Major Engineering Pty Ltd v Timelink Pacific Pty Ltd [2009] VSCA 83 | Case summary

Court of Appeal (Vic)|2009-04-30|Before: ASHLEY, REDLICH and DODDS-STREETON JJA

CONTRACT - Contract for supply of hydraulic cylinders for canting keel of racing yacht capable of withstanding maximum static force of 262 kN - Where finding of breach of contract by supplier overturned on appeal - Remitted question - Whether finding that cylinders failed at static force of not more than 262 kN open on evidence.

1 I have had the advantage of reading the reasons for judgment of Dodds-Streeton JA in draft. For the reasons which follow, I agree with her Honour that the appeal should be allowed.

2 The contractual terms found by the learned trial judge were that the cylinders -

(b) would have a working capacity to withstand a compression force of up to 262 kN in ocean racing conditions;

(c) would be designed and supplied so that the piston rods would not buckle or fail under compression when they were subjected to a working compression force of up to 262 kN in ocean racing conditions;

3 The meaning of those terms was affected by two considerations: Mr Jones' email to Mr Petty of 4 June 2002; and the fact that 262 kN was calculated by reference to the position at which the cylinder assemblies were most vulnerable -19° cant.

4 As to the first of those matters, in his email of 4 June Mr Jones referred to 'the maximum static loads (i.e. in the locked condition) shared by the two cylinders'. The load figures were later increased; but the concept of 'maximum static loads' remained.

5 The meanings of 'static load', 'maximum static load' and 'static forces' were addressed by a number of the witnesses. Mr Jones said that 'static load' meant 'if the thing is just simply sitting there, it would be the steady load under those conditions'. Professor Joubert contrasted 'the steady load' on a piston with 'suddenly imposed loads,' and 'slamming'. Dr Keays described the term 'static load' as ambiguous - it could be an actual load or an equivalent static load to a dynamic situation. In the present case he took it to be referring to a design load. Dr Baigent gave evidence that he understood the 'maximum static load' to be the 'worst loading condition calculated'.

6 In light of the evidence which I have just mentioned, reference to 'a compression force of up to 262 kN in ocean racing conditions' and 'a working compression force of up to 262 kN in ocean racing conditions' were understood by this Court, when the matter was previously before it, to mean a static force - or load - of up to 262 kN.

7 In a practical sense, this involved an unrealistic assumption - that loads imposed upon the keel in ocean racing conditions, and thus upon the cylinder assemblies, would be steady. It was, as Dodds-Streeton JA says, common ground that a lateral or impulse load suddenly applied to a cylinder assembly would cause it to fail at a lower magnitude of force than a load applied steadily and progressively. Nonetheless, forces of the former kind were to be treated as if they involved the imposition of static force.

8 At the time of failure, the cylinder assemblies were not being subjected to a steady load. These were the dynamic effects of which witnesses gave evidence. But the focus must be upon the maximum load imposed, however it came to be imposed.

9 There are two corollaries of what I have just said. First, if it could be established that the piston rods failed at less than the contractually specified threshold because of a sudden imposition of force, although they would not have done so had the same amount of force been applied by steady progression, the respondent would be entitled to succeed. Second, the fact that the yacht was subjected to dynamic conditions means that, converted to static load, the situation would have been constantly changing. Since, as I apprehend it, the evidence tended to show not only that a sudden imposition of force below the specified threshold might have a disproportionate effect, but also that dynamic forces might exceed the threshold, the task for the respondent of establishing that failure was caused by a load less than the threshold was rendered more difficult.

10 I turn to the second matter affecting the meaning of the contractual terms as found. The terms, by their language, were directed to the capacity of the cylinder assemblies to withstand a compression force - that is, a static force or load - regardless of the extent of cant. Nonetheless, the figure of 262 kN was evidently intended to address the situation of greatest vulnerability, when the keel was at 19° extension cant (conveniently, '19° cant'). It was common ground that, when the pistons were not at full extension, their ability to withstand load would increase. An ability to withstand a load of 262 kN at 19° cant would imply an ability to withstand a load in excess of 262 kN at 17° cant. The contractual terms, in my opinion, required the cylinder assemblies to withstand 262kN static force, or load, at 19° cant; and the question remitted by this Court on the earlier occasion needed to be understood and answered with such an understanding.

11 The keel was in fact canted at 17° when the piston rods failed.

12 If it could be said that, however the load was imposed (that is, steadily and progressively, or by dynamic forces), the cylinder assemblies could not have withstood 262 kN whatever was the extent of cant, then the fact of failure would mean that the respondent would establish breach. But in my opinion it would not follow, simply because the static load exceeded 262kN at time of failure at 17° cant, that breach would be established. It would all depend upon whether that load converted to less than 262kN assuming 19° cant.

13 Mr Jones' evidence, at its highest, supported a conclusion that the cylinder assemblies failed at less than a static force of 262kN because, via the keel, they would not have been exposed to any greater force in ocean racing conditions. Alternatively, if his evidence should be understood to mean that the cylinder assemblies must have been incapable of withstanding a force of 262kN at 19° cant, then it followed that they must have failed either at less than 262kN, or at least less than 262 kN adjusted upwards to allow for the keel being not fully canted.

14 In his calculation of the maximum force to which the cylinder assemblies would be exposed, Mr Jones built in a smallish safety factor.

15 Each of the other relevant witnesses, as Dodds-Streeton JA shows, considered that an additional - and generally substantial - safety factor should be applied to the maximum static load as calculated in order to give protection against the variable conditions which can be encountered at sea. Those conditions could be of two kinds. First, the effect of a suddenly imposed load rather than a steadily applied load. Second, simple magnitude of load - this disputing Mr Jones' proposition that in ocean racing conditions a force exceeding 262 kN would not be imposed upon the cylinder assemblies (whether that be taken to mean at all, or rather at their position of greatest vulnerability).

16 It can be said that the conditions in which the piston rods failed were not, as described, the extreme conditions which a safety factor is particularly designed to address. But that is distinct from the question whether the evidence justified a conclusion that the load imposed upon the cylinder assemblies in ocean racing conditions would never exceed 262 kN, or at least never exceed 262kN at their position of greatest vulnerability. As Dodds-Streeton JA shows in her analysis, only Mr Jones went so far; and his evidence revealed that in arriving at that figure he had allowed a safety factor which was much less than those proposed by the other witnesses. It was not correct for the learned trial judge to conclude that Mr Jones' opinion was relevantly ad idem with the opinions of the other relevant witnesses. Rather, it was idiosyncratic, and poorly justified.

17 Absent that path of reasoning to a conclusion favourable to the respondent, the question is whether evidence otherwise considered entitled a conclusion, on balance of probabilities, that the piston rods in fact failed when subjected to a static load which was equivalent to less than 262 kN at full extension.

18 In every case, determination of disputed questions turns upon consideration of all the relevant evidence. The finder of fact is not taken hostage to experts only because a question involves a matter of expertise. Nonetheless, proper respect must be accorded expert evidence, being evidence which is beyond the knowledge and experience of lay persons.

19 In an extreme case, science may present a 'blank negation'. That is, it does not provide any answer to a question posed. In such a case, a court may choose to rely upon an apparently persuasive sequence of events.[1]

20 I have given consideration to whether this case presented such a feature. The theoretical exercises and the practical tests failed to provide a clear answer to the critical question - that is, what static load was being applied to the cylinder assemblies when the piston rods failed - because none of exercises or tests replicated sailing conditions. On the other hand, the authors of the exercises and tests averred that their results could be applied to determine the probable static load at which the assemblies would fail. It was thus not a question of no answers being given by the experts; rather one of the reliability of the reasoning underlying the various answers.

21 But even if the scientific evidence had been no more than a blank negation, I consider that the respondent would not have been assisted by a Forst analysis. That is because there was no apparently persuasive sequence of events or series of facts showing, more probably than not, that the load being imposed on the cylinders at the critical time was less than the equivalent of 262 kN at 19°cant.

22 So it comes back, as I see it, to consideration of all the evidence.

23 First, there is the fact that the cylinders failed at 17° cant in the sailing conditions described by the learned trial judge[2] and by Nettle JA when the proceeding was earlier in this Court.[3]

24 Second, the keel, and hence the cylinder assemblies, were being subjected to lateral and impulse loads at the critical time. Such loads may cause a cylinder to fail at a lower magnitude of force than would happen if the same force, or load, was applied steadily and progressively. So it cannot be said, insofar as theoretical exercises or practical tests suggested that the pistons could have withstood a steadily applied load in excess of 262 kN at 19° cant, that they would do so when confronted by lateral or impulse loads of less than 262 kN.

25 Third, on the other hand, any calculation which suggested that the load imposed upon the cylinders would never exceed 262 kN in ocean racing conditions was suspect because such calculations did not replicate conditions in the water.

26 Fourth, there is then the fact that the calculations which yielded the various estimates of maximum load were made upon the assumption of a yacht lying horizontal, though static, with the entire weight of the keel horizontal and with a tendency to fall to the vertical. Nothing like that extreme situation was being encountered when the piston rods failed. But, as against that, the various calculations did not allow for the particular kinds of impact imposed by ocean racing,

27 Fifth, there is to be considered the evidence of the experts with respect to adding on a 'safety factor'. Mr Jones added on a safety factor represented by the difference between 218 and 262 kN. Other experts suggested that larger safety factors should be allowed, although they began from different starting points. Their evidence certainly implied not only that the maximum load arrived at by calculations might be exceeded in sailing conditions but that the calculated maximum load might be much exceeded. The highest safety factors proposed, of 4 and 5, were presented by or through a witness for the respondent.

28 Dr Keays spoke of the safety factor being added to the 'once in a lifetime load' which was the design load. But Professor Joubert, Dr Baigent and Mr Raymond all considered that the safety factor addressed the unpredictable effects of lateral and slamming loads.

29 Sixth, the yacht's canting keel was at least recent technology. It provided additional reason why a substantial safety factor was required. The effect of the dynamic forces to which the keel and the cylinder assemblies would be exposed at sea was less confidently predictable than with a keel of long-established design.

30 Seventh, as against a conclusion that the effect of slamming was such as to much increase the load to which the cylinders were subjected was the evidence of Mr Taylor, sailing master of the yacht, that in the 2005 Sydney to Hobart race, in similar sailing conditions, a pressure gauge fitted to the refurbished vessel demonstrated that slamming had a plus or minus 20 per cent effect - 800 to 1200 psi, with an average of 1000 psi.

31 It is true, as Dodds-Streeton JA says, that the witness's comparison of conditions in 2004 and 2005 was impressionistic, and that there was no evidence as to the configuration of the keel or hydraulics in 2005. I note also Professor Joubert's reservations about the usefulness of statistical data pertaining to measurement of pressure and accelerations. Again, I accept that there was difficulty, as the evidence stood, in simply grafting Mr Taylor's evidence onto a steady load calculation at 17° cant. But the witness's evidence seems to me nonetheless to have merited considerable attention Whatever its limitations, it gave some indication that slamming had small effect upon this vessel, in racing conditions, on this stretch of water, and in what were stated by an experienced yachtsman to be similar conditions to those which had prevailed in 2004.

32 But in the end, even if weight was attributed to Mr Taylor's evidence and it could be concluded that the effect of slamming was unlikely to have been great at the critical time, the question remains whether the respondent established that the piston rods failed when the actual load was below the equivalent of 262 kN at 19° cant.

33 Upon that question, I consider that the respondent failed to prove its case. Implicit in all that I have thus far said is the fact that no one can say, as a matter of record, what load was in fact being imposed upon the piston rods at the time of their failure, at least because no measurements were then being taken. Then, even if 262 kN at 19° cant was a supportable calculation of the maximum static load to which the cylinder assemblies would be exposed when a modest allowance for safety was superadded, in my opinion the burden of the expert evidence was that such a calculation made no sufficient allowance for the safety factor which, according to the direct evidence of other expert witnesses and their reference to the statements of

authorities, was necessary in order to address the lateral and impulse forces which are at work to greater or lesser degree, when a yacht is at sea. Whilst it is possible that the piston rods failed because a force less than the equivalent of 262 kN at 19° cant was suddenly - rather than steadily - applied, it seems to me no less likely that the piston rods failed because a force greater - perhaps significantly greater - than 262 kN equivalent was applied, a force in respect of which provision had not been made by incorporating a sufficient safety factor. The respondent's evidentiary difficulties were the greater, I consider, because of the difficulty of assessing at an instant in time the load imposed by ever-changing dynamic forces, notwithstanding that the load must be characterised as static. In short, in my opinion, the respondent failed at the point of onus - just as the appellant would have done had it carried the onus of proof.

34 I should add this: If I was wrong in saying that the true question was whether the respondent proved that the cylinder assemblies failed at less than the equivalent of 262kN at 19° cant, and if the question was whether the respondent proved that the failure occurred at less than 262kN (that is, regardless of the extent of cant), I consider that the respondent would still fail to satisfy the evidentiary onus. The difficulties for the respondent to which I referred in the preceding paragraph would continue to have application.

35 I have had the considerable benefit of reading in draft both the reasons of Dodds-Streeton JA and those of Ashley JA. Although they differ in their approach to the question which must be resolved, I agree for the reasons that they give that the respondent failed to discharge the onus of establishing a breach of the condition with the consequence that the appeal should be allowed. I agree with the orders that Dodds-Streeton JA proposes.

36 The issue in this appeal is whether the appellant, Major Engineering Pty Ltd ('Major'), is liable to pay damages for breach of its contract to supply the respondent, Timelink Pty Ltd ('Timelink') with a pair of hydraulic system cylinders, each capable of withstanding a compressive force of 262 kiloNewtons ('kN'), to operate the canting keel of Timelink's ocean going yacht. The piston rods of the two cylinders supplied by Major and installed in the yacht failed and broke off while it was competing in the 2004 Sydney to Hobart Yacht Race. Although no lives were lost, the canting keel became detached. The yacht capsized and suffered considerable damage.

37 The central question in the proceeding below was a straight forward, albeit technically complex, claim for breach of contract. The history of the proceeding, however, is complicated.

38 Following a trial in July 2005 ('the trial'), a judge of the Trial Division held, for reasons delivered on 4 August 2006 ('the first judgment') that Major was liable in damages to Timelink for breach of contract. He found an implied term that each of the hydraulic cylinders would have the capacity in operation to withstand a compression force of 262 kN together with an added safety factor of not less than two, that equated to a capacity of not less than 524 kN or greater. His Honour did not consider that the cylinders had that capacity or critical failure load. He had received expert evidence of the failure load based on both theoretical analyses and practical tests. In the first judgment, his Honour, on one view, did not wholly accept any of the theoretical analyses and rejected some of them, due to the difficulties of evaluation, appearing to prefer instead the practical tests conducted by Major on a replica cylinder, which indicated that the cylinders would fail at 309 kN. His Honour appeared to conclude that even if the results of that practical test were accepted, when the additional safety factor of not less than two was taken into account, breach of contract was established, as no theoretical calculation or practical test suggested that the cylinders had a capacity of at least 524 kN.

39 His Honour did not expressly determine whether the cylinders each had a 'maximum static working load' of not less than 262 kN, presumably because that was unnecessary to establish breach of the implied term he had found.

41 The Court of Appeal on 16 October 2007[4] held, in essence, that the trial judge had erred in implying a term that a safety factor must be added. Nettle JA (with whom Buchanan and Neave JJA agreed) held that the contractual requirement was to supply cylinders each capable of resisting a maximum static force of up to 262 kN, rather than a static force of a multiple of 262 kN by reference to a safety factor. The Court of Appeal considered that the trial judge had made no finding that the cylinders had failed in operation at a static force of less than 262 kN. It remitted for determination by the trial judge 'the sole issue of whether the static force at which the cylinders failed in operation was not more than 262 kN'.

42 On 30 November 2007, on the application of Major, the Court of Appeal reformulated the remitted issue as follows:

Whether the static force at which the cylinders failed at the point of failure described in paragraph 29 of the reasons for judgment of Nettle JA was not more than 262 kN.

43 Paragraph 29 of the reasons for judgment of Nettle JA described 'the point of failure' as follows:

At the point of failure, Wild Thing (by that time renamed Skandia), was on port tack heading in a south westerly direction towards the Tasmanian coast. She was about 70 nautical miles east of the Eddystone Lighthouse at the north-eastern tip of Tasmania. The wind was blowing a gale at between 30 and 40 kNots south-south-west and the prevailing swell was from the port bow, and thus from the south. The depth of the water was approximately 3,000 m. The majority of waves were four to six metres high and the yacht was following what was said to be a conservative sail plan. The yacht came off a wave which was larger than those then prevailing and the two piston rods failed and broke off. This meant that the keel head was no longer laterally restrained and thus, despite efforts of the crew to lash it down, it swung within the hull causing damage to surrounding components. The vessel was abandoned when it appeared that the keel might come away altogether and so cause the yacht to capsize. The crew were rescued. Their apprehensions were fulfilled. The keel became detached and the yacht capsized and suffered considerable damage.

44 On remittal, the trial judge heard further submissions. In a judgment delivered on 22 February 2008 ('the second judgment'), he held that 'the static force at which the cylinders failed at the point of failure described in paragraph 29 of the reasons for judgment of Nettle JA was not more than 262 kN'. His Honour gave judgment for Timelink for damages to be assessed.

45 By a Notice of Appeal dated 7 March 2008, Major appealed from the second judgment given on 22 February 2008 on the following grounds:

The learned trial judge, on the evidence before him, could not reasonably or properly have found that the respondent had discharged the onus on it to establish that, on the balance of probabilities, the static force at which the cylinders failed at the point of failure described in paragraph 29 of the reasons of judgement of Nettle JA in [2007] VSCA 228 was not more than 262 kN.
On the evidence before him the learned trial judge should have found that the Respondent had not discharged the onus to establish that, on the balance of probabilities, the static force at which the cylinders failed at the point of failure described in paragraph 29 of the reasons of judgment of Nettle JA in [2007] VSCA 228 was not more than 262 kN
The learned trial judge erred in fact and law in finding that:

the ocean conditions at the point of failure described in paragraph 29 of the reasons of judgment of Nettle JA in [2007] VSCA 228 subjected the cylinders to a static force of not more than 262 kN; 2. the cylinders failed when subjected to a static force of not more than 262 kN;

the respondent's loss and damage was caused by the cylinders failing by being subjected to a static force of not more than 262 kN

46 By a Notice of Contention dated 18 August 2008, the respondent made certain contentions, considered in detail below.

48 In 2002, Timelink, a company controlled by Grant Wharington, a well-known yachtsman, engaged Donald Jones, a yacht designer and design engineer, to design a new, 30 metre 'cutting edge' clean racing yacht to compete in the Sydney to Hobart Yacht Race and other major ocean yacht races. As the yacht was intended to compete in international races, it had to satisfy certain requirements, including those of the American Bureau of Shipping Guide for Building and Classifying Offshore Racing Yachts 1994 ('ABS Guide'). The yacht was initially called 'Wild Thing', but its name was subsequently changed to 'Skandia'.

49 Mr Jones decided, inter alia, that the yacht should have a canting keel, which was a fairly innovative feature. Unlike a conventional keel, which is fixed, a canting keel can move sideways. Timelink consequently required a pair of hydraulic cylinders to move and restrain the keel head.

50 Timelink's designer, Mr Jones, entered discussions with Mr Petty, the sales manager of Major, in relation to the supply of the hydraulic cylinders. Mr Jones had previously had satisfactory dealing with Mr Petty, whom he knew and respected. Major was the agent for Parker Cylinders ('Parker'), an American cylinder manufacturer, and also commissioned equipment from a local manufacturer.

51 In the course of the dealings between Mr Jones and Mr Petty, Mr Jones' requirements for the capacity of the cylinders to withstand force increased.

52 On 4 June 2002, Mr Jones sent Mr Petty a critical email which stated:

The cylinder arrangement I have decided on for WILD THING's canting keel includes two 5" x 930 mm stroke cylinders, one with a cylinder end as in the "Infinity Pin Eye Series Style R" with pin diameter 1.25" and a spherical bearing rod end for a 1.75" diameter pin. Oil connections are to be in the "Position 3" (Parker Hannifin). The other cylinder is to have spherical bearings for 1.75" diameter pins at both ends and oil connections at "Position 1".

Based on the data you gave me I am assuming 2" rod diameter and a retracted length for both cylinders of 1241 mm.

The maximum static loads (i.e. in the locked condition) shared by the two cylinders will be 44500 kg push force and 38267 kg pull force. Would you please check that my assumptions are OK and forward a quotation.

...

53 It is undisputed that the maximum static loads expressed in kilograms required to be borne by each cylinder equated to 218kN (push, or compression) and 188kN (pull, or tension).

54 Mr Petty did not respond to Mr Jones in relation to the two assumptions he was asked to check and Mr Jones took his silence as confirmation that they were correct.

55 In June or July 2002, Messrs Jones and Petty had further discussions about the required capacity of the hydraulic system. Nothing was said to cast doubt on the adequacy of a 2 inch cylinder shaft. The maximum pressure to be borne by each cylinder was, however, now increased by Mr Jones to 3,000 psi (which was the equivalent of a maximum compression force of 262 kN and a maximum tension force of 220 kN).

56 On 25 July 2002, Major submitted a quote of $1,604 per cylinder plus GST, which Timelink accepted on 25 July 2002.

57 The cylinders were manufactured to the order of, and supplied by, Major. The canting keel which was ultimately constructed was attached to the bottom of the yacht's hull on a pin running 'fore' and 'aft', allowing the bulb of the keel to be swung laterally. It ran through the yacht's hull so that force could be applied to the side of the keel head to move it sideways to a desired angle ('cant') and hold it there. The maximum extension was to an angle of 19°, while the maximum racing extension angle was 17°. The keel head was moved and restrained by the pair of hydraulic cylinders supplied by Major, to which pumps delivered oil at the required pressure. The cylinders were fixed in parallel to the head of the keel at one end and to the port (left) side of the yacht's hull at the other end. The cylinders were at their weakest, and had their lowest failure point, when fully extended. At racing extension, they could withstand greater pressure.

58 The cylinders operated satisfactorily throughout the 2003 sailing season and for some of the 2004 sailing season, but failed during the 2004 Sydney to Hobart Yacht Race at 1.15 am on 28 December 2004 at the racing extension angle of 17°.

59 The point of failure was described thus by the primary judge:

At the time of the incident, the yacht was on a port tack. This meant that the keel was canted to port and the keel head to starboard, held in place by the two extended pistons. What then happened was that, when the yacht came off the large wave, the forces applied to the keel were transferred to the keel head and then to the pistons which were in compression. Both pistons failed; the piston shafts buckled and snapped off, leaving the keel head unrestrained.[5]

60 In January 2005, Timelink issued a proceeding against Major seeking damages for breach of contract and negligence. The claim in negligence was not pursued at trial.

61 At trial, it was common ground that Major had entered into a contract to supply two hydraulic cylinders to Timelink. Major denied, however, a number of terms alleged by Timelink, including terms that the hydraulic cylinders supplied:

(a) would be reasonably fit for the purpose of controlling the canting keel on 'Skandia' in ocean racing conditions;

(b) would have a working capacity to withstand a compression force of up to 262 kN in ocean racing conditions;

(c) would be designed and supplied so that the piston rods would not buckle or fail under compression when they were subjected to a working compression force of up to 262 kN in ocean racing conditions; and

(d) ...

(e) would comply with the guide contained in the Parker Industrial Cylinder Products (Hydraulic and Pneumatic Cylinders) Catalogue ('the Parker Catalogue') in relation to required piston rod size selection for metric hydraulic cylinders based upon the required thrust (push) application.

62 The trial judge found that Major held itself out as a long established enterprise capable of providing technical consulting and other services in hydraulic systems, was an agent for Parker and similar suppliers and that Mr Petty was very experienced. Moreover, the calculation of the critical diameter of the piston rods was beyond the capacity of all but the most qualified specialists in buckling failure, and perhaps even them. His Honour concluded that, although Timelink had its own design engineer, it was entitled to rely on the accuracy of the expert advice of Major about technical aspects of the proposed hydraulic system.

63 The trial judge rejected term (a), because he did not consider that Major had assumed a general responsibility to ensure that the cylinders would cope with whatever forces might be imposed during ocean racing; and term (e), because he concluded that Mr Jones was not given, and did not see, the relevant Parker catalogue. He held that it was unnecessary to deal with term (d), as it had not been breached.

64 His Honour held that the contract contained terms (b) and (c).

I therefore conclude that the agreement between Timelink and Major contained a term that the hydraulic cylinders including the pistons would, in operation, have a capacity to withstand a compression force of 262 kN. I accept the term pleaded in paragraph 4(b) of the statement of claim.

For similar reasons I accept suggested term (c).[6]

66 His Honour's reasons for the acceptance of terms (b) and (c) were as follows:

Term (b) depends upon the requirement of Timelink that the cylinders be capable of withstanding a compressive [sic] force of 262 kN. Major Engineering recommended to Timelink's design consultant that Parker cylinders would be appropriate and provided him with material from the manufacturer which suggested that the piston rods should have a two inch diameter. Mr Jones made known to Major Engineering his requirement as to the capacity of the cylinders to withstand a certain force. The email of 4 June gives this requirement as a total of 44,500 kg in compression. This translates to 218 kN for each cylinder. The higher figure of 262 kN is derived from the capacity of the cylinder to withstand 3,000 psi which Mr Jones required.

It is apparent from my summary of the dealings between the parties that both the maximum pressure within the cylinder and the maximum working load to be imposed on the rod were discussed. In the abstract, the two are not related because there are many factors which might bear upon the thrust which is produced by a piston in a cylinder subjected to a pressure of 3000 psi. In the present case, however, these factors, or possibly the more significant factors,[7] were known to the two men. For practical purposes, Mr Petty knew that the five inch cylinder at 3000 psi would generate a thrust of 262 kN through the piston so that, in operation, the hydraulic cylinder assembly including the piston shaft must be capable of operating in this environment. His conduct prior to the delivery of the Major Engineering quotation and its acceptance shows that he accepted that this was so and, further, that Mr Jones understood this and that he relied upon it.

I was for a little while troubled by the thought that, properly construed, the email of 4 June, which is on any view a very significant document, fixed the performance capacity of the cylinders in compression at only 218 kN. On reflection, I think this is not correct. The subsequent conversations make this clear. Furthermore, Major Engineering, both at this time and on 5 January immediately after the incident and, indeed, at trial, appeared to accept that, if there was a performance specification, it was by reference to a 262 kN working load.[8]

67 At trial, the judge heard all issues, other than quantum, over 10 hearing days. Nine witnesses were called and cross-examined. Timelink called three factual witnesses (Messrs Wharrington, Taylor and Oxley), one factual/expert witness (Mr Jones) and two expert witnesses (Professor Joubert and Dr Keays). Major called one factual witness (Mr Petty) and two expert witnesses (Mr Raymond and Dr Baigent).

68 Timelink submitted that the cylinders did not have a working capacity of 262 kN in operation. Both parties adduced expert evidence on that question, based on both theoretical analyses and practical tests.

69 The expert witnesses agreed that the compression force which would cause a column to fail could be calculated by the 'Eulers' formula, and the more complex case of a stepped column or extended cylinder with two overlapping non-rigid parts (such as the cylinders) could be calculated by reference to the 'Roark' formula.

70 There were five theoretical analyses in evidence. They produced a range of results.

71 Timelink's expert witnesses, Professor Joubert and Dr Keays, each performed two analyses which produced a total of four different theoretically calculated failure loads for the cylinders.

72 Major's expert witness, Dr Baigent, performed a single theoretical analysis which produced one theoretically calculated failure load.

73 First, Professor Joubert, in his independent analysis ('Professor Joubert's independent analysis') applied the Roark formula to the cylinders extended to 2,171 mm (as they would be when the keel canted 19.5° to port). That produced a critical failure point of 194 kN under a compression load. Professor Joubert conceded, however, that his calculation was not precise and that if he had used more accurate cylinder dimensions, the failure load would have been greater.

74 Secondly, Professor Joubert adopted a calculation ('Professor Joubert's Brown analysis') made by his colleague, Dr Brown, to produce a more sophisticated theoretical estimation of the critical failure point for the cylinders of 260 kN at full extension. Dr Brown did not give evidence. Professor Joubert, while adopting Dr Brown's calculation, maintained that it should be reduced, due to the connection between the cylinder and the shaft.[9] He did not indicate the extent of the required reduction. Because Dr Brown's calculation was based on the cylinders at full extension (their weakest position), when adjusted by 8% for racing extension, the failure point would be about 283 kN (as counsel for Timelink conceded on the remittal hearing) or, as the appellant submitted, more accurately, 281.5 kN.

75 Thirdly, Dr Keays calculated a critical failure point of 236 kN at full extension[10] by applying the US standard ANSI (NFPA) formula T 3.6.37-199 ('Dr Keays' ANSI analysis'). When adjusted for racing extension, the failure point on that analysis would be 233 kN.

76 Fourthly, Dr Keays used a computer program called 'Strand', which had been devised by one of his students, to make a further calculation ('Dr Keays' Strand analysis'). That produced a different result, being a critical failure load of 195 kN (with 3.2mm initial crookedness) or 233 kN (with 0.8mm initial crookedness) at 17° (ie: racing extension at which the cylinders failed).[11] In his first report, in order to adjust for yielding and crookedness, Dr Keays reduced the maximum buckling load at racing extension to 194 kN, but in his second report, he accepted Dr Baigent's criticism that his figure for crookedness was inappropriate.

77 Fifthly, Dr Baigent, Major's expert witness, used a table of values calculated by Young and Budynas from Roark's work to calculate a critical failure force on the basis of three different variations of the ratio of the incremental inertia between the thicker and thinner parts of the calculus. Dr Baigent produced an asymmetric curve and determined from it the critical failure force for a calculus with the ratio for the actual cylinders in question. That produced an estimated critical failure point for the cylinders of 320 kN at full extension, ('Dr Baigent's analysis').[12] When adjusted to allow for racing extension, the failure point would be 345.6 kN. Professor Joubert and Dr Keays criticised Dr Baigent's approach. They considered that his calculation for the ratio of infinity was erroneous.

78 In the first judgment, the trial judge expressly rejected some of the theoretical calculations.

79 He rejected Dr Baigent's analysis, on the basis that the criticisms of Professor Joubert and Dr Keays were justified.

80 He rejected Professor Joubert's independent estimate, as the witness himself had conceded its imprecision.

81 That left Professor Joubert's Brown analysis of 260.6 kN, Dr Keays' ANSI analysis of 236 kN, and Dr Keays' Strand analysis of 233 kN at full extension. At race extension, those figures were 281.6 kN, 255 kN and 233 kN respectively.

82 His Honour observed: 'it is not easy for me to evaluate these various theoretical analyses depending as they do upon complicated and technical concepts and difficult mathematics'.[13]

83 However, on one reading, in the first judgment his Honour accepted Professor Joubert's Brown analysis and Dr Keays' ANSI and Strand analyses, although observing that all were likely to be too high, because they were based on fixed connections and he assumed that the ANSI-based calculation had an inbuilt safety factor. His Honour observed that the calculations varied from 281 kN to a figure of less than 260 kN.

84 His Honour stated 'I conclude that, on this basis, the critical failure point of the cylinders would be no higher than 230 kN'.[14]

85 His Honour then considered the practical tests of the capacity of the cylinders performed by Major, under the direction of Dr Baigent, on a replica cylinder built to the same specifications as the failed cylinders.

86 The first practical test was performed on 11 October 2005. Pressure was applied to the replica cylinder increasing to 3000 psi (262 kN) at full extension, which was its weakest state, yet it did reach buckling point at 262 kN. The test was not continued to the point of failure. The second practical test was performed on 21 June 2006 on the replica cylinder, this time at both a full extension and at the racing extension of 17°, at which it had failed at sea. The test cylinder did not buckle at racing extension (at which it is able to withstand more force than at full extension) until a compression force of 325 kN was applied. It did not buckle at full extension until a force of 299 kN was applied.

87 Dr Baigent concluded from the second practical test that the buckling load of the cylinders was 325 kN.

88 The trial judge accepted that Dr Baigent concluded from the second practical test that the cylinder had a buckling load at full extension of 309 kN (as the load of 325 kN ought to be reduced by 8% to take into account the increased length of the cylinder at full extension).[15]

89 In the first judgment, the learned trial judge rejected many criticisms of the practical tests advanced by Timelink.[16] They related to the connection to, and age of the spherical bearings, the presence of lateral force, the lack of a Southwell plot of deflection against load and non-conformity with AS 4100 - 1998 Steel Structures. However, the judge accepted that the following two criticisms (made by Professor Joubert) might have greater force:

(a) the set up of the test rig and application of compressive forces lacked the constant and often violent movement of the vessel as it travelled through the waves; and

(b) the compressive forces imposed on the cylinders in operation were not constant or constantly increasing, as in the practical test. In operation, the changing forces acting on the keel were transmitted to the cylinders as impulse (sudden) loads. (The learned trial judge added that such differential forces were noted and recorded on the yacht some time after the incident, and were not observed to be great.) [17]

90 The trial judge stated that he had no way of knowing whether those criticisms would invalidate the reported results and he preferred to bear them in mind when he came to compare the test results with the theoretical analyses and other relevant evidence.[18]

91 His Honour then appeared to hold that pursuant to the contract, the pistons in operation must have a capacity to withstand not only a compression force of 262 kN, but must also include an extra allowance for a safety factor.

92 His Honour found that Mr Jones had formed a view of the 'worst case scenario' for the conditions in which the keel would operate. Mr Jones assessed the worst case working compressive load to be 218 kN and had added to it, ultimately specifying a compressive working load of 262 kN.

93 His Honour observed that although the working compression load was 262 kN, it was 'generally accepted' that a working load and a critical failure load were not the same, because a column was not expected to work at its ultimate point of failure. The difference between the two points was referred to as a safety factor to cope with the uncertainties of operation. It was expressed as a ratio of one measurement to another (for example, buckling load to maximum calculated load).

94 The factor of safety depended on the circumstances, including 'the confidence in the estimated maximum working load, the reliability of the structure and the consequences of failure.' The safety factor was, his Honour found, 'a matter for the designer's judgement rather than a mathematical ratio'.[19]

95 His Honour considered that, in the present case, the designer would estimate the worst possible circumstances in which the keel would operate, and the supplier would add its own safety factor to the worst case scenario.

96 His Honour observed that there were various figures for the appropriate safety factor. They were as follows:

Evidence of Mr Jones on worst case scenario and safety factors

97 In cross-examination, Mr Jones said that although the ABS Guide dealt expressly only with fixed keels and did not refer to canting keels, he had regard to it in designing the yacht, including the keel.

98 Mr Jones testified that conformity with the ABS Guide was a 'bureaucratic' requirement for entering, for example, the Sydney to Hobart Yacht Race. He complied by doing 'everything specified in the book' and then, if dealing with a novel feature, he complied with the relevant rules. Nevertheless, Mr Jones did not consider that a canting keel was a novel feature.

99 Mr Jones testified that his calculation of 44,500 kg, if converted into kiloNewtons, produced 436 kN for both cylinders, and divided by two to give the load for each cylinder, it produced a 218 kN push force and a 188.2 kN pull force.

100 Mr Jones said that the static load meant 'if the thing is just simply sitting there it would be the steady load under those conditions.'

101 Mr Jones had required 'the components to be good for 3000 psi' by which -

I was merely telling [Mr Petty] in these particular conditions what the loads were under those conditions. In other words, although I was saying I wanted the cylinders capable of 3000 psi, these were in fact the maximum static forces that the cylinder would be expected to have to deal with.

102 He agreed that this meant that 'the load could not exceed 262 kN with 3000 psi'.

103 In cross-examination, the following exchange occurred:

Can you tell me what safety factor you incorporated into the design of the keel?

It depends on what aspect of the keel that one is talking about.

104 Mr Jones then explained that the calculation of 'the grounding moment' did not relate to safety factors. He continued:

What I have to do in order to work out what happens in the boat is take the operating conditions in the boat and do separate mathematics in the operating conditions, in other words with the boat sailing along through the water under different conditions and consider different wave patterns and so on, and I have to then calculate what is the maximum moment on the keel ... because it is the moment on the keel that transmits the forces on to the cylinders or on to other parts of the structure and that moment has several main components.

(1) The static component (which related to the angle of the keel in relation to the vertical in relation to the earth).

(3) The fin going through the water creating a lift and a side force and the boat coming off a wave more vertically.

(4) The dynamic loading, applied as a factor to the static loading of the keel at such an angle.

Then you calculate the total loading by adding those four things together, some of them are positive and some of them are negative and you get a total figure.

107 Mr Jones testified that, in his experience, the total was less than 'the statistic (static) and when the boat's out at an angle' and 'the calculation for ABS turns out to be bigger by a substantial margin than the sum of the other four items, it is therefore ... why, I believe ABS is generally the requirement because it is simply the worst case and you consider that.'

108 He stated that the forces other than the static load were difficult to calculate - for example, the side force on the keel due to the water could be calculated by computer programs 'but they are the things that determine part of the loading.'

109 As such, in Mr Jones' opinion, 'the ABS calculation is the more difficult one to meet' and he only made the other relevant calculations after he had sent the critical email on 4 June 2002.

110 The following exchange occurred in cross-examination:

Is the safety factor included in what you describe as these maximum static forces - Yes.

What is that safety factor. The safety factor would be such that I would not be exceeding the yield stresses which are required under ABS ...

111 The trial judge questioned Mr Jones as follows:

What figure did you arrive at when you brought into account all these dynamic forces. Well, it obviously depends on which particular regime you are talking about at the time.

HIS HONOUR: You made a calculation you said on a worst case scenario - on a worst case scenario my recollection is that I would have probably not [have] found a case where the combined loading was more than say 70 per cent of the loading provided for by ABS.

So that's a safety factor, if you adopt the ABS of what, 50 per cent - 30 per cent, is it - Yes.

130 I mean.

112 Mr Jones reiterated that the total load (taking into account the dynamic impulse loads etc), was 'never more than the static load as calculated by ABS, that's what I'm saying and therefore the ABS calculation is a worst case, ...'.

113 Immediately after the incident on 28 December 2004, Mr Jones sent Mr Petty an email which stated, inter alia, 'The pressure impulse caused when the boat fell off the wave must have been large compared with the design pressure which was, as I recall, about 3000 psi.' When questioned by the trial judge, Mr Jones testified that he did not now consider that the force on the cylinders had exceeded 262 kN but that at the time of sending the email, he had 'no reason at that stage to suspect the cylinder rods ...'.

114 The following exchange occurred between the trial judge and Mr Jones:

HIS HONOUR: Can I ask a question before re-examination. You've said, I think on a number of occasions, just baldly stated, that the forces that were imposed upon this vessel at the time it slid off the wave and suffered the incident we have heard so much about, could not have exceeded 262 kN on the head of the keel?---On the cylinders, yes.

MR JONES: Yes?---Yes.

HIS HONOUR: An thereby compression into the cylinders?---Yes.

HIS HONOUR: Given the fact you weren't there, given the fact that they are very complex activities and forces operating on the vessel at the time, why do you say that?

MR JONES: ---Well the calculations led me to believe that.

HIS HONOUR: Which calculations?

115 Mr Jones replied that he had calculated four sets of forces, some negative and some positive, but had never calculated forces in normal sailing conditions which were greater than about 70% of the ABS calculation.

116 When again asked why he asserted that the forces operating on the yacht when it slid off the wave could not have exceeded 262 kN, Mr Jones replied that although there could be very high slamming loads and very big accelerations up in the bow area, 'in the middle of the boat - and the keel is obviously fairly close to the centre of gravity ... the accelerations are not that great at all ... '

117 His Honour put to Mr Jones the evidence of Professor Joubert (in his third report) that, when designing a keel, the ABS Guide should be used to work out the various forces and a factor of safety should then be applied on top of that. (emphasis added). Mr Jones stated 'I don't agree with that'.

118 Mr Jones explained that Professor Joubert was mistakenly treating the ABS Guide as if it were the design or working load of the boat 'which it simply isn't'. Mr Jones said that the ABS Guide was merely a hurdle to be got over in order to enter the race.

119 Mr Jones stated that he had made 'lots of calculations' of the forces which would be operating on the cylinders, but no longer had them and there would be no way of checking whether his conclusion was right or wrong, other than for a measurement of the actual pressures on the cylinders in the ocean.

120 When the trial judge questioned Mr Jones about his retention of engineering computations, Mr Jones reiterated 'I cannot produce those.' His Honour asked 'what you are really saying to [counsel] and ultimately to me, well, you did the work, 'The figures were right, trust me'? Mr Jones responded 'That is what I am saying, yes'.

121 The trial judge then questioned further Mr Jones about safety factors.

122 Mr Jones testified that he calculated a pressure of 3000 psi (which was a bit more than 44,500 kg) and was a small addition over and above the ABS Guide loading.

123 He could not recall the figure he calculated for the kiloNewtons operating on the head of the keel, but reiterated that his calculation of forces, including dynamic forces, were less than the ABS Guide loading. His figure of 262 kN had a safety factor built in, over and above his 'worst case' calculation which was the transverse load case assessed on the basis of the ABS Guide.

124 Mr Jones testified that 'I only apply that factor of safety calculation to the loads associated with the weights, in other words to the - taking the column and ballast weight and the other thing - and working out what the load and what the moment on that is and then I multiply that by a factor to allow for dynamic loads.'

125 Mr Jones, nevertheless testified that when he specified 262 kN to Mr Petty, he would have expected him to add a substantial margin between operation and ultimate failure.

126 That accorded with his witness statement, in which Mr Jones stated that he -

provided Major ... with details of the maximum static loads for push and pull forces which I required the cylinders to accommodate, including a potential working capacity in compression of 262 ie ... obviously there would need to be an appropriate safety factor or reserve which would have to be built into the cylinders. I provided details of the working loads on the cylinders. It was up to the manufacturer and supplier to ensure an appropriate factor of safety to meet the designated working loads.

127 Professor Joubert prepared three reports. In his first report, he recognised that the cylinders initially worked satisfactorily for quite some time and the yacht completed the 2003 race without keel problems, but in the 2004 race 'some quite severe weather was experienced and a particular pounding may have imposed a peak load sufficient to cause a buckling failure. The piston rod and cylinder had no safety margin.'

128 In his first report, Professor Joubert calculated the steady load on a single piston due to the bulb and keel weight at 17° as 16.73 tonnes (equivalent to 164 kN). That was based on his acceptance of Dr Brown's calculation. Professor Joubert also stated that:

As the failing load on the pistons is about 26 tonnes then it is clear that normal sailing will not produce such loads. The extra momentary load of about 10 tonnes per piston must have been created by the slamming.

The loads due to slamming are difficult to estimate and equally difficult to measure.

Nevertheless it is my opinion that slamming could produce the kind of extra loading required to reach the failing load of about 26 tonnes per piston.

The compressive force on the piston at the time of failure was calculated to be 260.6 kN. The steady load ... was 164 kN. The extra load was caused by slamming.

In my opinion the prior successful operation of the hydraulic system occurred because:

The piston rods were not extended as far when the keel was canted to only 14%. The shorter length of exposed piston increased the buckling load.

The yacht did not suffer from suddenly imposed pounding loads to the same extent as occurred in the 2004 Sydney-Hobart race.

130 Professor Joubert stated that there was a gale during the 2004 race, but gales were often experienced and not especially dangerous. Pounding of yachts was also a regular experience.

131 While in his first report Professor Joubert assumed that the failure point of the pistons was about 26 tonnes or about 260.6 kN (based on the correctness of Dr Brown's calculation), he nevertheless acknowledged that 'it is usual for a vital component of a swing keel to have a substantial safety margin'. He referred to and appeared to enclose a relevant authority, Timoshenko, who held that 'in the case of suddenly applied or variable loads - a large factor of safety (larger than 2) becomes necessary'.

132 Professor Joubert estimated the steady working compressing force (highest steady force) on the cylinders when the keel was horizontal at 24.97 tonnes (c/f Mr Jones' requested 26.7 tonnes), but he noted that when sailing (as distinct from when the yacht was horizontal in the transverse load case), the loads in the pistons from the weight of the bulb and the keel would be reduced, and even further reduced by buoyancy forces to 164 kN.

133 Given that pistons failed (and Professor Joubert assumed that their failure point was 260 kN, as Dr Brown estimated) he attributed the extra loading which caused the failure to be due to slamming.

134 In contrast to Mr Jones, Professor Joubert considered a canting keel to be a novel feature. He stated 'you've got to be careful with your safety factors on new designs' and noted that the ABS Guide assumed that the yacht was on its side to establish loadings for design features supporting the ballast keel. However, it made no allowance for slamming or impulse loads.

135 Professor Joubert stated that he would not rely simply on the ABS Guide in designing a racing yacht. He considered that the ABS Guide was too weak in relation to the safety factor. He recollected incidents in which ABS Guide compliant keels had not withstood 'a black night, in a strong gale ... in big seas, not enormous, not mountainous, just big seas ...'.

136 In cross-examination, Professor Joubert stated that he would design a canting keel for a racing yacht thus:

ABS have got some good grounding rules, I would certainly follow that and I would make it a bit stronger like in a knock down case.

137 Professor Joubert initially testified that he would add a safety factor of two, because 'I don't want to drown, that's why'. Professor Joubert then revised the safety factor up to four. He stated that although two was normal for steel work, extra attention to the safety factor was necessary when dealing with a novel item like a canting keel. While two was a reasonable safety factor in normal conditions, Professor Joubert stated:

In the case of a yacht where you have suddenly imposed loads which have a much more severe effect on a structure than one that's built up in little bits and where you may have side loads, then you've got to have a reasonable safety factor. Many of these things are difficult to estimate. You keep talking about slamming, well, there's a can of worms for you. If you are up in the bow of the boat you get a big deceleration. If you are halfway back down the boat, nothing like what you get on the bow.

138 In his second report (responsive to Dr Baigent's practical experiments), Professor Joubert was critical of Dr Baigent's safety factor, of which he considered inadequate, as a factor of 2 was the minimum for experimental designs. He stated:

Even with a factor of 2, in my opinion, this is too low as it makes no allowance for yachting conditions. As noted in my final report ... Timoshenko suggested a factor of 3.5.

On the ocean in wave the steady loading may well be below the design load ... but as the yacht goes over the wave, every so often it pounds (slams) and the loading, in a fraction of time, suffers a large increase. A suddenly applied load can have a different effect to one applied in a slowly increasing manner especially when there are side forces as well as longitudinally compression force imposed by the pounding.

Professor Joubert concluded that the factor of safety is obtained by multiplying such factors together.

140 As to slamming loads, Professor Joubert stated that:

...a slamming load, including lateral forces (side loads), increased the tendency for the cylinder to bend and lowered the buckling load dramatically.

141 In cross-examination, the following exchange occurred:

Professor Joubert, do you remember this morning we were talking about safety factor of four - Yes

And we arrived at that figure of 981 kN - Yes

That was on a worst case scenario - You can always think of something that's even worse than the one you've thought about but ---

142 When asked if he would accept 750 kN as 'the sort of force to be taken into account', Professor Joubert stated that he would 'go back and look at the loading from some of the experimental things that one has done at the university and work out what sort of result ...'

143 Professor Joubert was asked: 'When you are addressing this safety factor, it's not what's known that is the problem, it's the risk of the unknown and that's why you come up with the four, so it's these very sort of impacts that you are going to have to take into account, are they not?' Professor Joubert stated 'Yes, they are part of the problem, part of it.'

144 As to large waves, Professor Joubert said that it was not the size of the wave that mattered, but its shape which determined the impact load.

145 Professor Joubert was asked about Mr Raymond's report, which envisaged the yacht falling 2.4 metres at 3 G forces. When asked if that were a realistic scenario, he replied 'Sounds a bit high to me but from all the work I've done - I've written about four or five papers on loads on yacht hulls and slamming; it's a difficult subject. It's not simple.'

146 As to the sea conditions on the day of the incident (which he had seen on video) Professor Joubert stated: 'I didn't think it was anything to worry about. Its just a normal - it might have been a gale. The motor boat that came out to rescue them was having no trouble at all in handling the seas.'

147 Professor Joubert did not consider that Mr Jones could be criticised for failing to include an allowance for impulse loads in his design process. In his third report he stated that instead:

the allowance for extra loads such as:

(i) impulse loads;

(ii) side loads;

(iii) imperfections in materials and manufacture,

are allowed for by the safety factor applied AFTER the steady load.[20]

148 In his oral testimony, Professor Joubert reiterated that 'the request for a working compressive force of 262 kN by Mr Jones in the circumstances 'was perfectly reasonable in line with the common practice of naval architects as 'an adequate working force for the operation of the cylinders'. Professor Joubert made clear that this did not mean that he thought 262 kN was the maximum force that could be encountered by the cylinders in the yacht in ordinary racing conditions, because, as the following exchange reveals, he expected the safety factor to be added to it:

When you add safety factor considerations, when are they taken into consideration? - afterwards.

You mean by the manufacturer of the cylinder, is that what you are getting at - Well that's what one expects, or what I would expect, anyhow.

149 In the first report, Dr Keays dealt with the ABS Guide for designing a yacht keel and associated fixtures and fittings which provided 'an indication of the magnitude of loads' for racing yachts.

150 Dr Keays explained that the ABS Guide required, relevantly, a transverse load for the design of the keel and its attachments to the hull. The transverse load was based on the yacht lying flat in the water with the keel out of the water.

151 Dr Keays calculated that in the present case, when the cylinder rod was fully extended, the compression force would be 220 kN. He determined a buckling point of 240 kN at the racing cant of 17°, but said that the effects of yielding and crookedness would produce a lower failure load.

152 He acknowledged that there was also transient dynamic force on the keel which, according to his 'rough analysis', was similar to that of the design load. He did not, however, present the 'rough analysis' and the trial judge held that because it could not be tested, that evidence should not be accepted.

153 Further, Dr Keays ultimately considered that it was necessary to add to the design load 'an associated safety factor', which reflected 'the consequences of a failure and the confidence the code writers have in the calculation process leading to the design load or material capacity.'

154 In cross-examination, Dr Keays did not dispute Professor Joubert's assertion that the ABS Guide was too weak. Rather, he stated 'I can't form an opinion as to that because my expertise on this is not as wide as his and it's certainly not - in the matter of yacht design for dynamic loads.' Dr Keays asserted that he had used the safety factor of two in the ABS Guide as a reference. He stated:

You must calculate the load in accordance with the ABS Guide which says that the yacht on its side, then you calculate from that action what the loads are on the various components and if you use the ABS Guide, it suggests that everything should be designed with a safety factor of two.

155 Dr Keays ultimately did not, in terms, disagree with Professor Joubert's safety factor of four. He stated that when designing an unusual structure, he would use the ABS Guide as one reference, then employ other references to suggest a safety factor. He concluded 'I may well come up with say, let's work to 2½, three, four' and would then do a further analysis.

156 Dr Keays acknowledged that his calculation of the transverse load case of 222 kN, based on the ABS Guide, did not include any impulse loads. It was simply the design load calculated from the ABS Guide.

157 In relation to the maximum static load requested by Mr Jones in the email of 4 July 2002, Dr Keays said a 'static load' was ambiguous - it could mean either an actual load or an equivalent static load to a dynamic situation, depending on context - but in the particular context of the email, Dr Keays stated that it referred to 'a design load and I would be looking up design charts'.

158 Dr Keays was questioned in cross-examination as follows:

You respond by saying "By my simple estimate the design working force in the piston rods would be about 220 kN. I consider the requirement of 262 kN working load as reasonable. This design load is the once in a lifetime load and could be expected in ocean racing in Bass Strait" ... do you mean "once in a lifetime load" as being inclusive of safety factor - No.

So the safety factor is on top - of the once in a lifetime load.

Yes. For instance, if your once in a lifetime load happened the first day that you took the car out of the garage you would break your rear axle ... and if it happens once in a lifetime it could happen in the first five minutes or the last five minutes of a lifetime.

159 Dr Keays opined that, by the reported state of the sea 'the race conditions were not extraordinary ... The sea state, there were waves there but I hadn't any evidence to suggest that they were extreme or extraordinary'.

160 Dr Baigent prepared two reports. In his first report, Dr Baigent reported on the first practical test. He concluded that the critical buckling load of the cylinders was well in excess of the maximum static load specified by Mr Jones, based on both his theoretical analysis and the experiment.

161 In the supplementary report, Dr Baigent reported on the second test.

162 He also referred to the ABS Guide, which did not consider canting keels, but indicated that a designer should independently research the peculiarities of novel features. For the keel connection case, the ABS Guide had a safety factor of two. (That meant that the keel connection must be capable of supporting a load which was twice that of the weight at the keel bulb). Dr Baigent said that for the transverse load (the weight of the keel acting at its centre of gravity) when the yacht was on its side, there was an inherent factor of safety of 1.5.

163 Dr Baigent concluded that the cylinder forces calculated by Mr Jones:

...are similar to the transverse loading on the keel, described in the ABS Guide ... . However the loads do not have any factors of safety applied to them ... . It is my opinion that the ABS Guide requires the keel attachment which in this case is the hydraulic cylinders (and the keel pin), to have a load factor of 2. That would mean, that for design purposes, the pair of cylinders would need to support a total load of 89006 kg compression and 76706 kg tension.

It is apparent that Mr Jones has not taken into account any impulse loads in his calculations.

164 Dr Baigent considered that Mr Jones made no concession for the fact that the load applied to the cylinders at the time of failure could have been significantly greater than 262 kN by reason of impulse loading. He stated:

It is my opinion that the impulse loading is precisely the reason why the cylinder rods failed. Furthermore, it is my opinion that the impulse loading applied loads that were significantly greater than those calculated by Mr Jones.

Major Engineering Pty Ltd v Timelink Pacific Pty Ltd

At a glance

Court

Decision date

Before

Source

Judgment (339 paragraphs)

Parties