| JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA LOCATION : PERTH CITATION : HOLDEN -v- MACMAHON CONTRACTORS PTY LTD [2013] WADC 202 CORAM : MCCANN DCJ HEARD : 14, 15, 17 & 28 OCTOBER 2013 DELIVERED : 20 DECEMBER 2013 FILE NO/S : CIV 1032 of 2011 BETWEEN : MICHAEL HOLDEN Plaintiff
AND
MACMAHON CONTRACTORS PTY LTD
First Defendant
ENVIROCOAT (WA) PTY LTD
Second Defendant
Catchwords: Torts - Negligence - Unsafe workplace - Liability of workplace principal - Liability of equipment manufacturer - Turns on own facts
Contract - Liability of equipment hirer - Turns on own facts Legislation: Civil Liability Act 2002 s 5B, s 5C
Law Reform (Contributory Negligence and Tortfeasors' Contribution) Act1947 s 7(1)(c) Result: Judgment for the plaintiff against first defendant for damages in the sum of $800,000
Plaintiff's claim against second defendant dismissed
First defendant's cross claim against second defendant dismissed
Representation: Counsel:
Plaintiff : Mr A A Nolan (14 October)
First Defendant : Mr T Hammond
Second Defendant : Mr P Jarman
Solicitors:
Plaintiff : Trewin Norman & Co
First Defendant : HBA Legal
Second Defendant : Jarman McKenna
Case(s) referred to in judgment(s):
Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; (2009) 239 CLR 420
Beer v Duracraft Pty Ltd [2004] WASCA 192
Black Pool Rock Co Pty Ltd & Blue Waters Pty Ltd t/as O'Connor Pattern Makers v By Design Group Pty Ltd t/as BDG Machine Tools [2006] WADC 138
Briginshaw v Briginshaw (1938) 60 CLR 336
Chamberlain v The Queen [No 2] (1984) 153 CLR 521
Courtney v Medtel Pty Ltd [2003] FCA 36
Department of Housing and Works v Smith [No 2] [2010] WASCA 25
Dovuro Pty Ltd v Wilkins [2003] HCA 51; 215 CLR 317
Fitzpatrick v Job t/as Jobs Engineering [2007] WASCA 63; Aust Torts Reports 81-891
Jones v Dunkel (1959) 101 CLR 298
Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; 52 NSWLR 705
Podrebersek v Australian Iron and Steel Pty Ltd (1985) 59 ALR 529
Pollock v Wellington (1996) 15 WAR 1 at 3
Pownall v Conlan Management Pty Ltd (1995) 12 WAR 370
TNT Australia Pty Ltd v Christie [2003] NSWCA 47
Wyong Shire Council v Shirt (1980) 146 CLR 41
Introduction 1 In this matter the plaintiff claims damages from the defendants (MacMahon and Envirocoat) in respect of personal injuries which he suffered in the course of his employment at the Sinclair mine near Leonora on 9 April 2008. MacMahon admitted liability to the plaintiff. 2 The parties have agreed the plaintiff's damages in the sum of $800,000 inclusive of workers' compensation and interest. 3 MacMahon also commenced proceedings against Envirocoat claiming contribution pursuant to s 7(1)(c) of the Law Reform (Contributory Negligence and Tortfeasors' Contribution) Act 1947 (the LR Act), an indemnity pursuant to a contract between them and damages for breach of warranty. 4 The plaintiff seeks judgment against Envirocoat for the agreed damages in the event that MacMahon succeeds in tort against Envirocoat. He took no part in the trial save to give evidence on behalf of MacMahon.
Non-contentious factual background 5 The Sinclair mine is located approximately 80 km from Leonora in a dusty and hot environment. It was owned by Xstrata and was newly commissioned as at 9 April 2008. MacMahon was the principal construction and mining contractor. 6 The plaintiff's accident occurred in the maintenance area, which was an open air space approximately the size of a football field. It was divided into areas for fuel and oil storage and for crib huts, offices and containers for tools and spares. There was no sealed hardstand, so vehicles parked on a dirt surface. 7 Lighting was provided by trailer-mounted lighting plants and there was no flood lighting. 8 The plaintiff was employed by a labour hire company, TR7, to operate a Hitachi excavator under the instruction, supervision and direction of MacMahon. He was injured during the very first nightshift. 9 Mr Brendan Price was employed by MacMahon as a mechanical fitter (ie a heavy machine serviceman), but on the relevant night he was also assigned to operate the service truck. The service truck's role was to provide mobile refuelling and lubricating facilities for MacMahon's plant, including the Hitachi excavator. 10 Mr Price's first task on the relevant night was to fill the Hitachi excavator's hydraulic oil tank. For some unknown reason the equipment on the service truck would not function properly and the plaintiff decided to help Mr Price. The accident happened whilst the plaintiff was standing under the awning-style door of a service bay located in the side of the truck. Both of the struts which were supporting the door gave way which allowed the door to swing down and hit him forcefully to the back of his helmet. His head and neck flexed forwards, causing significant spinal injuries. 11 There is no dispute that the accident involved the catastrophic failure of the strut on the right side of the door. The remaining strut (on the left side) was then unable to support the weight of the door by itself. 12 Envirocoat trades under the name Equipment Placement, and manufactured the service truck to their own design. They hired it new to MacMahon for use at the Sinclair mine pursuant to an agreement entered into on 1 December 2007. 13 Material terms of the hire agreement were as follows: (i) The monthly rental was $25,000. MacMahon was responsible for the conduct of minor repairs, service and maintenance to a total of $1,000 per month. (ii) Envirocoat warranted that: (c) by clause 5(c), only original equipment manufacturer parts would be used in the repair or modification of the equipment. (iii) By clause 6, Envirocoat agreed to indemnify MacMahon for claims arising out of or connection with the agreement, reduced proportionally to the extent that the claim was caused by a negligent act or omission of MacMahon.
The service truck 14 The following findings are based upon the photographs in exhibit 1, the manufacturing drawings (exhibit 1.50 – 1.70) and the uncontested evidence of two expert witnesses, Mr Martin Simms and Mr William Jack Apgar. 15 The service truck consisted of a steel module mounted on a fixed chassis Mack Metroliner truck. 16 The module was 5600 mm in length, 2374 in width and 1700 mm in height. The chassis itself stood 1320 mm above ground level, so the total height of the module was 3020 mm. 17 The module was divided into differently sized tanks for the storage of fuels and oils and a compartment for hose reels and pumps (the service bay). The service bay was located on the right-hand side of the module immediately behind the driver's side door of the truck. It was approximately 2500 mm in length, 1200 mm in width (depth) and 990 mm in height. 18 The service bay was accessible by two equally-sized doors which were separated by a jamb. The jamb was approximately 90 mm in width. Each door was hinged at the top and thus opened outwards and upwards like an awning. In the fully-open position each door was held in position with a deflection of 17 - 18 degrees below the horizontal (Simms, 1.138 and exhibit 3) by two struts which acted as cantilevers. In that position the outer (bottom) edge of the door was 2025 mm (6ft 8inches) above ground level. 19 Each service bay door was fabricated from two millimetre thick steel plate and was 1205 mm in length and 990 mm in width (height) when closed. The weight of each door was approximately 25 kg (Simms, exhibit 1.138). When closed it was secured with a latch. 20 The left service bay door provided access to the diesel fuel pump and reel and pump and the right door provided access to the oil pumps and reels. 21 The service bay was not illuminated. There was a lamp above the driver's door but it did not shine into the service bay.
The working history of the service truck before the accident 22 MacMahon took delivery of the truck in December 2007 after its representatives and those of Envirocoat thoroughly inspected it at Envirocoat's premises. The truck was found to be in full working order. The struts on the service bay doors were not specifically inspected, but any defects would have been self-evident because the inspection involved the opening and closing of the doors. I find that the unit was in full working order at the time. 23 The truck arrived at the Sinclair mine in December 2007 and went into immediate service. 24 It was common ground in evidence that best practice mandated that the hoses be rewound and the service bay doors closed whilst the truck moved between items of plant. However, the plaintiff and Mr Price accepted (25 and 41) that the invariable practice at the Sinclair mine (and at other mines at which they had worked) was quite different in that the truck would be driven around with the service bay doors open and the fuel hose dragging on the ground. This was done to save time. 25 Mr Jonathon Pearce was employed by MacMahon in April 2008 as a mechanical fitter. His duties included servicing vehicles at the Sinclair mine. Based on his uncontested evidence (exhibit 2) I find as follows: (i) The service truck underwent a weekly maintenance service which consisted of a walk around to inspect items such as the lights, tyres, engine and coolant. (ii) It underwent a full service every 250 hours in which an extensive maintenance schedule was followed and the vehicle was serviced as required. The gas struts were not specifically checked. However, as with the delivery inspection referred to earlier, I find that any defects would have become obvious because a full service required the service bay to be accessed which, in turn, required the doors to be used. (iii) Mr Pearce carried out a full service of the truck on 3 April 2008. At the time it had been used for 792 hours, that is to say, it was the vehicle's third full service. To his knowledge, no faults had been reported in relation to the service bay doors (or specifically the struts) prior to 3 April 2008. He also believed that there were no problems with them on that date because he would have made a note if there had been, especially an obvious problem such as a door 'drooping quite significantly'. 26 Based on this evidence, it is very probable that the struts on the service bay doors were in normal working order and free of any known defects as at 3 April 2008, and I find accordingly.
Evidence about the accident 27 The plaintiff testified that he and the rest of the night shift travelled to the mine from Leonora and arrived after 7 pm which, he said, was 'a good hour late'. He attended a pre-shift meeting and was allocated to operate the Hitachi excavator. He was present when Mr Price was allocated the service truck and appeared to be upset about it. The plaintiff 'noticed him reacting quite badly' and volunteered to help him to 'get his head straight' (24). 28 After the meeting the plaintiff made his way to the excavator and did his pre-start check. Mr Price arrived in the service truck and was still not 'in a very good mood' (20). Mr Price proceeded to connect a hose from the service bay of the truck to the hydraulic oil tank of the excavator and activated the pump in the service bay. But for some reason the oil did not flow. Mr Price went 'backwards and forwards' trying to sort it out (21), so the plaintiff went to the service bay to see if he could help identify the problem. He testified as follows (22): I was standing under the rear door and I got – I felt a blow to the back of my head, it pushed the helmet forward over my eyes and drove my chin into the chest. 29 Given that Mr Price 'was upset at the time', the plaintiff's immediate reaction was that Mr Price had punched him. So, he 'tried to fight Brendon' (22). 30 In cross-examination the plaintiff totally disagreed (26) with the proposition that he was standing under, and was thus struck by, the front service bay door. He insisted that it was the rear door. 31 He gave no evidence that either door was drooping before the accident, or of any other noticeable defect. 32 Mr Price testified that he was 6ft 2 inches tall and weighed 155 kg at the time. He was a qualified heavy duty mechanic and fitter and was employed as such by MacMahon at the Sinclair mine. He testified that the pre-shift meeting (or 'handover' as he described it) finished at about 6.15 to 6.20 (30). He was 'a bit peeved' (37) because, in his opinion, the mine was understaffed with fitters. He objected to being allocated to the service truck when he was also the sole member of the maintenance crew for the shift (29). He had never driven the service truck before and had not been 'passed out' on it, meaning that he had been given no induction and was not formerly certified to operate it. This contravened MacMahon's standard procedures (Mr Donald Frost 49 – 50). 33 At the time the excavator was in the service area because it had been undergoing maintenance. He was initially required to attend to its hydraulic oil supply. The excavator was the only one on site and the shift manager wanted it back in service as soon as possible. He therefore felt like he was 'under the pump' (29). 34 He testified that he 'couldn't work out how to use the service truck at the start' (31) and the plaintiff came to give him a hand. They 'couldn't work out how to get the pump engaged' and he was 'constantly going to and from the service truck to the digger' and using 'a fair bit of guesswork'. The production boss 'was on [his] back … it was a pretty stressful occasion' (31). 35 He was unsure whether both service bay doors were open, but was sure that the front one was open because he needed to access the hydraulic oil hose and pump. He found himself inconvenienced because the open door was below the level of his eyes. Eventually he went to lift the door up (32): I've actually lifted it up with no force. I've actually lifted it up just so that I could walk under it … I've gone to walk underneath it so I've let go of it, and its come down and hit Michael on the back of the head. 36 He testified that this occurred very quickly, that is to say, before he could walk under the door (34). He immediately apologised to the plaintiff. 37 Mr Price examined the door to find out what had caused it to fall and observed that the 'push on mount' of the right strut had broken away on the 'door side' (34 – 5). I accept this evidence and therefore find that the strut remained properly connected to the door jamb. He believed that the breakage had occurred on an earlier shift and that the push on mount 'must have just been cradling in … [the] eyelet where it pushes on' (34). He adopted his statement in which he said (1.102): [I] investigated the reason behind the door suddenly dropping and found that the [right] strut where it locates and locks to the door flap was broken and the locator has just been resting on top of strut. 38 The implication in this evidence is that the connection between the strut and the door had been broken before his shift and had been temporarily manipulated together by someone else. (I shall refer to this as Mr Price's failure hypothesis.) 39 Mr Price testified that the plaintiff began to complain of pain and discomfort in his neck and head a few minutes after the accident and departed to attend the first aid officer. The matter was then reported to the shift supervisor and Mr Price 'tagged' the service truck out of service (35). 40 In cross-examination Mr Price was adamant that the accident involved the front service bay door and not the rear door (as the plaintiff testified). I accept Mr Price's evidence on that point. He was just as definite about it as the plaintiff, but gave a very cogent reason to support his version, namely the accident occurred whilst he was attempting to access the hydraulic oil hose and pump controls which were located in the front half of the service bay. 41 I accept the plaintiff's evidence that the accident occurred at approximately 7.20 pm. This is corroborated by his accident statement (exhibit 1.21) and a timeline contained in MacMahon's incident investigation report (exhibit 1.18). It follows that it was night-time and the area around the service bay where the plaintiff and Mr Price were working was very dark, as the latter testified. I am satisfied that there would have been some dim, ambient light from surrounding lights, but this would not have been effective in the confined space between the excavator and the service truck and under the service bay door. 42 I accept Mr Price's evidence that the forward service bay door was below his eye-line before the accident (ie well below 6 feet 2 inches) and that it collapsed immediately after he lifted it above his head and released it. I was impressed by that (and other) evidence which was given sincerely and apologetically, and it is consistent with his contemporaneous report (exhibit 1.102), all of which was against his own interests, in a sense, because it is evident that he has never doubted that his action in lifting the door triggered its collapse. He had no need to lift it unless it was too low for him to pass under. 43 It follows that the service bay door was drooping below its design height by as much as approximately 30 cm before the accident occurred.
The causes of the accident 44 I must determine the cause or causes of the service bay door drooping before the accident (the first failure phase) and also of the ultimate collapse of the door (the second failure phase). 45 The determination of these issues is dependent on an inferential (circumstantial) process which is reliant on expert evidence. 46 In a circumstantial case a fact is taken to be proven if the court is satisfied (ie, can infer) based on the whole of the evidence that it is more probable than not that the fact occurred (Chamberlain v The Queen [No 2] (1984) 153 CLR 521, 536, Gibbs CJ and Mason J). By 'more probable is meant no more than that upon a balance of probabilities … an inference might reasonably be considered to have some greater degree of likelihood' than others that are open. (Jones v Dunkel (1959) 101 CLR 298, 310 Menzies J). 47 But, this is not an arithmetical exercise. I am required to be actually persuaded as to the probability of a fact being true (Briginshaw v Briginshaw (1938) 60 CLR 336). Nor should I confuse mere conjecture with reasoned conclusion (Jones v Dunkel, 305, Dixon CJ, 309 – 310, Menzies J). 48 Inferences from actual facts that are proved are just as much part of the evidence as those facts themselves (Jones v Dunkel, 309, Menzies J). 49 An expert is permitted to give evidence of an opinion (which would otherwise be hearsay) with respect to a factual issue which requires expert elucidation if he or she is qualified by training or experience (or both) to do so. Opinion evidence is admissible for the purpose of assisting the court to make findings of fact. 50 As with all witnesses, the court is entitled to accept all of a particular expert's evidence, or none of it, or accept some and reject the rest, or simply to put it to one side. In this way findings can be drawn from evidence and opinions of more than one expert, irrespective of who adduced the evidence. 51 Opinion evidence must be based upon facts or stated assumptions that are proven (or bear a sufficient correlation to facts which are proven) and must be explained in such a way that the court can comprehend it and make the necessary findings, or at least understand why he or she should adopt it or defer to it. (Pownall v Conlan Management Pty Ltd (1995) 12 WAR 370; Pollock v Wellington (1996) 15 WAR 1 at 3, per Anderson J, Beer v Duracraft Pty Ltd [2004] WASCA 192 per McLure J, as her Honour then was, [78] – [80] and Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; 52 NSWLR 705, Heydon JA, as his Honour then was, [64].) 52 The assistance to be derived from expert evidence, ie its weight, may also depend to some extent on the degree of specialisation involved in the relevant expert field, because some fields are more esoteric than others. 53 In this case expert evidence was given by Mr Simms and Mr Apgar. Mr Simms is a mechanical engineer with extensive professional, practical and forensic qualifications. Mr Apgar is a chartered engineer with extensive experience in engineering, industrial research, design and forensic consulting. I found their evidence to be helpful to the extent that it provided explanations of technical or scientific principles, but I have found that some of their opinions on causation do not sit well with the evidence. In the result, I have tended to act upon the former category of evidence, but not the latter, on which I have been able to make my own findings. 54 I commence with uncontentious technical evidence in relation to the struts and the history of their use by Envirocoat. 55 The design and operation of the struts was virtually the same as for the type of pneumatic strut or closer which is used on hatch-back motor vehicle doors and vans and which most lay-persons would be familiar with. 56 Each strut consisted of a rod which slid in and out of a cylinder containing pressurized gas. The cylinder was fully enclosed at one end and had a seal at the other through which the rod could slide. Based on the photographs (exhibit 1.9 – 1.10), the outer end of the rod and the outer end (base) of the cylinder were attached to the door jamb and the door respectively. 57 As a door opened each rod slid out of its cylinder, thereby extending the length of the strut as a whole. In order to open the door it was necessary for a person to release the latch (which of itself provided a force which kept the door fully closed), pull out the bottom of the door (the lower edge) and then push or pull upwards. That process was assisted by the application of force supplied by the compressed gas within the cylinder acting on a piston attached to the internal end of each rod. The same pneumatic force also held the rod in the fully extended position, whereupon the strut acted as a cantilever supporting the door in the fully open position. 58 In order to lower the door from the fully open position it was necessary for a person to reach up and pull downwards on the outer (lower) edge with sufficient force to overcome the cantilever force of the struts. That human force was assisted by the downward (gravitational) force resulting from the mass (weight) of the door itself. During the closing process each rod receded into the cylinder and the piston compressed the gas within. 59 The maximum length of each strut (i.e. including the 'stroke' of the fully extended rod) was 525 mm, of which the stroke comprised 220 mm (exhibit 1.151). It follows that the length of the fully compressed strut was about 305 mm. 60 Based on Mr Simms' reports (exhibits 1.151, 153, 1.156 and 3), I find that the rod end of each strut was fixed 555 mm from the top of the door jamb and 435 mm from the bottom. The cylinder end was located 205 mm from the top edge of the door and 785 mm from the bottom. 61 Based on the evidence of Mr Price and Mr Apgar (exhibit 1.120), I find that the ends of each strut were connected to the jamb or door by a plastic fitting comprising a moving ball joint which clipped into a ball stud (or 'cup' or 'eyelet' as it was also described in the evidence). The ball stud was mounted onto the door jamb or the door. The stud was made of a relatively high-strength plastic which was still flexible enough to allow the ball fitting to snap into it. 62 Gas struts are rated to different levels of compression. The struts in this case were rated to 400 Newton (the equivalent of a loading of approximately 31 kg: Mr Simms at 58). 63 However, pneumatic gas struts function like a spring and as such exert increasing force as they are compressed (that is, the strength of the strut increases as the door closes). In the present case the struts were rated to 520 N when fully closed (Mr Simms 1.138). It follows that the strut is more effective in the sense that it provides more opening 'assistance', and more closing 'resistance' when it is partly open compared to when it is fully opened. 64 Mr Simms explained (58-59) that the technical expression which describes the application of force in a particular direction is a 'moment'. A closing moment is applied by gravity through the door to the hinges, whilst an opening moment is applied by each strut to the door. The opening or closing moment is augmented by any additional force in the relevant direction provided by another agency such as pulling or pushing by the operator or friction. 65 The force or moment also depends upon the speed and acceleration (if any) of the door, which creates momentum. So, a door which was free-falling through a certain height would create more force (a stronger closing moment) than a door which was free-falling through a lesser height, or not free-falling at all, that is, it was being pushed or held up (Mr Simms: 77). 66 When the opening moment is greater than the closing moment the door will tend to open until the struts are at full extension, and it will tend to close when the closing moment is greater than the opening moment. When the two moments are in equilibrium the door will be stationary. The significance is that the loss or weakening of a strut (by a loss of gas compression, for example) would diminish the opening moment and the door would tend to close of its own accord unless it was supported by an additional force (e.g. someone holding it up). 67 Mr Simms explained (58) that the force required to open a door is not constant and depends upon the extent to which it is open. He said that the force 'gets larger and larger and larger' the further it is opened and this would be perceived by the operator as the door becoming heavier in the absence of the pneumatic assist from the struts. 68 Mr Simms stated (exhibit 1.14) that, based on his calculations, in fully operational condition neither of the two struts was strong enough to hold the door fully open if the other failed. That evidence was not challenged, Mr Jardine (97) concurred with it, and I accept it. 69 Mr Apgar also referred in the same context to a phenomenon called hysteresis (127 - 129). He testified: The gas struts because of the friction which is necessary for the damping they provide has a significant amount of hysteresis so the force of lifting will be less than the force required to pull it down. … [If] we had more than double the lifting capacity, then the force might be significantly higher than the weight of the door. … … [If] you design it so it has an adequate holding force, that could in fact be less than the lifting force, so you're only getting lifting assistance. It's not doing all the work for you, so again there's a range of design criteria. If you made it so that it would lift the door all by itself then you require quite a lot of lifting capacity or gas strut capacity, but if you had it so that it was only assisting, so that you're only having a lift of [say] a few kilos of mass instead of 20, that's the other end of it, so there's a range of possibilities, but one of the things you have to deal with is the hysteresis which is the force in one direction will be less - if it's applied by the strut, will be less than the force required to make the strut retract. … … I've done quite a few lifting investigations, lifting 20 kilos is a major effort for most people. It would take a fairly fit man to lift that much, but pulling down 20 kilos, most people could do that. … [If] you had a 40-kilo lifting capacity, the door weighed 20, so half of that capacity is just holding the door up [and the balance is redundant], then you'd only have to apply 20 to bring it down, 20 plus the friction to bring it down … 70 Based on the above principles, I conclude that: (i) The differential between opening and closing moments will affect the ease with which a door will open or close. An excessive differential in favour of the opening moment may render the door unsafe to open (since it would tend to spring out forcefully when the latch was released) or difficult to close. Conversely, an excessive differential in favour of the closing moment would tend to make the door difficult (too heavy) to open. (ii) The door will come to rest when the opening and closing moments are in equilibrium which, in turn, will depend upon the extent to which the door is open and the prior momentum (if any) of the door and the direction of that momentum (closing or opening). (iii) Therefore, Mr Simms' calculation at [68] is not necessarily applicable to a situation when the door is only partly open, that is to say, there will be a point at which one fully operative strut may provide a sufficient opening moment to equalize the closing moment and cause the door to come to rest in a drooping position. Mr Simms accepted this proposition (72). 71 Mr Rocky Jardine is a highly experienced and qualified motor mechanic who was employed at all material times by Envirocoat as a leading hand foreman. Mr Brian Bondi has been a director of Envirocoat at all material times. He is a qualified boilermaker/welder with very extensive experience in the mining and construction industry. 72 They testified (89, 91, 98 and 103 – 104) that MacMahon's service truck was about the 100th built by Envirocoat. They selected the service bay door struts from a range of readily available proprietary brands using a combination of experience and trial and error, rather than an abstract design process. The process involved a trade-off between struts which, on the one hand, provided sufficient force (opening moment) to assist the operator to lift up the door and then automatically hold the door in the cantilever position whilst, on the other hand, still allowing the operator to pull it down again without difficulty. They also testified that to the best of their knowledge Envirocoat had never had any complaints or other service problems with the struts apart from this case. 73 I turn now to address the expert evidence in relation to the causes of the first and second failure phases. 74 Mr Simms hypothesized (exhibit 1.143) that the service bay door failed for two reasons. First, the 'root cause' was that both gas struts had lost compression due to gas leakages which caused the door to droop to a height where it became an annoyance to Mr Price. Mr Price must have forcefully lifted the door to improve access and in doing so 'pushed the end out of the plastic end fitting of the [right] gas strut allowing the strut to fall free'. Given that the remaining (left) strut had lost compression, it was unable to prevent the door falling and hitting the plaintiff. I shall refer to this as Mr Simms' failure hypothesis. 75 He said that under most conditions, gas loss usually occurs slowly, although environmental factors could have an accelerating effect. Eventually the problem will impact adversely on the lift of a strut (exhibit 1.141). So, in his opinion, the two struts had most likely operated at reduced compression 'for some time before the accident' (all emphasis is mine), that is, slow leaks begun 'some time before the accident' (1.143) and only become noticeable gradually. 76 Mr Simms also addressed (73) the hypothesis that an acute or radical gas leak happened a few days before the accident (i.e. after the truck was serviced on 3 April 2008): If it was known with certainty that the door was opening fully and positively at some point in time and a week later was drooping down, I would expect that either something had happened to cause rapid deterioration [of the strut] such as scratching of the rods so that the seals are not sealing properly anymore and the gas is escaping, the gas and the oil is escaping, I can't envisage any particular mechanical damage, other than a gross mechanical damage such as a strut breaking off, that would cause that. … Because the rod, as it goes into the barrel of the strut, the rod passes through a seal and it's a seal that keeps the gas and oil inside … [and] if the rod was to be scratched by whatever means, then the gas would tend to leak out and it would deteriorate, and it would deteriorate, and it would deteriorate in proportion to the magnitude of the scratch, so big scratch rapid deterioration, little type fine scratch there's probably very little deterioration. 77 He continued to say that mine-site dust would be capable of causing a scratch of this kind. 78 Mr Simms excluded the possibility that the right strut was already completely broken and providing no 'assist' before the night shift because, he believed, 'anybody opening the door would immediately know it [had failed] because it would become heavy to lift the door [without] that assist from the [missing] gas strut' (74). 79 Mr Apgar substantially concurred with Mr Simms' opinions, including his failure hypothesis (exhibit 1.123). In his oral evidence Mr Apgar also agreed that loss of compression due to gas loss is usually progressive and tends not to occur in a radical way. Accordingly, he believed it to be 'unlikely' that one of the strut cylinders could have leaked enough gas after 3 April to cause the door to start noticeably drooping (exhibit 1.37 – 1.38). 80 In his report he suggested that the most likely part of the connection to fail was the 'cup' or 'eyelet' (rather than the ball joint itself). On that basis he accepted the premise underlying Mr Price's failure hypothesis to the effect that the right strut could continue to function if a broken connection had been temporarily manipulated back into place before the door was opened (137, 140 and exhibit 1.119).
Analysis and findings in relation to causation 81 I turn now to make findings in relation to the causes of the first and second failure phases. 82 I begin with the first failure phase. 83 Based on the evidence of Mr Apgar (136), I accept that the normal working life of each strut would be in the order of three years, depending on the environment. Struts are sacrificial parts which are inexpensive to replace and are never repaired. It follows that it would be unusual for a new strut to noticeably lose compression within four months and/or do so without being replaced. 84 Given that there were no noticeable problems with either strut on 3 April 2008 and in the light of the expert evidence that a slow loss of compression would have become progressively noticeable over a lengthy period of time, and not over a mere week, I am satisfied that the probability of slow leaks being at fault is very low. 85 I am not much persuaded by the hypothesis that an acute or radical loss of compression occurred either. There is no evidence of any damage having been found on either strut apart from the ruptured connection on the right strut and no evidence of any oil leaks being found either. Nor was there any evidence of an event or agency (including accidental blunt force) which could have caused a serious scratch or lesion on an acute or radical basis, it being assumed (in the absence of evidence to the contrary) that the environmental conditions (including dust) were no worse at the Sinclair mine than at any other mine where struts have been used on vehicles supplied by Envirocoat. 86 Further, based on the evidence, I find that it is very improbable that both struts on the same door lost compression (for any reason and either slowly or acutely) simultaneously. 87 In conclusion, I am satisfied that a partial loss of compression due to gas leakage (whether unilateral or bilateral, chronic or acute) is improbable and some other form of structural failure must be considered. In other words, I do not accept that Mr Simms' failure hypothesis is likely, at least in respect of the first failure phase. 88 Having regard to Mr Simms' evidence at [78] above, which I accept, I find that it would have been very noticeable to Mr Price if the right strut was not working at all when he began to open the door, because of the substantial extra force that would have been required to lift it. He gave no evidence of having experienced that phenomenon. Further, if the strut had been pivoting or dangling from its connection to the door jamb (see [37] above), it is likely that it would have obstructed the door and prevented it from fully closing (as Mr Apgar testified: 140). To be precise, the available space from the point where the rod was connected to the jamb to the bottom of the service bay was 435 mm, but the fully extended strut measured 525 mm. Again, Mr Price gave no evidence to support a finding that the door was obstructed (ajar) when he went to open it (remembering that it was necessary to unlatch it first). 89 The remaining two hypotheses to explain the first failure phase are, first, that the right strut was totally intact and fully operational when Mr Price went to open the door, but he broke the strut connection in the process or, second, it was already broken and had been manipulated together by someone else and was still capable of providing some lifting assistance for at least part of the opening of the door (i.e. Mr Price's hypothesis). 90 Envirocoat contend that the former hypothesis is consistent with the fact that Mr Price was in a truculent mood, so truculent in fact that the plaintiff's first thought after being struck was that he had been assaulted by Mr Price and had to fight him. There is some merit in that submission. Mr Price's evidence that he was only 'a bit peeved' at the relevant time must be taken to be an understatement in light of the plaintiff's evidence. I accept that he was angry. Combined with the stress that he felt from his supervisor, I also accept that he would have had little patience with a service bay door that was getting in his way and, thus, could very well have lifted it out of the way in a peremptory fashion. But that falls a long way short of supporting a finding that he used such excessive or egregious force as to completely rupture a perfectly sound strut connection. More importantly, I am inclined to accept Mr Price's denial in evidence that he used excessive force and lifted the door in an essentially normal way. In my assessment he was a fundamentally honest witness. He testified in a straightforward, frank manner and readily-made concessions. 91 Mr Apgar said that the strut would provide resistance to someone forcing it in the opposite direction (142), but accepted that a connection could be ruptured if the strut was forcefully hyper-extended (138 – 139). Mr Simms concurred (exhibit 1.142). 92 Mr Bondi expressed the opinion that it was simply not possible to push the door to the point where the connection would break (102), but I do not accept that evidence which is contrary to the experts' opinions and, quite frankly, common sense. I am not inclined to accept that it was impossible for a person such as Mr Price to force the door upwards with sufficient force to rupture a sound connection. However, as will now be discussed, the hypothesis that he did so is not supported by the objective facts or science. 93 For one thing, there is no evidence that the left strut was damaged by being hyper-extended which, it seems to me, could well have happened if the right strut suffered that fate. 94 More importantly, this particular hypothesis predicates that Mr Price snapped the end connection of the strut by pushing the door at least as far as the fully open position (if not further). But, on that scenario, the door would not have stopped falling at the 'drooping' position after he released it. Based on Mr Simms' calculations ([68] above) which I have accepted, and remembering the momentum that would be generated, the closing moment of the door would have overwhelmed the opening moment of the left strut and the door would have substantially closed itself. 95 Therefore, I accept Mr Price's evidence and find that he did not forcefully open the door and did not, of himself, break the strut connection. 96 Assuming that the right strut was temporarily connected, it could have provided a temporary assist whilst the door was first being opened and ceased to do so before it reached the fully open position. This is Mr Price's hypothesis and it is supported by Mr Apgar's evidence. In my opinion that could have occurred without Mr Price becoming aware of it, because the door itself would have impeded his vision whilst the strut fell away and the darkness would have hindered his ability to notice the broken strut hanging from the door jamb. 97 Mr Price's hypothesis is also consistent with the science, namely it is possible for an equilibrium point to be achieved (especially whilst the door is being opened and the momentum is upwards) at which a single, fully operational strut (i.e. the left strut) could of itself hold the door partly open (i.e. drooping). 98 To return to Mr Simms' failure hypothesis, and with very great respect to he and Mr Apgar, it seems to me that the hypothesis that both struts must necessarily have been experiencing compression loss begs the question and overlooks the undisputed science, which allows of the possibility that a single, fully-operational strut could support a door in a partly open position. It all depends on how the door comes to be in that position and, in particular, whether the door had reached a height and achieved a downward momentum at which the closing moment would overcome the opening moment. 99 I have not overlooked the fact that Mr Price's hypothesis predicates that an earlier operator or operators ignored safe working practices and failed to report the fault in the right strut. Carelessness of that kind is not unheard of. 100 To sum up, the possible explanations for the first failure phase, and my assessment of them, are as follows: (i) A slow loss of compression due to a gas leak is extremely improbable, especially if such is said to have happened to both struts. (ii) An acute or radical decompression of one or both struts due to agencies such as blunt force or misuse is feasible and cannot be ruled out, but such must have occurred between 3 and 9 April and there was a lack of corroborative evidence to support that it occurred. (iii) The rupture of the right strut connection by Mr Price when he was initially opening the door is improbable because the hypothesis predicates that he used excessive force, which he denied, and it is inconsistent with the fact that the door did not close (droop) more than it did. (iv) The hypothesis that the right strut connection was already broken before Mr Price opened the door is supported by the facts and the science, and the only issue is whether it was dangling from the door jamb or had been temporarily re-fitted (Mr Price's hypothesis). In my view, the issue is academic since MacMahon's culpability would be the same, but I find that Mr Price's hypothesis is the more consistent with the facts and the science and I accept it as being the most probable of all the hypotheses. I find that the collapse occurred because the connection on the cylinder end of the strut was already damaged and the strut fell away from the door at or about the height at which the door reached the 'drooping' height. At that stage it ceased to provide an 'assist' to Mr Price and it is entirely feasible that he misinterpreted the sensations of the extra 'weight' (see [67] above) and of the door reaching equilibrium (the opening and closing moments equalising) as the door reaching the fully open position. 101 I therefore find that the cause of the first failure phase was the collapse of the already – damaged right strut whilst Mr Price was in the process of opening the door. 102 It is not possible to make a finding as to how the strut was damaged in the first place. Blunt force or repeated, excessively forceful openings (excessive wear and tear) suggest themselves. Mr Simms suggested that the latter was 'very likely' in his first report (exhibit 1.142). But two comments must be made about excessive wear and tear. First, Envirocoat could hardly be liable unless such excessive wear and tear was reasonably foreseeable and I am not satisfied that it was. On the contrary, there is no evidence to suggest that was any such general practice at the Sinclair mine, or any mine for that matter. If anything, the evidence was that the doors were abused by being left open, but there is no evidence that that compromised the strength of the struts. Second, even if excessive wear and tear had happened it is unlikely that the actual catastrophic rupture would have occurred when Mr Price initially opened the door, for reasons which I have explained. 103 The second failure phase could only have occurred if the closing moment of the door increased sufficiently to overcome the opening moment of the left strut. According to the science and Mr Simms' calculation ([68] above) that would have occurred when Mr Price lifted the door above his head and then released it, leaving gravity and the momentum of the door to take over. 104 On my findings it is irrelevant how much force Mr Price used during the second failure phase because the result was pre-ordained by the laws of physics as soon as he released the door (removed his own support) from above head height. 105 I am unable to make a finding as to how quickly the door closed, because the left strut would still have provided some resistance to the falling door, but it is irrelevant.
Liability - legal principles 106 I turn now to summarise the legal principles. 107 Section 5B of the Civil Liability Act 2002 (the CLA) applies to the plaintiff's and MacMahon's tortious claims. It provides as follows: 5B. General Principles (1) A person is not liable for harm caused by that person's fault in failing to take precautions against a risk of harm unless – (a) The risk was foreseeable (that is, it is a risk of which the person knew or ought to have known); (b) The risk was not insignificant; and (c) In the circumstances, a reasonable person in the person's position would have taken those precautions. (2) In determining whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (amongst other relevant things) – (a) The probability that the harm would occur if care were not taken; (b) The likely seriousness of the harm; (c) The burden of taking precautions to avoid the risk of harm; (d) The social utility of the activity that creates the risk of harm. 108 The CLA does not codify or wholly supplant the law of negligence and one must give consideration to common law principles (Department of Housing and Works v Smith [No 2] [2010] WASCA 25 per Buss JA [77] – [83]). 109 MacMahon owed the plaintiff a duty of care which was analogous to that owed by an employer (TNT Australia Pty Ltd v Christie [2003] NSWCA 47). As such, MacMahon owed a duty to, amongst other things, provide and enforce a safe system of work and provide and maintain safe equipment. 110 As for Envirocoat, a manufacturer owes a duty of care to consumers and users of its product (Dovuro Pty Ltd v Wilkins [2003] HCA 51; 215 CLR 317). The duty is to exercise reasonable care to prevent the product from causing foreseeable harm to the consumer. This is not an absolute duty (Fitzpatrick v Job t/as Jobs Engineering [2007] WASCA 63; Aust Torts Reports 81-891) and its content should not be overly informed by hindsight (Dovuro [34], McHugh J). 111 So far as the contractual warranties are concerned, Envirocoat warranted that the equipment on the service truck would be 'of the best quality (and of merchantable quality)' consistent with the service provided and 'free of defects' and would be suitable for use at the Sinclair mine. 112 Mr Hammond did not submit that these warranties imposed any strict or absolute liability on Envirocoat. In my opinion, the emphasized words qualify the word 'best'. That is to say, on the true construction of the provision Envirocoat was not required to provide the best available equipment. Rather, the quality of the equipment was to be determined by its intended purpose which, in this case, was (relevantly) providing opening assistance and cantilever support for a 25 kg door/awning. 113 Mr Hammond submitted, and I accept, that a product may be unfit for its purpose if it has a defect which unacceptably increases the likelihood of its failure even if it appears to be functioning appropriately (Courtney v Medtel Pty Ltd [2003] FCA 36; Black Pool Rock Co Pty Ltd & Blue Waters Pty Ltd t/as O'Connor Pattern Makers v By Design Group Pty Ltd t/as BDG Machine Tools [2006] WADC 138). 114 Based on my findings, fault for the first failure phase lies with one or more previous operators of the service truck for whom MacMahon is vicariously liable. That person or persons manipulated a temporary and unsafe solution for the broken right strut (the cause of which can never be known) and failed to report the matter. Workers such as Mr Price and the plaintiff were placed at risk. I am also satisfied that MacMahon was itself directly negligent for failing to properly train and accredit Mr Price on the use of the service truck and for failing to supervise him and the other culpable employee(s), and for its failure to enforce a proper system of work for Mr Price and the plaintiff. On the relevant shift Mr Price had no knowledge of how to operate the equipment in the service module (he resorted to 'guesswork'). So, the task he was supposed to be performing took excessive time, was frustrating and in due course the plaintiff was unnecessarily placed at risk. Further, self-evidently, neither Mr Price or the plaintiff was even aware that there was something wrong with the service bay door until too late. The risk inherent in the fault could, and should, have been easily removed by replacing the damaged strut. In the meantime, and it if was vitally essential for the truck to be used, the operator could have been warned of the danger and furnished with a stout pole 6 foot 8 inches in length and obliged to use it. 115 I turn now to consider MacMahon's allegations of negligence and/or breach of contract against Envirocoat. 116 MacMahon relies on causes of action based in tort (product liability and under the LR Act), breach of contract and a contractual indemnity. However, MacMahon accepts that on the true construction of the contractual provisions, the damages to which they are entitled for breach of contract are commensurate with the amount to which it is entitled by way of contribution in tort and, further, its entitlement to a contractual indemnity is conditioned (ie reduced) commensurately with their (MacMahon's) contribution to the loss. In other words, irrespective of the cause of action, MacMahon's monetary remedy is limited to the extent to which it is entitled to contribution in tort. 117 MacMahon's case is based on the premise that that the struts were not suitable for the conditions in which they were used. In other words, it is contended that Envirocoat ought to have supplied struts which could resist, or better function in, the environment in which the service truck operated having regard, if necessary, to the foreseeability of the treatment which they received at the hands of MacMahon's employees. 118 The evidence canvassed four options by which it was suggested that the risk could have been practically reduced. First, by the use of strut connections made of metal instead of plastic. Second, by the installation of a drop down mechanism (i.e. PVC piping as shown in exhibit 1.31) that would lock the strut in place when the door was raised (necessitating manual removal by the operator). Third, by the use of folding metal hinges rather than gas struts. Fourth, by the use of stronger gas struts (i.e. with greater compression) so that either strut could wholly support the door if the other failed (i.e. built-in redundancy). 119 MacMahon also submits by way of over-arching contention that the 'trial and error' design system which Envirocoat employed was inadequate and that they should have sought and implemented professional design input from a mechanical engineer or similarly qualified person. 120 Mr Simms testified (64) that he would not have used plastic strut connections in a hot environment such as the Sinclair mine because plastic is known to deteriorate as a function of heat, but he acknowledged that this was only said in hindsight (exhibit 1.140). He recognized that premature failure would only occur if someone 'tried to forcefully over-extend the rod' (exhibit 1.141). He said that there was a range of metal-ended struts that could have been used at negligible extra cost. He also testified (ts 69) that he would have built in redundancy. 121 Mr Apgar agreed that the four options would be efficacious. It was he who suggested the third option (metal hinges). That system is similar to that which is used on portable bridge and picnic tables. He testified that the advantage lies in the fact that folding metal hinges provide a rigid, unbending cantilever which can only be broken when the operator loosens the hinge. However, he accepted that metal hinges are old-fashioned technology. He said (125) that gas struts had 'pretty well taken over' because they were compact and provided 'additional lift' (i.e. additional to the manual force provided by the operator). 122 Whilst he accepted that metal strut connections would be desirable, he did not fully share Mr Simms' view that they were always preferable in a hot environment. He testified (ts 126) that there are plastics available which are known to be better suited to such conditions than metal. Mr Simms tended to speak of plastic in general terms when obviously not all plastics are the same. I did not find his evidence about the first option to be persuasive. 123 Mr Bondi and Mr Jardine both testified that Envirocoat now uses metal strut connections and that the cost differential compared to plastic connections is negligible, but did not accept that this connoted acceptance that plastic was unsuitable. 124 I return now to discuss the four options and make findings about them. 125 Based on the evidence I accept that metal can be at least as strong as plastic as the raw material for a strut connection. However, without evidence of what caused the initial rupture of the connection in this instance, and without any evidence of the properties of the connection or the rest of the strut, it is difficult to make a finding that a strut with a metal connection would have fared any better or, for that matter, that some other component of the strut such as the cylinder seal or piston would not have failed, and with a similar outcome (namely the first failure phase). As a matter of common sense, I proceed on the basis that a load-bearing component such as a strut may simply fail at the point of least resistance if subjected to excessive force, especially by hyper-extension. Mr Simms pointed this out in his first report (exhibit 1.143 at (iii)). At best, metal connections may have reduced the risk which led to the first failure phase. 126 I do find that the use of metal connections was reasonably practicable and also accorded with contemporary standards and, of course, Envirocoat is now using them, but that does not prove that the plastic used in this case was inadequate in terms of the reasonably foreseeable forces to which it could be exposed. I am concerned that all of the evidence about the preferability of metal connections was imbued with hindsight and given in a vacuum about the structural strength of the strut as a whole. In my opinion MacMahon has failed to prove that the plastic connections were unfit for their intended purpose. 127 I am also satisfied that the provision of a drop-down locking mechanism was reasonably practicable and efficacious. MacMahon's own operating procedures called for it (exhibit 1.35) and such has since been implemented. However, there is no evidence to suggest that the use of locking mechanisms is industry standard. One can understand why. The deterioration of a gas strut (either by radical or chronic means) is something which becomes obvious and is easily rectified by routine maintenance, or ought to be so. In my opinion the use of a drop-down locking mechanism is merely an optional, additional safe-guard, the use of which is dependent on the preferences of the individual user. It was also capable of being specified by MacMahon for inclusion in the service truck by Envirocoat or retro-fitted, but they did neither until after the accident. 128 I am not satisfied that the third alternative (folding metal hinges) would be reasonably practical in the circumstances of this matter because the hinges would not provide any pneumatic assist for either opening or closing the door, and the operator would be exposed to the full weight of the door after manipulating the hinges. So, it would still be necessary to have some form of pneumatic assistance. In other words, for all practical purposes the third alternative would need to include redundancy, unless some form of lightweight material other than steel was used for the door panelling. Either way, the third alternative introduces technical design and practical issues which were not explored in the evidence and I am unpersuaded that it is practical. 129 The fourth option (redundancy) is superficially attractive. But there is no evidence as to the specification of the struts and as to how the same would be configured, or that such would be acceptable to McMahon. Based on the evidence, I accept that in normal operating conditions the extra force required to render each strut independently capable of preventing a catastrophic collapse of the door would have significantly increased the force required to shut the door and would have significantly increased the risk of the door forcefully opening, and striking the operator (Mr Jardine, 98). The door had to be capable of comfortable and safe use by operators of varying statures and strength. 130 I accept the evidence of Mr Jardine (91) and Mr Bondi (103) that the struts in this case were chosen after a process of trial and error. I further accept that such was appropriate under the circumstances, noting that neither Mr Simms or Mr Apgar had any difficulty with it. Mr Simms said that in-service experience and product development is appropriate and just as effective as professional and technical design in many instances (ts 140),with which Mr Apgar 'totally' agreed. He said (ts 130) that 'an experienced person – experienced for the product … is almost always superior to any data sheet'. Allowing for a degree of hyperbole in that statement, I accept that it is applicable to the present matter in which the design and specification of the doors did not call for esoteric technical knowledge. 131 I am not persuaded that Envirocoat should have provided for greater redundancy. 132 Against that background, I turn to consider the allegation that Envirocoat failed to provide equipment of best and merchantable quality, consistent with the service required and free of defects, and suitable for operation on a mine site (statement of claim pars 11(a) and (b), 12(a), (b) and (c)). Neither Mr Simms or Mr Apgar identified any actual fault with the type of strut chosen by Envirocoat and they accepted that the design was consistent with many other proprietory brands which were available and widely used throughout the relevant industry. There was no expert evidence given as to the force required to break the struts or any strut of any kind. Further, there was no evidence of the analysis of the plastic that was used in the struts. Mr Simms acquired and examined a similar one from a supplier, but it was not subjected to any form of destructive or other scientific testing. 133 It is common ground that the struts were fully operational when the truck left Envirocoat's possession and I have further found that such remained the case until 3 April 2008. There is simply no evidence to suggest that there was anything wrong with the right strut until it was found to be damaged at some point between 3 and 9 April 2008, and Envirocoat did not warrant that such could not or would not occur. Mr Jarman submitted that no adverse finding could be made in the absence of any evidence which could prove what happened to the strut in the 6 days leading up to the accident (i.e. as to the cause of the strut connection failing) and pointed out that no evidence was adduced of any latent defect. There is much to be said for these contentions and I accept them. 134 In his submissions Mr Hammond endeavoured to place weight on a passage in Mr Simms' first report (exhibit 1.143) in which Mr Hammond contended that Mr Simms had said that the gas struts in this instance were of inadequate quality and durability and that it would have been preferable if Envirocoat had used metal struts of known origin for which technical data sheets were available. But Mr Simms qualified that interpretation in a later report in which he said (exhibit 1.183): In my conclusion I did not actually conclude that the gas struts used were of inadequate quality or durability, but rather I formed the view that their quality and durability were unknown and since the supplier was unable to provide me with technical data, this raised concerns as to their provenance and quality. I therefore formed the view that it would have been preferable to use struts of known origin and for which technical data was available. 135 So, he was being critical of the selection process, not the struts themselves. 136 It is known that MacMahon's employees would drive the service truck around the mine site with the service bay doors open which, according to the experts, is not ideal practice. I cannot find that the service bay door in this matter was damaged because of that practice, but it does illustrate the ever-present risk of mishandling by the operatives. I am satisfied that Envirocoat knew or ought to have known (through Mr Bondi and possibly Mr Jardine) of that sort of risk, including even occasional excessive force, and needed to allow for it in the design and specification of the service bay doors. But, they were also entitled to take into account the fact that any defect in the operation of the doors consequent on any damage would be readily discernible and able to be corrected. 137 For completeness, I am not satisfied that Envirocoat was required to provide for 'repeated forceful openings' (to use Mr Simms' phrase). 138 For these reasons I reject the allegations (statement of claim par 11(a), 11(b), 12(a), 12(b) and 12 (c)) that Envirocoat failed to ensure that the struts were of best and merchantable quality, consistent with the service required and free of defects and of suitable quality for the purpose of operation on a mine site. 139 McMahon also contends (statement of claim par 11(c)) that Envirocoat was negligent in that it allowed or permitted MacMahon to use the service truck when it knew or ought to have known that it was unsafe to do so. Mr Jarman submitted that there is no evidence that Envirocoat had any such knowledge or means of obtaining such knowledge. I accept that contention. All the evidence suggests that until the plaintiff's accident Envirocoat had received no complaints, had no problems and had every reason to believe that the struts in question were reliable in all foreseeable conditions and would, if required, be replaced before they became unsafe. 140 Mr Hammond correctly argued that the test of foreseeability and breach is not whether 99 trucks out of 100 had no problems, nor is it that Envirocoat had received no complaints. The test is whether an identified risk of injury was neither far-fetched nor fanciful (Wyong Shire Council v Shirt (1980) 146 CLR 41). But it remains to identify the risk. I accept on the expert evidence (see Mr Simms at 1.142 for example) that there is always a risk that a plastic strut connection will rupture due to excessive force or wear and tear – it all depends on the regularity, nature and amount of force or wear and tear. But, the fact is that until April 2008 no usage or treatment of Envirocoat's door struts had been known to cause risk of physical harm or given grounds for concern of any kind. In short, Envirocoat's experience is relevant. 141 For these reasons, I am satisfied that MacMahon has failed to make out any of its allegations of negligence or breach of warranty. In particular, I am not satisfied that Envirocoat failed to exercise reasonable care in the design and construction of the service bay doors. Similarly, I am not satisfied that MacMahon has established that the service bay doors (or their constituent parts) were not of 'best quality (and of merchantable quality)' and free of defects or that the equipment was not suitable for its intended purpose. 142 It follows that MacMahon is not entitled to an indemnity from Envirocoat. 143 It further follows that Envirocoat is not liable to the plaintiff. 144 In the event that I am wrong in making these findings, I turn to consider whether any negligence or breach of warranty on Envirocoat's part was a cause of the plaintiff's accident. At its highest from MacMahon's point of view, Envirocoat could only be liable for a latent defect in the strut connections. 145 The relevant principles in terms of tortious responsibility (which is the ultimate question in this matter) are referred to in s 5C of the CLA which provides as follows: 5C. General principles (1) A determination that the fault of a person (the tortfeasor) caused particular harm comprises the following elements – (2) In determining in an appropriate case, in accordance with established principles, whether a fault that cannot be established as a necessary condition of the occurrence of harm should be taken to establish factual causation, the court is to consider (amongst other relevant things) – (3) If it is relevant to the determination of factual causation to determine what the person who suffered harm (the injured person) would have done if the tortfeasor had not been a fault – (4) For the purpose of determining the scope of liability, the court is to consider (amongst other relevant things) whether and why responsibility for the harm should, or should not, be imposed on the tortfeasor. 146 The factual causation test is a statutory statement of the 'but for' test of causation (Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; (2009) 239 CLR 420 [55], per the Court). The breach of duty need not be the only cause. 147 In so far as contribution under s 7(1)(c) of the LR Act is concerned, the following principles were enunciated by the High Court in Podrebersek v Australian Iron and Steel Pty Ltd (1985) 59 ALR 529, 532 – 533 (emphasis added): The making of an apportionment as between a plaintiff and a defendant of their respective shares and the responsibility for the damage involves a comparison both of culpability, i.e. of the degree of departure from the standard of care of the reasonable man … and of the relative importance of the acts of the parties in causing the damage … it is the whole conduct of each negligent party in relation to the circumstances of the accident which must be subjected to comparative examination. The significance of the various elements involved in such an examination will vary from case to case; for example, the circumstances of some cases may be such that a comparison of the relative importance of the acts of the parties in causing the parties will be of little, if any, importance. 148 The original cause of the first failure phase is not known and cannot be inferred, but the fault for the failure to take remedial action until after the second failure phase lies entirely with MacMahon or persons for whom MacMahon is vicariously liable. There was an obvious patent danger that should have been swiftly and totally ameliorated and was of the very kind that MacMahon and any other mining contractor should readily deal with. Indeed, it was MacMahon's contractual duty to do so. 149 In my opinion, even if a case could be made for liability against Envirocoat in respect of a latent failure in the connections, or for the provision of unsuitable connections, the fault became patent in good time to be appropriately dealt with. 150 In my view, any culpability that could attach to Envirocoat over such a matter is, in all the circumstances, of such minimal importance as to be ignored under relevant principles of tortious and contractual causation, and should also be rejected in the exercise of the court's discretion under s 7(1)(c) of the LR Act. 151 In my opinion all of the blame for the plaintiff's accident should in accordance with the relevant principles be attributed to MacMahon.
Conclusion 152 For these reasons I determine that: |