Engineer who studied fluid mechanics and thermodynamics expert enough !

Hatziandoniou v Ruddy [2015] NSWCA 234

Accident – Truck versus motorbike

Issue whether contact between truck and bike occurred in truck lane or motorbike lane, which would determine liability of truck or motorbike.

AT trial evidence of engineer rejected as not expert evidence; overruled on appeal.

Expert evidence not admitted

26. Given that the central question in the trial was the location of the point of impact, and that that could be explicated by reference to the fluid discharge, solicitors acting for the appellant retained an expert, Mr William Bailey, to provide a report. Mr Bailey is a mechanical and biomedical engineer. He appended to his report a detailed curriculum vitae. At the commencement of his report he set out those aspects of his specialist knowledge and experience specifically relevant to his investigation of this accident. Included in that list was:

“conduct and interpretation of crash tests and other physical testing of vehicles and components which is applicable to the assessment of vehicles/component damage, especially regarding pre-impact vehicle manoeuvres, crash causation and injury mechanisms”.

27. He then provided a summary of his conclusions. Those relevant are:

“7.  The most compelling physical evidence of the crash was a trail of fluid from the motorcycle that commenced after the impact and ran along the roadway in the southbound lane (ie the plaintiff’s correct lane of travel) and approximately 0.5 m from the centreline and essentially parallel with it.

8.  Because:

– The bike was not deflected at an acute angle from the side of the truck after initial contact but continued along a path parallel with the side for several metres

–  When fluid from a downward directed pipe located on the offside of the radiator began to be deposited on the roadway, the bike was travelling approximately parallel with the centreline and approx 0.5 metre within the southbound lane.

–  Coolant under pressure would commence flowing almost immediately after the hose was disconnected.

–  Engagement of the rotating wheel nuts on the truck had forcefully contacted metal parts on the offside of the bike including the radiator and the engine at a location consistent with the hose being disconnected on impact.

it is concluded that the motorcycle was probably on its correct side of the roadway when the impact with the offside front wheel occurred.”

28. The remainder of Mr Bailey’s report was an explanation of his reasons for reaching these conclusions. Under a heading “Nature and distribution of debris post impact, including fluid discharge from the bike” appears the following:

“a)  The debris recorded on the roadway is the fluid discharge from the dislodged hose and radiator pipe on the offside [of] the motorcycle. Using permanent features of the site that were visible in police photographs it was earlier determined that the fluid trail commenced approx 8 metres south of the line where the seal changed on the roadway. The fluid trail was located in the southbound lane approximately 0.5 metres from the centreline. The fluid trail is obscured by absorbent material added by road authorities and the lateral location may be a little closer or further than 0.5 metres.

b)  Because:

�  Coolant is maintained under pressure of approx 10psi and the pressure will cause it egress [sic] at any break in the system (eg disconnected hose)

–  The outlet pipe is located below mid height within the header tank, so coolant will flow by gravity

–  The engine was running and the water pump will continue to pump coolant from the engine to the radiator even after coolant can no longer be drawn into the engine from the radiator.

–  The coolant was hot and would have minimal viscosity (ie resistance to flow)

discharge from at least the downturned pipe end and probably the hose end, would begin immediately upon disconnection.

The pipe is located approx 0.6 metres above the roadway when the bike is upright and it was probable the deposit on the roadway began shortly after the hose was disconnected.

c)  The fluid trail on the roadway appears to continue along a path approximately parallel with the roadway, indicating that the bike was travelling approximately parallel with the roadway when fluid began to be deposited.

d)  Scape [sic] visible approximately half way along the truck indicates the bike was travelling approximately parallel with the truck for at least several metres.” (Blue 423-4)

Mr Bailey restated his conclusion that the motorcycle was probably on its correct side of the roadway when the impact with the truck occurred.

29. At the trial, objection was taken to the admissibility of Mr Bailey’s report. The basis of the objection lay in Mr Bailey’s qualifications. A voir dire was conducted. In his evidence in chief Mr Bailey was asked if he had studied “anything in relation to fluid dynamics”. He replied:

“Yes, it was a requirement that all engineers taking a BE in mechanical or industrial completed courses in fluid mechanics and also in thermodynamics which were relevant to this particular report.”

30. When asked how central to his study the science of physics was, he replied:

“In a sense mechanical engineering is the application of physics to the real world. It’s at the core of mechanical engineering. Taking physics in its broadest context.”

31. In cross-examination, the following questions were asked and answers given:

“Q.  … Have you any training or expertise or experience in dealing with the flow of liquids from a motorcycle engine?

A.  Only in so far as it’s analogous to flows from other types of engines but not – I haven’t done any studies of flow from motorcycle engines but I note a close correlation with cooling systems that are used in motor vehicles generally.

Q.  The difference of course between motor vehicles and motorbikes is that on a motor bike the engine is much more exposed to the outside air or the wind passing past a bike. Would you agree with that?

A.  Yet, it is, to a degree.

Q.  Have you inspected or tested the flow of liquids from a motorcycle at all?

A.  Not from a motorcycle, no.

Q.  Have you carried out any testing on a motorcycle to confirm the way in which liquids would escape from a motorcycle?

A.  Not from a motorcycle.

Q.  That’s fairly central to your opinion here, is the escaping of the liquids from a motorcycle and where they would end up on the ground, isn’t it?

A.  That’s correct. But I made those opinions based on the close correlation between that type of a pressure vessel and pressure vessels with which I am very familiar in motor vehicles generally.”

He rejected a proposition that there was a difference between pressure vessels in a motorcycle and pressure vessels in a motor car. He was again asked if he had done any testing to see how liquids are affected by the movement of a motorcycle through air. He acknowledged that he had not.

32. Immediately following the voir dire, the trial judge delivered a judgment in which he excluded part of Mr Bailey’s report. He made reference to the decision of the High Court in Dasreef Pty Ltd v Hawchar [2011] HCA 21; 243 CLR 588 and said:

“In this case Mr Bailey has training, study and experience as an engineer. Part of that training and study obviously has something to do with hydraulics but he has never ever in his evidence tested the flow of liquid from a motorcycle engine, interpreted or tested the flow of liquids or done any testing which would enable him to express the opinions which he stated in para 8 of his report.

There is, therefore, in my opinion, no basis upon which I could conclude that the opinion which he has given in relation to pt 8 [sic] is based on his specialised knowledge, training, study or experience. Accordingly, part of Mr Bailey’s report is not admissible. Paragraph 8 is rejected, on p 4.”

33. Counsel for the respondent then successfully objected also to paragraph 7 of the report, and objected to some other pages, which included that part of the report which discussed the nature and distribution of debris post impact, including fluid discharge from the motorbike.
34. His Honour said:

“Any evidence that relates to a determination made on the basis of the spillage or expulsion of coolant is rejected.”

That was the extent to which the excluded aspects of the report were specified.

35. The trial then proceeded with witnesses as to damages, and evidence given by the respondent.

The rejection of the expert’s report

38. The starting point in considering the admissibility of Mr Bailey’s report is the identification of the fact in issue in the proceedings to which his evidence was said to be relevant: Evidence Act 1995 (NSW), s 55. In this case, that fact is easily identifiable: it is the location on The Putty Road of the point where the two vehicles collided. The evidence derived from eyewitnesses was unsatisfactory; at the very least, a greater degree of confidence as to that location could be obtained from supplementary evidence. The appellant sought to obtain that supplementary evidence through the opinion of Mr Bailey. Mr Bailey approached that fact by examining the location and source of the liquid on the road. He reached the conclusions set out above.
39. Section 76 of the Evidence Act renders inadmissible evidence of an opinion to prove the existence of a fact in issue. That prohibition is subject to the exception contained in s 79(1), which provides:

“(1)  If a person has specialised knowledge based on the person’s training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge.”

40. For evidence to be admissible under s 79 it must satisfy two criteria: (i) the proposed witness must be shown to have “specialised knowledge based on the person’s training, study or experience”; and (ii) the opinion expressed must be wholly or substantially based on that training, study or experience: Dasreef at [32].
41. The primary judge appears to have rejected the evidence of Mr Bailey as failing to satisfy both criteria: he acknowledged that Mr Bailey had training, study and experience as an engineer, but discounted his evidence of having completed courses in fluid mechanics and thermodynamics, and of the close correlation between pressure vessels on motorcycles and those in motor vehicles generally, with which Mr Bailey was very familiar. Indeed, his reference to Mr Bailey’s training having “had something to do with hydraulics” could be seen as inappropriately dismissive and certainly as failing to consider Mr Bailey’s unchallenged evidence as to that part of his training and experience.
42. The finding that there was no basis upon which to conclude that Mr Bailey’s report was based on his specialised knowledge, training or experience is unsustainable on both counts. His qualifications included the conduct and interpretation of crash tests, and other physical testing of vehicles and components applicable to the assessment of damage.
43. The primary judge adopted the submission of counsel for the respondent that, since Mr Bailey had not “tested the flow of liquid from a motorcycle engine”, he was not qualified to express the opinions that he had.
44. This was an unduly narrow approach to the question of the qualifications of Mr Bailey to express his opinion as to the mechanism by which the fluid came to be where it was on the road. Mr Bailey had training in fluid dynamics, and expertise in cooling systems in motor vehicles; that expertise was sufficient to support an opinion about the operations of a breached cooling system in a motorcycle. One of the benefits of expertise is that it enables the person who has the relevant “training, study or experience” to extrapolate from the general to the particular. Mr Bailey had the requisite specialised training to enable him to draw conclusions about the particular circumstances of this collision. (Those conclusions would, of course, be subject to cross-examination, and to any contrary evidence adduced on behalf of the respondent.)
45. It follows from the above that Mr Bailey’s evidence was wrongly excluded. The only possible consequence of that conclusion is that the verdict and judgment must be set aside and a new trial ordered. There must be a new trial because, on the exclusion of Mr Bailey’s evidence, he was not cross-examined, and counsel for the respondent forbore to tender the report obtained on behalf of the respondent. It will be necessary for the competing expert evidence to be properly evaluated in a new trial.
46. Although, associated with this ground of appeal was a complaint that, having excluded parts only of the report, the primary judge failed to consider that which remained, the Court was not directed to any other relevant conclusion or opinion.
47. The conclusion that Mr Bailey’s opinion evidence was wrongly excluded makes it unnecessary to resolve the other issues raised in the appeal concerning liability.