Carpenter v Hinkley - [2008] WADC 161

JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA
IN CIVIL

LOCATION: PERTH

CITATION: CARPENTER & ANOR -v- HINKLEY [2008] WADC 161

CORAM: SCHOOMBEE DCJ

HEARD: 21-23 JULY 2008

DELIVERED : 24 OCTOBER 2008

FILE NO/S: CIV 905 of 2007

BETWEEN: LEIGH STANLEY CARPENTER
First Plaintiff
RHONDA MARGARET CARPENTER
Second Plaintiff
AND
BRENTON CRAIG HINKLEY
Defendant

Catchwords:

Tort - Duty of care - Worn bearing in harvester disintegrating and causing fire - Fire damage to neighbouring farm - Harvester inherited - Failure to have harvester inspected by skilled and competent mechanic - Whether breach of duty of care - Whether failure of bearing and it causing fire foreseeable - Whether reasonable farmer would have had bearings inspected prior to harvesting season

Legislation:

Civil Liability Act 2002 (WA) s 5B and 5C
Civil Liability Act 2002 (NSW)

Result:

Plaintiff's claim allowed

Representation:

Counsel:

First Plaintiff                :     Mr M Greenland
Second Plaintiff            :     Mr M Greenland
Defendant:     Mr G Hancy

Solicitors:

First Plaintiff                :     Greenland Legal Pty Ltd
Second Plaintiff            :     Greenland Legal Pty Ltd
Defendant:     Kott Gunning

Case(s) referred to in judgment(s):

Bennett v Minister of Community Welfare (1992) 176 CLR 408
Burnie Port Authority v General Jones Pty Ltd (1994) 179 CLR 520
Cox v New South Wales [2007] NSWSC 471
Drinkwater v Howarth [2006] NSWCA 222
Eutick v City of Canada Bay Council [2006] NSWCA 30
Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54
Haileybury College v Emanuelli [1983] 1 VR 323
Haris v Bulldogs Rugby League Club [2006] NSWCA 53
Hazelwood v Webber (1934) 52 CLR 268
Hughes v Lord Advocate [1963] AC 837
Maronis Holdings Ltd v Nippon Credit Australia Pty Ltd (2001) 38 ACSR 404
Martin v The Trustees of the Roman Catholic Church of the Archdiocese of Sydney [2006] NSWCA 132
McDonald v Sydney South West Area Health Service [2005] NSWSC 924
Mercer v Commissioner for Road Transport (1937) 56 CLR 580
Mount Isa Mines Ltd v Pusey (1970) 125 CLR 383
New South Wales v Fahy (2007) 236 ALR 406
Permanent Trustee Australia Ltd v Boulton Permanent Trustee Australia Ltd (1994) 33 NSWLR 735
Pledge v RTA (2004) 78 ALJR 572
Roads and Traffic Authority of NSW v Dederer (2007) 81 ALJR 1773
Ruddock v Taylor [2003] NSWCA 262
Vairy v Wyong Shire Council (2005) 223 CLR 422
Waverley Council v Ferreria [2005] NSWCA 418
Wyong Shire Council v Shirt (1980) 146 CLR 40

SCHOOMBEE DCJ: On 19 December 2005 the defendant was harvesting barley on one of his farming properties near Gnowangerup when he noticed that he suddenly found it difficult to turn the steering wheel on his harvester. He looked backwards to see whether something was wrong with the rear wheels and noticed a 3‑4 m² patch of fire diagonally behind the harvester. The fire spread at a rapid pace and raced into the plaintiffs' neighbouring property, where it destroyed a substantial part of the plaintiffs' farming property, including crops and live-stock.
The defendant had inherited the harvester at the beginning of 2005 from a deceased neighbouring farmer. It was a Case International 1440 harvester ("the harvester") and the defendant knew that it was approximately 20 years old and had done about 4000 hours of work.
It is common cause between the parties that the fire was caused by a failure of the bearing inside the idler pulley on the harvester which failure resulted in overheated components of the bearing falling to the ground and igniting the barley stubble. (This is admitted by the defendant in his amended defence.) The plaintiffs' case is that the failure of the bearing was caused by wear and tear, whereas the defendant pleads that it is impossible to determine what caused the failure of the bearing or, if it can be determined, it was the unforeseen disintegration of the separators that held the balls in place within the bearing. The plaintiffs further say that the defendant owed them a duty to take reasonable care to prevent damage by fire to the plaintiffs' property as a result of the use of the harvester on the defendant's property and that the defendant breached this duty by failing to have the idler pulley and bearing inspected by a skilled and competent mechanic prior to the 2005/2006 harvesting season. The plaintiffs say that the defendant was also negligent in that, prior to the fire, the defendant removed the V‑belt underneath the pulley in order to take off the hydraulic pump for repairs, but did not inspect, or competently inspect the pulley and bearing and did not detect wear in the bearing.
The plaintiffs further plead that if the idler pulley had been inspected by a skilled and competent mechanic prior to the fire, he would have noticed signs of wear in the bearing and would have recommended and carried out a replacement of the bearing.
The parties have agreed the quantum of the plaintiffs' losses and the only relevant issue for this court to decide is whether the defendant is liable to the plaintiffs for a breach of a duty of care. This essentially involves the questions whether the defendant owed the plaintiffs a duty of care, whether he breached any such duty of care and whether the fire would have been prevented if the defendant had taken the steps which the plaintiffs say he should have carried out. The main factual issues which are relevant to these questions are:
(a)whether the bearing failed by reason of wear and tear;
(b)whether it was foreseeable by a reasonable person in the position of the defendant that the bearing could fail by reason of wear and tear and that this might cause hot material to fall onto dry stubble and cause a fire;
(c)if this was foreseeable, whether the defendant was required to have the harvester inspected prior to each season or from time to time by a skilled and competent mechanic in order to eliminate or minimise the risk of a fire being caused by wear and tear in the bearing;
(d)whether the wear and tear in the bearing would have been detected during a pre-season inspection by a skilled and competent mechanic and whether such a mechanic would have advised the defendant to replace the bearing; and
(e)whether the defendant or his representatives carried out an adequate and competent pre-season inspection of the bearing.

Mr Martin Simms

Mr Martin Simms gave evidence on behalf of the plaintiffs. He has a Bachelor of Applied Science in mechanical engineering as well as 20 years experience in private practice as an independent consulting engineer.
Mr Simms explained the mechanical operation of the idler pulley and the bearing. He said that the idler pulley sits on top of a V-belt which is connected to a pulley on the gearbox on one side and a pulley on the hydraulic pump on the other side. The hydraulic pump controls the steering of the harvester. The purpose of the idler pulley is to provide tension to the V‑belt which connects the other two pulleys. The idler pulley ("the pulley") is fitted to a bell crank (elbow shaped) arm and sits at the bottom of the longer end of the arm. The pulley is fitted to the arm by a ball bearing ("the bearing"). The bearing consists of an inner spindle, part of which is machine forced into an aperture at the end of the arm. The remainder of the spindle is covered by an outer casing in which there were most likely two rows of rolling ball elements. The balls roll in two grooves cut into the outer casing and also on the inner spindle. The balls are separated by a cage which is likely to have consisted of a plastic material and served to keep the balls apart from each other and in position. (The defendant referred to the cage as "the separators".) On the outer end of each cage there is a seal to keep out dust and moisture and to keep in the grease. The ball bearing was most likely of the "sealed for life" type which means that it cannot be re-lubricated. The outer casing containing the bearing balls would have been machine forced into the centre of the pulley.
Most of the bearing was destroyed as the result of its failure and the only parts remaining for inspection were the spindle which was still attached to the arm and the outer casing which was still inside the pulley. However, it was common cause between the parties that the bearing was likely to have been of the type described and that the balls, cages and seals would have been destroyed as a result of the failure. It was also common cause between the parties' experts that as a result of the loss of the balls the outer casing would have run directly on the spindle for some time and that this caused the spindle to be worn virtually half way through where it emerges from the arm.
It was also common cause that a different kind of bearing, a pivot bush, was originally fitted into the elbow of the arm. The pivot bush consists of a metal cylinder which is forced into the aperture in the elbow and then turns on a snug fitting shaft. The metal cylinder was still partly visible inside the elbow of the arm after removal of the arm from the harvester.
A tension rod is connected to the end of the shorter part of the arm which rod pulls the arm and pulley in a downward direction to supply the tension on the V-belt.
Mr Simms gave evidence that he was provided with the pulley that had fallen off the harvester as well as the arm that had been attached to the pulley. At the time these were provided to him the arm was no longer attached to the pulley as the inner components of the bearing had been destroyed. In addition to the pulley and arm originating from the harvester Mr Simms was also supplied with a similar pulley and arm which was still connected by way of a bearing. In addition he was supplied with photographs of the inside of the harvester indicating where the arm and the pulley were situated. Mr Simms did not inspect the harvester, but said that he had investigated a number of harvesters on previous occasions and was familiar with their general functioning.
Mr Simms provided two reports, dated 4 May 2006 and 4 June 2008 respectively. In his reports, as augmented by oral evidence, Mr Simms explained that although the bearing is sealed for life, it inevitably fails after a period of time because the balls or the groove in which they run ("the race") starts fatiguing. The balls then lose their shape which damages the seals. This in turn allows grease to escape or become contaminated by dust or crop particles which may further damage the seals. Further, as the inner parts of the bearing wear down they become hotter, which causes the grease to become thinner and escape more rapidly. Once the bearing starts to fatigue there is a spiralling effect caused by the damage to the seals, the ingress of contaminating material and the loss of grease. The fatigue of the inside parts of the bearing may also result from the seals wearing in the first instance therefore allowing dirty material to ingress which contaminates the grease and causes wearing of the balls.
Mr Simms expressed the view that in this case it was most likely that the bearing had failed by reason of fatigue and it having reached the end of its life span. He said that this was apparent from the fact that the balls and seals were totally worn away causing the outer casing to run directly on the shaft without lubricant. This was indicated by the part of the shaft protruding from the arm being almost halfway worn through. Mr Simms said that it was likely that the outer casing would have run on the inner shaft for approximately 20 to 30 minutes to cause that damage to the shaft.
Mr Simms gave evidence that because the bearings inevitably fail they need to be tested for wear and tear from time to time. This was achieved by holding the pulley with one hand at the back and one hand at the front of the pulley and rocking it by alternatively pushing with one hand and pulling with the other in order to feel whether there was some movement and whether a clicking noise could be heard. That would indicate that the bearing was no longer equal or round. Another way to test for wear and tear was to take the V‑belt off the pulley and to spin the pulley freely in the direction that it would normally rotate. If a rumbling sound was heard this indicated that the balls and grooves in the bearing were no longer smooth.
In the case of this particular harvester Mr Simms said that there was also a strong indication of wear and tear of the pivot bush, as this was worn to such an extent that not only the metal cylinder of the pivot bush had partly worn away, but also the steel of the arm at the 12 o'clock position on one side and the 6 o'clock position on the other. Although the pivot bush was oval or pear shaped, the wear was excessive at the narrow end of this shape. This indicated that the pulley was probably running at a slight angle to the belt which would have increased the bearing load horizontally and would have caused greater wear and tear on the bearing.
Mr Simms was of the view that the wear of the pivot bush would have developed over a substantial period of time. In support of this view he relied on the undamaged arm and pulley which had been supplied to him and which showed the same pattern of wear at the 12 o'clock position on one side and the 6 o'clock position on the other, but to a lesser extent. Mr Simms said that it was unlikely that the extreme wear on the pivot bush was caused by large and unbalanced dynamic forces during the final minutes of the failure of the bearing in the pulley as suggested by Dr Chew, the defendant's expert. Mr Simms was of the view that this would require very high forces which would cause rapid, unexpected and aggressive wear and that one would see high abrasion and almost no build-up of dirt or debris on the bush if that had occurred.
Mr Simms said that he did not agree with the proposition that the same excessive force which caused the spindle of the bearing to be deformed and partly worn away also caused the excessive wear of the arm at the pivot bush. He was of the view that the force that caused the spindle to deform was caused by the outer casing of the bearing rubbing on the spindle, but said that this was not an excessive force which would have caused a deformation at the pivot bush. Further, Mr Simms stated that if the excessive wear in the pivot bush had been caused by large and unbalanced dynamic forces resulting from the final disintegration of the bearing, one would have expected the excessive wear to occur on a horizontal plane and therefore 90°degrees from where it did occur. Mr Simms described the likelihood of the excessive wear on the pivot bush having been caused in the final minutes of the failure as "exceedingly small".
Mr Simms gave evidence that it was likely that the whole component, including the arm, the pulley and the pivot bush was designed to have a similar life expectancy and that if the pivot bush showed severe signs of wear and tear, that should have indicated to anyone inspecting the pivot bush or the pulley that the bearing inside the pulley was also likely to require replacement. Mr Simms gave evidence that the high degree of wear at the pivot bush, particularly the fact that it had eaten into the metal of the arm would have resulted in substantial movement of the pulley upon rocking it.
Mr Simms was further of the opinion that it was unlikely that the failure of the bearing was caused by the disintegration of the cage which separated the balls. The cage was normally well lubricated by the grease and there was little loading on it. It should therefore have had the longest lifespan of the parts inside the bearing and there was no reason for it to fail first.
Mr Simms also stated that it was very unlikely that the bearing would have failed by reason of a manufacturing defect. He explained by way of a graph that the longer a bearing lasts after the period during which the first 10 per cent of bearings generally fail, the less likely it is that the bearing was inherently defective. In other words, the longer a bearing lasts, the more likely it is that its failure was wear and tear and not a manufacturing defect. Mr Simms said that he had made the assumption that the bearing in the pulley was part of the original assembly of the arm, pulley and pivot bush and as the pivot bush was so badly worn, it was likely that the bearing inside the pulley was an old bearing. Another factor which led to the conclusion that the bearing was likely to have been old was that the rim of the pulley was badly worn and discoloured on one side. The reason why the rim was more worn on one side was because the tension rod had pulled the arm slightly over to the side of the harvester so that the pulley was running at a slight angle to the V‑belt.
Mr Simms came to conclusion that the likely cause of the bearing failure was normal wear and tear or premature wear due to the ingress of dust leading to the deterioration of the seals and ultimately a loss of lubrication. He said that the normal wear and tear or the ingress of dirt and loss of lubrication would have taken longer than 60 hours to develop before causing the catastrophic failure of the bearing.
Mr Simms was of the view that it was likely that the pulley had not been properly inspected prior to the commencement of the harvesting season. He said that if the whole component had been properly inspected by rocking the pulley or spinning it without the V‑belt, it would have been obvious that the pivot bush was badly worn and this would have indicated that it was likely that the bearing inside the pulley also needed replacement. Inspection of the pulley would also have indicated that the pulley was running at an angel to the V‑belt and that the pulley bearing was therefore subjected to additional loading. Mr Simms gave evidence that the fact that the pulley was running at an angle to the V‑belt could either have been only because of the arm being pulled over slightly by the tension rod or because additionally the oval shape of the pivot bush had worn out excessively at its narrow end.
Mr Simms said that it was unlikely that a bearing which had already been subjected to extended use would show no signs of excessive wear or seal leakage when inspected during a pre–season check, but would then fail catastrophically within only 30 to 60 hours of further use. He was of the view that if the pulley had shown no movement upon rocking, the bearing would still have been in a good enough condition to last for hundreds of hours.
Mr Simms stated that in his view the wear of the pivot bush also indicated that there was either inadequate lubrication or deficient maintenance for that part as the pivot bush would have taken a long time to wear to the extent of causing the deformation in the arm. Mr Simms said that an inspection of the grease nipple on the pivot bush revealed dirt around its collar and indicated that a grease gun had not been used on this nipple for some time. The condition of the grease inside and around the bearing also indicated that it had not been greased for some time.
Mr Simms further pointed out that there was dark discolouration on the outer rim of the pulley wheel. He said that this indicated that the pulley had momentarily stopped turning on a number of occasions prior to the final failure and that the rubber belt on the outer surface of the pulley had heated the pulley sufficiently to char the paint and turn it black around the outer rim. Mr Simms stated that the discolouration would not have been something that would have been visible at a pre–season inspection, as this was likely to have only occurred during the final stages before the bearing disintegrated and the pulley stopped working. However, the discolouration on the outer rim of the pulley indicated the stop start motion of the pulley during its final minutes. Mr Simms did not agree that the discolouration could have been caused by burning crop material as suggested by the defendant's expert, Dr Chew. Mr Simms said that the pulley would have stopped turning at the time that the fire had started.

I accept the evidence given by Mr Simms in its entirety. The conclusions that he arrived at were well substantiated and he explained fully in cross-examination on what basis he had arrived at his views and why he rejected the other possibilities raised by the defendant's expert, Dr Chew. It was put to Mr Simms that the conclusions that he arrived at were based on speculation as the inside parts of the bearing were not available for inspection and it was not known whether the bearing was part of the original assembly. It was also put to Mr Simms that the objective facts on which his conclusions were based were limited and were insufficient to support his views. Mr Simms readily conceded that he could not say that his conclusions were 100 per cent certain to be correct, but said that on the basis of the objective facts known and his experience of how the relevant parts interact and wear, he was of the view that his conclusions could be substantiated on a balance of probabilities.
I agree that whereas the objective facts are limited, Mr Simms has arrived at his conclusions in a well-reasoned and logical manner. The main issue on which he could be criticised is the assumption that the bearing was part of the original assembly. However, there is no evidence to the contrary and on the basis of the evidence by Mr Simms and also Mr Harris (the next witness) it is more than likely that if the bearing had been replaced, the pivot bush would also have been replaced.

Mr Dale Harris

Mr Harris is a heavy duty diesel mechanic who operates his own business servicing farm machinery and vehicles. He did an apprenticeship from 1987 to 1991 in the United Kingdom and also attended some further training courses. He specialises in farm machinery, including harvesters, and was employed in working as a mechanic in that area until he started his own business in 2001. Mr Harris gave evidence that he is regularly asked by farmers in the Katanning area where his business is based to check their farm machinery prior to the harvesting season and that approximately 20 to 25 per cent of all harvesters he services are Case International Harvesters. Last year his business serviced approximately 48 harvesters.
Mr Harris said that a pre–season service usually takes about 4 to 8 hours during which the machine is run at full speed and everything is checked including all bearings and belts. In order to check the bearing in the idler pulley he would have felt whether the pulley was excessively hot and would have listened for any noise in the bearing. He also has a digital thermometer which is pointed up the pulley to measure the heat and a stethoscope to listen to bearings which are hard to get to. Mr Harris stated that noise in the bearing is an early sign of failure. In addition he would check whether there was any movement in the pulley by rocking it. If the pulley moved more than 1 to 1 ½ millimetres it suggested that there was a problem with the bearing. As a further test he would take off the V‑belt and spin the pulley to hear whether it made any noise. If there was a lack of lubrication in the bearing or water had entered it, the pulley would make a noise. Mr Harris said that although the idler pulley is situated above head height, it was reasonably accessible by the use of a 3 foot step ladder.
Mr Harris further gave evidence that the pivot bush in the arm supporting the pulley tended to wear out and this would also be indicated by a movement in the pulley. If the bush had worn out it would be replaced. In that case he would also as a matter of course replace the bearing in the pulley, because it made practical sense to replace a bearing costing approximately $40 at the same time. The labour in taking off the belt, pulley and arm on another occasion just to replace the bearing would involve double that cost. Mr Harris stated that he always serviced the arm with the pulley including the pivot bush and the bearing as a unit.
Mr Harris gave evidence that he was trained to employ this method of inspection and service and that he would expect any competent mechanic to have taken the same basic steps.
Mr Harris gave evidence from the perspective of what he does and would have done in servicing the idler pulley assembly. Evidence of the particular practice that an expert employs is not admissible as this only shows what the particular expert does and not what the industry standard is: Maronis Holdings Ltd v NipponCredit Australia Pty Ltd (2001) 38 ACSR 404 at [380] and Permanent Trustee Australia Ltd v Boulton Permanent Trustee Australia Ltd (1994) 33 NSWLR 735 at 738.
However, Mr Harris also said that he was trained to use this particular method of inspection and service and that he would expect any competent mechanic to have taken the same basis steps. Accordingly, I accept that Mr Harris's evidence is sufficient to show that the method of inspection employed by him is what a reasonable and competent mechanic would have done. This was also confirmed by Mr Simms who gave evidence to similar effect.

Mr Peter Masson

Mr Masson also gave evidence for the plaintiffs. He is a self‑employed insurance assessor and inspected the harvester after the fire.
Mr Masson said that he noticed a build–up of grain dust and oil on the harvester. Mr Masson gave evidence that the defendant told him that the harvester had harvested approximately 300 acres of barley prior to the fire breaking out.

Mr David Townsend

Mr Townsend is a farmer in Rocky Gully but also worked for the defendant from time to time. During the harvesting season at the end of 2005 he drove a truck carting the defendant's grain to the silo. His diary indicated that he had driven the truck on 9, 10, 12, 13, 14, 15, 16 and 19 December 2005. On the days that he had been carting grain the defendant had harvested barley. However, Mr Townsend was not able to say whether the Case International 1440 harvester was used on each of those days, as the defendant also owned another harvester.
Mr Townsend also assisted the defendant in the maintenance of the Case International 1440 harvester. He put oil into the motor and greased all grease nipples. He could not specifically remember having greased the nipple on the pivot bush, but said that he had greased every nipple that he could see. Mr Townsend gave evidence that the grease nipple on the pivot bush would have been accessible from the top of the harvester with a flexi–head on the grease gun.

Mr Arthur Thornton

Mr Thornton is a 55 year old farmer whose farm abuts that of the defendant. Mr Thornton said that he had no formal mechanical qualifications but had learnt from his father who was a mechanic in the army in the war. Mr Thornton had maintained all his own machinery including harvesters, throughout his years on his farm.
Mr Thornton gave evidence that in November 2005 he assisted the defendant to take off the hydraulic pump on the harvester as it needed repairs and also assisted him to replace the hydraulic pump. In order to take off the hydraulic pump it was necessary to remove the V‑belt from the idler pulley. Mr Thornton stood on a two gallon drum in front of the harvester so that he could access the pulley. He first released the spring on the rod exerting tension on the arm and then wriggled the belt off the bottom of the pulley by holding it with both hands at the underside of the pulley wheel. In doing so he rocked the pulley wheel from side to side in the direction that the wheel normally turns. During this process the defendant was lying on top of the harvester trying to lift the weight of the pulley slightly off the V‑belt. A similar procedure was applied in reverse when the belt was put back onto the pulley wheel. In this instance the defendant just dropped the pulley from above onto the V‑belt to get it back into position.
Mr Thornton said that after having worked with the pulley in the process of taking off the belt and refitting it he had no concern that there was anything wrong with the pulley or the arm. Mr Thornton admitted that the work that he had done on the harvester was not an exercise of inspecting for wear, but only involved the steps necessary to take the hydraulic pump off and refit it.
Mr Thornton said that he also assisted the defendant with the maintenance of the harvester during December 2005. He said that he checked the oil in the engine and greased every nipple that required greasing on every day that the harvester was used.

Mr David Wellard

Mr Wellard is also a farmer next door to the defendant. He acted as the fire control officer when the fire broke out. He said that the wind blew in an easterly, south-easterly direction on the day of the fire, but did not say how strong the wind was.
Mr Wellard gave evidence that he drove over the paddock where the fire had started after the fire had been brought under control and found the pulley lying in a burnt area roughly 50 metres from the western edge of the fire.

The defendant

The defendant gave evidence that he owns four farming properties and has been farming in his own right for 17 years after he took over the family farm. Prior to that he worked for Mr Walker from whom he inherited a farming property and the harvester.
The defendant said that prior to the fire breaking out he had harvested approximately 1000 acres over 7 – 8 days. He agreed that he had told Mr Masson that the harvester had harvested approximately 300 acres of barley prior to the fire, but said that this was mentioned in what he regarded as a casual conversation and that he established later with the assistance of Mr Townsend's diary that he had been harvesting for 7 – 8 days prior to the fire. The defendant stated that he would harvest for 8–10 hours per day and that the harvester would do about 8 acres per hour. It would struggle to do 10 acres per hour.
On the basis of this information it does not seem possible to determine how many hours the harvester had done prior to the fire. As the defendant owned and employed two harvesters and Mr Townsend's diary does not indicate which harvester was employed on what day, it is not clear how many hours the harvester had done. If it is assumed that the information supplied by the defendant to Mr Masson was more or less correct and that the harvester did about 8 acres per hour, then it would have been employed for approximately 37.5 hours prior to the fire breaking out. The defendant said that it would have taken the harvester about 40 hours to do 300 acres.
The defendant confirmed that he and Mr Thornton had removed the hydraulic pump and reinstalled it in the manner described by Mr Thornton. The defendant said that apart from lifting the pulley, he did not move it and did not feel any sideways movement in the pulley. He admitted that he had no mechanical training and was not looking for wear at the time when the hydraulic pump was removed and replaced. The defendant said that he had not noticed any problem with the pulley or arm during the work performed.
The defendant agreed that he had not inspected the pulley and arm for wear after inheriting the harvester. He said that to his knowledge the harvester was last inspected by a trained mechanic when it received a new motor in March 2004. However, he thought that Mr Walker had maintained the harvester by greasing it and checking belts for tension, but he had not done this himself.
The defendant admitted freely that he knew before the fire started that bearings could wear out and seize up and that if that happened hot metal could drop to the ground. He also agreed that he knew that if he did not maintain the harvester, there was a chance that it could start a fire.
The defendant gave evidence that on the day of the fire he had driven the harvester about 4 kilometres up a farm track and back in order to unload the box. He then started harvesting barley. He suddenly noticed that the steering wheel became very difficult to turn and when he looked behind him, he saw the patch of fire which spread tremendously quickly. The defendant said that the fire raced at the speed of a person running, but in all directions at the same time. The crop in which the fire had started had a lot of rye grass and other vegetation at the bottom of it and the paddock next to it had been unused for some time and was covered in oat stubble which was about three feet high and was also full of rye grass and self‑sown oats. The defendant stated that seeing the rapid spread of the fire was a terrifying experience.
The defendant gave evidence that 3 – 5 days after the fire Mr Wellard brought the pulley to him which he had found in the field. The defendant stated that he also took the arm off the harvester and that at that time it was much dirtier and greasier than it was at the trial. He kept the pulley and arm in a cupboard on a concrete floor in his shearing shed until it was required for the trial.

Mr Richard Priestley

Mr Priestley is a loss adjustor and was also engaged in respect of the fire on the defendant's property. He was provided with the damaged pulley and inspected the arm which was still on the harvester. He asked the defendant to take the arm off. Mr Priestley took the arm with him to be photographed. Before he put the arm into his car he wiped it with a rag in order to remove the dirt and grease on the outside of the arm. Mr Priestley said that in doing so he wiped some of the grease and dirt into the aperture of the arm where the pivot bush was situated. He did not wipe out the inside of the aperture.
At a later stage Mr Priestley returned the arm to the defendant, but when he saw it again he noticed that the defendant had kept the arm in an open shed where it was exposed to dust and grain dust.

Dr Chew

Dr Chew gave expert evidence on behalf of the defendant. He has a PhD in mechanical engineering which he attained in 1980 and has operated his own business as a consulting engineer since 1988.
Dr Chew was provided with essentially the same information as Mr Simms. However, Dr Chew also inspected the harvester and took photographs of it and of the defendant and Mr Thornton demonstrating how they had removed the hydraulic pump and reinstalled it. Dr Chew provided two expert reports, dated 27 March and 20 July 2008 respectively and also gave oral evidence to further explain his reports.
Dr Chew was of the view that the cause of the bearing's failure could not be determined on a basis of balance of probabilities because the majority of the component parts had not been recovered and could not be examined. He listed a number of causes that could also have been responsible for the failure of the bearing. These causes seem to be either related to defective manufacture or fitting, or to factors associated with contamination, loss of lubricant or wear and tear.
Dr Chew agreed with Mr Simms that problems with a bearing are normally detectable by rocking the pulley and observing movement in the pulley and by listening for rumbling noises made by the pulley while in operation. However, he was of the view that in the case of the idler pulley it would have been difficult to hear noises during service as the pulley was situated close to the engine and the engine noise would have drowned out the bearing's rumble. Dr Chew was not asked whether the pulley could have been checked for unusual noises by taking off the V‑belt and spinning it. Dr Chew also thought it impractical to check the pulley for movement by rocking it, as the pulley was 2.2 metres above the ground and within a confined space where a number of other machinery parts made it difficult to access it. He was further of the view that in contrast with a motorcar bearing, the ratio of the pulley to the bearing was substantially smaller and the movement would therefore have been smaller.
As regards the manner in which problems with the bearing can be detected, I prefer the evidence given by Mr Simms and Mr Harris. Both explained quite clearly that a sideways movement in the pulley can be easily detected by rocking the pulley and that a movement of 1 to 1 ½ millimetres would have been of concern. Mr Thornton explained that he stood on a 2 gallon drum in order to be at shoulder level with the pulley and Mr Harris said that it was sufficient to stand on a 3 foot step ladder. From the photographs included in Dr Chew's reports it does not seem difficult to place one hand behind the pulley and one in front in order to rock it. Further, both Mr Simms and Mr Harris said that the proper way of checking for noise was to take off the V‑belt and spin the pulley.
I am satisfied that if the bearing had been substantially worn or contaminated at the time of a pre‑season inspection prior to the fire and if that inspection had been carried out by a person with sufficient knowledge of the procedure to follow and what to look out and listen for, the impending problem with the bearing would have been detected.
However, the first issue is whether it can be said that on a balance of probabilities the bearing was substantially worn or contaminated to the extent that this would have been detected by a competent inspection. As I have indicated Dr Chew was of the view that other reasons for the failure of the bearing could not be excluded and that the cause of the failure could not be determined on a balance of probabilities. Dr Chew came to the conclusion that the excessive wear in the pivot bush most probably occurred at the time when the bearing failed and that large and unbalanced dynamic forces increased the wear rate of the pivot bush to the extent of causing the excessive wear. However, Dr Chew did not give any more detailed explanation of how the large and unbalanced forces would be generated and why they would have caused the excessive wear at the particular 12 o'clock and 6 o'clock positions.
I prefer Mr Simms' reasoning in this regard, namely that the wear in a similar position on the arm attached to the undamaged pulley indicates that this is a type of wear that is caused in the normal operation of the pulley and that the excessive wear in the arm attached to the failed pulley shows that it must have been subject to particularly lengthy wear and tear. Mr Simms then concluded that if the pivot bush had been subjected to a long period of wear, it was likely, in the absence of evidence to the contrary, that the bearing in the pulley had also been exposed to lengthy periods of wear and tear. Mr Simms' view was further strengthened by the fact that the rim of the pulley wheel showed signs of wear where the V‑belt had run in a slightly angular position.
If all these objective facts are taken together, it is a reasonable conclusion that on a balance of probabilities the bearing had reached the end of its lifespan by reason of wear and tear and that this was the cause of the bearing's failure. Once it is accepted that the bearing failed because of wear and tear, the plaintiffs have proven that this would have been detected upon a proper and competent inspection of the pulley arm assembly. Mr Simms and Mr Harris both gave evidence that substantial wear would have been detected upon a proper inspection and Mr Simms said essentially that if the bearing had still been in a such a good condition at the time of a pre-season inspection that it showed no movement and made no noise, it would have lasted hundreds of hours more and would not have failed within 30 – 60 hours of harvesting. Mr Harris further said that he would have advised any owner or user of a harvester to replace the bearing if the pivot brush had shown signs of wear and tear.
A number of the other potential causes listed by Dr Chew are also causes which are likely to have indicated a potential problem upon a proper pre-season inspection, such as insufficient lubrication in the bearing, contamination by abrasive matters in the bearing, ingress of moisture in the bearing and loss of lubrication due to seal damage or leakage. As explained by Mr Simms, a loss of lubrication or contamination of the grease leads to damage of the balls and grooves, which in turn leads to damage to the seals, which causes more loss of lubrication and ingress of dirt and therefore more damage to the balls and grooves.

Dr Chew did not explain the other potential causes of the bearing failure listed by him. However, I accept the evidence of Mr Simms that any manufacturing fault or error in fitting the bearing or its components would have been likely to have caused a failure of the bearing at a much earlier stage. Dr Chew seems to have mainly relied on the alternative cause of the cage around the balls having failed. However, as referred to earlier, Mr Simms discounted that possibility on the basis that the cage carried the least loading. I accept Mr Simms' opinion in preference to that of Dr Chew. In the absence of evidence that the bearing had been replaced at some stage, common sense together with the objective facts as interpreted by Mr Simms leads one to the conclusion that the bearing was old and worn and had reached the end of its natural life span.
Dr Chew also came to the conclusion that there was no visible lack of maintenance of the harvester, as there was grease in the lubrication groove in the pivot bush. Further, although the grease nipple to the pivot bush was free of grease, this could have been the result of inadvertent handling of the arm after the fire.
Mr Simms indicated by way of a photograph that the dirt on the grease nipple to the pivot bush showed that it had not been used in recent times. He also said that the grease trapped in the grease groove inside the arm was dirty and had not been purged with new grease for some time. Mr Priestly gave evidence that he may have inadvertently wiped grease and dirt from the outer surface of the arm into the aperture of the arm where the pivot bush had been. This was not put to Mr Simms for his comment. It is therefore not clear whether the dirty grease inside the aperture in the arm could have been wiped in there by mistake. However, the lack of use of the grease nipple to the pivot bush indicates a failure to grease that particular component part.
In my view it is not necessary to decide whether the harvester was badly maintained by a lack of greasing or not. It would only be a further factor pointing to a lack of general maintenance and the likelihood that the bearing was old and worn and had not been recently inspected or replaced. In my view this has already been established on a balance of probabilities on the basis of the objective facts identified by MrSimms and the conclusions that he has drawn from those facts.
I therefore also do not accord any weight to the evidence of Mr Masson regarding the build‑up of grain, dust and oil on the harvester.

Bearing failed by reason of wear and tear

Accordingly, I have come to the conclusion, based on the evidence by Mr Simms, that the plaintiffs have established on a balance of probabilities that the bearing failed by reason of wear and tear.

The defendant's duty of care

The defendant admitted in par 5(b) of his re-amended defence, dated 15 July 2008, that he owed the plaintiffs a duty to take reasonable care to prevent damage to the plaintiffs' property as a result of using the harvester on the defendant's property. During his opening address counsel for the defendant submitted that the duty of care was more appropriately described as a duty to take reasonable care to prevent damage from fire to the plaintiffs' property as a result of using the harvester on the defendant's property. The court accepted that this was the correct formulation of the relevant duty of care and counsel for the plaintiffs did not object to this.
Counsel for the defendant submitted that the duty of care should not be more circumscribed, for example, by the duty of care being linked to an obligation by the defendant to properly maintain the harvester. Counsel for the defendant referred to Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54; (2002) 194 ALR 337 at 336 where McHugh J cautioned against the danger of formulating a duty of care in specific terms. His Honour pointed out that to formulate the duty in specific terms invited error because it was likely to mix a question of law (whether a duty existed) with a question of fact (whether a breach occurred).
Gummow and Hayne JJ also pointed out that a duty of care that was formulated retrospectively as an obligation purely to avoid the particular act or omission said to have caused the loss, was of its nature likely to obscure the proper enquiry as to breach.
I therefore accept the formulation of the duty of care proposed by counsel for the defendant and agree that it should not be described as a duty not to cause damage by fire to the plaintiffs' property by reason of a lack of maintenance of the harvester.

The defendant's breach of the duty of care

The essential question in this case is whether the defendant breached his duty of care to the plaintiffs not to cause damage by fire to their property by reason of the use of the harvester on the defendant's property.
The present case is governed by the provisions of the Civil Liability Act 2002 ("the Act"). Section 5B of the Act provides the following with regard to breach of a duty of care:
"General principles
(1)A person is not liable for harm caused by that person's fault in failing to take precautions against a risk of harm unless –
(a)the risk was foreseeable (that is, it is a risk of which the person knew or ought to have known);
(b)the risk was not insignificant; and
(c)in the circumstances, a reasonable person in the person's position would have taken those precautions.
(2)In determining whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (amongst other relevant things) –
(a)the probability that the harm would occur if care were not taken;
(b)the likely seriousness of the harm;
(c)the burden of taking precautions to avoid the risk of harm;
(d)the social utility of the activity that creates the risk of harm."
In Waverley Council v Ferreira [2005] NSWCA 418 at [27] Ipp JA held that s 5B of the Civil Liability Act 2002 (NSW), which is in the same terms as s 5B of the Act, was consistent with the common law pursuant to which a court was also required to identify what a reasonable person in the position of the defendant would have done by way of response to a reasonably foreseeable risk. Ipp JA further pointed out at [55] that the matters set out in s 5B(2) of the Civil Liability Act 2002 (NSW) were, in substance, a reiteration of the remarks by Mason J in Wyong Shire Council v Shirt (1980) 146 CLR 40 at 47 – 48. These remarks, often referred to as the Shirt‑formula, are the following:
"In deciding whether there has been a breach of the duty of care the tribunal of fact must first ask itself whether a reasonable man in the defendant's position would have foreseen that his conduct involved a risk of injury to the plaintiff or to a class of persons including the plaintiff. If the answer be in the affirmative, it is then for the tribunal of fact to determine what a reasonable man would do by way of response to the risk. The perception of the reasonable man's response calls for a consideration of the magnitude of the risk and the degree of the probability of its occurrence, along with the expense, difficulty and inconvenience of taking alleviating action and any other conflicting responsibilities which the defendant may have. It is only when these matters are balanced out that the tribunal of fact can confidently assert what is the standard of response to be ascribed to the reasonable man placed in the defendant's position.
The considerations to which I have referred indicate that a risk of injury which is remote in the sense that it is extremely unlikely to occur may nevertheless constitute a foreseeable risk. A risk which is not far-fetched or fanciful is real and therefore foreseeable. But, as we have seen, the existence of a foreseeable risk of injury does not in itself dispose of the question of breach of duty. The magnitude of the risk and its degree of probability remain to be considered with other relevant factors."
The first question that must be assessed pursuant to s 5B(1) of the Act is whether the risk was foreseeable, in other words, whether it was a risk of which the defendant knew or ought to have known, and whether the risk was not insignificant. The risk in this case was that if the harvester was not inspected on a regular basis by a competent and skilled mechanic, a bearing in the harvester might fail by reason of wear and tear and cause a fire to start in dry crops or stubble which could then spread to a neighbouring property where it could cause loss and damage. There is no real issue in this case whether the risk was foreseeable, because the defendant admitted readily that he knew before the fire started that bearings could wear out and seize up and that if that happened hot metal could drop to the ground. The defendant agreed that he knew that if he did not maintain the harvester there was a possibility that a worn bearing could start a fire on his property.
It would also have been foreseeable to a reasonable person in the position of the defendant that a fire which had started on one property could easily spread to a neighbouring property, particularly as the harvesting occurred on 19 December 2005, that is, in the middle of summer. There was no evidence led of how hot it was on that particular day, but MrWellard said that the wind blew in an easterly, south easterly direction on the day of the fire. Despite the lack of evidence regarding the temperature on that day, in my view a court may take judicial notice that every farmer knows that there is a high danger of fires spreading through fields of dry grain or stubble in the middle of summer.
It seems that s 5B(1)(b) of the Act has imposed a higher test for the foreseeability of risk than the test contained in the first part of the Shirt‑formula, because it requires that the risk also be "not insignificant". The Act implemented recommendations of the Review of the Law of Negligence Final Report, dated September 2007, which was prepared by a review panel appointed on 2 July 2002 by the Minister for Revenue and Assistant Treasurer, the Honourable Helen Coonan (the "Ipp Report"). In par 7.12 the Ipp Report referred to the statement by Mason J in Wyong Shire Council v Shirt (supra) that a foreseeable risk was a risk which was not "far‑fetched or fanciful". The Ipp Report then expressed the concern that lower courts might be in danger of ignoring the second part of the Shirt‑formula and might come to the conclusion that there had been a breach of duty merely because the risk was foreseeable without taking the next step and asking what precautions a reasonable person would have taken in light of the foreseeability of the risk. In order to deal with this perceived problem the Ipp Report suggested in par 7.15 that the Shirt‑formula be modified by the replacement of the phrase "not far‑fetched or fanciful" with the words "not insignificant". The report stated that the phrase "not insignificant" was intended to indicate a risk that was of a higher probability than the risk described by the phrase "not far‑fetched or fanciful", but not so high as might be indicated by a phrase such as "a substantial risk".
Counsel could not refer me to any authority in which the phrase "not insignificant" was considered in detail in the context of the Act or an equivalent Civil Liability Act in other States. Counsel for the plaintiffs submitted in his supplementary submissions, dated 26 September 2008, that the Courts have equated this expression with a risk that was not far‑fetched or fanciful. Counsel for the plaintiffs further pointed out that in New South Wales v Fahy (2007) 236 ALR 406 at [79] per Gummow and Hayne JJ, and at [129] ‑ [131] per Kirby J, the High Court declined to reconsider the Shirt‑formula despite being invited to do so on the basis that the Civil Liability Act 2002 (NSW) included a requirement that the risk not only be foreseeable but also not insignificant.
Although the High Court has declined to review the Shirt‑formula, it seems that at least the New South Wales Court of Appeal has interpreted s 5B of the Civil Liability Act 2002 (NSW) as requiring that an additional factor be proven which goes beyond the risk being not far‑fetched or fanciful, because the cases generally make the point that the risk was foreseeable and also not insignificant: see, for example, Waverley Council v Ferreira(supra) at [69], per Ipp (with whom Spigelman CJ and Tobias JA agreed); Martin v The Trustees of the Roman Catholic Church of the Archdiocese of Sydney [2006] NSWCA 132 at [8] per Giles JA; Haris v Bulldogs Rugby League Club [2006] NSWCA 53 at [96] – [97] per Santow JA (with whom Mason P and Ipp JA agreed). However, no explanation is given of what a "not insignificant risk" entails.
Counsel for the defendant referred the court to Drinkwater v Howarth [2006] NSWCA 222 at [19] in which case Basten JA (with whom Tobias and Hodgson JJA agreed) said that where the plaintiff was "clearly at risk" (of injury), it could not be said that the risk was insignificant. Counsel for the defendant relied on Eutick v City of Canada Bay Council [2006] NSWCA 30 at [103] where Campbell AJA (with whom Giles JA and Ipp JA agreed) pointed out that the plaintiff carried the onus of establishing that the relevant risk was not insignificant.
Even if the phrase a "not insignificant risk" requires an additional factor to be proven which goes beyond the requirement that the risk be not far‑fetched or fanciful, it follows from what I have said about the foreseeability of the risk that it was not an insignificant risk. The defendant readily admitted that he was aware of the possibility of a bearing becoming worn and starting a fire and his response to the question asked in this regard did not indicate that he considered the risk insignificant. Mr Simms also gave evidence that bearings will inevitably start failing by reason of wear and tear and that upon their final disintegration hot material or flaming grease is likely to drop to the ground. The risk of a fire spreading from burning stubble or crops on one farm to another in the middle of summer is also not an insignificant risk.
The next question pursuant to s 5B(2) is what precautions a reasonable person would have taken in response to the risk. In Waverley Council v Ferreira (supra) at [51] ‑ [52] Ipp JA explained that this question required the consideration of the four factors listed in s 5B(2)(a) – (d) of the Act and that the first two factors should be weighed against the second two factors.
The first factor to be considered is the probability that the foreseeable harm would occur if care were not taken. Neither the plaintiffs nor the defendant presented any evidence regarding how often fires have been caused in the past by reason of a worn bearing or the malfunctioning of any other mechanical part of a harvester or how probable this risk is considered to be in the farming community. However, the defendant admitted readily that he knew that a bearing could wear out and that this could cause hot metal to drop to the ground. Although the defendant only said that he knew that if he did not maintain the harvester there was "a chance that it could start a fire", the manner in which he admitted this did not indicate that he thought this to have been an unlikely possibility.
In Waverley Council v Ferreira (supra) at [48] – [49] Ipp J pointed out that the probability of the harm occurring if care is not taken is a factor which the court should take into account. It is not necessary that the probability of the harm occurring be established on a balance of probabilities.
The evidence of Mr Simms has shown that there is a high degree of probability that a worn bearing will disintegrate at some point in time and that this will cause either a hot piece of metal or plastic or flaming grease to fall to the ground.
There was no evidence by the plaintiffs about how readily a piece of hot metal or plastic can cause a fire to start in dry stubble, but I am of the view that this is a matter of which judicial notice can be taken. In Haileybury College v Emanuelli [1983] 1 VR 323 at 330 – 331 Murphy J came to the conclusion that it was reasonably foreseeable that if the metal parts of a trailer were dragged at speed along a bitumen road surface, the parts could become very hot, causing sparks to fly off and igniting a fire in the roadside grass. His Honour seems to have taken judicial notice of the fact that most people in Australia are aware that fires can be started in roadside grass by sparks and that a fire could travel at great speed. His Honour made the following comment in this regard:
"In Australia, most people are aware that some fires which ravaged country areas in summertime used to be started by sparks from steam trains. It is also well known that country roadside verges are frequently cleared of dry grass in summer in order to avoid the risk and consequence of a fire being started by human agencies such as cigarettes, accidents, over heating of grass from exhaust pipes or anyone of a great number of causes. During summer in country areas, fires may not be lit in the open, and severe fines are imposed on those who offend. On days of total fire ban no fire may be lit in the open anywhere in Victoria, and in some circumstances, chainsaws, tractors and like engines with exposed exhaust may not be used."
Murphy J further referred to the decision of the High Court in Hazelwood v Webber (1934) 52 CLR 268 at 278 where the special risks of risks of fire in a community such as the Australian country were adverted to by the High Court. Murphy J then came to the conclusion that evidence as to the special risks of fire in the Australian countryside was unnecessary, when, "at every turn in summer we are constantly reminded of them".
Accordingly, it may be accepted, even though no specific evidence was led in this regard, that there was a reasonably high degree of probability that a fire would start in the dry stubble on the defendant's land if hot material from a disintegrated bearing fell on the ground.
The next factor to be considered under s 5B(2)(b) is the likely seriousness of the harm. This was clearly significant and it would have been obvious to any reasonable person in the position of the defendant that if a fire started in his fields it could quickly spread to neighbouring properties and cause considerable damage to property and livestock.
The third factor listed in s 5B(2)(c) is the burden of taking precautions to avoid the risk of harm. As indicated earlier, MrHarris gave evidence that he is regularly asked by farmers in the Katanning area to carry out a pre‑season service which usually takes about 4 to 8 hours. There was no evidence as to the expense of such a pre–season service. In Waverley Council v Ferreira (supra) at [78] Ipp JA came to the conclusion that the defendant has an evidentiary burden to establish that the burden of taking precautions would have been unreasonable. The defendant gave no such evidence. Mr Harris, who gave evidence on behalf of the plaintiffs, said that in the previous year his business had serviced approximately 48 harvesters. In my view it can be deduced from this evidence that carrying out a pre‑season service of a harvester is not an extraordinary burden or expense which farmers can generally not be expected to take or afford. It is likely to be less expensive for farmers to carry out their own pre-season service and many farmers presumably do so. However, the fact that a certain practice has been adopted over many years does not necessarily mean that this is not a negligent practice: Mercer v Commissioner for Road Transport (1937) 56 CLR 580 at 589.
There is, of course, no reason why a farmer who has the requisite skill and competence cannot service his own harvester. However, where a farmer does not have the necessary training or experience to know how to test for faulty bearings, the expense of employing a skilled and competent mechanic does not appear to me to be an unreasonable requirement.

The fourth factor pursuant to s 5B(2)(d) is the social utility of the activity that creates the risk of harm. This factor does not appear to be relevant to the present case. In so far as it is applicable, in my view the activity that creates the risk of harm is not harvesting crops as such, but the harvesting with a harvester that has not been regularly inspected by a competent and skilled mechanic for mechanical faults that may develop during the next harvesting season. In my view there is no social utility in this activity. This is not a situation where, for example, the defendant had no choice but to use a vehicle in an emergency even though he knew it not to be in a serviceable condition (cf the remarks by Ipp JA in Waverley Council v Ferreira(supra) at [50]).
Taking into account the seriousness of the risk of a fire developing on the defendant's land and spreading to neighbouring properties, the probability of this occurring where a bearing fails because of wear and tear and the burden occasioned by employing a skilled and competent mechanic to do a pre–season check of a harvester, I am of the view that a reasonable farmer's response to the risk would have been to have carried out a pre–season service of the harvester by employing a skilled and competent mechanic.
The finding that a reasonable response to the risk would have been to have carried out a pre–season professional inspection is reinforced by the fact that driving a harvester on land covered with dry crops or stubble is a reasonably dangerous activity because of the risk of fire and therefore attracts a higher degree of care. In Burnie Port Authority v General Jones Pty Ltd (1994) 179 CLR 520 the High Court held that under the common law of Australia any special rule relating to the liability of an occupier for fire escaping from his premises has been absorbed into the more general principles regarding the law of negligence. However, the majority (Mason CJ, Deane, Dawson, Toohey and Gaudron JJ) said the following at 554:
"… the standard of care remains 'that which is reasonable in the circumstances, that which a reasonably prudent man would exercise in the circumstances'. In the case of [a dangerous substance or a dangerous activity of a kind which might attract the rule in Rylands v Fletcher], however, a reasonably prudent person would exercise a higher degree of care. Indeed, depending upon the magnitude of the danger the standard of 'reasonable care' may involve 'a degree of diligence so stringent as to amount practically to a guarantee of safety'."
Although the reasonable response is to be assessed on the basis of the four factors listed in s 5 B(2) of the Act and not on the basis of the common law, the fact that driving a harvester over land containing dry crops is a dangerous activity also impacts on at least the first two factors, namely the probability of the harm occurring and the likelihood of serious harm. The danger of driving a harvester is that it brings into close contact the mechanical parts of a large machine running on petrol or diesel and containing oil, with highly inflammable plant material whilst various parts of the machine become hot in the process.
Counsel for the defendant submitted that there was no evidence of the practice that other farmers in the Gnowangerup farming community adopt in relation to the service of their harvesters and no expert evidence to the effect that a reasonable farmer would carry out a pre–season service on his harvester. However, I am of the view that evidence of the practice of other farmers would have been just another factor to take into consideration and, as indicated earlier, not necessarily a conclusive factor, as it may have been a negligent practice. As regards any expert evidence of what a reasonable farmer would do, such evidence is not necessary for the court to make its own finding as to what a reasonable farmer's response would have been to the risk of the harvester causing a fire by reason of some mechanical failure. The court has been assisted in this assessment by the evidence of Mr Simms and Mr Harris.
Counsel for the defendant further relied on the fact that the operator's manual for the harvester did not require an annual inspection of the pulley and did not warn that the bearing might get worn and disintegrate. There was also no such instruction or warning in the workshop manual for the harvester. However, the operator's manual and workshop manual also do not specify, for example, that the oil needs to be changed on a regular basis. Mr Harris gave evidence that a competent mechanic would check for worn bearings during a pre‑season inspection of a harvester. Moreover, the defendant admitted that he knew that the bearing could wear out and that this could cause hot metal to drop to the ground.
Whereas the fact that the operating instructions and workshop manual of the manufacturer do not contain any advice about regular inspections or a warning regarding the wear and tear of bearings is one of the factors to consider when assessing a reasonable response to the foreseeable risk, this does not detract from the conclusion that a reasonable response to the foreseeable risk was to have the harvester regularly inspected by a competent and skilled mechanic.
Counsel for the defendant further submitted that a court should be careful not to judge the question whether reasonable care had been exercised by the defendant by retrospectively asking whether the defendant's actions could have prevented the plaintiffs' loss and damage and only focussing on the exact manner in which the damage was caused. Counsel for the defendant relied on Roads and Traffic Authority of NSW v Dederer (2007) 81 ALJR 1773 where Gummow J referred at [65] to the following statement by Hayne J in Vairy v Wyong Shire Council (2005) 223 CLR 422 at [128]:
"When a plaintiff sues for damages alleging personal injury has been caused by the defendant's negligence, the enquiry about breach of duty must attempt to identify the reasonable person's response to foresight of the risk of occurrence of the injury which the plaintiff suffered. That enquiry must attempt, after the event, to judge what the reasonable person would have done to avoid what is now known to have occurred. Although that judgment must be made after the event it must seek to identify what the response would have been by a person looking forward at the prospect of the risk of injury."
It is, of course, correct that looking at what the defendant would have foreseen prior to the fire occurring and what a reasonable person in his position would have done to prevent or minimise the risk of fire would not necessarily have focused on the failure of a bearing in the harvester. However, it would at least have been foreseeable prior to the fire that some mechanical failure of the harvester might cause hot pieces of metal to drop to the ground or sparks being emitted from the engine or the exhaust and that this might cause the dry crop or stubble to ignite.
It has been established law since the English Court of Appeal decision in Hughes v Lord Advocate [1963] AC 837 that a defendant does not have to foresee the exact manner in which damage to the plaintiff's property may occur: Mount Isa Mines Ltd v Pusey (1970) 125 CLR 383 at 390, 403 and 413 ‑ 414. As long as the damage that occurred is of the same "kind" or "sort" as the damage foreseeable (in this case, damage by fire caused by a mechanical fault in the harvester), the damage is not considered to be too remote in the context of the foreseeability of loss or damage.
Further, in this case the defendant gave evidence that he did foresee the risk of fire as the result of hot parts from a failed bearing dropping to the ground. But even if the foreseeable risk would have been of a more general kind such as the risk of fire resulting from some mechanical failure or malfunctioning of the parts of the harvester, this would still have satisfied the requirement of foreseeability and called for the regular maintenance of the harvester in a professional manner.
Accordingly, the court has not assessed with hindsight what the defendant should have done and has not only focussed on the particular manner in which the risk eventuated. The finding that a reasonable person in the position of the defendant would have had a pre–season service conducted by a competent and skilled mechanic is appropriate even when the question is asked what that person looking forward at the prospect of a more general risk of mechanical failure would have done.
Even if I am wrong in my finding that a reasonable farmer would have conducted a pre–season service of his harvester by employing a skilled and competent mechanic, I am of the view that a reasonable response to the foreseeability of the risk of fire being caused by a failed bearing would have been to have this particular harvester serviced by a competent and skilled mechanic. The defendant had inherited the harvester at the beginning of 2005 and knew that it was approximately 20 years old and had done about 4,000 hours of work. The defendant did not know to what extent the harvester had previously been serviced apart from the fact that it had received a new engine in about March of the previous year when it was still owned by the deceased neighbouring farmer. The defendant said that he presumed that the pulley would have been inspected at that time, but it was apparent that the defendant had no specific knowledge in that regard. In any event this was more than 20 months prior to the day of the fire. Accordingly, the fact that the defendant knew that this harvester had seen many years of service and had no knowledge of the extent of its regular maintenance in the past means that a reasonable response to the foreseeable risk would have been to arrange for an overall service by a skilled and competent mechanic.
The evidence of the defendant and his assistant, Mr Thornton, that I have earlier referred to, establishes that they were not skilled and competent mechanics and did not know how to properly test for a worn bearing. They did not take any of the stops recommended by Mr Harris in order to test for wear and tear in the pulley or the pivot bush.

Causation

The only remaining question is whether the defendant's conduct in failing to have the harvester serviced prior to the harvesting season commencing is causally related to the fire and the loss suffered by the plaintiffs.
The manner in which causation is to be determined is prescribed in s 5C(1) of the Act which provides as follows:
"(1)A determination that the fault of a person (the 'tortfeasor') caused particular harm comprises the following elements –
(a)that the fault was a necessary condition of the occurrence of the harm (factual causation); and
(b)that it is appropriate for the scope of the tortfeasor's liability to extend to the harm so caused (scope of liability)."
In Ruddock v Taylor [2003] NSWCA 262 at [89] Ipp JA explained that the principles that formed the basis of s 5D of the Civil Liability Act 2002 (NSW) were in accordance with the principles applying to causation in common law. Section 5D(1) of the Civil Liability Act 2002 (NSW) is in the same terms as s 5C(1) of the Act apart from the fact that the NSW Act refers to "negligence", whereas the Act refers to "the fault of a person".
In McDonald v Sydney South West Area Health Service [2005] NSWSC 924 Harrison AsJ also came to the conclusion that s 5D of the Civil Liability Act 2002 (NSW) imposed a similar requirement to the common law and referred to the two tiered test for causation posed by Hayne J in Pledge v RTA (2004) 78 ALJR 572 at 574 ‑ 575." Hayne J stated the following at [10].
The questions that are relevant to legal responsibility are first, whether, as a matter of history, the particular acts or omissions under consideration (here the acts or omissions which led to the presence of the foliage, and the parking bays, and the absence of warning signs) did have a role in the happening of the accident. It is necessary then to examine the role that is identified by reference to the purpose of the inquiry – the attribution of legal responsibility. It is at this second level of inquiry that it may be necessary to ask whether, for some reason, the person responsible for that circumstance should nevertheless be held not liable. But that kind of policy inquiry apart, it is necessary to identify the nature of the role which the conduct in question played in bringing about the damage suffered.
The first issue to be determined is therefore whether the fault of the defendant in not having the harvester serviced by a competent and skilled mechanic was a necessary condition of the occurrence of the fire. This question deals with factual causation and has also been described as the "but for" test: Cox v New South Wales [2007] NSWSC 471 at [154].
In Bennett v Minister of Community Welfare (1992) 176 CLR 408 at 420 – 421 Gaudron J explained that in the case of an omission, the question of factual causation is answered by reference to what would have happened if the act that was omitted had occurred. Gaudron J said the following in this regard:
"…a case based on omission or a failure to act will, in certain respects, fall for analysis in a way that differs from that appropriate for a case based on a positive act. Thus, in the case of a positive act, questions of causation are answered by what in fact happened. In the case of an omission, they are answered by reference to what would or would not have happened had the act occurred.
…
And although it is sometimes necessary for a plaintiff to lead evidence as to what would or would not have happened if a particular common law duty had been performed, generally speaking, if an injury occurs within an area of foreseeable risk, then, in the absence of evidence that the breach had no effect, or that the injury would have occurred even if the duty had been performed, it will be taken that the breach of the common law duty caused or materially contributed to the injury."
(Footnotes omitted.)
This means that once it is accepted that it was foreseeable that driving a harvester which had not been serviced by a skilled and competent mechanic might cause a fire to develop by reason of a mechanical fault and it is established that the fire occurred by reason of a failed bearing, it follows that a failure to have the harvester serviced caused the loss, unless there is evidence that the failure to do so had not effect.
In this case there was no evidence that the defendant's breach of his duty by not having the harvester serviced professionally had no effect. On the contrary Mr Harris gave evidence that wear and tear in a bearing would have been detected by a competent mechanic employing the methods of testing for movement in the bearing that he described. Further, Mr Harris said that if a competent mechanic had noticed wear and tear in the pivot bush by employing the same method of testing, he would have recommended that the bearing be replaced in addition to the pivot bush. The evidence of Mr Simms established that the pivot bush on the harvester was badly worn. Mr Simms also said that it was unlikely that a bearing which had been subjected to extended use would show no signs of excessive wear when inspected during a pre–season check, but would then fail catastrophically within only 30 to 60 hours of further use. He was of the view that if the pulley had shown no movement upon rocking, the bearing would still have been in a good enough condition to last for hundreds of hours.
Accordingly, it is very likely that if a competent and skilled mechanic had inspected the harvester prior to the harvesting season he would have detected that the pivot bush and the bearing were badly worn and would have recommended to the defendant to have both replaced. In this event the fire and the resultant loss and damage to the plaintiffs would not have occurred.
The second issue raised in s 5C(1) of the Act, that is, whether it is appropriate for the scope of the tortfeasor's liability to extend to the harm so caused, deals with policy or normative issues: Ruddock v Taylor (supra) at [87]. This issue is not relevant in the present case, as it does not involve any issues of remoteness or the question whether the defendant materially increased the risk.
The remaining sub‑sections of s 5C of the Act are also not relevant to the facts of the present case.

Conclusion

Accordingly, the plaintiff's have established that the failure of the bearing was caused by wear and tear, that there was a breach of the defendant's duty of care and that the breach caused the loss and damage. The plaintiffs are therefore entitled to the damages in the amount as agreed between the parties.