indirectly through a combination of several items of information or alarms are determined either through fault tree analysis or through mathematical models of process parameters. Some parameters which are of special interest as well, such as; cylinder liner wear, scuffing, piston ring function, metal temperature in covers, pistons and liners, metal temperature in exhaust gas valves. The cylinder liner wear is usually measured by the change in electrical resistance of a wear sensor placed in the upper part of the cylinder, where the wear rate is greatest ( high temperature and pressure, and low piston velocity ). The advantages to be gained from condition monitoring in ship operation are very promising and the technique must be regarded as being in its early stage of development. Condition monitoring requires instrumentation of high accuracy to assist in evaluating the overall situation of a system, and hence the maintenance.

Maintenance Management
Maintenance is the single most important factor in the upkeep of modern society, and there are few areas in which it plays such a dominate role as shipping. But we are all aware that maintenance is expensive, there is clearly an optimum maintenance strategy, and it is not easy to decide what it is, for it differs from ship to ship. Modern ships require different maintenance strategies from old, run-down ships, for which the word “repair” is probably more appropriate than “ maintenance “. Maintenance work is required when the properties of a construction or equipment deteriorate through age and use to the point where performance is adversely affected. Through maintenance we seek to control or slow down the rate of deterioration, and we want to do this for a number of reasons. In the case of a ship or an offshore installation there are five basic considerations:


 * 1) The owner obligations in terms of safety and seaworthiness.
 * 2) Preservation of capital by prolonging the economic life of a ship or rig and improving its second life value.
 * 3) Preservation of performance as a cargo carrier or drilling unit by improved availability and efficiency.
 * 4) Preservation of efficiency as regards operating expenses.
 * 5) Environmental effects on the complements and its performance.

With the increased unit value of ships and cargoes and the increased hazards, environmental pollution, various strategies have been employed to ensure operational safety and reliability.

No ship owner can afford to have his ship lying idle for any length of time because of machinery or other equipment breaking down. Nor can ship owners accept that maintenance expenses run so high that potential profit is absorbed by the cost of repairs and maintenance work. The combined effect of loss of production and excessive repair expense may in fact put the ship owner out of business. One of the primary responsibilities of a ship owner and ship management Company is that the ship hull structures, machinery and equipment are maintained and operated in conformity with the applicable rules and regulations and any relevant additional requirements, procedures and standards established by the Company. That responsibility starts from the top Managers of the Company, who should be committed to direct efforts, resources and investments in order to ensure that their ships are properly maintained and operated by qualified and competent crew. Such a Company’s commitment from the top is the first element to be verified by the ISM Auditors. The International Maritime Organization's (IMO) purpose in creating the Code was to "Provide an international standard for the safe management and operation of vessels and of Pollution Prevention”. The international Management Code for the Safe Operation of Ships and for Pollution Prevention, (ISM Code), provides an international standard for safe management and operation of ships and for pollution prevention. It addresses the need for commitment to safety management from the highest level of the organization. As required by the International Safety Management Code – ISM Code, the ship owner and ship management company should ensure that the ship hull structures, machinery and equipment are maintained and operated:

- The ship maintenance should be in conformity with the applicable rules, regulations, requirements, procedures and standards established by the company. - The ship maintenance procedures should be implemented ashore and on board properly.

The ship maintenance procedures should be documented, and should ensure that applicable statutory, class, international conventions (e.g. SOLAS, MARPOL) and the port state requirements are met, and that compliance is maintained in the intervals between third party surveys and audits. Paragraph 10 of the ISM Code “ Maintenance of The Ship and Equipment “ states the following:

10.1 The Company should establish procedures to ensure that the ship is maintained in conformity with the provisions of the relevant rules and regulations and with any additional requirements which may be established by the Company.

10.2 In meeting these requirements the Company should ensure that:


 * 1) Inspections are held at appropriate intervals;
 * 2) Any non-conformity is reported, with its possible cause, if known;
 * 3) Appropriate corrective action is taken;
 * 4) Records of these activities are maintained.

10.3 The Company should establish procedures in its SMS to identify equipment and technical systems the sudden operational failure of which may result in hazardous situations. The SMS should provide for specific measures aimed at promoting the reliability of such equipment or systems. These measures should include the regular testing of stand-by arrangements and equipment or technical systems that are not in continuous use.

10.4 The inspections mentioned in 10.2 as well as the measures referred to in 10.3 should be integrated into the ship’s operational maintenance routine.

Maintenance and repair may be defined by the consequence of imperfect components and construction or may be of an imbalance in the system to which the component belong. There could be many reasons; poor construction, faulty assembly on board, mechanical wear, damage due to vibration. There could be mishandling or operational errors. Since no chain is stronger than its weakest link, the consequences of a defect in one place may result in serious damage elsewhere. Some developments of errors from my experience on board ships while sailing: a leaking sea water cooling pipe for generator engine was replace on dry dock, the part which replaced was from the suction till the inlet of a cooler, when testing the new pipe for tightness, other pipes develop leaks due to the higher pressure, sea water leakage may destroy electric panel or lead to flooding and so on. Here is another development: fire in the bridge of a vessel was on dry dock, a fire occurred early morning at 08:15, a lack of responsibility lead to a complete destruction of the navigation equipment of the vessel, the fire was quickly extinguished. In the past one kept machinery going until it stopped by itself. Due to the robustness of the components, low power, etc., one could in most cases recondition or repair the damaged unit on the spot by primitive means. In those days, ship spent in cases a great deal of time in port for other reasons, permitting repairs to be executed with little or no off-hire of the ship. Various maintenance systems are available today in the markets, some are rather sketchy, other quite sophisticated or elaborate. Undoubtedly, the more developed systems all have their individual advantages. I am not in a position to discuss the different maintenance systems available in markets today, rather than discussing a simplified system for showing all its benefits and advantages to be applied in our market today.

Roles of Classification Societies
The purpose of a Classification Society is to provide classification and statutory services and assistance to the maritime industry and regulatory bodies in regards to maritime safety and pollution prevention, based on the accumulation of maritime knowledge and technology. The objective of ship classification is to verify the structural strength and integrity of essential parts of the ship’s hull and its appendages, and the reliability and function of the propulsion and steering systems, power generation and those other features and auxiliary systems which have been built into the ship in order to maintain essential services on board.

Classification Societies aim to achieve this objective through the development and application of their own Rules and by verifying compliance with international and/or national statutory regulations on behalf of flag Administrations. More than 50 organizations worldwide define their activities as providing some form of marine classification services, however, not all meet the definition given. Some that do form the International Association of Classification Societies (IACS). It is estimated that the Members of IACS collectively class over 90 percent of all commercial tonnage involved in international trade worldwide. Classification Rules are developed to establish standards for the structural strength of the ship’s hull and its appendages, and the suitability of the propulsion and steering systems, power generation and those other features and auxiliary systems which have been built into the ship to assist in its operation. Classification Rules are not intended as a design code and in fact cannot be used as such. A vessel built in accordance with the applicable Rules of an IACS Member Society may be assigned a class designation by the Society on satisfactory completion of the relevant surveys. For ships in service, the Society carries out surveys to verify that the ship remains in compliance with those Rules. Should any defects that may affect class become apparent, or damages be sustained between the relevant surveys, the owner is required to inform the Society concerned without delay. The classification of a vessel is based on the understanding that the vessel is loaded, operated and maintained in a proper manner by competent and qualified crew or operating personnel.

A vessel may be maintained in class provided that, in the opinion of the society concerned, it remains in compliance with the relevant Rules, as ascertained by periodic or non-periodic survey. One of the basic requirements of the Rules is that once classed, it is incumbent up on the owner to present the vessel for periodic surveys is a condition of class. It is also an obligation of the owner to present a vessel for survey that has sustained damage which may affect class, These surveys provide a means for the society to determine that an enrolled vessel is properly maintained in the sense that it continues to meet the Rule requirements and to that extent continue to be structurally and mechanically fit for its intended service, Periodic surveys are required annually and more concentrated surveys intervals of four to five years, with intermediate surveys for most vessels. Periodical surveys are performed by field surveyors of the Classification society. These require individuals with substantial training and experience in this marine specialty. They carefully follow the requirements of the Rules in conducting a periodic survey of a vessel to Determine that the vessel, in fact, adheres to those requirements. To assist them, field surveyors have the benefit of circular letters, prepared by the society’s headquarter, which are guidance notes relative to the particulars and peculiarities of certain types of vessels, components, structural arrangements or other unique features. In performing periodic surveys, it is the intent of the society to prevent a vessel from falling into substandard condition as determined by the vessel’s ability to meet the Rule requirements.

The periodic survey requirements are based upon a vast number of ship-years of service experience. These are continually reviewed and examined for their effectiveness in view of industry developments. Also, a recurring problem in a particular type of vessel component or structural arrangement can be identified and isolated for closer scrutiny and, if considered appropriate by the society’s technical committees, revisions to the Rules can be made. It is the owner’s responsibility to maintain the vessel. The field surveyor, and thus the class society, can only record reports and recommend in accordance with what is seen at the time of a survey. If the vessel should be found in sub standard condition in the sense that it is not in compliance with the class requirements, then recommendations are made for corrections. If the corrections are not made in keeping with the requirements of the Rules, then the society would terminate the vessel’s classification. Today many governments have authorized the societies to act on their behalf. This work has increased substantially in recent years with the proliferation of national regulations, and International codes and conventions such as those of Loadline-1966, Tonnage 1969, Marine Pollution Prevention- 1973 and Safety of Life at Sea-1974, MODU Code, Bulk Chemical Code and other Codes together with Their associated protocols and amendments.

Similar to classification requirements, certain Statutory Regulations require periodic surveys to determine that the vessel is being maintained as required by those regulations and in that sense does not become deficient. Some of the surveys required fm these International Conventions and Codes parallel those required by class whereas others do no, However, the class societies are working to schedule class and statutory surveys to the best advantage of the owner – a procedure which is popularly called harmonization of surveys.

The majority want the classification society to carry out enough examination to assess the vessel’s condition properly and to insist on repairs necessary to maintain its fitness for service, at least until the next scheduled survey, to help them fulfill their obligation to maintain the vessel in a condition required to maintain its classification. The classification society requirements reflect what in our collective judgment is the extent of examination needed to serve that purpose. Feedback so far reveals that most owners appear to be satisfied with the new requirements. Other surveys which have been considered by classification societies are tail shafts, intervals for boiler surveys, and examination of the ship’s bottom, together with related items such as rudder and sea chests.

Contributions
Ayman Alakkawi