SURVEY OF MACHINERY ‘The survey of machinery items is carried out fo assess the condition at the time of survey by the Classification Society. The survey period is fixed at a FIVE year period, but if all machinery items were to be surveyed at one time, then this would place @ heavy workload on the personnel onboard, Itis more usual for the surveys to be staggered as part of a Continuous Survey of Machinery (CSM), where the various items of machinery are to be opened for survey in rotation. However before Class will allow your vessel to use CSM, they will require thet the vessel operates @ Planned Maintenance Scheme (PMS). PMS's may be based on calendar or running hours calling for items to be opened out for inspection and overhaul at specified periods. Alternatively the machinery may be monitored for condition and performance, whereby items need only be opened out for examination when readings indicate deterioration. This arrangement is listed as PMS(CM). Many PMS schemes are made up of a combination of the two methods of maintenance CSM surveys should be arranged to ensure that the interval between consecutive examinations of each item would not exceed five years. It is usual for approximately one-fifth of the machinery to be examined each year. Various costs are associated when a survey is carried out. The cost ofa survey for a surveyor visit would start at US$700, and this would rise if a number of surveys were required as the surveyor would be onboard for a longer time. For instance a full Annual Survey would be in the region of USS8000. In order to reduce this cost, Class will allow the surveys to be carried out by the Chief Engineer of the vessel. All Chief Engineers operating the Scheme on a ship must hold a valid Certificate of Authorisation. A copy of this authorisation is attached at the back of this handout, and lists all the items the Chief Engineer CAN survey. Also from Class Rules, there is a list of the items that ONLY THE SURVEYOR CAN SURVEY, The Classification Society would check the surveys carried out onboard by the Chief Engineer’s at the Annual audit. These should be held within three months before or after the due date and it is recommended that they be harmonised with the ship's Annual Survey. Atthe annual audit the Chief Engineer is required to make available the maintenance and monitoring records. These records should include: Statements signed by the Chief Engineers for each item that the Owner requires to be credited for class. These statements should give details of repairs carried out and spare parts used + The Chief Engineer is to provide written details of any breakdown or malfunction of essential machinery. Such details should include the main cause of failure. + AnLR Certificate of Authorisation for all Chief Engineers who have signed the statements. Class 1 (Motor) -1- © South Tyneside College‘The dates of items to be credited for Class will be aligned to the date of the confirmatory survey regardless of when the Chief Engineer carried out his survey. Any other surveyable items of machinery not covered by the Scheme will be surveyed and credited in the normal way. The survey status information given to the Shipowners/ Managers with “Quarterly Listings' or ‘Class Direct! will carry a memorandum entry under “items to be noted’ APPROVED PLANNED MAINTENANCE ANNUAL AUDIT DUE (date) It would be prudent for the Chief Engineer to ensure that when the Survey becomes due, as listed from the CSM, that the item of machinery is also due for overhaul. Thus when #2 piston is due for survey, then the running hours of that piston would be close to the overhaul limit under the PMS, To enable these two programme to be aligned, then the Chief Engineer should forward plan when the various survey and PMS work are required This planning should include: When each survey is due. As listed under the CSM. Align the running hours with the survey. Hence this would require the piston to be overhauled every 2.5 years, or every 1.7 years so ensure that the following survey and overhaul are still aligned. Ensure that the spare gear to carry out the inspection is available. Using the Chief Engineer to survey on behalf of Class will reduce costs, but these can be further reduced if the machinery can be surveyed without the need for overhaul. One of the three programmes under the Condition Monitoring system (PMS(CM)) would be used to assess the machinery condition without the need for dismantling Integrated Condition || Monitoring System ere VMS Machinery ‘Lubricating oil Vibration Monitoring Analysis Monitoring System MS = Vibration Monitoring System One of the most effective techniques for determining the condition of rotating machinery is vibration monitoring. The equipment used for vibration measurement should be capable of determining vibration amplitudes over the frequency spectrum of the machine, Class 1 (Motor) © South Tyneside CollegeAfter establishing the vibration signature of the machine itis acceptable to record only the signal values of overall vibrations. These are used as an indication to determine when an analysed signature should again be taken for diagnostic purposes. The overall readings are to be recorded at regular periods and plotted so that rates of change and comparison with the limits can be ‘made, Maintenance actions that affect the trend of readings are to be clearly indicated on the plot. a glfle Biase] s | 2/8 fiulels gl sls B)e|8 12) 4) 2/8 2/2] £/21o/8] a) a] 8 elle eieleieelel2 S155 & [5 le | ls] 3 la [ Feeer | si A fe ] Max. aceaptable motor vibration x soneplabe 3 | la _| wvsec Max, acceptable pump vibration oe ul Velocity ~ 1 1 y 4 at | it 2 9 4 & 6 7 8 9 10 11 12th Month Month Vibration velocity against month Having decided on the machines to be monitored, the next step is to specify the faults that are to be identified and the selected suitable vibration parameters to be measured. Each vibration or performance parameter is assigned a level at which an alarm will be generated, indicating that action or repair is required. Details of the points on each machine at which measurements are to be taken, and the type of parameter to be measured must be given; for example, velocity (mm/s rms), acceleration (mm/s? or‘g’). Care is needed when setting these limits, or alarm levels, to ensure that machinery faults are correctly identified carly in their development, and to maintain the user's confidence in the system. The alarm levels used by LR are based on the recommendations given in Intemational Standards, modified by the results of service experience. © South Tyneside College Class 1 (Motor)STUDENTS REQUIRING MORE IN DEPTH KNOWLEDGE OF VIBRATION ANALYSIS SHOULD CHECK THE PRESENTATIONS IN THE MARINE LEARNING CENTRE NAMED “VIBRATION ANALYSIS PARTS 1 & 2” METRIC MACHINERY VIBRATION SEVERITY CHART g2 8 Valugs shown are for Me ‘00 treed tending akon 2 i é i i ti i i, a a ip: 2: is eae i Sos irene 2s ' a a2 General machinery vibration severity chart (metric units). imaisec Timvuce. mmieee Class 1 (Motor) -4- © South Tyneside CollegeLubricating Oil Analysis This has already been discussed in the class notes in the Lubrication Section. The recommendations on page 8 of the notes lists the recommendations made by LR. LR has published some points on oil analysis, which could guide the Chief Engineer when submitting his oil analysis programme to LR for approval, Two particular areas were explored from 1987: white metal bearings and oil lubricated stemtubes, The project confirmed that the traditional oil analysis procedures were relevant in the assessment of lubricating oil conditions but need to be supplemented by efficient wear metal and /or particle analysis, if machinery health or condition monitoring is to be used to determine maintenance and survey practices. Following on from this study, a project was started in 1994 to evaluate the performance of on- line, optical transducers capable of determining wear debris concentration levels in lubricating, oils. A series of trials were undertaken to determine their accuracy, repeatability of ‘measurements, portability, sensibility to pressure, and their ease of use. The results indicated that there were serious drawbacks within the transducers tested that made them less attractive for marine use, but there was potential for the filter blockage technique in the future. Machinery Monitoring. LR investigated a number of possible areas that would indicate the health of running machinery. Initially software models were produced that were validated on test machinery operating with various known faults. This required high speed data pick ups (combustion monitoring) and slow speed data (fresh water temperature, engine speed, etc). The results indicated that when a fault appeared the results from the analysis were inconclusive, and that steady state operational ‘measurements tended to give a higher probability in fault prediction A complementary approach to determining the condition of a machine is to use performance monitoring, For simple items such as pumps it would be normal to record discharge pressure and power at the same time as the vibration readings are taken, For reciprocating machinery more sophisticated monitoring would be necessary. Combustion pressure-time curves give information regarding the overall condition of piston rings and liners, the balance of the engine and condition of fuel pumps and valves, This type of monitoring will be required in order to permit LR approved Chief Engineers to survey main engine crankshaft and bearings in single engine installations. The following data would be required to be recorded to assess the condition of the Main propulsion diesel engine under a PMS(CM) scheme. © Shaft horsepower. Engine and shaft rev/min, Cylinder pressures - time curves, Oil fuel injection pressure - time curves. Charge air pressure. Exhaust gas temperatures, Engine cooling systems temperatures and pressures. Engine lubricating oil system temperatures and pressures. tee eree Class 1 (Motor) © South Tyneside CollegeTurbo-charger rev/min and vibration Lubricating oil analysis data Crankshaft deflections Main bearing temperatures wees For Auxiliary engines to have the following parameters monitored ¢ Exhaust gas temperatures. Engine cooling systems temperatures and pressures. Engine lubricating oil system temperatures and pressures. Turbo-charger rev/min and vibration, Lubricating oil analysis data One item of machinery that has been routinely surveyed without dismantling would be the oil lubricated screwshafts. The stern bearing must have a facility for measurement of bearing wear down and two temperature sensors should be fitted. ‘The following information is also required: Lubricating oil analysis carried out at regular intervals not exceeding six months, The oil samples are to be taken under service conditions and are to be representative of the oil within the stern tube, Each analysis is to include the following minimum parameters: ‘water content, ¢ chloride content; bearing material and metal particles content; © oil ageing (resistance to oxidation). The surveyor would also check the records of © oil consumption, © bearing temperature, © bearing wear down. Hence the system that should be introduced to enable machinery assessment without dismantling ‘would often be the combination of the three programmes, Vibration, Oil Analysis, and Machinery Monitoring. As stated for the main diesel engine, the machinery monitoring would include lubricating oil analysis, but not vibration (due to the inherent vibration levels within the engine making fault detection difficult) Should condition monitoring be required for the steering gear, then the PMS(CM) scheme could consider: © Vibration levels of the electric motors ¢ Vibration levels of the hydraulic pumps * Oil analysis of the system oil Function tests of the system performance: Class 1 (Motor) © South Tyneside Collegedoves Lloyd’s Register of Shipping APPROVED SCHEME FOR THE SURVEY OF MACHINERY BY SHIPS’ CHIEF ENGINEERS ON SHIPS CLASSED WITH THE SOCIETY (THIS SCHEME DOES NOT APPLY TO OWNERS’ SUPERINTENDENTS) Under this scheme, parts of machinery as listed herein may be surveyed and overhauled by the ship's Chief Engineer whilst the ship is at sea, or at a port where the Society is not represented provided the following conditions are fulfilled: ADMINISTRATIVE ARRANGEMENTS 1. The prescribed form of application for approval, Form 3563 — Application for Approval, is to be completed giving the principal patticulars of the Chief Engineer including name, age, qualifications and experience. 1.1 He should hold a first class certificate of competency or equivalent and in general have Worked on the Owner's vessels for at least 3 years since obtaining this certificate, 1.2 Ifthese particulars are found to be satisfactory the Society will issue a letter to the employer, hereinafter named ‘the Employer, as named on Form 3563 — Application for Approval, authorising the approved Chief Engineer to carry out surveys under the terms of the scheme, 1.3 Acertificate of authority will be issued for the Chief Engi he remains in the employment of the Employer. er, and will be valid only while 2. When approval has been granted the Employer is to arrange for copies of the Certificate of ‘Authorisation to be kept on board the ship for the information of the Master, Chief Engineer and the Society's Surveyors. 21 Inthe event of a Chief Engineer leaving his employment the Employer is to inform the Society in writing in order that the Certificate may be cancelled, PRACTICAL APPLICATION 3. With regard to stand-by units, for example auxiliary engines and main lubricating oil purnps,it will be the responsibilty of the Chief Engineer, in consultation with the Master in their joint capacity as representatives of the Employer, to ensure that such items are only opened up for examination Under favourable conditions so that no hazard, including fire, to the ship or cargo would result from breakdown of a working unit 3.1 The number of ausiliary generator sets must be such that all services essential to the propulsion and safety of the ship, together with preservation of the cargo, can be supplied when any two of the sets are not working. One of these two sets could then be overhauled while the other remained available as the stand-by set. 4, After a survey by the Chief Engineer at the first port where the services of the Society's Surveyors are available, the Surveyors are to be shown the relevant entry in the log book and given 2 copies ofa statement in English signed by the Chief Engineer describing the item he has surveyed, its condition as found, and any repairs effected. 4.1 Parts which have been replaced by spares are to be retained and shown to the Surveyor. Class 1 (Motor) © South Tyneside College42 43 Items such as auxiliary engines, independently driven pumps and compressors are to be examined under working conditions by the Surveyor who, if not satisfied, will have the right to require any item to be opened out for his inspection. The Surveyor will issue an interim certificate to the Owners and forward his report to the Committee in the usual way. 4.3.1 The Surveyors are not authorised to accept statements by the Chief Engineers Who are unable to produce valid Certficates, 5. Its to be understood that the Owners will carry out as much of the machinery surveys as practicable at ports where the Society is represented. 6. Any item which constitutes a qualification of class is excluded from this scheme. 7. The Employer is to instruct his Chief Engineers that the survey of auxiliary engines is to proceed as indicated below: TA 72 73 74 78 78 1 78 The engine is to be completely opened up and a careful examination made of all cylinders, liners, covers, valves, valve gear, pistons, piston rings, top and bottom end bearings, gudgeon pins, crankcase door fastenings and explosion relief devices, The top halves of ll main bearings are to be removed and at least two bottom halves turned out for inspection. if these are found in good condition the remaining bottom halves need not be disturbed, A very careful examination is to be made of all crankpins and journals for cracks especially at the filets and in the vicinity of oll holes. The crankweb deflections are to be measured and recorded. N.B. Care must be taken to ensure that the joumals are resting on the main bearings when the readings are taken, The cylinder liners are to be gauged and the wear recorded, The lubricating oil cooler is to be opened, examined and tested Any direct driven lubricating opened up and examined. 1umps, cooling pumps, eir compressors, etc., are to be It is to be verified that all safety devices are in efficient working condition. & A Confirmatory Survey is to be carried out by the Society's Surveyor as follows:- 84 82 83 a4 Class 1 (Motor) Atleast one main bearing and one bottom end bearing to be selected, opened up and inspected together with the joumal and erankpin. In engines having more than four cylinders at least two main journals, crankpins and their bearings are to be examined The deflections of the crankwebs are to be measured and compared with those recorded by the Chief Engineer. The engine is to be examined running under load and the governor and circuit breaker tested. All safety devices, remote controls, and automatic alarms to be tested. © South Tyneside CollegePARTS OF MACHINERY WHICH MAY BE EXAMINED 1 10. "1 12, 13. 14, 6. 16. 17. 18, 19. Class 1 (Motor) Main engine cylinder covers. Main engine valves and valve geer. Main engine cylinder liners. Main engine pistons and piston rods, Main engine connecting rods, crossheads, top end bearings and guides. Main engine detuners. ‘Main engine scavenge pumps and blowers except where only ane units fitted. ‘Main engine oil fuel injection pumps and oil fuel booster pumps, Main engine driven pumps, e.g. bilge, lubricating oil, cooling water Independently driven pumps, e.g. bilge, ballast, fre, freshwater cooling, sea water cooling, lubricating oil, oil fuel transfer. Main engine fresh water and lubricating oil coolers except where there is only one cooler for each service. Low pressure heaters used in high viscosity fuel systems of oil engines. Air compressors. Windlasses, Forced or induced draught fans and engines. Auxiliary oll and steam engines, including their coolers and pumps (providing that the number of generator sets is such that all services essential to the propulsion and safety of the ship, also the preservation of refrigerated cargo, can be supplied when any two sets are not working — one of these sets can then be overhauled while the other remains as ‘stand-by’. Refrigerated Cargo Ships: - Reciprocating refrigerant compressors; - Brine pumps; - Condenser cooling pumps; = Liquid refrigerant circulating pumps. Liquefied Gas Carrying Ships: - Reciprocating refrigerant compressors; - Reciprocating cargo gas compressors; - Condenser cooling pumps; = Circulating pumps (where fted). Inert Gas Systems: + Independent gas generators; = Scrubber units; - Blowers. © South Tyneside CollegeAuthorised Chief Engineers may carry out surveys of all the machinery items for which they are authorised, at sea or in port, whichever is the most convenient. ‘The following machinery items remain to be dealt with by a LR Surveyo: Machinery damage, repairs and alterations Main engine crankshaft and bearings in single engine installations Reduction/increase gearing, flexible couplings and clutches. Holding down bolts and chocks. Crankcase doors, crankcase and scavenge relief devices Boilers and all other pressure vessels. Boiler fuel oil heaters. ‘Steam pipes and starting air pipes. Maneuvering valves and bulkhead stop valves. Steering machinery. Pumping arrangements. Electrical equipment other than auxiliary motors. Screwshaffs, stern bearings and propellers. Sea Connections. Main Engine controls and controls associated with Class Notations, e.g: UMS, CCS, ICC, IP and DP. Engine Trial First start arrangement trial Inert Gas Systems except for: Scrubber units. Blowers. Independent Gas Generators. ee eerercsesesoes eeoeeee ‘The confirmatory survey carried out at the time of the annual audit by LR s Surveyor will then comprise checks of: * Condition monitoring records + Bearing clearances. + Signs of wiped or broken white metal in the crankcase, Shrink fit reference marks © Bedplate structure. Chief Engineer's are no longer restricted to ports or places where LR is not represented, as is the case with the basic * Approved Chief Engineers Scheme'. It will not be necessary to have confirmatory surveys carried out at the next port after each examination by the Chief Engineer and reports may be filed and dealt with at the annual audit. Chief Engineers are to be reminded that overhaul of machinery items whilst at sea must not compromise the redundancy/standby functions which are requirements of Classification Rules. Class 1 (Motor) -10- © South Tyneside College