ML20195B315

Evaluations of Bearing Failures in Fairbanks-Morse Diesel Engines at Enrico Fermi Unit 2 Reactor

ML20195B315
Person / Time
Site:	Fermi
Issue date:	02/28/1986
From:	Leonard L CALSPAN CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
CON-NRC-05-83-216, CON-NRC-5-83-216 F-5896-012, F-5896-12, NUDOCS 8605290182
Download: ML20195B315 (44)

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{{#Wiki_filter:l' I EVALUATIONS OF BEARING FAILURES IN FAIRBANKS-MORSE DIESEL ENGINES AT THE ENRICO FERMI UNIT 2 REACTOR l ~ FRC Project 5896-012 E USNRC Contract NRC-05-83-216 Task TAM-212 Prepared for Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 NRC Project Officer: P. Cortland FRC Engineers: L. Leonard and H. C. Rippel tL b kol 8605290182 860228 February 28, 1986 ErvW5d7 fa gadg

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PDR dlt Prepared by: Reviewed b : Approved by: fit;OO'#fbd zG.t JL em4-Prific pTAuthor 'Departmen%Iredor M7,AI Date: Date: 2 M Date: 1 FRANKLIN RESEARCH CENTER OF ARVIN N The views expressed in this report are not necessarily those of the J U. S. Nuclear Re'gulatory Commission Distribution: PDR RIDS: H003 ~ s

I I I b i EVALUATIONS OF BEARING FAILURES IN FAIRBANKS-MORSE DIESEL ENGINES AT THE ENRICO FERMI UNIT 2 REACTOR I FRC Project 5896-012 USNRC Contract NRC-05-83-216 Task TAM-212 Prepared for Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555

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NRC Project Officer: P. Cortland FRC Engineers: L. Leonard and H. C. Rippel I February 28, 1986 Prepared by: Reviewed b - Approved by: s&w $t ss!-, ~ Princ'pWAuthor Departmen[Diredor Date: MM Date: 2 Date: 2 -2% M 4 'i FRANKLIN RESEARCH CENTER h The views expressed in thes report g3 RVigA N are not necessar61y those of the U. S. Nucl ear Re'gul atory Comni ssi on Distribution: PDR RIDS: H003 s

F-5896-012 ) I CONTENTS I Section Title Page 1 INTRODUCTION 1 2 ANALYSES AND DISCUSSION. 2 I 2.1 BEARING SURFACE ANALYSES 2 2.2 BEARING MATERIAL 5 I 2.3 LAPPING COMPOUND AND BREAK-IN LUBRICANT 7 2.4 LUBRICATING OIL 8 3 CONCLUSIONS ON FAILURE ANALYSES. 9 4

SUMMARY

OF MEETING AT MONROE, MICHIGAN, 1/24/86, AND I FRC CONCLUSIONS AND RECOMMENDATIONS. 33 APPENDIX A OIL ANALYSIS REPORT APPENDIX B OIL SPECIFICATION DATA I I

I I

I 111 I

II F-5896-012 1. INTRODUCTION At the request of the Nuclear Regulatory Conunissicn (llRC), Franklin Research Center (FRC) has conducted a study of factors contributing to bearing failures that occurred during qualification tests of Fairbanks-Morse diesel I engines at the Detroit Edison Company (DECO) Enrico Fermi Unit 2. Damaged bearings, samples of lubricating oil, lapping compound, and break-in lubricant were evaluated, using scanning electron microscopy, metallography, chemical analyses, and hardness testing. FRC also attended a meeting held at DECO's Monroe, Michigan, site on January 24, 1986. At this meeting, there were presentations and discussions concerning the bearing failures and ways to mitigate them. A summary of this information and FRC's conclusions and recommendations relative to the meeting are contained in Section 4 of this report. I I I I I I -I I F-5896-012 ~ L 2. ANALYSES AND DISCUSSION ~ 2.1 BEARING SURFACE ANALYSES 2.1.1 " Frosted" or Dull Surfaces The upper main No. 5 and crank No. 5 bearings from Engine 13 were submitted for analysis. The bearings, whic were removed from the engine following a series of start-up tests, exhibited dull, roughened, " frosted" I surfaces at several locations around each bearing. Examples of this condition L are shown in Figures 1 and 2. The distribution of this surface damage rela-tive to the orientation of the bearings and the direction of shaft rotation e (as reported to FRC by NRC personnel) is sketched in Figure 3. Since the damage did not correlate with the location of the maximum loading, it appeared b that erosion, corrosion, or cavitation mechanisms could have been the cause. In addition, material separated from the affected surface could then have e { adhered to either the shaft or the bearing, thus accounting for the scoring of the surfaces and the adherence of particles shown in Figure 1. h To more clearly define the nature of the surface alteration, samples from 3 various locations with different types and levels of damage were studied in the SEM. As shown in the series of micrographs in Figure 4 through 8, the j dull visual appearance of a frosted surface resulted from the highly irregular nature of the surface on a microscopic scale. The less damaged areas had experienced individual dents and subsequent smearing of each dent's raised I Repeated multiple denting and smearing occurrences appear to be edges. responsible for the more heavily damaged surface regions at the locations indicated in Figure 3. The occurrence of this denting primarily in the ordinarily non-loaded areas of the bearings can be attributed to three possible mechanisms: (1) the l bearing could have made light contact with particulates adhering to the shaft; (2) free particles larger than the gap between the shaft and the bearing could have been drawn onto the gap, thus leaving an imprint; or (3) there could have been high velocity impacting of the surface by lubricant borne particulates. The first possibility appears remote since particulates on the shaft would have led to pronounced scoring, particularly in the area of maximum loading, I and such was not the case. Furthermore, since the shaft, as would be I.....

r I F-5896-012 expected, was reported to have been significantly harder than the bearing, any particulates would be much more likely to embed in the bearing. Evidence of angular particulates having plowed into the bearing surface, as seen in Figures 4 and 5, supports the second possibility stated above, whereas the high density of dents without any embedded particulates lends I evidence to the third possibility. It should also be kept in mind that aluminum bearings are less efficient at catching and embedding particulates than softer babbit bearings. Therefore, the particulates would continue to circulate (if they were smaller than the 5-micron filter in the system) and cause denting. Accordingly, it must be concluded that hard particules had been cirulating with the lubricant. The nature and source of the particulates is described further in Section 2.3. 2.1.2 Bearing Outside Diameter Surfaces The outside diameter (OD) surfaces of the bearings were also studied to determine if some staining present was an indication of improper mounting. As shown in Figures 9 and 10, the minor staining correlated with lubricant seepage, whereas the more pronounced patches of deposited material appeared to I reflect fretting between the bearings and mounting blocks. Energy dispersive x-ray analysis (EDXA) of the deposited material showed the presence of iron, nickel, and copper. The first elements would be consistent with a steel or iron block, but the source of the copper is not clear. However, at this point, this does not appear to be a critical question since the extent of the deposits and staining does not seem excessive or indicative of improper mounting of the bearings. 2.1.3 Surface Scoring I A second group of bearings from Engine 11 was analyzed to characterize the nature of surface scoring that was noted after a second set of start-up ,I tests. Representative examples of surface deterioration are shown in the macrographs in Figures 11 through 14. The non-uniform scoring wear pattern in Figures 11 and 12 indicates a poor conformity between the shaft and the bearing. At the relatively early stage of bearing surface damage, little I 1 I F-5896-012 aluminum could have transferred to the mating shaft. Therefore, a non-uniform build-up with resultant non-uniform wear appears an unlikely cause for the pattern. In addition to the non-uniform wear in the load zone, the contact surfaces exhibited metal flow across the recessed end of the segment and the outer edge of the bearing's load zone, as shown in Figures 13 and 14. This is evidence of a high degree of contact between the bearing and the journal. I Since inadequate clearance and/or lack of lubrication, especially during " dry" starts, is commonly responsible for the initial bearing wear leading to metal I transfer to the shaft, it appears that both of these factors could have played a role in the bearing surface degradation. Various stages in this surface degradation were documented in scanning electron microscope (SD4) micrographs. In Figure 15, the initial stages of shallow scoring and surface cracking are evident. The small patches of tin in the bearing are randomly distributed and are meant to act as a temporary safeguard lubricant until mating sliding surfaces conform and an oil film is established. In wear areas of the bearing that appeared very polished on visual examination, the SEM micrographs of Figure 16 show that the tin had flowed and become elongated streaks in the equally flowed aluminum matrix. This initial flow and polishing represents a " running-in" of the surface and -I would be stable if an oil film could be maintained to prevent further contact with the shaft. In areas exhibiting the later stages of surface degradation, it was difficult to observe the tin particles, which could be observed readily in specimens that were damaged to a lesser damage. The individual scoring defects in the more heavily worn areas exhibited - very smooth surfaces at their bases, as shown in Figures 17 and 18. Since some of these scoring lines had tongues of metal that were in the process of being removed, as in Figures 18 and 19, it appears that the pieces that had been removed had failed by a fatigue process rather than by a plowing mechanism. That is, a crack had initiated and undermined the surface, and then the mating surfaces repeatedly opened and closed on each other, thus flattening and smoothing the fracture surface, prior to exfoliation. The high . I localized stress responsible for the narrow strings of surface material p F-5896-012 removed can be attributed to the presence of bearing metal picked up by the shaft during earlier stages in the failure process. The fatigue damage and surface flow on the bearings is clear evidence that an adequate lubricant film had not been maintained between the mating i sliding surfaces either because of improper clearances, i.e., misalignment between the shaft and the bearings, or insufficient oil, particularly during start-up. It is significant to note that there was no evidence on the Engine 11 bearings of the frosted type of damage that was on the bearings from Engine 13. This would indicate that the particulates responsible for the frosting were not present in Engine 11 during the testing sequence. ( 2.1.4 Inside Diameter Surface Staining One bearing was submitted for the analysis of a large stained patch on the contact surface of the non-loaded half of No. 5 main upper bearing from Engine 11. It was reported to FRC that this stain was noticed when the residual oil was wiped from the bearing after it was removed from the diesel. The stain, shown in Figure 20, was found to be superimposed on top of the wear-in lines on the bearing surface, masking these lines to various degrees. Therefore, it appears that material had deposited on the bearing during the inactive period prior to disassembly and that there may have been some contamination of the lubricant. EDXA established the presence of traces of sulfur and chlorine in an organic deposit (elements lighter then sodium, i.e, carbon, oxygen, etc., are not detectable by the EDXA technique employed). Since no particulates were [. detected in the deposit, it is concluded that the deposit in and of itself was not a contributory factor in the scoring or spalling degradation described in { previous sections. However, if the deposit originated from fuel oil dilution of the lubricant, such dilution could have been a factor in the failure to maintain a lubricant film sufficient to preclude spalling or scoring. 2.2 BEARING MATERIAL Tests were conducted to assure that the bearing material and/or hardness was within the specifications for the type of aluminum alloy customarily used in sliding bearing applications. -

~ F-5896-012 2.2.1 Chemical Composition of Bearing Material The results of chemical analyses on two main bearing segments (13-5UB and 11-SUT), one crank bearing segment (13-SUT), and the composition of cast aluminum alloy 850.0, which is commonly used in sliding bearings, are as follows: 13-5UB 13-5UT ll-5UT Alloy 850.0 Tin 6.00 5.99 5.95 5.5-7.0 Copper 0.930 1.00 0.925 0.0-1.3 Nickel 0.892 0.925 0.790 0.7-1.3 Iron 0.245 0.524 0.140 0.7 max Magnesium 0.002 0.019 0.007 0.10 Aluminum 91.47 91.23 91.75 Remainder I It is clear that the composition of the analyzed bearings meets the chemical specification for aluminum alloy 850.0. Thus, failure cannot be attributed to substandard alloy composition. I 2.2.2 Bearing Microstructure The expected microstructure for cast alloy 850.0 consists of a dendritic distribution of tin pacticles and accicular NiA1 in an aluminum solid-3 solution matrix. As sho e in the examples in Figure 21, the microstructures of the bearings agreed with that normally anticipated, and no evidence of casting deficiences was noted. The differences in interdendritic spacing in the two micrographs in Figure 20 most likely reflect different cooling and solidification rates. I A cross section cut through a scored or spalled region was prepared to determine if the microstructure, particularly the tin phase, influenced the a cracking path. As shown in Figure 22, there was no indication of such behavior. In addition, the base of the fracture appeared smooth in profile, consistent with the direct views of the scoring or spalling defects shown in Figures 17 and 18.... - -

I I F-5896-012 2.2.3 Hardness The strength level of several bearing samples was determined by measuring the hardness of metallographic samples. The results were as follows: Bearing Rockwell H Hardness I 13-5UT crank 95 I 13-5UB main 92 11-5UT main 93.5 I For an 850.0 alloy, these hardness levels indicate that the material had been subjected to a T101 temper, which entails an aging treatment plus 4% cold working. An aging treatment alone should have resulted in a hardness of 85 Rockwell H. The cold working significantly increases the yield strength I (nominal compressive yield increases from 10,950 psi to 24,640 according to data in Volume 1 of the Eighth Edition of the ASM Metals Handbook). I Thus, the extruded flow of surface metal pointed out in Figures 13 and 14 can be attributed to high loads rather than to the material's yield strength I being below its rated value. 2.3 LAPPING COMPOUND AND BREAK-IN LUBRICANT Samples of the lapping compound and the break-in lubricant that had been used in preparing the journal surfaces of the shaft and in the initial fit-up of the shaf t in the bearings were analyzed to determined if either could be ( the source of the particulates found embedded in the surfaces of the Engine 13 bearings discussed in Section 2.1.1. It was reported to FRC that the break-in lubricant, which was a viscous black liquid, contained graphite and lapping compound. As shown in Figure 23, both the lapping compound and break-in lubricant contained angular particulates whose sizes, shapes, and composition (Mg, A1, Si, Cu, and Fe) matched those of the particulates embedded in the Engine 13 bearings. Thus, the lapping compound and/or the break-in lubricant can be considered the source of the particulates. In addition to the mineral particulates, the lapping compound contained a much finer powder rich in lead and chromium which did not appear to have contributed to the frosting damage. I k

r-I F-5896-012 I 2.4 LUBRICATING OIL An unused sample of the lubricating oil, Shell Caprinus R 40, was submitted for analyses to determine if its characteristics, in particular its viscosity, met those specified by the supplier of the diesel engine and hence those expected by the operator (i.e., Detroit Edison). The report from I Phoenix Chemical Laboratory, which is appended to this report, indicates that the viscosity did indeed meet the viscosity specifications (192.0 cs at 40'C and 14.66 cs at 100*C, converted from data in the specification sheet, a copy of which is also appended to this report). However, both the iron and water content were high, indicating some contamination of the oil prior to receipt by FRC. No such contamination was reported in data from Detroit Edison for samples routinely taken after each shutdown of an engine. Thus, it is not clear whether the initial oil supply was somehow contaminated or if it contriteited in any way to the degradation of the bearings in Engine 11. I I I I I I I ..I F-5896-012 3. CONCLUSIONS ON FAILURE ANALYSES Based on the previous findings, the following conclusions were reached:

1. The " frosted" surface appearance on bearings from Engine'13 was the I

result of particulates having impacted or indented the surface. Based upon their sizes, shapes, and composition, the particulates had originated in a lapping compound that was used to polish the journal and which also was included in a break-in lubricant when assembling the shaft in the bearings.

2. Staining on the outer diameter surfaces of Engine 13 bearings did not I

appear to indicate an improper seating of the bearings in the mounting blocks.

3. Scoring damage on Engine 11 bearings was the result of sliding induced fatigue, which, in turn, was caused by inadequate clearance (i.e.,

improper alignment) and/or insufficient lubricant film. Surface flow I was further evidence of high contact load between the journal and the bearing.

4. Staining on the inner diameter surface of an Engine 11 main bearing I

indicates there may have been contamination or dilution of the lubricants. Such dilution could have been a significant factor in the failure to maintain an adequate lubricant film between the bearing and I the journal.

5. The bearing material, microstructure, and hardness were characteristic of a standard cast aluminum sleeve bearing alloy. Defective or I

substandard material did not play a role in bearing failures.

6. A sample of lubricating oil met the manufacturer's viscosity I

specifications, but water and iron (most likely metallic iron or iron oxide particulates) were excessive. It is not known whether this is characteristic of the bulk source or if '.he oil sample had been mishandled. I I I I _g_

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F-5896-012 ~' af" - c; e I A. 50X 4 _.l T B. 150X Figure 4. SEM micrographs showing an area of pronounced frosting on the 13-SUB main bearing. The surface is very irregular and embedded particulates containing Mg, A1, Si, Ca, and-Fe are indicated by arrows in A and are clearly evident in B. l

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SUMMARY

OF MEETING AT MONROE, MICHIGAN, 1/24/86 AND FRC RECOMMENDATIONS A meeting was held at DECO's Fermi Unit 2 site at which DECO: its consultant, Dr. Lee Swanger of Failure Analysis Associates (FAA); and Colt Industries, manufacturers of the Fairbanks Morse diesel generators, made [ presentations. DECO described the history of the generators including the problems, diagnosed the causes of the problems, and then proposed corrective actions. DECO concluded that the failures to date in the upper bearings can be attributed to a combination of possible factors which include: h a. long-time inactive storage b. contamination c. lack of lubrication during rapid starts { d. misalignment e. lubricant inadequacies. Dr. Swanger discussed the design of sliding bearings, in general, and presented the results of analytical studies of the loading and lubrication of ( the upper main and connecting rod bearings in the diesel in question. He concluded that the design and lubrication, i.e., film thickness, were adequate { for the application. Colt basically agreed with the information given by DECO and FAA and {- stressed their reconsnendation that disassembly inspection be discontinued owing to the potential for introducing misalignment and contamination into the system. They felt that feeler gauge measurements of the gap between bearing sections was an adequate technique for monitoring bearing condition and recommended a wear-in test to " season" the bearings prior to the qualification tests. Based upon its own investigation, the above presentation, and the discus-sions which followed them, FRC offers the following comments and reconunenda-tions: [ [ - .m

L IL F-5896-012 e L 1. There may be some differences of opinion among the investigators as to the relative importance of each of the above factors as contribu- { ting to the failures. Nevertheless, this should not be of major importance as DECO appears to have addressed all of the various parameters in its proposed solutions to the bearing problem. It is p felt that such steps as flushing the system to remove contaminants, L using accurate alignment procedures, employing manual lubrication prior to all starts, using a lubricant which has been demonstrated to be effective in similar engines, and using a " seasoning" or run-in h procedure to eliminate "high spots" on the journal / shaft interfaces will all contribute to a greater reliability of the bearings. How-ever, since no tests with dry starts are included in the proposed l test envelope, there remains a question as to how DECO will handle this issue. 2. DECO and Colt propose to monitor the state of a bearing by analysis l I of the oil after each shutdown and by measuring the gap between the halves of each bearing (every 6 months). However, all the experience at Fermi Unit 2 to date has shown that these monitoring steps can j only determine if a bearing has experienced a failure. They cannot indicate if the bearing is beginning to fail. Analyses of the oil after each engine run did not indicate any bearing problem, although l heavily damaged bearings were found on disassembly. Accordingly, I only by direct observation of the bearings can it be demonstrated unequivocally that all the various steps implemented by DECO have been successful in precluding bearing wear and failures. Thus, it is l recommended that, as a minimum, 50% of the upper main bearings should be visually inspected after removal of the caps. l While it is a valid argument that disassembly and reassembly can alter bearing position (alignment) and/or introduce contaminants, it I is felt that the need to verify fully the effectiveness of all the i fixes in the initial qualification tests outweighs the possible l problems inherent in the evaluation process. If the run-in or I " seasoning" process is, indeed, effective in preventing bearing failures, the repeat of such a procedure (although time consuming) l could be reemployed following the inspection, providing the bearings are in good condition. 3. The analytical analyses of engine bearing performance characteristics (performed for Detroit Edison by L. Swanger of FAA) are judged to be sufficiently rigorous for the intended purpose. The analysis included the necessary ingredients of: a. Establishment of " polar loading diagrams" for each bearing via a dynamic analysis of the engine hardware operating at rated speed and rated power. b. " Journal Orbit Analyses" to establish time varying magnitudes of " peak oil-film pressure" and " minimum oil-film thicknesses" during operation..

L r l" F-5896-012 L While resulting maximum values of " peak oil-film pressure" are of the order of 80% of the maximum capability of the aluminum-6% tin bearing F material (hence satisfactory), minimum values cited for " minimum oil-film L thickness" (133 micro-inches) are, in our opinion, somewhat too small in light of the large-size (8-inch-diameter) hardware involved allowing s little margin for error with regard to bearing alignments, transient [ overload, and the like. There are, however, dozens of other identical Fairbanks-Morse diesel engines operating at the same power-speed condi-tions (hence, identical bearing loadings) that, apparently, have not had { the degree of bearing failures experienced by the Fermi Unit 2 units. [ [ [ [ [ [ [ [ [ [ [ -.

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I

I jI APPENDIX A

E

. = OIL ANALYSIS REPORT 1 !I !I FRANKLIN RESEARCH CENTER OfVISION OF ARVIN/CALSPAN 20th & RACE STREETS, PHILADELPHIA.PA 19103

AREA Coor 312 TELEPMoNE 772 - 3577 I 3 o-20enix Vaem.ica ma aoratory,.nc. I FUEL AND LUBRICANT TECHNOLOGISTS 3053 SHAK E SPE ARE AVENUE CHICACO. lLL. 60647 December 20, 1985 RECEIVED FROh! Franklin Research Center 20th 6 Race Sts. I Philadelphia, PA 19103 SAhf PLE OF Oil LABORATORY NO. 5 12 19 27 AfARKED Caprinus R 40 I Aluminum, ppm 6.1 Iron, ppm 31.1 I Chromium, ppm 0.15 Viscosity 0 40*C., cs. 190.4 Viscosity 0 100'C., cs. 14.55 Karl Fischer Water, ppm 1509 I i A. A. Krawetz 1 lI I l <ihib

[ [ [ [ APPENDIX B m B[ OIL SPECIFICATION DATA [ [ [ [ [ [ [ [ [ [ FRANKLIN RESEARCH CENTER OfVISION OF ARVIN/CALSPAN 20th & RACE STREET 5. PHILADELPHIA PA 19103

g. .,, c,.. y,. e SOC:17-80 (Supersedes SOC 17 77) - g Technica Bulletin She l Oil Comaany Olt DISTRIBUTORS OF PHitA., INC. ) FORD STREET BRIDGE AND RAMP WEST CONSHOHOCKEN, PA. 19428 PHONE: 215 825 0600 Caprinus* R oil 40 B A high basicitylubricating oil i especially developed for I extended servicein j g large medium-speed diesel engines. 1I lI 1 Product Description cluded~ are GE, EMD, ALCO, Fairbanks-Morse and other similar diesels. Caprinus R oil 40 is a highly alkaline engine oil developed to meet the performance requirements Field Test Results I of modern medium-speed diesel engines in Extensive field testing of Caprinus R oil 40 railroad, marine and stationary power applica-confirmed its excellent retained alkalinity benefits tions. Its high it'itial basicity and excellent as well as its outstanding dispersancy. Test en-equilibrated long-term basicity effectively meet g nes were remarkably clean and had low wear. the requ!rements imposed by higher cylinder Deposits, including those in critical ring belt horsepower, extended drain intervals, reduced oil areas, were at a minimum. consumption (less make-up oil), and the effect of New GE 3600 HP U368 locomotives were used high suifur fuels. In one test. OperatinD in high speed passenger / Caprinus R oil 40 has an initia! TON-E of 10.2 freight service, three locomotives pulled about 40 (ASTM D 2896), and usually will equilibrate to a rail cars and auto carriers at an average speed of I TBN-E of about 2.0 to3.0 in service. it is available in approximately 60 mph. Mileage averaged over one viscosity grade,SAE40. 180,000 miles per engine during the 12-month test The oil has been approved by General Electric period. Engine inspections at the completion of Company as a Supe rior Class il" Higher Alkalinity" the test indicated outstanding lubricant perfor-lubricant. It has been classified in the " Extensive mance. On an engine cleanliness rating (10= use" category by Electro-Motive Division of clean), a typical cylinder was reted at 9.1 using g General Motors Corporation. Caprinus R oil 40, compared to an overall average 3 of 7.5 for cylinders from an engine in similar il APP cations service using a competitive Class 11 oil. The entire Caprinus R oil 40 is recommended for all medium-engine reflected this cleanliness advantage for speed 2-stroke and 4-stroke diesel engines in-Caprinus R.

[ Table I compares the ring belt performence of Power assembly wear was minimal, sludge de-Capnnus R with a fully approved oil und at posits were nil. Top compression rings had an av- { Cnother railroad under slightly dif ferent operating erage EMD chrome ring rating of 1.5, and allother conditions. critical parts such as trunnion bearings, rings and Engine oils were changed at four to six-month grooves, and cylinder liners were within or near intervals (70-100,000 miles). Alkalinity equilibrat-new parts specifications. Silver trunnion bearings [- ed ai 2.3 TBN E (D 664) with Caprinus R oil, were in excellent condition. compared to slightly over 1.0 for the reference oil. In the EMDs, used oil sikalinity equilibrated at Five new EMD SD45-2 engines were also used 3.0 TBN-E (D 664) after about two or three months ( in a 12-month field test in coal hauling service. of service. The commercial reference Ciass 11 oil This service usually involved three locomotives equilibrated at 2.0 TBN-E. There were no oil pulling a 10,000-ton train at about 35 mph average changes during the test period. f speed. Mileage for the period was about 92,000 in EMD power units, Shell recommends a "no miles for each engine. As with the GE units, the scheduled oil drain" service practice when sup-L engines had lowl wear and were remarkably clean piemented with an adequate oil analysis pro-when inspected at the close of the test period. gram. { Table 1/ Piston Ring Belt Performance - GE U368 Engines Commercial Caprinus R oil 40 Class 11 Oil Locomotive Type GE U36B. Railroad A GE U368. Railroad B Miieage 171,790 179.516 114.000 126.000 Piston Ring Groove Falling. Percent Compression Ring Number 1 22 16 50 25 Compression Ring Number 2 32 25 40 45 Compression Ring Number 3 9 5 15 30 Oil Control Ring 0 0 0 0 [ l [ [ [ [ [ [

t c L Figure 1/ Comparison of Used Oil Alkallnity in GE U36B Engines r Lr C L-- 10 (10.2 by ASTM D 2896) i s h r %\\ Caprinus R oil 40. Railroad A % ans m "'s" " M M M em Emu e emnassus e e a ea L Commercial Class 11 Oil. Railroad B 0 50 100 150 200 Oil Use Days p Figure 2/ Comparison of Used Oil Alkalinity in EMD SD45-2 Engines L 10 ( (10.2 by ASTM D 2896) 8 D a \\ f-0' ( g 4 Caprinus R oit 40 t-2 Class 11 Reference System Oil 1 0 100 200 300 400 Oil Use Days Fl Typical Properties of Caprinus R oil 40 e Property ASTM Test Method Value Gravity. ' API D 1298 23.5 Viscosity at 100*F, SUS D 445 1000-1050 Viscosity at 210*F, SUS D 445 77-80 Viscosity index D 2270 65-69 Flash Point. 'F D 92 475 Pour Point. 'F D 97 5 TBN-E D 664 94 D 2896 10.2 TAN-E D 664 0.8 Initial pH D 664 9.5 Sulfated Ash,%w D 874 1.1-1.2}}