Consideration
139 In the present case, the primary judge considered the issue of lack of novelty at [47]-[161] of the Reasons. Although the focus of Sandvik's challenge is to the primary judge's finding that the Colrok drilling system used right-hand rope thread (dealt with specifically at [109]-[124]), it is necessary to consider the treatment of that aspect in the context of the primary judge's consideration of the lack of novelty issue as a whole. This is because the other parts of this section of the Reasons contain relevant findings and observations regarding the evidence of the witnesses.
140 The following is an outline of the way in which the primary judge approached the factual issues concerning the Colrok drilling system:
(a) The primary judge introduced the evidence of Mr Geatches at [48]-[55]. At [56], the primary judge described that, in the mid-1980s, Colrok began installing cable bolts. At [57], the primary judge said that Messrs Geatches and Webb decided that using a (non-percussive) rotary drive head was more likely to be successful in the particular mining environment they were facing. The primary judge went on to state that:
To increase the speed of uncoupling the drill rods, Mr Geatches thought to use rope-threaded connections. He tried to source suitable drill rods with right-hand rope threads, but without success. In his evidence-in-chief, Mr Geatches said that he did find drill rods with right hand rope thread (male at both ends) available, but they were 19 mm or 20 mm only across the flats, and thus too small for driving the big rotary drill bits that were to be used for the installation of the cable bolts at Stockton. It was put to him in cross-examination that he was mistaken in his recollection that he had found these drill rods, a subject to which I shall return.
(b) The primary judge stated, at [58], that:
In the result, Messrs Geatches and Webb, and Brian Woolnough, a mining engineer at Colrok, decided to make their own set of male/female right-hand rope-threaded drill rods with a diameter of 25 mm. Mr Geatches sourced Q7 steel from Roy Gambly (now deceased) at Awaba Road in Toronto. Mr Gambly was, according to Mr Geatches, "a fine precision machinist" who did a lot of machining for Colrok. He made the ends for the new drill rods: an end with a male right-hand rope thread, and an end having a hexagonal outer profile (32 mm across the flats) with an internal female right-hand rope thread. They were made to specifications provided by Mr Geatches, although it became clear, under cross-examination, that he could not recall the actual form of the instructions which he gave to Mr Gambly. That is a subject to which I shall return in due course below. Mr Gambly made about ten sets of the drill rod ends in that first batch. Then, in Colrok's own workshop, Murray Pearson, a leading hand fitter employed by Colrok, inserted the spigots for the ends into a section of drill pipe and welded around both ends to make the drill rods.
(c) The primary judge stated (at [59]) that, in operation, the female end of a drill rod was inserted (and here he quoted from Mr Geatches' affidavit) "directly into the drive chuck (which was in effect an adaptor) on the drill rig, which had a hexagonal shaped socket." His Honour stated that:
The chuck drove the rod by engaging with the hexagonal external surface of the female end of the drill rod. The new drill rods proved very successful. Being easy to extend and to uncouple, their use led to an increase in the speed at which rods could be inserted into and removed from a drill string. In part, this was because there was no longer the need to uncouple (ie by unscrewing) the lowermost rod from a male shank adapter when building or [disassembling] the drill string. These were the rods that Mr Geatches and his colleagues described as "speed rods". In Mr Geatches' recollection, it was in the mid to late 1980s that Colrok reached this point.
(d) At [61], the primary judge stated that Colrok used these rods in the late 1980s at Ellalong Colliery to drill the holes required to install cable bolts for the establishment of secondary roof support in restitution work after a roof collapse on a conveyor road. His Honour set out an extract from Mr Geatches' second affidavit which identified, step by step, the process of assembling and disassembling a drill rod string using the method that had been developed. This description included a reference to right-hand rope thread in step 1:
Step 1 A drill bit was connected to the male end of the first (top) Geatches Rod in the drill string. This was done via a drill bit adaptor. The adaptor had a female right hand rope threaded end that coupled with the right hand rope thread at the male end of the Geatches Rod. The drill bit was connected to the drill bit adaptor.
(e) Having set out Mr Geatches' evidence, the primary judge referred, at [64], to Sandvik's submission that Mr Geatches' evidence, to the extent that it related to the development and use of the rods described above, should not be accepted at all. The primary judge noted the following points made by Sandvik:
They point out, correctly, that that evidence was not supported by the production of any of the chucks or drill rods used, of any contemporaneous drawings or sketches of the rods, of the specifications provided to Mr Gambly, of any photographs of the components that Mr Gambly supplied to Colrok, of any drawings, sketches or photographs of the rods that Colrok assembled from those components, or of any drawings, sketches or photographs of the components actually used at Ellalong.
(f) The primary judge stated the following by way of response to those submissions (at [64]):
In a number of respects, the applicants' use of the word "any" in these criticisms reflects the fact that it has not been established that there ever were artefacts of the kind mentioned. It was not suggested on behalf of the applicants that either Mr Geatches or the respondent had selectively opted to withhold from the eye of the court objects, photographs or drawings which might have been led in evidence. Elsewhere in his evidence, Mr Geatches made it clear that he did not regard his rods as inventive (unlike another, in some respects similar, item which he devised, and for which he applied for a patent), and he had, I would hold, no reason, before he retired from Colrok in 1994, to anticipate that a record of their development or use might later be useful in litigation. I regard the absence of the things referred to by the applicants from the evidentiary record as relevantly neutral in its impact on the task in which the court is engaged: the fact is that there is no such evidence, but that fact should not introduce an additional element of unreliability into the evidence which was led.
(g) The primary judge then considered, at [65]-[75], what were said by Sandvik to be five "errors" in Mr Geatches' evidence. These "errors" are repeated in Sandvik's written submissions on appeal referred to in 131 above (the second and third "errors" in the submissions at trial having been combined into the second "error" in the appeal submissions). The primary judge rejected each of the alleged errors for the reasons given in this section of the Reasons. In a number of cases, the point was made that Sandvik had not cross-examined Mr Geatches upon the particular area of inconsistency which it subsequently sought to raise by way of criticism of his evidence (see, eg, [66], [71], [74]). The primary judge summarised his conclusions in relation to the five alleged errors at [75]:
For the reasons I have given, I do not accept that Mr Geatches' evidence should be regarded as likely to be the less reliable on account of what the applicants referred to as "errors" made by him. To the extent that the matters canvassed above might be viewed as errors - and for the most part they were not - I consider that they were either irrelevant, or at most tangential, to any assessment of the reliability of his evidence. I am also bound to add that, in a number of respects to which I have drawn attention, the applicants appear here to be taking advantage of dimensions of Mr Geatches' evidence that were not, it seems, considered, at the time, to be of sufficient importance to warrant a direct challenge while he was under cross-examination.
(h) The primary judge then turned to consider the evidence of two other witnesses - Messrs Yates and Nielsen - whose evidence supported that of Mr Geatches.
(i) Mr Yates' evidence was considered at [77]-[87]. As recorded at [81], he gave evidence that the extension drill rods being used at Ellalong Colliery by Colrok in 1990 featured a male rope-threaded end and a hexagonal-shaped female end. The primary judge then set out an extract from Mr Yates' affidavit detailing the drilling process he had observed. At [82], the primary judge noted that it was submitted on behalf of Sandvik that Mr Yates' affidavit evidence, which supported that of Mr Geatches, should not be accepted. At [83], the primary judge noted Sandvik's submission that Mr Yates' evidence was based "purely on recollection of events occurring some 25 years in the past". The primary judge observed, in relation to that submission:
That is true so far as it goes, but the question remains whether the recollection, when held up to the light and placed in the context of other evidence available to the court, is seen to be reliable. The fact that 25 years have passed is relevant to, but by no means determinative of, the answer to that question.
(j) The primary judge then considered a number of other submissions regarding the reliability of Mr Yates' evidence (at [84]-[87]). One particular issue concerned (what his Honour described as) a "stumble" in the course of Mr Yates' evidence during cross-examination. The point was clarified during re-examination (which his Honour permitted over objection). There was also further cross-examination, which his Honour permitted, following re-examination. His Honour stated that he "was left with a firm satisfaction that the evidence set out in [Mr Yates'] affidavit fairly reflected his own recollection of the drilling method which he observed at Ellalong" (at [87]).
(k) Next, his Honour considered the evidence of Mr Nielsen (at [88]-[93]). In addition to giving evidence that the Colrok drilling system featured a hexagonal drive chuck, Mr Nielsen gave evidence that the thread which he saw on the rods at Ellalong Colliery was a rope thread (at [91]). Also, the drawing which formed part of his evidence (set out at [92] of the Reasons) identified the thread as "rope thread". The primary judge summed up Sandvik's submissions, and his conclusions, on Mr Nielsen's evidence at [93]:
In submissions made on its behalf, the applicants were unable to go further than to point to some possible explanations for Mr Nielsen having been mistaken about what he saw at Ellalong. They referred to the passage of time since the events in question, to the fact that he was not directly involved in drilling and did not physically handle or closely inspect the rods and chuck which he saw, to the dim lighting conditions in the mine, and to his imperfect recollection of the outside profile of the chuck. It was suggested that Mr Nielsen might in fact have seen a chuck into which an adaptor was to be inserted, but failed, in the dimly lit conditions, to notice any adaptor nearby. But Mr Nielsen's credibility, and the reliability of his recollection, were not undermined by indirect considerations of these kinds. I was left with the firm impression that he had a clear recollection of what he had seen at Ellalong, as stated in chief and as generally depicted in his drawing reproduced above.
(l) The primary judge then turned to consider Sandvik's submissions regarding the nature of the drilling system utilised by Colrok. At [95]-[99], the primary judge considered Sandvik's submissions based on the photograph reproduced at [95] of the Reasons. At the conclusion of this discussion, the primary judge stated (at [99]) that "[t]aken overall, Mr Yates' evidence is strongly consistent with that of Mr Geatches".
(m) The primary judge then considered submissions made by Sandvik regarding water sealing (at [100]-[108]). The issue here was a factual one, namely whether Colrok was likely to have used the system described by Mr Geatches when, according to Sandvik, it would not have been viable in practice due to the lack of an adequate water sealing system. It was in this context that his Honour considered the evidence of Mr Weaver in some detail, as noted above. Ultimately, in relation to this issue, the primary judge concluded at [108]:
The result of my consideration of all of this evidence is that, if otherwise Mr Geatches' evidence about the system used at Ellalong is to be accepted, it was not undermined by the proposition that that system would not have worked because of the leaking of water at the point of engagement between the chuck and the lowermost rod. He explained the sealing arrangement which he used, and there was a sufficient, credible, engineering response to the applicants' contention that that arrangement would not have worked. The practical viability of a similar arrangement may not have been Mr Weaver's experience, but the fact that his arrangement did not work does not persuade me that Mr Geatches' arrangement could not have worked, or most likely did not work.
(n) The primary judge then came to the issue concerning whether the Colrok drilling system used right-hand rope-threaded connections, which is the focus of Sandvik's submissions on appeal. This issue was addressed at [109]-[124] of the Reasons. We consider this section of the Reasons in more detail below.
(o) The primary judge concluded at [125] that he accepted Mr Geatches' evidence about the extension drilling system which Colrok used at Ellalong Colliery, stating that, subject to the matters referred to earlier in the Reasons, "there was nothing in his evidence, or in the way that he dealt with the questions put to him under cross-examination, that would provide any basis to doubt the reliability of his recollection".
(p) The primary judge considered Sandvik's submission that, in circumstances where Quarry Mining had not called Mr Woolnough (a foreshadowed witness who had prepared an affidavit which had been filed) and had not provided an explanation for its failure to call him, prior public use had not been strictly proven (at [126]-[128]). The primary judge stated that Sandvik's point was well made, and that Quarry Mining's unexplained failure to call Mr Woolnough had given him substantial cause to pause. The primary judge then stated at [128]:
However, having paused, I find that the situation remains that I have the direct observation of three then workers in the industry whose evidence is credible. The court is not required to act upon inference, and in that sense the respondent's allegation has been strictly proved. By limiting its evidentiary case in the way that it did, the respondent ran the risk that, for one reason or another, that case might not have crossed the bar. But the view I take is that it did cross the bar, and I would not be justified in turning away from that view by reason of what was, apparently, the respondent's choice not to conduct a more comprehensive evidentiary case. In short, I would hold that the belt was sufficient for the respondent's purposes. It did not also need the braces.
(q) The primary judge also concluded that the same drilling system was used at Macquarie Colliery (at [129]).
141 We now focus on the section of the Reasons ([109]-[124]) which specifically addressed whether Quarry Mining had established that right-hand rope thread was used in the Colrok drilling system. The primary judge explained the way the issue arose at [109]:
It is, [the applicants] say, quite unlikely that Colrok's system involved the use of rope-threaded connections between the rods. It is the respondent's case that rods with such connections were not commercially available in right-hand configuration, and that Mr Geatches had to have the ends for his "speed rods" specially made by Mr Gambly. For the purposes of this argument, the applicants accept that case. But they say that, with the technology which he had available to him in his workshop at the time, it is most improbable that Mr Gambly was able to build rope threads. It is more likely that he built ends with another coarse, wave-like, thread, such as what was described as the "T-thread", but which was not a rope thread as such and which, therefore, would not have come within the terms of Claim 1. Indeed, it was the T-thread which counsel for the applicants put to Mr Geatches had most likely been the thread used by Mr Gambly.
142 The primary judge referred in some detail to the evidence of Mr Clair at [110]-[115]. This included the following description of what rope thread is, and the ways of making it:
110 In para 67 above, I have referred to Mr Clair from Nupress Tools. It is now necessary to refer to his evidence about rope threads, and to do so in some detail. He said that a rope thread was a broad thread which got its name because (in the case of an external thread) it looked somewhat like a piece of rope loosely wound around the shaft. Rope threads had a particular configuration which was set by an international standard. They were unlike other conventional threads commonly seen in everyday components in that they were curved in all three dimensions. Also, a rope thread had a very large cross section width (or pitch) at 12.7 mm. As far as Mr Clair was aware, rope threads were used solely in the mining industry.
111 Mr Clair said that the machining of rope threads was a very specialised skill, one that was known (even when he made his affidavit in May 2015) to only a few in Australia. He named only five business[es] in Australia, including his own and those of the parties in this case, who had ever made rope-threaded components. He said that there were three ways to make such components: on a manual lathe, on an off-centre copy lathe and on a computer numerical control ("CNC") lathe (the latter of which, it became clear under cross-examination, was to be understood as including also a numerical control (or "NC") lathe). He explained that lathes worked by rotating the component being machined at speed and applying a cutting tool to the surface of the component to cut away metal from it. The cutting tool is moved both along the axis of rotation and perpendicular to that axis to cut the required profile. Cutting tools took one of two forms: a form tool (a tool that had the form or shape of the thread to be cut), and a single point tool (a tool with a sharp point or tip which did the cutting).
143 The primary judge then outlined Mr Clair's evidence regarding the machining of an internal female rope thread of the relevant size (being 25 mm in diameter: see the Reasons at [58]). We set out the relevant passage in full, given the centrality of this aspect of the evidence to Sandvik's arguments on appeal:
112 Mr Clair said that, in the case of a threaded component, there would be matching male and female components. The machining of an external rope thread was reasonably straightforward as it could be done with a form tool. No specific machine was required for that, only a precision ground form tool. The machining of an internal thread was, however, more difficult because the cutting tool would be working inside a narrow space. In this situation, the cutting tool needed to extend longitudinally into the bore of the component, and then press laterally into the wall of the bore to cut the thread. The diameter of the bore limited the thickness of the tool. Also, the pressure applied to the cutting tool to machine the thread was high, such that the cutting tool would tend to bend as it was pressed against the wall of the bore. An additional difficulty arose as a result of the large 12.7 mm pitch length. The large cross section of a rope thread made a huge surface contact area on which it was very difficult to get the required surface finish using a form tool.
113 Mr Clair said that one way in which it might have been possible to machine a rope thread was to use a manual lathe and a form tool. Such a tool would have had a cutting blade with a contour that matched the thread, being long enough to cover a single pitch length (12.7 mm). Because the rope thread had an asymmetric shape in cross section (viewed axially) the form tool had to move longitudinally along the length of the work as the component rotated. That is, on a standard engine lathe, for every revolution of the component, the cutting tool would have moved longitudinally the length of one pitch (12.7 mm). The result was that machining a rope thread would have required the cutting tool to move much faster than in the case of machining a conventional thread with a pitch of 2-3 mm. For any given rate of rotation of the component in the lathe, the speed of the surface being machined would depend on the size of the bore: the surface of a small bore would be travelling more slowly than the surface of a larger bore rotating at the same number of revolutions per minute ("rpm"). Consequently, for smaller thread sizes the lathe would have been spinning at a higher rpm rate than for larger thread sizes. However, the rate at which the cutting tool moved in and out of the bore longitudinally was the same regardless of the size of the bore: 12.7 mm per revolution. This meant that, for smaller threads, the cutting tool had to move in and out longitudinally very rapidly, at a rate which was beyond the capacity of standard engine lathes.
114 Mr Clair said that, as a result of the inability to use sufficiently rigid cutting tools and the limitations of lathes, the machining of small diameter, internal, rope threads with form tools on manual lathes was extremely difficult. He was not aware of anyone who had actually machined a rope thread by this technique other than a rod supplier in Melbourne called Goldfields Diamond Drilling Co Pty Ltd. He described what I understood him to regard as a highly idiosyncratic approach to machining which was taken by that company. The method was "long and tedious and required special in house form grinding." Stephen Fleming, employed by that company during the period to which Mr Clair's evidence relates, was not aware of this approach or method, and it is unnecessary for me to make any finding about this aspect of the latter's evidence.
115 Mr Clair said that, as at the mid-late 1980's, it would have been theoretically possible for someone to machine right-handed rope-threaded components of 32 mm or larger diameter. He expressed the opinion, however, that it would not have been possible to produce smaller right-hand rope threads, such as those of 25 mm diameter, "because of the difficulty involved in using small form tools, and the fact that several pieces of expensive toolmaking equipment would be required."
116 Mr Fleming, to whose evidence I have briefly referred, took issue with Mr Clair's evidence in a number of respects, specifically in areas where the latter had emphasised the difficulty of machining rope threads. However, Mr Fleming's evidence related wholly to NC and CNC machining, where, he said, the making of rope-threaded components, even where the diameter was less than what Mr Clair proposed as the absolute minimum for internal machining, was conventional and, as I understand it, commonplace. But, to the extent that I have referred to Mr Clair's evidence to date in these reasons, it has been in the context of the use of a manual lathe. Mr Fleming's evidence did not touch upon that area. With respect to the production of rope-threaded components on a manual lathe, Mr Clair's evidence remains unchallenged by Mr Fleming. And, as counsel for the applicants pointed out, at least relevantly to the matter presently under discussion, it was not challenged during cross-examination. The significance of Mr Clair's evidence about machining with a manual lathe, of course, lies in the circumstance that, according to Mr Geatches who gave the only evidence on the subject, Mr Gambly's lathe was a manual one.
(Emphasis added.)
144 The primary judge's reasoning in relation to the issue was as follows. Again, we set out these paragraphs in full given their significance to the arguments on appeal:
117 If there were no evidence from persons who had physically viewed Colrok's "speed rods", and the question were the subject of inference from indirect indications, I would be disposed to the position that the respondent had not established that the connections on those rods were rope-threaded ones. Mr Clair's evidence in particular would have influenced me to that result.
118 But there is evidence from persons who had physically viewed those rods. The first of these was Mr Geatches himself. He could not recall the actual terms in which he provided instructions to Mr Gambly. He thought that he "would have" shown Mr Gambly a (then commercially available) left-hand threaded rod (as used in percussive rotary drilling) and asked him to make the same item, but in right-handed configuration.
119 It was suggested to Mr Geatches under cross-examination that he mistook the threads produced by Mr Gambly for rope threads, something with which he was familiar in their left-handed configuration. It was put to him that the threads actually machined by Mr Gambly were "T-threads", a coarse wave-like thread that was much easier to produce and, according to Mr Clair, could readily have been achieved on a manual lathe. Under cross-examination, Mr Geatches said that he thought that he had heard of a thread identified as "T", but he was not familiar with it. He was taken to the set of technical drawings to which I have referred in para 67 above, which related to T-threads. Mr Geatches appeared to understand the drawings, but he was manifestly unfamiliar with the product there identified. It was put to Mr Geatches that T-threads provided extremely quick coupling and uncoupling, to which his response was, "No experience with them so I can't comment." It was put to him that T-threads were suitable for rod diameters of 25 mm or thereabouts, to which his response was, "If you say." He said that he had "never seen them". He was shown a marketing brochure, not in evidence but marked "MFI-1", with a very clear, close-up, photograph of a male T-thread on the end of a rod or shaft of some kind, and he said that it was not a thread with which he was familiar in 1989. He was shown what purported to be one of the respondent's own catalogues, also not in evidence but marked "MFI-2", depicting what counsel suggested were T-threaded items, and he reiterated that, in 1989, he was not familiar with "coarse threads of that type" (counsel's words). When it was put to him that what Mr Gambly made was "a coarse wave-like thread that was a T-thread, not a rope thread", Mr Geatches' response was, "incorrect".
120 It was made quite clear on behalf of the applicants that they made no suggestion that Mr Geatches was doing otherwise than genuinely attempting to recall events of about 25 years ago. The honesty of his evidence was not challenged. From his evidence summarised above, I gathered that Mr Geatches knew enough about his subject, and recalled enough of the events of which he spoke, to be able to affirm the proposition that the threads made by Mr Gambly were rope threads rather than some other kind of threads, specifically T-threads. When he was under cross-examination, he gave me no impression that he did not know what he was talking about, or that he was unable to make distinctions at the level required by the nature of the matters with which he was required to deal.
121 Turning next to the evidence of Mr Nielsen, I have referred above to the drawing which he made of the rods which he observed at Ellalong, and to his evidence that the threads on the rods were rope threads. When asked under cross-examination about T-threads, he said that he was "not too sure" about them. He said that he did not know the difference between a rope thread and a T-thread. But he was familiar with rope threads, because left-handed configurations of them had been used at one of his previous workplaces, Tahmoor Colliery. When it was put to him that he could not, with any certainty, say that the coarse thread that he drew was a rope thread rather than a coarse wave-like thread such as a T thread, his response was, "No, it was a rope thread. That there was a rope thread. I … don't know what … you say is a T-thread but that was definitely a rope thread." Mr Nielsen was a diesel fitter by trade, and his firm recollection of what he saw at Ellalong deserves, on account of that circumstance, to be given some weight. I should add that there was nothing in the way that he gave his evidence that would cast any question upon the reliability of his recollection.
122 Mr Yates also gave some evidence on this subject. Additionally to this evidence as set out in para 80 above, under cross-examination he said that, at Ellalong, "the drill rod had a female rope thread on the bottom of it which took the male rope thread at the top of the next rod". That evidence was not, as it happened, responsive to the question which he had been asked, but, for whatever reason, Mr Yates was not challenged on it.
123 When the evidence of Messrs Geatches, Nielsen and Yates is taken together, the respondent's factual case that rope-threaded connections were used between the drilling rods used by Colrok at Ellalong is a strong one. Those witnesses, particularly Mr Geatches, were legitimately cross-examined by reference to circumstantial factors which might be thought to raise problems with that case, and which may well have been fatal if the case were wholly an inferential one. But it is not. None of these witnesses had any interest in the outcome of this proceeding, and it was not suggested that they proceeded otherwise than conscientiously in the giving of their evidence. Each was asked whether he had consulted with the others before making his affidavit, and answered in the negative. The two who were cross-examined on the subject of rope threads remained positive and convincing in affirming that that is what they saw at Ellalong. The evidence of all three should be accepted.
124 I find, accordingly, that, in the system of extension drilling used by Colrok at Ellalong Colliery, the connections between the drilling rods were right-hand rope-threaded ones.
(Emphasis added.)
145 It is not suggested by Sandvik that the primary judge's summary of Mr Clair's evidence was inaccurate in any way. Sandvik's contention is that, given Mr Clair's evidence regarding the difficulty of machining internal female rope thread of the relevant size on a manual lathe (which, Sandvik submits, the primary judge accepted), and given that Mr Gambly had only a manual lathe, the primary judge ought not to have accepted Mr Geatches' evidence that right-hand rope thread was used in the Colrok drilling system.
146 For the following reasons, we do not accept Sandvik's contention that the primary judge erred in his findings in relation to the Colrok drilling system and, in particular, in finding that right-hand rope thread was used in that system.
147 First, each of Messrs Geatches, Yates and Nielsen gave evidence to the effect that right-hand rope thread was used in the Colrok drilling system. As noted by the primary judge, none of these witnesses had any interest in the outcome of the proceeding, and it was not suggested that they acted otherwise than conscientiously in the giving of their evidence. The evidence of Mr Geatches to this effect is referred to in the Reasons at [58], [61] (Step 1), [118]. The evidence of Mr Yates to this effect is referred to in the Reasons at [81], [122]. The evidence of Mr Nielsen to this effect is referred to in the Reasons at [91], [121]. There was no suggestion that these paragraphs did not accurately reflect the evidence of these witnesses.
148 Second, the primary judge formed a favourable view of the evidence of these witnesses, based on his observations of the giving of their evidence during the trial. In the course of discussing the first alleged error in Mr Geatches' evidence, the primary judge said (at [66]) that Mr Geatches answered a question "in a way which, to my observation, reflected a thorough command of the subject". In the context of the right-hand rope thread issue, the primary judge referred in some detail to the cross-examination of Mr Geatches (at [119]). The primary judge said that he "gathered that Mr Geatches knew enough about his subject, and recalled enough of the events of which he spoke, to be able to affirm the proposition that the threads made by Mr Gambly were rope threads rather than some other kind of threads" (at [120]). The primary judge also stated: "When he was under cross-examination, he gave me no impression that he did not know what he was talking about, or that he was unable to make distinctions at the level required by the nature of the matters with which he was required to deal." In relation to Mr Yates' evidence, after discussing the "stumble" during cross-examination, and the clarification during re-examination, the primary judge stated that he "was left with a firm satisfaction that the evidence set out in [Mr Yates'] affidavit fairly reflected his own recollection of the drilling method which he observed at Ellalong" (at [87]). In relation to Mr Nielsen, in the context of discussing submissions to the effect that Mr Nielsen may have been mistaken about what he saw at Ellalong Colliery due to the passage of time and the fact that he was not directly involved, the primary judge said that "Mr Nielsen's credibility, and the reliability of his recollection, were not undermined by indirect considerations of these kinds. I was left with the firm impression that he had a clear recollection of what he had seen at Ellalong, as stated in chief and as generally depicted in his drawing reproduced above" (at [93]). In the context of the right-hand rope thread issue, the primary judge referred to Mr Nielsen's evidence during cross-examination and stated that "there was nothing in the way that he gave his evidence that would cast any question upon the reliability of his recollection" (at [121]). Thus, this is a case where the findings at first instance were based, in part, upon the primary judge's observations of the witnesses giving evidence at trial. Moreover, the primary judge was immersed in the evidence as a whole during the course of an eight-day trial. The appellate court is not in a comparable position.
149 Third, the primary judge addressed the evidence of Mr Clair in some detail and was alive to the tension between that evidence and the evidence of Messrs Geatches, Yates and Nielsen that right-hand rope thread was used by Colrok. The primary judge said that, if there were no direct evidence from persons who had viewed Colrok's "speed rods" and the question were the subject of inference, he would be disposed to the position that Quarry Mining had not established that the connections on the rods were rope-threaded ones. His Honour stated that Mr Clair's evidence in particular would have influenced him to that result (at [117]). However, there was direct evidence from Messrs Geatches, Yates and Nielsen to the effect that right-hand rope thread was used. That evidence was (at least in the case of Messrs Geatches and Nielsen) tested during cross-examination. In our view, it was open to the primary judge to reason in the way that he did, namely to prefer the direct evidence of Messrs Geatches, Yates and Nielsen over the, in effect, circumstantial evidence of Mr Clair.
150 Although Sandvik's written submissions on appeal stated that Mr Clair had given evidence that it "would not have been possible" to produce manually the internal female rope threads in rods of the small size claimed by Mr Geatches, Sandvik's submissions to the primary judge were expressed in terms of "extremely difficult" rather than "impossible". We were taken to the transcript of final submissions, in which senior counsel for Sandvik said (at trial transcript 658):
The next point was that the notion of right-hand rope threads being brought into existence by Mr Gambly, we say, your Honour, is unlikely, very unlikely. The net effect of the evidence - the unchallenged evidence of Mr Clair, the toolmaker that your Honour heard evidence from - is that it's extremely difficult - he couldn't say impossible, but extremely difficult - to machine a thread such as that on a hand lathe.
We think this is an accurate characterisation of the overall effect of Mr Clair's evidence. In [115] of the Reasons, although the primary judge notes that Mr Clair said that it would not have been possible to produce smaller right-hand rope threads, this statement was followed with the quotation from his evidence: "because of the difficulty involved in using small form tools, and the fact that several pieces of expensive toolmaking equipment would be required". Also, in [114] of the Reasons, the primary judge referred to Mr Clair's evidence that the machining of small diameter, internal rope threads with form tools on manual lathes was "extremely difficult".
151 One of the points relied upon by Sandvik, both before the primary judge and on appeal, was that the affidavit and oral evidence of Messrs Geatches, Yates and Nielsen was not supported by any objective contemporaneous evidence, such as examples of the extension rods or drive chucks, or drawings or photographs of these items. The primary judge referred to this submission at [64], noting that it was not suggested that either Mr Geatches or Quarry Mining had selectively opted to withhold from the Court objects, photographs or drawings which might have been led in evidence. The primary judge found that there was no reason for Mr Geatches to have retained objects, drawings or photographs of this kind when he retired from Colrok in 1994. The primary judge considered that the absence of such evidence was relevantly "neutral" in its impact on the task in which the Court was engaged: "the fact is that there is no such evidence, but that fact should not introduce an additional element of unreliability into the evidence that was led" (at [64]). This passage demonstrates that the primary judge was mindful of the absence of contemporaneous objective evidence to support the evidence of Messrs Geatches, Yates and Nielsen. We consider that it was open to the primary judge to reason in the way that he did in relation to the absence of such material.
152 To the extent that Sandvik relies on the alleged errors in Mr Geatches' evidence referred to in 131 above, we consider that each of these points was appropriately dealt with by the primary judge in the Reasons at [65]-[75]. It was open to the primary judge to reject each of these submissions for the reasons that he gave in that section of the Reasons.
153 Sandvik also submitted, in its written submissions in reply, that the unreliability of Mr Geatches' recollection about events occurring 25 years earlier was further demonstrated by his evidence about the instructions he gave to Mr Gambly for the production of the rods, referring to trial transcript 290-292. This is not one of the alleged errors referred to in 131 above. The evidence relating to Mr Geatches' instructions to Mr Gambly is referred to in the Reasons at [118]. The primary judge evidently did not consider that Mr Geatches' recollection should be treated as unreliable on the basis of this evidence: see the Reasons at [120]. Having reviewed the pages of the transcript relied upon, we do not consider that this provides a basis to disturb the primary judge's findings.
154 It follows from the above that we reject Sandvik's challenge to the primary judge's conclusion that claims 1, 2, 4 and 7 were anticipated.