| JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA LOCATION : ALBANY CITATION : BAYNES -v- MSR AGRIMOTIVES (WA) PTY LTD [2013] WADC 85 CORAM : MCCANN DCJ HEARD : 15-17 APRIL 2013 DELIVERED : 7 JUNE 2013 FILE NO/S : ALB CIV 12 of 2010 BETWEEN : NATHAN BAYNES Plaintiff
AND
MSR AGRIMOTIVES (WA) PTY LTD
Defendant
Catchwords: Contract to recondition a prime mover engine - Implied term that services would be performed with reasonable skill and diligence - Breach by defendant - Turns on own facts Legislation: Nil Result: Judgment for the plaintiff
Damages assessed in the sum of $61,516.85
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</Order> Representation: Counsel:
Plaintiff : Mr J S Hodgkinson
Defendant : Mr A P Hershowtiz
Solicitors:
Plaintiff : Haynes Robinson
Defendant : Jarman McKenna
Case(s) referred to in judgment(s):
Atanasoska v Inghams Enterprises Pty Ltd [2009] WASCA 17
Briginshaw v Briginshaw (1938) 60 CLR 336
Browne v Dunn (1894) 6R 67 HL
Chamberlain v The Queen (No 2) (1984) 51 ALR 225
Pollock v Wellington (1996) 15 WAR 1
Pownall v Conlan Management Pty Ltd (1995) 12 WAR 370
Swick Nominees Pty Ltd T/As Swick Drilling Australia v Norncott Pty Ltd [No 3] [2013] WASC 173
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MCCANN DCJ: The plaintiff is a farmer from Badgebup near Katanning in South Western Australia. 1 The defendant carries on an automotive mechanics business in Katanning specialising in heavy diesel trucks, tractors and trailers. Mr Michael Rocco is a director. 2 In 2008 Mr Baynes bought a used F16 Volvo prime mover. According to Mr Rodney Style's report (exhibit 10) the vehicle was built in 1989 and had in excess of 500,000 km on the odometer. Mr Baynes said it had actually done 1.5 million km (27). The engine broke down shortly after Mr Baynes took delivery. The failure had something to do with a cracked engine head which caused a valve to drop into a piston (Baynes 8, 15). The vendor gave Mr Baynes two reconditioned cylinder heads as compensation. 3 In or about June 2008 Mr Baynes entered into a verbal agreement with Mr Rocco on behalf of the defendant to have the engine reconditioned. 4 It is common ground that it was an implied condition of the agreement that the defendant would perform that work with reasonable skill and diligence. 5 The defendant completed the work in late October 2008 and Mr Baynes collected the vehicle on 28 October 2008. He paid the defendant $42,997.93. 6 Subsequently Mr Baynes drove the prime mover intermittently for heavy haulage purposes associated with his farming business. He encountered a number of problems including another cracked cylinder head and issues with the fuel and oil lines and a lack of engine power. 7 The engine seized when Mr Baynes attempted to start it in mid-March 2010. By then the vehicle had been driven for approximately 15,000 kilometres after the recondition. It has not been driven since. 8 It is common ground that the cause or mechanism of the engine seizure was the failure of the number 4 crankshaft bearing which overheated and fused with a crankshaft journal. That, in turn, caused two thrust bearings (or thrust segments) to be dislodged and permanently jam the crankshaft. (Page 4)
9 Mr Baynes contends that the seizure was caused by a want of reasonable skill and diligence by the defendant in reconditioning the engine. He claims damages in the sum of $61,516.85 comprising the cost of replacing the engine with another reconditioned engine ($60,122.95) and the cost of the initial examination and report on the engine failure by Mr Glen Bagnell ($1,393.90). At trial he abandoned a claim for consequential damages arising from the loss of the use of the prime mover ($954.45 per week). 10 The defendant denies liability and puts Mr Baynes to strict proof of the cause of the failure mechanism (for which a number of hypotheses were raised in evidence) and as to its want of skill and diligence in respect of the same.
Technical background 11 At the risk of over-simplification, the basic components and assemblage of a Volvo F16 diesel engine are as follows. 12 Uppermost is the rocker cover. Below that, in descending order, is the rocker gear, manifold, head (which contains inlet and exhaust valves), engine block (which contains liners and pistons), crankshaft (connected to the pistons by conrods) and oil sump. 13 There are six pistons and thus six conrods driving the crankshaft. 14 The engine block is a single piece of cast metal. The crankshaft sits underneath and is held in place by steel caps (known as 'bearing caps') from below. The bearing caps are bolted snugly into the engine block. 15 The crankshaft is thus located (and rotates) inside a tunnel between the bearing caps and the engine block. To be more precise, the upper half of the tunnel comprises a semi-cylindrical void in the engine block which is mirrored below by a semi-cylindrical void in the caps. The diameter of the tunnel is known as the 'bore'. 16 The oil sump has a capacity of 38 litres and supplies oil at pressure throughout the engine by means of pumps and galleries. 17 The internal, moving surfaces of the crankshaft are made of slightly ovoid-shaped, toughened stainless steel cylinders known as 'journals'. Each journal rotates inside a bearing, of which there are seven. 18 Each bearing consists of two identical halves ('shells') which fit snugly opposite each other; one in the engine block and one in the bearing (Page 5)
cap. In this way the two shells form a cylindrical bearing when the cap is bolted into the block. 19 Each shell (and thus the bearing) consists of three laminated metal layers. The external layer (or 'leaf' as I shall call it) is made of steel. In situ it is in contact with the metal lining of the engine block or bearing cap. The second leaf is made of bronze. The third and inner-most leaf (the internal leaf) consists of a 'Babbitt metal' which is a pewter-like alloy (Mr Martin Simms 149 – 150). It is softer and has a lower melting point than the other two layers and the journal, so it wears at a faster rate than them. 20 As such, the bearing is a sacrificial part which can be replaced, as occurred when the engine was reconditioned in this case. 21 Each bearing shell has an inbuilt tension or torque (or self-springiness) which helps it to make a firm contact with the surface of the engine block or the bearing cap. This outward force is known as 'crush'. The crush increases when the cap is bolted in situ so that the friction between the external leaf of the bearing and surface of the engine block or bearing cap exceeds the friction between the internal leaf and the journal. As a result, the bearing remains stationary and the journal spins inside it when the crankshaft turns. 22 Each bearing shell has a small metal lug (known as a tang) in one corner of one end. The tang clips into a slot in the engine block or bearing cap (as the case may be) and helps to hold the shell in place. 23 Each shell overlaps the cap or engine block by an extremely small margin when it is inserted into the cap or engine block. Bolting (torquing) the cap into the block squeezes the lips and tangs downward which in turn forces the shells outwards, so enhancing the crush in the bearing (Simms 152 - 155). 24 The shell that goes into the engine block has a circular aperture at the uppermost point of the circumference (90 degrees to the horizontal or 12 o'clock on a clock face). In situ this aperture lies opposite an aperture in the engine block (which I shall call the oil portal). When the engine is running oil is pumped through the oil portal and into a miniscule void (known as the 'running clearance') between the internal leaf and the journal. The oil provides lubrication and thus reduces friction and heat gain. (Page 6)
25 In situ, the running clearance widens (to about 2-6 one thousandths of an inch, or 0.05 – 0.15mm: Rocco 119) at the top and bottom of the bearing. In other words, the bearing does not have exactly the same circularity as the journal. This is designed to facilitate crush and the ingress and circulation of oil. 26 The thrust segment is a flat, crescent-shaped piece of metal which clips into the bearing cap/and engine block assembly on either side of each bearing. Its role is to stabilise the forward thrust or movement of the crankshaft through the tunnel. (The design specification allows movement of up to 5 one-thousandths of an inch or 0.127 mm: Rocco 122). 27 As can be seen, everything is designed to operate to very fine tolerances. In layman's terms, there must be very tight and snug fits which nevertheless leave sufficient scope for movement of oil and the moving parts.
The recondition of Mr Baynes' engine 28 Mr Baynes took the prime mover to the defendant's workshop on the back of a low loader. He agreed to pay for the engine to be reconditioned on a cost plus labour basis, which Mr Rocco estimated would amount to $30,000. 29 Mr Baynes requested that the engine be reconditioned out of the chassis, which involved additional work and hence cost, because he wanted the reconditioned engine to last (8). He testified, and I accept, that he was content when he ultimately paid an extra $12,997.93 because he was prepared to pay what it took to get a good job done. 30 I accept the following definition of 'recondition' (Style, exhibit 10 page 2; emphasis added): 31 A reconditioned engine should be good for about 500,000 km (Style 70). (Page 7)
32 Mr Rocco did the work himself with the assistance of two employees who he supervised. I accept his evidence about the work that he did (112 – 126). 33 He refurbished the cylinder head using the two reconditioned heads provided by Mr Baynes (one of which later failed) and four of the original heads. These were stripped, cleaned and sent to a local workshop (Barry Marris Engineering) for re-machining. 34 Mr Rocco purchased an 'engine kit' consisting of new engine parts such as piston heads, rings, gaskets, bearings and liners. 35 With the pistons removed Mr Rocco removed, cleaned, inspected and measured the crankshaft which 'looked [in] excellent condition' (114). Using internal and external micrometers he measured the 'wear limits and … new limit' of the crankshaft journals, checking for 'ovality and taper'. He concluded that it 'was a very good crankshaft' (114 – 115). 36 He examined the block and bearing caps (which were also cleaned). These were found to be in good condition with 'no chasing marks or anything like that' (115). 37 He also examined the original crankshaft bearings (which were being replaced) to gain an appreciation of the 'prior history' of the engine. He testified (115 – 116; emphasis added): Upon inspecting the old bearings as a general check … they were in good condition. … The old bearings were nothing untoward or nothing. … No real problems there, no, no. They came up quite good. 38 Mr Rocco inserted the new bearing shells into the bearing caps and the engine block making sure that the oil holes and portals were in alignment. He said (116) that 'they had enough tension in there'. 39 At some point Mr Rocco examined the 'bore of the block and cap and concluded that 'it was nice and cylindrical, and flat' (139). 40 The crankshaft was lowered into the engine block so that it sat 'snugly into the block' (117). Mr Rocco then bolted the bearing caps over (Page 8)
the crankshaft and into the engine block, and inserted a substance known as 'Plastigauge' as he did so. Plastigauge is a thin, malleable rod that is deformed by crush when a bearing cap is bolted into an engine block. 41 Next Mr Rocco removed the caps and Plastigauge which he compared to a chart provided by the engine manufacturer. This allowed him to check the running clearances. The amount of squeeze on the rod signifies the amount of running clearance: excessive squeeze signifies inadequate clearance whilst inadequate squeeze signifies excessive clearance. 42 In this case Mr Rocco was satisfied that the bearing clearances met the specification. (They 'came in at 2 on my gauge, on the minimal side, which is excellent': 119). 43 He then re-attached the bearing caps and bolted them into place with a tension wrench set to the specified torque, which was 280 foot-pounds (121). 44 All other necessary components were installed and the reconditioning of the crankshaft was finished. 45 Mr Rocco then checked his work, including the alignment of the bearing cap bolts and the 'endfloat' of the crankshaft (the amount of forward and backward movement), which he found was within specification (ts 122). 46 Next, Mr Rocco checked the 'line bore' (ie, the tunnel bore) by hand-rotating the crankshaft. He found that it 'spun freely', which signified to him that there was no problem with the bore (122 – 123). He testified (122; emphasis added, see also 136): If I had a problem with line bore … [the crankshaft] would not turn and it would be crazy for me to go any further.
The cause of the number 4 bearing failure – common ground 47 I find that the failure mechanism of the bearing involved the following stages (not necessarily in this exact sequence): (Page 9)
(3) The oil portal and the aperture in the bearing ceased to be aligned. Any alignment thereafter was brief and limited to each occasion that the aperture rotated past the portal. (4) This compromised the lubrication of the bearing, causing friction and heat to build up further. (5) At some point when the engine was not operating molten parts of the internal leaf cooled so that the bearing became fused with the journal. In effect, the external leaf of the bearing now became the crankshaft journal and the engine block and bearing cap surfaces became the bearing. This further exacerbated the lubrication, friction and heat problems. (6) The molten alloy also extruded outside the bearing and into contact with two thrust segments. (7) When that material cooled the thrust segments fused with the bearing and the journal. (8) At the next attempt to start the engine it gradually built up enough power to rotate the crankshaft which dislodged the pair of fused thrust segments. They prevented the crankshaft from rotating and the engine came to a permanent stop. (9) Debris from the bearing extrusion was transported throughout the crankshaft and scored several surfaces. 48 There was common ground between the experts about this mechanism, although only Mr Simms went into the detail referred to in parenthesis at (2) [see [87] below]. 49 There is an issue for me to decide (if possible) as to how or why stages (1) and (2) happened. (I shall refer to this cause as 'the trigger mechanism'). As to stage (1) (which may have happened after stage (2) began), it was necessary for the crush and tangs that held the bearing in situ to be overcome by friction from the crankshaft journal. Put differently, something must have occurred which altered the relativity between the force holding the bearing in situ and the force exerted on the bearing by the journal.
Overview of the parties' evidence 50 Mr Baynes, Mr Bagnell and Mr Rocco testified. I have no hesitation in accepting them as honest witnesses. (Page 10)
51 In this case the determination of the issue as to the trigger mechanism cannot depend on the direct evidence of the lay witnesses. Rather, it depends upon inferences to be drawn from circumstantial evidence having regard to the expert assistance available to me. 52 In a circumstantial case a fact is taken to be proven if the trier of fact is satisfied (ie, can infer) based on the whole of the evidence that it is more probable than not that it happened (see Chamberlain v The Queen (No 2) (1984) 51 ALR 225, 237 - 238). 53 So, proof of a disputed fact does not predicate knowledge of its truth, but rather persuasion of its probability. But, this is not an arithmetical exercise. I am required to be actually persuaded as to the probability (see Briginshaw v Briginshaw (1938) 60 CLR 336). 54 In addition to giving direct evidence of circumstantial facts, a witness is permitted to give evidence of an opinion (which would otherwise be hearsay) in respect of a factual issue which requires expert elucidation if he or she is qualified by training or experience (or both) to do so. This evidence is admissible for the purpose of assisting the judge to make findings of fact. 55 The judge is entitled to accept all of a particular expert's evidence, or none of it, or accept some and reject the rest, or simply put it to one side. In this way, findings can be drawn from evidence and opinions received from more than one expert, irrespective of who adduced the evidence. 56 Opinion evidence must be based upon facts that are properly proven, and must be explained in such a way that the judge can understand it and make the necessary findings, or at least understand why he or she should adopt it or defer to it (see Pownall v Conlan Management Pty Ltd (1995) 12 WAR 370; Pollock v Wellington (1996) 15 WAR 1 per Anderson J at 3 and Atanasoska v Inghams Enterprises Pty Ltd [2009] WASCA 17). 57 The assistance to be derived from expert evidence, ie, the weight of that evidence, may depend to some extent on the degree of specialisation involved in the relevant expert field, because some fields are more esoteric than others. So, in this case I have found myself entirely reliant on the experts when it comes to determining that the failure mechanism involved stages (1) to (9) or as to the relative melting points of various metals, but having received and understood their opinions I am well-placed to form opinions about related matters. Nor am I wholly reliant upon the experts when it comes to understanding the importance of good lubrication, the effects of friction and faulty running clearances. (Page 11)
58 Mr Style is an automotive engineer and was called by the plaintiff. Mr Simms is a mechanical engineer and was called by the defendant. Both were well qualified by training and expertise to give opinion evidence. Mr Simms was tertiary-educated whereas Mr Style obtained his professional qualifications through various trade certificates and diplomas. As far as I can discern, neither pathway is necessarily superior to the other, but the difference did influence the way in which each gentleman gave his evidence. Mr Simms was more articulate and scientifically circumspect than Mr Style, who tended to be dogmatic and his report (exhibit 10) was a little disorganised. 59 Accordingly, during the hearing I tended to be drawn to Mr Simms' evidence. Having said that, Mr Style has worked exclusively with automotive engines throughout his lengthy career (including as an educator). The overall result is that the weight of Mr Style's evidence improved with analysis away from the hearing itself.
Possible trigger mechanisms 60 The following hypotheses were canvassed in the evidence. Some of them overlapped and some were only straw-men or red-herrings: (i) Defective bearing shells (ii) Faulty oil squirters (iii) Inadequate or contaminated oil (iv) Contaminated fuel (v) Over-revving or lugging the engine (by the driver) (vi) Faulty installation of the bearings (by the defendant) (vii) Excessive crush
Timing of the trigger mechanism 61 In Mr Simms' opinion (exhibit 12.3, p 5 and 175) the engine could not have run for hours with a spun bearing. 62 Mr Style did not agree. In his opinion it is not impossible for an engine to run for hours at a time and for many thousands of kilometres with a spun crankshaft bearing. He testified (80) that he had come across crankshafts which had done so; one had as much as 125,000 km of use. Mr Bagnell said something similar ('a long time'; 40). (Page 12)
63 Mr Style's and Mr Bagnell's evidence was based on anecdotal evidence. I accept their evidence about their experiences but, as Mr Simms pointed out (175), it is logically fallacious to assert that an engine that is found to have been operating satisfactorily with a spun bearing must have been doing so for thousands (if not tens of thousands) of kilometres based purely on the fact that the engine had done so. One could have no way of knowing when it became a spun bearing in the first place. In other words, there is no way of excluding the possibility that Mr Style and Mr Bagnell had occasionally made serendipitous discoveries of something that was of recent aetiology, which is not surprising having regard to the number of engines that they have seen in their long careers. 64 Mr Style's reasoning requires me to accept that a spun bearing could function quite satisfactorily for lengthy periods and/or for many thousands of kilometres. That does not sit comfortably with the science as explained by Mr Simms, who rejected Mr Style's opinion as 'preposterous' (175). 65 I am reluctant to accept Mr Simms' pejorative, but I do at least accept that a bearing in which the exterior leaf operated as the journal with a radically compromised oil supply would not, and could not, operate effectively in the long term. But, the evidence does not allow me to make a finding as to the probable life span of a spun bearing, either generally or in this particular case, because the evidence did not condescend to enough particularity. Resolution of that issue must take into account a number of possible variables. The first is that the bearing would not necessarily fuse with the journal immediately after the tangs failed. Mr Style said that initially the bearings might spin centrifically with the journal (65), which makes sense and I accept it. Also, depending upon the oil pressure (about which I received very little evidence) there might continue to be some transfer of oil via the portal to the external leaf of the bearing (Style, 81, 84). The engine's pattern of use would also need to be considered. I cannot exclude the hypothesis that failure stages (1) to (5) could happen without progress to stage (6) if the prime mover was habitually used for relatively short journeys. Mr Baynes gave evidence of making a wool delivery to Perth (9), but otherwise I gathered that he drove it within the district to places such as Katanning, Narrogin and grain receival depots (9 – 11, 22).
Product failure 66 Having regard to the manufacturers' rigorous manufacturing and quality control procedures, both experts heavily discounted the possibility (Page 13)
of a manufacturing defect in the bearing shells. Mr Simms testified that the likelihood was 'very, very low' (163: see also 188). 67 No assessment could be made of the bearing shells themselves since they were too damaged by the seizure and subsequent removal. However, no defect was found in the other pairs of bearing shells. 68 I find that there is an extremely low likelihood that the trigger mechanism was a defect in the bearing shells. This finding is supported by the fact that Mr Rocco found no problem with the running clearances when he performed the Plastigauge test (139).
A fault with the oil squirters 69 Mr Style noted in his report that the number six oil squirter was broken and the number 5 oil squirter was loose when he examined the engine. 70 This finding was pleaded as a particular of the defendant's want of skill and diligence, but it is a red herring. The oil squirters are used to lubricate the piston cylinders, not the crankshaft bearings. Therefore, any causal connection between any faults with them and the bearing failure is an impossibility. 71 Mr Style only mentioned this for completeness. Any criticism should be reserved for whoever pleaded the statement of claim.
Inadequate or contaminated oil 72 This hypothesis warrants some attention, if for no other reason than that Mr Baynes regularly complained about excessive oil consumption. He testified, and I accept, that he regularly topped up the sump using a recommended oil. Mr Rocco testified that he found external leaks (128), but the problem was never properly resolved. 73 On examination by Mr Bagnell in August 2010 there were 22 – 23 litres in the sump (40). Both experts agreed that this was adequate and excluded loss of oil pressure. 74 No oil-related damage was found on any of the bearings or relevant engine surfaces (58, 96 – 7 and 100) except the number 4 bearing. The experts therefore accepted that the lubrication was only compromised in respect of that bearing, and that was a consequence of the trigger mechanism and not a cause. (Page 14)
Contaminated fuel 75 There is evidence to support a finding that the engine performance suffered from fuel contamination and I find accordingly. 76 In October 2009 Mr Rocco found that the fuel filters were very dirty and contaminated with sludge and water. He inspected the tanks and discovered a large quantity of sludge (130). The reconditioning work did not involve the fuel tanks in any way, so they had not previously been inspected whilst Mr Baynes owned the vehicle. 77 It was suggested on behalf of the defendant that Mr Baynes was responsible for the dirty condition of the fuel system because the farm fuel supply was contaminated. 78 Mr Baynes denied that suggestion. He testified that the prime mover used the same fuel from the same tanks as his other farm machinery, with which he had no problems. Those tanks were regularly filled by the same contractors who supplied other farmers and service stations in the district. He readily acknowledged that a smaller, mobile tank (known as a 'nurse tank') that was used to refuel machinery in the paddocks could be contaminated because of the dirty conditions in which it was used, but he insisted that the prime mover was never refilled from the tank. I accept his evidence for the following reasons. 79 I am satisfied that Mr Baynes is a competent and experienced farmer who took proper care of all of his machinery. He purchased the prime mover for the long term and was prepared to pay whatever it took to make sure that it did last (8). And he left no stone unturned to resolve the various performance problems that he had with the engine. I find it very difficult to believe that he did not properly fuel it (or lubricate it for that matter). 80 Next, on the evidence it is clear that the fuel problem emanated from the contaminated tanks on the prime mover. There is no way of knowing when they became contaminated and it is improbable that it occurred during the short period that Mr Baynes owned the vehicle. That reasoning is corroborated by the fact that Mr Baynes complained of performance problems with the engine at all material times. So, I am satisfied that there was a problem with the fuel lines, but it had nothing to do with Mr Baynes' operation of the vehicle. 81 In any event, I find that this hypothesis is another red-herring. I am satisfied based on the experts' evidence (Style 59, Simms 145; see also (Page 15)
Rocco; 130) that fuel quality could only impact on the power and performance of the engine, but not the crankshaft bearings. That finding is corroborated by the absence of any damage to the six cylinders or the bearings other than number 4.
Over-revving or lugging the engine 82 This hypothesis predicates operator error in that Mr Baynes failed to properly run-in (or 'bed-in') the reconditioned engine. The notion of running-in or bedding-in an engine is reasonably foreign to a contemporary lay-person who is accustomed to driving modern, domestic vehicles. However, it is common ground that it is important in the case of a new or reconditioned prime mover engine. 83 There was a dispute between Mr Rocco and Mr Baynes as to what the former said to the latter about bedding-in the vehicle. Mr Rocco testified (126 - 127) that he requested Mr Baynes to check for visible oil and water leaks, 'to run at the correct revs and to use the correct gears, particularly on hills'. Later he testified (137) that he told him 'not to lug the engine and not over-rev'. He said that he instructed Mr Baynes that he wanted the vehicle returned to the workshop after 1,500 km. He said that Mr Baynes rejected this advice and said that he would check and replace the oil himself. 84 Mr Baynes denied this evidence and testified that he was only told 'to run it in how I would normally drive the truck' (17), save that he was told 'not to run the truck lightly'. He said that Mr Rocco told him to change the oil after 5,000 km. 85 Very little turns on this issue because the prime mover ended up going back to the defendant on a regular basis anyway, starting at around 1,000 km (Baynes 17, 19). However, I accept Mr Baynes' evidence about what he was told, and was not told, because it made no sense for the parties to be discussing the return of the vehicle after only 1500 km of use when, to both their knowledge, Mr Baynes needed it for the harvesting season (Baynes 8, Rocco, 111). 86 That still leaves the issue of operator error. As I understand the evidence, it is common ground that bedding-in allows the engine components to settle into their positions and, in effect, achieve optimal synchronicity (my word). So, it is common ground, and I accept, that it is necessary for a new or reconditioned engine to be operated with care during the bedding-in stage, which is around the first 10,000 km of use. (Page 16)
87 Mr Simms testified (and I accept) that it is necessary to avoid 'lugging' or over-revving during this (or any) period. He described this as follows (179; emphasis added): 88 In practical terms 'the simple description of lugging is if you started to go up a hill in a particular gear and the engine starts to dig in and dig in …' (Simms 169). In response to a somewhat leading question from myself, Mr Simms agreed that lugging can occur when a driver is 'too lazy to change gears'. Mr Rocco described lugging as using 'too high a gear up a hill' (137 – 138). 89 Mr Simms described over-revving as 'almost the reverse scenario' which can occur when a driver fails to change down to use the engine as a brake whilst descending a hill (169). 90 The defendant contends that Mr Baynes may have compromised the bedding-in of the engine by making incorrect gear choices and over-revving the engine, which Mr Baynes did not admit to. (He testified that he could not over-rev it because of a limiter installed by the defendant; 26). 91 There is nothing to support the defendant's hypothesis save for the fact that the number 4 bearing failed, since no-one else is in a position to comment on Mr Baynes' driving. But, I reiterate what I said at [79] above. Mr Baynes did not impress me as a person who did not know how (Page 17)
to drive the prime mover properly, or who would abuse it, and I do not accept that he did, or could have done so, to such an extent as to bring about the failure of the bearing in the manner described by Mr Simms. In this respect, Mr Simms believed that lugging or over-revving could only be the trigger mechanism in 'extreme circumstances' (169; emphasis added). 92 I am satisfied that it is extremely unlikely that the trigger mechanism was lugging or over-revving of the engine. 93 I note, however, that Mr Simms' evidence quoted at [87] above was nevertheless very helpful in explaining how the failure of the internal leaf could occur progressively, commencing with intermittent contact with the journal through to cracking and delaminating with ever-increasing (excessive) contact and friction.
Faulty installation of the bearings 94 As with the previous hypothesis, which predicated operator error, there is no evidence to suggest that the bearing shells were wrongly installed apart from the catastrophic failure of the number 4 bearing itself. 95 I am satisfied that any problem with the shells themselves, or their installation, would have been detectable using the Plastigauge test, which Mr Rocco carried out. I accept his evidence that the test revealed no abnormality. Indeed, based on his evidence I find that the clearance was excellent. 96 Thus, the faulty installation hypothesis must be rejected.
Excessive crush 97 As I have said, correct force (crush) between the bearing and the bearing cap or engine block is important. Insufficient crush or excessive crush may cause bearing failure. 98 Insufficient crush occurs when the bearing assembly is not sufficiently torqued, that is to say, the bearing cap is not bolted tight enough and the bearing is left too loose. 99 Excessive crush occurs when excessive pressure is applied to the bearing within the assembly. It is common ground that this may occur for a number of reasons, including manufacturing error (already eliminated) and over-torquing the bearing cap (over-tightening the bolts), or tunnel misalignment. Under excessive crush the shells will tend to warp (Page 18)
inwards, creating one or more points of 'excessive or too frequent' contact (as Mr Simms described it at 179) between the internal leaf and the journal. 100 I accept Mr Rocco's evidence and find that he bolted each bearing cap with a torque wrench set to the manufacturer's specification. It is common ground on the evidence that this eliminated the risk of either under-torquing or over-torquing. 101 I turn now to consider excessive crush caused by tunnel misalignment (defective tunnel bore). 102 It is common ground that tunnel misalignment (including unevenness) is a potential problem which must be checked for when reconditioning and corrected if necessary. Remedial work entails sending the engine block and caps (ie, the tunnel components) to a workshop to have the tunnel bored by a special machine. Depending upon the outcome of that process, the workshop would also fine-tune the bore by machining the caps. 103 Mr Style did not nominate a particular trigger mechanism in his report (exhibit 10) although excessive crush caused by misalignment (including unevenness) of the tunnel was included amongst the hypotheses. He fixed upon this hypothesis in his oral evidence (59, 64, 67, 77 – 78, 79 – 80, 102). He testified that the diameter and evenness of the tunnel bore (which must be 'exactly right': 64) could have been checked using a mandrel or laser checks (59) or a 'tunnel bore gauge or a Vernier' (80) and thus corrected if necessary. He testified (102; the intercalations are mine): … the fitting of bearings is a multi-part task and to check the crush [the tunnel bore] was an important part as well as checking the clearance [the Plastigauge] so, as a result, if it had have [been] tunnel bored [which it was not] and if all the other variables such as tension … clamping it together [torquing in the bolts and shells] and all that had been right – if it had been checked after it had been partly reassembled [the tunnel had been checked without the crankshaft in situ] … this should not have happened. 104 Mr Style continued to make it clear that he regarded it to be important that the line bore 'was checked when they put the bearings back in'. 105 Mr Style relied on a process of deduction (or, more correctly, exclusion) to arrive at his opinion. In my view his reasoning is persuasive provided that it is not foreclosed by evidence and the other hypotheses can be excluded. (Page 19)
106 Mr Simms believed that this case is just one of those instances in which the trigger mechanism can never be known (171). He felt that there was insufficient evidence to enable anyone to 'absolutely conclude'. But I note that in forming that view he may have set the evidentiary standard much higher than applies to my deliberations. 107 I shall return to this hypothesis later.
Mr Rocco's assessment of the tunnel bore 108 I accept Mr Rocco's evidence that he visually examined the tunnel components, checked the old crankshaft bearings and rotated the crankshaft when it was in situ. He was satisfied that there was no evidence to suggest tunnel misalignment. 109 Mr Style testified (and I accept) that the Plastigauge test was irrelevant to this aspect since it only measured the working clearance between the internal leaf of the bearing shell and the journal. That was only apt to identify a potential crush problem associated with the quality (ie, shape) of the bearing. 110 Mr Rocco did measure the journal diameter using micrometers, but he gave no evidence of having measured the tunnel bore. The latter subject came up during cross-examination. He was asked about having the tunnel re-bored and said that there was 'no evidence to lead me to that by my checks of the crankshaft, block condition and bearing inspection' (135). He expanded upon this in re-examination (139): And when I inspected … the bore of the block and cap I saw no evidence of any chaffing, high spot, low spot. It was nice and cylindrical, and flat. 111 It is by no means clear from this evidence whether Mr Rocco was saying that he inspected the bore and cap separately (as semi-cylinders) or in situ as a tunnel (a cylinder). I shall proceed on the basis that the former was the case for two reasons. First, it was and is my impression that when he used the word 'it' he was referring to the bore of the block and cap in each instance and not in situ as a tunnel. That construction is supported by his use in this context of the plural 'tunnels' in the phrase 'respective halves or tunnels' (117). Second, he did not say when he made those inspections, but it was my impression from the narrative that he gave (particularly at 116 – 117) that the bearing caps were never fitted into the block before the crankshaft was lowered into place. On the contrary, he explicitly described a process involving fitting the shells, checking the (Page 20)
tangs, lowering in the crankshaft and then fitting on the caps for the first time. 112 Either way, I find that Mr Rocco did not take any empirical measurements or make any other checks of the tunnel itself (or its component semi-cylinders) of the kind that Mr Style had in mind. 113 The defendant contends that Mr Rocco did all that was necessary. Mr Simms supported that contention (157, 160 – 164, 171 and 175). He said that it was not normal to empirically test for crush. He said that would 'only be of value if there was a problem' (ie, a problem was identified by the other checks: 181). 114 Mr Simms testified that a freely rotating crankshaft denotes an acceptable assemblage (175). It is common ground, and I accept, that hand-rotating the crankshaft is a means of testing for unwanted contact between the bearings and the journals. But, its efficacy is dependent upon the degree of contact (if any) between the misaligned bearing and the journal. As Mr Simms said (185), a warped (ie, excessively crushed) bearing would act like an 'old-fashioned brake' on the journal but, self-evidently, the efficacy of a brake depends upon the force (friction) and regularity with which it is used. Mr Simms allowed that the contact between the bearing and the journal could vary between a 'grip' and a 'nip' (174), and that the rotation test depended on the experience of the operator and the subjective feel of the rotating crankshaft (175). But herein lies a problem for the defendant, because it appears from Mr Rocco's evidence that he applied a more simplistic standard, namely whether the crankshaft would turn or not (see [46] above). I have reservations about the practical efficacy of the test if an experienced mechanic (such as Mr Rocco) could misunderstand its limitations. 115 It is essential to bear in mind that very fine tolerances are involved. I accept Mr Style's evidence (64) that the working clearances in the tunnel must be 'exactly right'. Based on all the evidence, I find that taking empirical measurements would be more reliable than the qualitative, subjective judgments which Mr Rocco made by feel and with the naked eye. I find that they did not exclude the possibility of a subtle problem with the tunnel alignment going undetected and hence the potential for a risk of excessive crush going undetected. 116 I am also concerned that Mr Simms was too dismissive of Mr Style's opinion that the tunnel bore should be empirically measured (see [113] above). In fact, I am not sure that Mr Simms addressed it at all. In the (Page 21)
context of testing crush he gave evidence which seemed to relate to testing the shells in the cap and block (173 – 174). 117 The defendant contends that the condition of the old bearing shells would have disclosed evidence of a tunnel misalignment if such was present. Mr Simms testified that a bearing which was out of line would have something 'unusual about the wear pattern' and would show excessive wear and so on' if the 'tunnel bores were no longer collinear (157). I understand this as a general proposition. 118 However, he did not go so far as to suggest that the old bearing shells would show signs of their own imminent catastrophic failure if there was a tunnel misalignment. Based on Mr Simms' evidence I can only find that the old bearings would show whatever signs of wear were consistent with the entire history of the engine (at least 500,000 km of usage in this case, probably much more) during which the bearing caps and shells would have adapted to any change in their environment, which could have been gradual and subtle in the case of a tunnel misalignment. 119 I am not persuaded that Mr Rocco's self-described 'general' inspection of the old bearings was sufficient to exclude misalignment of the tunnel. 120 In conclusion, Mr Style has enormous experience in his field. I accept his opinion that any material tunnel misalignment is best tested for using a bore gauge or Vernier and such should have been done in this case.
Conclusions in relation to causation and liability 121 The defendant relied upon Mr Simms' evidence and contended that it is impossible on the evidence to make a finding about the trigger mechanism on the balance of probabilities and unapologetically relied upon the onus of proof. 122 As required, I have taken an all-of-evidence approach to the issues from which, in my opinion, one hypothesis emerges as the probable cause of the number 4 bearing failure, namely excessive crush instigated by misalignment of the tunnel. 123 I further find that this caused misalignment of the cap so causing the bearing to warp, which increased the friction between the journal and the bearing which, in turn, led to ongoing compromise of the bearing and ultimately to stage (1) above. By that stage catastrophic failure was (Page 22)
inevitable, the exact timing of which depended on the subsequent use of the engine and the evolution of stages (2) to (5). 124 In making these findings I have been mindful that a circumstantial case which is reliant on deduction by a process of elimination is potentially fraught by the fallacy that a hypothesis is correct because it is the only one left. It is necessary to exclude remote and speculative theories and weigh up the remainder, always remembering the nature of the fact-finding process and onus and standard of proof. Further, my findings must be supported by evidence – an assumption is not evidence (Swick Nominees Pty Ltd T/As Swick Drilling Australia v Norncott Pty Ltd [No 3] [2013] WASC 173 [153]). Unlike Swick, I received evidence in this case as to how the crankshaft worked, as to what could theoretically have gone wrong and as to what might have actually gone wrong. And an experienced expert alighted upon one of them as the cause. 125 I have been personally persuaded to the required standard to make my findings because tunnel misalignment was a real and not speculative risk which had to be appropriately addressed (as Mr Rocco wrongly thought he had done). The absence of any qualitative signs of misalignment on visual examination of the old bearings or in the tunnel components themselves, or upon hand-rotating the crankshaft, did not necessarily preclude the risk of a small but important misalignment when they were in situ, particularly having regard to the fine tolerances involved. With all due respect to Mr Rocco, I find that he left this real risk open. Given the relative unlikelihood of each of the other hypotheses, I find that this risk materialised and that it caused the bearing failure. This finding is consistent with a progressive disintegration scenario which Mr Simms described (at 179) and Mr Style's opinion that the degree of the impediment (friction) could 'gradually get worse' (84), which I find, is consistent with a small misalignment which did not make its presence felt until the crankshaft was turned at operational revolutions. 126 In his closing submissions Mr Hershowitz pointed out that Mr Rocco's evidence was basically not disputed (which is correct) and thus submitted that the plaintiff could not succeed. That argument must fail because I have accepted all of Mr Rocco's evidence about what he actually did. Mr Baynes is entitled to succeed because of findings that are open about things that Mr Rocco did not do. 127 Mr Hershowitz also submitted that Mr Style failed to adequately expose his reasons for alighting upon tunnel misalignment for the trigger (Page 23)
mechanism and also cited the rule in Browne v Dunn (1894) 6R 67 HL which requires a party to be given a proper opportunity to address potentially adverse evidence or findings. I am satisfied that there has been no breach of the rule because the defendant was always on notice of the basis on which my findings have been made. Mr Style explicitly raised tunnel misalignment in his report (exhibit 10, page 7). It is true that he was non-committal until he gave his oral evidence, but he was nonetheless very firm about it then. I am also satisfied that the hypothesis and hence my findings fall within the purview of the statement of claim and Mr Hodgkinson's opening address (2). 128 I accept that there is some force in Mr Hershowitz's submission about the amount of explanation in Mr Style's evidence. But I am not persuaded to reject his opinion. Moreover, I must decide the case based upon my understanding of the evidence in respect of causation, much of which was furnished by Mr Simms. Further, I arrived at my conclusion using a process of reasoning which Mr Style did explain, namely deduction by exclusion. The plain facts are that failure stages (1) to (9) occurred and there was a trigger mechanism which could only have come from seven hypotheses. Some of those hypotheses must be completely rejected and misalignment is the most probable of the others, principally because it presented a real risk that was not fully addressed during the reconditioning of the engine and the others are very unlikely. 129 Finally, I am satisfied that Mr Rocco's failure to empirically measure the tunnel bore was a breach of the defendant's duty to exercise reasonable skill and diligence since the risk was foreseeable and the tests which were apt to detect any material misalignment (as was present in this case) were practicable and readily available to him.
Quantum 130 Mr Bagnell testified in relation to quantum. He said (37) that it is feasible to have the existing engine reconditioned again, but it would be more time efficient and cost-effective to purchase another reconditioned engine. He estimated the cost of doing so at $60,122.95 including GST, excluding the cost of installation, for which there is no claim. 131 He testified that reconditioning the existing engine would involve having the block 'checked and line bored … seeing as the bearing has spun' which 'would have taken metal off the bore of the crankshaft' (42). The crankshaft would also have to be 'x-rayed and tested for hardness, straightness' (42). So, he felt that rebuilding the existing engine would not be cost-effective (37, 42). (Page 24)
132 This evidence was not strongly contested by the defendant. Mr Rocco simply testified that he believed it would be feasible to rebuild the existing engine for 'pretty much' the same cost as the original build, ie, $42,000 including GST (141). 133 I prefer Mr Bagnell's evidence. He condescended to more detail and, in particular, took into account that rebuilding the existing engine would include diagnostic measures and additional reconditioning costs (such as line boring) which were not part of the original work. Having regard to my findings these diagnostic and remedial measures must be allowed for. So, Mr Rocco's rough estimate was obviously too low. 134 I accept that it is reasonable for Mr Baynes to abandon the existing engine and purchase another on a reconditioned basis at a cost of $60,122.95. There is no evidence as to the salvage value of the existing engine (if any) and I make no allowance for that. 135 I am also satisfied that it was reasonable for Mr Baynes to incur the expense ($1,393.90) of having the engine examined by Mr Bagnell after the breakdown and he is also entitled to damages for that sum. 136 Accordingly, I assess damages in the sum of $61,516.95 and the plaintiff is entitled to judgment in that sum.
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