Industrial Court of New South Wales CITATION: Inspector Jones v JT & LC Tippett Pty Ltd and Anor [2007] NSWIRComm 26 This decision has been amended. Please see the end of the judgment for a list of the amendments. Prosecutor: Inspector Stephen Jones PARTIES: First defendant: JT & LC Tippett Second defendant: RD & LF Tippett FILE NUMBER(S): IRC 2587 and 2588 of 2005 CORAM: Backman J CATCHWORDS: Occupational health and safety prosecutions - defended hearings under s 8(1) of the Occupational Health and Safety Act 2000 - employee suffers serious injuries when cleaning debris from counter-rotating rollers on a potato harvester known as a Grimme Windrower while Power Take Off (PTO) was engaged - relevant risk to safety - alleged failures to provide and maintain a safe system of work and to provide an adequate system of isolating the rollers while they were being cleaned considered - alleged failure to ensure that rollers were adequately guarded considered - held: failure to provide adequate instructions to employee for cleaning the rollers proven - held: failure to provide a system of adequate isolation while cleaning the plant, as a result of inadequate instructions and the failure to provide an interlocking guard proven - held: failure to ensure rollers adequately guarded not proven - held: failure to provide an adequate system of isolating the plant while cleaning the rollers by reason of failing to provide an emergency stop button or trip device were not proven - s 28 defences - held: s 28 defences made out in relation to failure to provide an adequate system of isolating the Windrower while cleaning the rollers as a result of the failure to provide an interlocking guard - held: s 28 defences not made out in relation to failures to provide a safe system for the cleaning of the Windrower and an adequate system of isolating the Windrower by reason of adequate instructions for the cleaning of the rollers - both defendants found guilty of an offence under s 8(1) - orders. LEGISLATION CITED: Occupational Health and Safety Act 2000 Drake Personnel Ltd t/a Drake Industrial v WorkCover Authority of New South Wales (Inspector Ch'ng) (1999) 90 IR 432 Environment Protection Authority v Sydney Water Corporation Limited (1997) 98 ACrimR 481 Morrison v Powercoal Pty Ltd and Another (2004) 137 IR 253 CASES CITED: Riley v Australian Grader Hire Pty Ltd (2001) 103 IR 143 Shannon v Comalco Aluminium Ltd (1986) 19 IR 358 WorkCover Authority of New South Wales (Inspector Byer) v Cleary Bros (Bombo) Pty Ltd (2001) 100 IR 182 WorkCover Authority of New South Wales (Inspector Mulder) v Arbor Products International (Australia) Pty Ltd (2001) 105 IR 81 HEARING DATES: 29/05/2006, 30/05/2006, 31/05/2006. Written submissions: 15/06/2006, 29/06/2006, 17/07/2006. DATE OF JUDGMENT: 14 February 2007 Prosecutor: Mr P Skinner, of counsel Solicitors: Carroll & O'Dea LEGAL REPRESENTATIVES: Defendants: Mr K Bennett, of counsel Solicitors: Belbridge Hague, Solicitors & Notaries JUDGMENT: - 21 - INDUSTRIAL COURT OF NEW SOUTH WALES CORAM: BACKMAN J Wednesday, 14 February 2007 Matter No IRC 2587 of 2005 INSPECTOR STEPHEN JONES v JT & LC TIPPETT PTY LTD Prosecution under s 8(1) of the Occupational Health & Safety Act 2000 Matter No IRC 2588 of 2005 INSPECTOR STEPHEN JONES v RD & LF TIPPETT PTY LTD Prosecution under s 8(1) of the Occupational Health & Safety Act 2000 JUDGMENT [2007] NSWIRComm 26 1 The defendants, RD & LF Tippett Pty Ltd and JT & LC Tippett Pty Ltd have each pleaded not guilty to a charge under s 8(1) of the Occupational Health and Safety Act 2000 (the Act). 2 The defendants operated as partners trading as Tippett's Scrub Hill Pastoral Co (the business). The business employed between 5 and 15 people to work in the growing and harvesting of potatoes on a property known as "Whroo" at Kyalite in New South Wales. 3 The charges concern events that took place at the property on 19 January 2004. On that day, Anthony Desmond Butcher, Timothy John Willie and Daniel James Peterson were employed by the defendants to harvest potatoes. Mr Willie drove a tractor to which was attached a potato harvester called a Grimme Windrower. Mr Butcher also drove a tractor to which was attached another type of potato harvester. Mr Peterson drove a third tractor to which was attached a chaser bin. The Windrower dug and lifted the potatoes, including the green leaved foliage at the top of the potatoes, and grouped them into a row for Mr Butcher's harvester to collect. The potatoes were then transferred to the chaser bin. 4 The Windrower was constructed of spades for lifting out the potatoes and two independent webbing conveyors, a front conveyor (the first web) and a rear conveyor (the second web). The first web was designed to convey potatoes, soil and foliage from ground level up to an elevated position and then transfer the potatoes onto the second web. A rubber coated friction drive roller drove the first web from the rear. Along the lower rear corner of the first web and friction driver roller was a counter rotating roller (haulm roller). The purpose of this roller was to create an in-running nip point to grip haulm (potato foliage tops) and pass it forward and out on the ground. At the rear and below the haulm roller was the second web. After the haulm was removed, the second web conveyed the remaining potatoes to the rear of the Windrower. 5 During the course of the potato harvesting, the nip point area of the Windrower from time to time became blocked with dirt, debris and pieces of potato which had to be cleared away. When this occurred, the tractor's Power Take Off (PTO) was disengaged and the debris cleared. Once the task was completed and the area unblocked, the PTO was engaged, and harvesting resumed. At some point during the day, Mr Willie recalls the Windrower becoming blocked again. The blockage caused the second roller to stop turning with the result that the web also stopped. He proceeded to clear the blockage with a crowbar. At the time he sat on a bar on the roller while putting his foot on another bar, "... to bounce the bar to get it (the roller) to go". The PTO had been disengaged during this process. He then asked Mr Peterson to put the PTO in gear to see if the webs and the roller turned. He put his foot on the roller in an attempt to, "bounce the stuff on the bottom roller", but his foot slipped. Mr Peterson, who was watching Mr Willie, turned off the PTO. Meanwhile, Mr Butcher had walked alongside the Windrower and climbed onto the machine. Neither Mr Willie, nor Mr Peterson, say they were aware that Mr Butcher had climbed onto the machine. When Mr Butcher climbed onto the machine, according to him he observed that the second web had stopped moving and proceeded to put his left foot on the web. At that time, he assumed that the PTO had been disengaged. The web started to move and his foot became jammed between the main web and the haulm roller. Mr Butcher suffered serious injuries as a result of the accident, including crushed bones, dislocated left ankle as well as torn muscles, sinews and ligaments on his left ankle. 6 Both defendants have each been charged with one offence under s 8(1) of the Act. The charges contain identical allegations against both defendants arising from the same facts and it is therefore convenient that they be dealt with together. The elements of an offence under that section which the prosecutor must prove beyond reasonable doubt in order to establish the offences are: (i) the defendants were employers; (ii) the defendants' employees were at work; (iii) the defendants failed to ensure the safety of their employees. 7 The charges against each defendant have been particularised in the Applications for Order as follows: The Defendant, on the said date at the said site, contrary to section 8(1) of the Occupational Health & Safety Act 2000 (NSW), failed to ensure the health, safety and welfare at work of all the employees of the Defendant employer, and in particular, Anthony Desmond Butcher. The Defendant failed to provide and maintain a safe system of work for the cleaning of plant, being a "Grimme Windrower" harvester, in that a person could access moving parts of the plant while cleaning the rollers of the plant, thereby placing them at risk of injury. In particular, there was no adequate system of isolating the plant while the rollers were being cleaned. The Defendant failed to ensure that the rollers were adequately guarded. Whether the defendants were employers 8 A group certificate in Mr Butcher's name for the financial year ending 30 June 2004 designates Tippett's Scrub Hill Pastoral Co as payer. The evidence discloses that the two corporate defendants jointly operate the business as a partnership. The prosecutor represented by Mr Skinner, of counsel, submitted that the group certificate and relevant ASIC extracts, as well as admissions contained in a record of interview of John Trevella Tippett, a director of the defendant, JT & LC Tippett Pty Ltd, are decisive of the issue. The ASIC extracts confirm that both defendants are corporations and that the registered proprietors of Tippett's Scrub Hill Pastoral Co as at 19 January 2004 were the two defendants. The defendants represented by Mr Bennett of counsel made no submissions in relation to this element of a charge under s 8(1) and the matter did not appear to be in issue between the parties. 9 Based on the foregoing considerations, I therefore find beyond reasonable doubt that the defendants were employers in relation to the charge alleged against them under s 8(1) of the Act. Whether defendants' employees were at work 10 Equally, I find, based on the group certificate and the ASIC extracts referred to above, that Mr Butcher was employed as an employee jointly by the defendants in partnership, trading as Tippett's Scrub Hill Pastoral Co. Again, the matter was not in issue between the parties. 11 The prosecutor, in submissions, informed the Court that the charges apply only to Mr Butcher as an employee. They do not purport to extend to Mr Willie, for example, since according to the prosecutor, it is conceded that Mr Willie's own actions "... could well have prevented proof of causation of a risk specific to him, and/or a maintainable defence in that regard by each defendant". 12 The issue then becomes whether at the time of the alleged offence Mr Butcher was at work. The evidence concerning the events leading up to the accident have already been canvassed to some extent. That evidence reveals that on 19 January 2004, Mr Butcher, together with his fellow workers, Mr Willie and Mr Peterson, commenced the task of harvesting potatoes on the defendants' farm. Mr Butcher drove one of three tractors to which was attached a potato harvesting machine. As the potatoes were harvested and placed in a row by the Windrower, Mr Butcher's potato harvester deposited the potatoes into the chaser bin. This work commenced at about 7am and continued with some interruptions which occurred, according to Mr Butcher, when the windrower became jammed with potato heads and had to be unblocked. Mr Butcher said this event happened "a couple of times or a few times", that day. Mr Butcher was involved in the process of unblocking the rollers on the Windrower at the time of his accident. It may be readily concluded to the requisite standard from this evidence, that Mr Butcher was at work at the time of the alleged offences under s 8(1). Whether the defendants failed to ensure Mr Butcher's safety: the risk to safety 13 The prosecutor's case against both defendants is that Mr Butcher was at risk of being injured because he could access moving parts of the Windrower while cleaning its rollers. Moreover, this risk to safety, the prosecutor asserts, is apparent from the evidence of the accident itself. In Drake Personnel Ltd t/a Drake Industrial v WorkCover Authority of New South Wales (Inspector Ch'ng) (1999) 90 IR 432, Wright and Walton JJ observed (at 452) that the circumstances leading up to and including an accident in relation to a charge under the occupational health and safety legislation concerning an alleged failure to ensure worker safety, will provide relevant evidence of the existence of the risk to safety. This is not to say, as their Honours emphasised, that the accident itself constitutes the offence or is "an element of the offence", rather it is the alleged failure of an employer under s8(1), for example, to ensure the safety of employees that gives rise to the risk or risks: Drake Personnel at 449, 450. 14 The prosecutor relies on the circumstances of the accident as having evidentiary value in providing proof that there existed a relevant risk to safety. Many authorities in this jurisdiction have referred to the accident as a manifestation of the risk to safety thereby providing the necessary evidentiary connection. The facts here disclose that the Windrower contained a number of hazardous components, including the counter-rotating rollers, between which was the in-running nip point where Mr Butcher's foot was caught and pulled in. Workers had access to this nip point formed by the first web and the counter-rotating haulm roller when they climbed onto the body of the machine in order to clear any blockages in the nip point area as a result of dirt, debris and pieces of potato. According to the expert report of Mr Richard Sulman, tendered on behalf of the defendants, due to the low set position of the nip point in relation to the second web, feet are the most likely parts of the body exposed to this hazard. 15 The risk arose when access was gained to the nip point area, and the componentry was operating because the PTO was engaged. Even when the PTO was disengaged, Mr Sulman expressed the view in his report that due to the size and plurality of the components on the Windrower, significant momentum was nevertheless exhibited because of overrun. It follows therefore that the risk to safety was extant even when the PTO was disengaged, although the period during which this could occur was unspecified in the evidence. I asked Mr Sulman during his oral evidence, whether he could estimate how long it would take for the componentry in the Windrower to stop rotating once the PTO was disengaged. Mr Sulman's response is reproduced below: A. I can say with confidence that it won't stop instantaneously but without understanding the condition of the PTO brake, because as the machine gets older the brake performance changes and there is a function of brake and there is a function of size of the equipment. So it is a very variable situation, and it is one that as a designer you don't look to rely upon because the variability in that, so you don't expect a period of time to be there that that machine will come to cessation, because there is a number of those factors I mentioned. 16 Mr Tippett, who was authorised by letter to speak on behalf of the business, was interviewed by the prosecutor some months after the accident. In that interview, he said that the Windrower was purchased by "the Family Trust", second hand in 1998. In relation to maintenance of the machine he said it was maintained daily, "with normal greasing and that sort of thing ... before its operated", and, that every 12 months it underwent a "major overhaul". This evidence provides an insufficient foundation upon which to make a finding in relation to the performance or condition of the PTO brake referred to by Mr Sulman in his response to the question concerning overrun. Nevertheless, it seems at least from Mr Sulman's response that once the PTO was disengaged it would not have stopped the rollers rotating instantaneously and so to that extent the risk of safety remained for an indeterminate short period after the PTO was disengaged. 17 The risk to safety arising from access to the in-running nip point identified above was known to Mr Tippett before the accident to Mr Butcher. In his interview he nominated the various risks or hazards following a question he was asked regarding whether a risk assessment had ever been conducted on the machine. His responses are extracted below: A. We did a general risk assessment and we knew where the risks were regarding the operation of equipment and consequently this would have been referred to when training someone on how to use the equipment. Were these documented? A: No, this was done verbally as is the training. What risks were identified and how were these controlled? A: The risks on the machine are things like PTO shafts, chains and sprockets and moving parts and the reversing rollers which Anthony got caught in. These reversing rollers are inside the machine and requires a person to climb at least 1.5m to access them. You physically have to climb into the machine to get caught. The way to control this is to ensure that the equipment is turned off when people were required to access the rollers. The only other option is to put a guard over the top, however this would have no real value given you would have to take it off to clean the roller and therefore provides no real barrier. All other guards are in place as per the manufacturers specification and were in place at the time of the accident, these are in place at all times when the machinery is being operated. 18 The above responses suggest that the workers were required to access the rollers and other moving parts by climbing onto the machine and that the only available procedure for "controlling" the risks presented by the "reversing rollers" was to ensure that the PTO was disengaged beforehand. 19 The charges against both defendants particularised three alleged failures to ensure the safety of Mr Butcher. They are: (i) a failure to provide a safe system of work for the cleaning of the Windrower, and; (ii) a failure to provide an adequate system of isolating the rollers while they were being cleaned, and; (iii) a failure to ensure that the rollers were adequately guarded. Whether a safe system of work for cleaning the Windrower 20 In his interview Mr Tippett was asked a series of questions in relation to the "specified way" of cleaning debris and weeds from the rollers of the Windrower, and how the procedure was communicated to Mr Butcher. Mr Tippett answered these questions in the following way: A: If the rollers become blocked you would remove the blockage by hand using a shovel or a crowbar until it was reasonably clear and then you run the machine again. The cleaning must always be done while the machine is turned off. A: If he [Mr Butcher] was doing it by himself he would have to turn the tractor off, clear the machine and then get back in the tractor to turn it on again. The communication would have been given to him verbally. He would have been taken out and shown directly, Anthony has been employed here for at leat 4 or 5 years and he was a leading hand not just a casual employee. He would be expected to show some leadership in these matters because the other two workers were actually casuals. As I have seen what these machines can do I would have communicated this to all people working with the machine and I am a hands on person and would have taken any employee to the machine and showed them the task and highlighted the dangers. 21 Mr Tippett's explanation as to the instructions received by Mr Butcher in relation to the procedure for cleaning the rollers suggests not what was actually said to Mr Butcher but rather what Mr Tippett's practice purportedly was for explaining the procedure, or what Mr Tippett's understanding of someone else's practice purported to be, or what someone else said. The explanation therefore provides little confirmation that Mr Butcher was in fact the recipient of the instructions, by either Mr Tippet or by someone else. 22 In the interview Mr Tippett was also asked what training and level of supervision generally was provided to Mr Butcher to assist him in carrying out his duties while harvesting potatoes. Those questions and responses are extracted below: What level of supervision does Anthony receive whilst carrying out his duties? A: He would have had a foremen over the top of him who would have had regular contact with him and he would have been supervising the harvesting and was in charge of the harvesting operation. Whilst not being with Anthony the whole time, he would have been in the paddock with Anthony approximately 6 to 10 times per day. He had the responsibility of keeping the machinery going. He has been employed with us for 10 years and then left. He started with us again May 2002 and was here for about 18 months before leaving again in June this year. What type of training was provided to Anthony in carrying out his duties? A: If he was going to drive the potato harvester somebody would have to go out with him and he would be shown exactly how to do the job, sitting with him in the tractor and this may take half a day. Once he got started and developed competency, he would receive further training over the next few days and for as long as required until he was fully competent. Training would be ongoing, particularly if there was a drop in standards say for example the potatoes were being bruised or damaged. I would maintain contact also with the UHF radio. What type of training was provided to Anthony specifically in relation to the piece of equipment? A: He would have driven a potato harvester before getting onto the windrower and the training would have been identical in both cases. This would have done (sic) by the foreman who would have operated this equipment a lot more than I would have. Do you have any written documentation regarding the training provided to Anthony? A: No, it was done verbally and on the job. Anthony would have someone with him until such times he was considered competent and Anthony was now at the point in terms of competency to start training others if the need arose. 23 Again Mr Tippett's responses suggest what Mr Tippett's practice was in relation to training and supervision of farm employees, or what Mr Tippett's understanding was of someone else's practice, or what someone else said concerning training and supervision. It does not assist in determining what training and supervision Mr Butcher actually received in relation to the task of harvesting potatoes on the property. 24 In his oral evidence Mr Tippett explained that the system of instruction in relation to the various items of machinery used on the property by employees, including Mr Butcher was the "buddy system". It was also, he said, not documented at all because the workers, "were not extremely well-educated". New employees he said, usually received instructions from either himself, the foreman or the leading hand. The instructions he said were verbal and included instruction both on the operation of the machines as well as indicating dangerous parts including moving parts and the PTO shafts. Guards on the machines were also identified and the employees told to remove them. These instructions usually took about one hour. In relation to clearing blockages from the Windrower Mr Tippett said the employers were told to first stop the machine by disengaging the PTO, then climb onto the Windrower and dislodge any debris either by hand or using a crowbar, "or something like that", then return to the tractor and engage the PTO. If the blockage still had not cleared the process was repeated although Mr Tippett volunteered that one could stand on the tractor axle in order to look into the Windrower. 25 Mr Tippett was then questioned as to whether he or any one else gave instructions to employees in relation to being on or near the Windrower when the PTO was engaged. Mr Tippett replied: A. All machinery when it is going is dangerous and to climb on a machine when it is moving is inherently dangerous because it is moving. It is a live piece of machinery and there is a number of dangerous points on the machine and you try and instil into them that machines are quicker that what you are. People seem to have bravo and all the rest of it but machines are quicker than what you are. 26 Mr Tippett was asked whether he instructed employees that they were not to be on the Windrower while the PTO was engaged to which he replied: A. We instruct them never to be on the machine when the PTO is engaged. 27 There then followed a series of questions about the resident foreman on the property at the time of accident, a person identified by Mr Tippett only as "Tuck". A number of questions were asked in relation to Mr Tuck's duties and responsibilities in the area of safety at the property. Mr Tippett explained: A. Tuck at the time had been with me for 9 to 10 years and one of his jobs was to make sure that the harvesting was happening and the men were performing to their tasks and to make sure - part of his job was if new employees came, to go with them and start them on the job. Q. During the course of the day what, would he carry out random inspections? A. Tuck, yes, he would be around very often. If he would be in the Ute driving around making sure that part of the operation was going or, in the situation of growing potatoes you have quite often one crop coming on when harvesting one, you have another one which is going to be mature or to be started harvested within a week or something. You might be irrigating a circle here, men would be working there, you are driving past or pulling up to see if there is a problem all the time. You are in constant contact is really what I am saying. Q. You have looked at the practical aspects. His role with respect to ensuring that employees safely carry out their duties, what was that? A. His job was, if I didn't - he at that stage was probably more doing the instructing operation of machines, his job was to instruct them on the safe operation of the machinery and to help them if there was any breakdowns. He usually carried a large toolbox on his Ute. The machines we have our ground engaged machines and they do breakdown quite regularly, not quite regularly but they do breakdown, so they do need maintenance. So part of his job was to help with repairs or to repair the machines, help them and if there were any problems they usually got him on the UHF and would say "such and such has happened would you come and help us sort this problem out". Q. During the course of that he ensured employees were carrying out their work safely? A. I would hope so. Yes, I presume so, it was part of his job. Q. Did you speak to him, did you check with him from time to time that that was happening? A. Safety was discussed fairly regularly because we actually --. Q. Just don't tell me about that, I asked you a question, did you check with him from time to time to see whether that was happening? A. yes, I checked with him from time to time. Q. Tell us how safety was regularly followed up? A. Safety is, because of the people we have working for us, we have a lot of young people, safety is followed up all the time. Q. When you say it is followed up all the time, what do you mean by that? A. It is discussed. Q. And it was discussed in what form, in the shed or during meetings? A. It is discussed if you are taking men out in the morning to start the machine you would be saying, this is happening and that is happening. If this PTO guard is broken you would be asking why is it broken and not replaced, and stuff like this. Q. They are practical things? A. They are practical things. Q. How does that impact on the safety aspect, if you could focus on that? A. The safety aspect is part of the practical things. If the machine is not properly guarded there is a problem and the discussion with the men is that there has to be a continual watch on safety. You talk to them and tell them these machines are dangerous. 28 Mr Tippett agreed that safety matters were raised with Mr Butcher. When asked what was said to Mr Butcher on the point Mr Tippett gave the following responses: Q. Would you tell the court what you said to him [Mr Butcher] or what you would say to him? A. Well when you are walking around the machines I would think, with a potato harvester, the nip point on a potato harvester is a very dangerous point and I think -- Probably the potato harvester, the windrower and potato harvester were on the same philosophy so, I'm sorry, the nip point on a potato harvester is a very dangerous point because the rollers are moving, reversing at a very quick rate and so consequently if you are anywhere near it, you just don't get a second chance. Q. On that specific issue, the rollers and the fact you don't get a second chance, did you raise that with Mr Butcher? A. Yes. Q. What did you say to him to the best of your recollection? A. To the best my recollection I would have said that these things are really dangerous and that you don't get a second chance and just don't think that you can beat them. HER HONOUR: Q. Would you clarify something for me Mr Tippett. You say to the best of your recollection, do you have any precise recollection of having a particular conversation with Mr Butcher about those matters? A. No, I would think that - look, if you want me to give you an exact time and exact date -- Q. I am not asking you that, do you actually recollect having a conversation? A. Yes, I probably recollect having a conversation because there has been injuries in the potato industry before and I am very conscious about this part of the machine. 29 Mr Tippett also said that he could not recall seeing anyone on the Windrower while the PTO was engaged. 30 Mr Tippett's evidence reveals that the system for cleaning the rollers on the Windrower when they became blocked, at least insofar as he understood it, involved a few basic steps namely: (i) disengage the PTO; (ii) climb onto the back of the Windrower and dislodge the debris using hands, a crowbar or some other available implement; (iii) return to tractor and engage PTO; (iv) repeat the procedure if blockage not cleared; (v) at no stage climb onto the Windrower while the PTO is engaged. 31 It is apparent from Mr Tippett's evidence that the system applied equally to one person working alone or several persons working together. In relation to safety aspects and the Windrower, Mr Tippett said the foreman instructed employees on the safe operation of the machinery and that safety matters were, "followed up all the time" through discussion. This discussion took place apparently at the same time as operational matters were discussed. Mr Tippett gave no evidence as to the content or substance of these discussions apart from advice given to employees that they must keep, "a continual watch on safety", and that, "these machines are dangerous". Nor was there any evidence as to the duration of the discussions or the level of attendance or participation in the discussions. In relation to Mr Butcher, Mr Tippett was unable to recall specifically whether he had told Mr Butcher that the rollers on the Windrower were dangerous. The basis upon which he says he "probably recollected" telling Mr Butcher that the rollers were dangerous was that he was aware of injuries being suffered in the potato industry, and he was "very conscious" of the counter-rotating rollers in the machine (presumably because he regarded them as dangerous). 32 It follows from this evidence that there existed a basic, general procedure in relation to cleaning the Windrower at the property which, given the very serious risk to safety posed by the machinery, in my opinion was inherently flawed (an aspect to which I will return shortly). Nor was Mr Tippett able to articulate how the procedure was brought to the attention of farm workers apart from rather vague references to ongoing discussions with the foreman during which workers were told in general terms that the Windrower and its parts were dangerous, and that the machine should not be physically accessed if the PTO was engaged. More importantly the evidence does not reveal whether Mr Butcher was told about or instructed in the procedure. The evidence at its highest is that Mr Tippett "probably recollects" telling Mr Butcher that the rollers were dangerous but this recollection is not based on any actual recollection of instructing Mr Butcher. Rather his recollection is based on his knowledge of injuries suffered by unidentified workers in the potato harvesting industry generally and the potential hazards posed by farm machinery used in the industry such as the Windrower. In relation to Mr Tuck's role in safety matters and ensuring that employees were carrying on their jobs safely Mr Tippett could only say that he presumed and hoped Mr Tuck was making sure employees performed their work safely. Mr Tuck was not called to give evidence. 33 Mr Butcher also gave evidence during the proceedings. He was fully aware prior to his accident that the counter-rotating rollers on the Windrower posed a serious danger when the PTO was on. He confirmed in his evidence that shortly before his accident Mr Willie was attempting to unblock the rollers while standing on the Windrower and that the procedure utilised by the workers to unblock the rollers included asking Mr Peterson to turn the PTO on and off while Mr Willie at least was still on the Windrower. Mr Butcher also was aware that it was unsafe to be on the Windrower while the PTO was engaged although it is unclear on the evidence whether his awareness was derived from what someone had told him or what he had worked out for himself. In relation to this latter possibility he said in his evidence that it was, "just commonsense. You don't do that anyway". Earlier in his evidence he had agreed that when he was originally instructed in relation to the procedure for cleaning the rollers following a blockage, part of the instruction he received was that he should disengage the PTO before he commenced the cleaning. 34 Mr Butcher's knowledge of the procedure and the extent of his instruction in relation to that procedure, suggest that he had received little if any instruction on how to safely clean the rollers, or if he had, it was a sufficiently long period before the accident for him to have forgotten it. It will be recalled from the evidence of Mr Tippett that the procedure was not documented apparently because Mr Tippett regarded the farm workers as not well-educated. It was also a simple procedure consisting of a few basic steps. Just prior to the accident Mr Butcher in his evidence explained that he climbed onto the second web where it was blocked and attempted to assist Mr Willie who was also on the machine attempting to clear the blockage. He says that at that point both he and Mr Willie were asking Mr Peterson to turn the PTO on and off. He was watching the web under his feet and he saw that it had stopped. At that time (presumably because the second web was not moving) he assumed that the PTO was off. He then says he put his foot on the web and that is when his foot was dragged in between the main web and the counter-rotating rollers. 35 Mr Butcher's evidence as to the extent of his knowledge of and instruction on the procedure for clearing a blockage from the rollers at the time of his accident was: Q. What had you been told at that point of time about how to unblock the machine in a similar situation where it had got blocked up? A. Well, just to unblock it, basically. Q. Sorry? A. Just to unblock it and assess the situation and unblock it. Q. Who told you that? A. I don't - I can't remember whether I have actually been told that. Q. You can't remember any specific moment of having discussed that? A. No, or how to unblock it specifically. Q. How long had you been doing that sort of job? A. As soon as I started working for John Tippett, back in 2000. Q. Had you ever been given any written instructions as to how to go about unblocking the machine? A. No, not that I can remember. Q. Had you ever had any sessions where you, with someone from that farm, had been taken through in some formal way, how to unblock the machine? A. I had been given a basic run down of the operation of the machine and how it runs, yes. Q. Who gave you that? A. Tuck Routen. Q. He was the foreman on the farm? A. I think so. Q. When did that happen, as best you can recall? A. When I first started digging potatoes. Q. What did the general run down involve? A. The basic operation of running the potato harvester or Windrower machine. Q. Were you told anything specifically about unblocking it when it became blocked? A. Not really. Q. The way you were working that day in relation to the blockage - was that the way you worked always when there was a blockage? A. Well, if - yeah. If there's a blockage you assess the situation and unblock it the best way you can, I suppose. Q. Would that always involve getting up on top of the machine? A. If you have to, yes, to go and unblock that specific web, yes. 36 Mr Butcher also agreed in his evidence that he had never seen any employees cleaning the rollers on the Windrower while the PTO was engaged, nor had he before the day of the accident ever attempted to unblock the rollers while they were operating. Mr Butcher also agreed that the foreman, Mr Tuck, had a practice of driving around and checking, "to make sure things were moving". He also said that Mr Tuck gave him a "basic rundown" on the machinery and that this consisted of the operational aspects of the tractor and the Windrower. He could not remember whether Mr Tuck or any one else had demonstrated to him the operation of the tractor pulling the Windrower, but in any event he said he was very familiar with the operation of the Windrower because he had stripped it down and reassembled it as part of a maintenance programme. He realised that all moving parts of the Windrower were dangerous and he was aware that the PTO should be off when clearing the blockages in the Windrower. He said however that he remained on the Windrower with Mr Willie just before his accident to check that everything was in order and that he put himself in a safe position away from the moving parts. Finally he said that he could not recall Mr Tippett speaking to him about the dangers of reversible (counter-rotating) rollers. 37 Mr Willie said he had been instructed in relation to the procedure for cleaning the rollers as outlined by Mr Tippett in his evidence although Mr Willie described the procedure as involving only one employee working alone driving the tractor and clearing any blockages. Mr Willie also said that at the time of the accident he did not follow the instructions. He agreed that to this extent he knew he was doing the wrong thing and had acted "disobediently, contrary to those instructions". At another point in his evidence he explained his reasons: Just making use of, I was there, instead of getting back off the machine and doing it myself, I could, you know, save a bit of time. They were right behind me and I was trying to keep everything going; you know, they help me keep going. They can still keep going so I didn't think I was going the wrong thing at the time. 38 Mr Peterson in his evidence said that he had not received any instructions in relation to the procedure for cleaning the rollers at or prior to the accident although he had received instructions from Mr Tuck after the accident. 39 As I earlier remarked the prevailing procedure for cleaning the rollers as outlined by Mr Tippett and put forward by him as a safe procedure, was inherently flawed. This is because in my opinion the procedure was not confined to one employee acting alone cleaning the rollers but allowed for the involvement of several employees. Had the procedure been confined to one employee the possibility of that employee being exposed to moving parts of the Windrower, specifically the in-running nip point between the main web and the haulm roller, was remote. With more than one employee involved, the procedure if correctly followed, entailed the employees climbing on to the machine to clean the debris from the rollers, climbing off the machine so the PTO could be engaged by whoever sat in the cabin of the tractor in order to check whether the blockage was cleared, and then climbing on again if the blockage had not been cleared. Unlike the employee acting alone (and who had to physically disengage and engage the PTO switch which was located in the cabin of the tractor) considerations such as expediency and convenience may well have taken precedence over a procedure that required both time and some inconvenience and was relatively easy to circumvent. Indeed this is precisely why Mr Willie in his evidence extracted above said he chose to ignore the prevailing procedure. 40 Even if I had found the prevailing procedure was a safe system for the employees cleaning the rollers I find that Mr Butcher, for the reasons I set out earlier in this judgment, did not receive sufficient instructions in relation to the procedure to enable him to perform his work safely. If he received any instructions at all, his knowledge of what the procedure was at the time of his accident was limited either because the initial instructions were inadequate or he had received them so long before the accident date that he had forgotten them, or a combination of both. Mr Butcher's limited appreciation of the dangers posed by the counter-rotating rollers when the PTO was engaged was starkly illustrated by his evidence that he believed when he was on the Windrower while the PTO was engaged, he was in a safe position because he was away from the moving parts. 41 Section 8(1) of the Act obliges employers not just to provide instructions at some initial stage in order to enable their employees to perform their various tasks safely. Over time it is imperative that initial instructions are checked and reinforced and work practices constantly monitored to ensure compliance. There is no evidence that this obligation was met in relation to Mr Butcher. The obligation on employers to actively ensure employees are following instructions so that unsafe work practices do not develop over time was the subject of comment in Riley v Australian Grader Hire Pty Ltd (2001) 103 IR 143 at 146: Similarly, it is important for employers to actively ensure that instructions given are both sufficient for and complied with by employees. We refer to the judgment of Walton J, Vice President in WorkCover Authority (NSW) (Inspector Glass) v Kellogg (Australia) Pty Ltd (1999) 101 IR 239 at 257 as follows: "In any event, the mere stipulation of procedures and instructions to carry out the work may not be enough to satisfy the requirements of s 15 of the Act. The employer should ensure that procedures and instructions are actively and positively complied with by employees. In State Rail Authority (NSW) v Dawson (1990) 37 IR 110 at 121 and 125 the failure by a foreperson to supervise a qualified and experienced linesperson to the extent of instructing the employee as to the safest available method (where the employer had laid down a procedure for work and various methods of performing the work were available) would constitute a breach of s 15 (although in that matter it was found the failure was that of the foreperson and not the employer). I note that in an English High Court case, Pope v Gould (HM Inspector of Health and Safety, 20 June 1996, unreported but cited at p 44 of Redgrave's Health and Safety , 1998, Third Edition) it was held in England, under the equivalent of s 15, that it is not a sufficient defence for an employer to demonstrate that he had instructed the employee to operate machinery in a particular way and the employee had not followed his instructions. There, it was held, that the legislative provision was not concerned solely with the giving of instructions; rather it imposes upon the employer positive duties in relation to ensuring safe systems of work and safe machinery. It was held not to have been sufficient for instructions of a health and safety nature merely to have been given to employees; an employer must also ensure that those instructions are carried out (see also Haynes v CI & D Manufacturing Pty Ltd (1995) 60 IR 149 at 181-182, Kirkby v A & MI Hanson Pty Ltd (1994) 55 IR 40 at 53 and McMartin v Broken Hill Proprietary Co Ltd (1998) 100 IR 241 at 245)." 42 Those comments apply with equal force to the present circumstances. I therefore find beyond reasonable doubt that both defendants failed to ensure the safety of Mr Butcher by failing to provide and maintain a safe system of work for the cleaning of the Windrower. 43 I should add before leaving this issue that the prosecutor's reliance on the failure of the defendant to provide an adequate system of communication between the employees while cleaning the rollers was in my view misplaced. In my opinion a system of communication in the circumstances which led up to the accident would constitute both an unacceptable and an inconsistent component of the prevailing procedure for cleaning the rollers, dependent as it was on the employees being on the Windrower while the PTO was at certain times engaged. The act of alighting from the machine would have been a sufficient signal to Mr Peterson located in the cabin of the tractor that the PTO could be safely engaged. In any event the issue was raised rather belatedly and it is not at all clear from the particulars as set out and relied upon by the prosecutor in both charges that the failures as alleged incorporated allegations of insufficient or inadequate communication. Nor did the prosecutor's opening remarks contain any references to an alleged failure to ensure safety by reason of an inadequate system of communication. In the circumstances even if the evidence had been capable of supporting an inference that an inadequate system of communication exposed Mr Butcher to a risk to his safety I would have been disinclined to make the finding, on the basis that the defendants had insufficient warning that the prosecutor would rely on an inadequate system of communication: see WorkCover Authority of New South Wales (Inspector Byer) v Cleary Bros (Bombo) Pty Ltd (2001) 100 IR 182 at [54]. 44 Although not strictly necessary I would observe finally in relation to the particular alleging a failure to provide a safe system for cleaning the rollers, that the fact that Mr Willie disobeyed his instructions would not necessarily exculpate the defendants or otherwise discharge them from their statutory obligations: see for example Riley v Australian Grader Hire at [15]; WorkCover Authority of New South Wales (Inspector Mulder) v Arbor Products International (Australia) Pty Ltd (2001) 105 IR 81 at [45] - [46]. Whether adequate system of isolating the Windrower 45 The second particular relied upon by the prosecutor in relation to both charges alleges that the defendants failed to ensure Mr Butcher's safety by failing to provide an adequate system of isolation while cleaning the rollers. According to the prosecutor this particular is made out by the evidence in relation to the inadequacy of instructions given to Mr Butcher. In addition in relation to this particular the prosecutor relies on alleged failures to have in place either on the Windrower or on the tractor, an interlock device (also referred to as an interlocking guard) and an emergency stop button near the in-running nip point. 46 The evidence relied upon by the prosecutor going to the issue of the adequacy of instructions given to Mr Butcher in relation to this particular, is the same evidence relied upon by the prosecutor to make out the earlier particular concerning the system of work for cleaning the rollers. That evidence has already been canvassed in this judgment. Having found that the instructions given to Mr Butcher, if any, for cleaning the rollers were inadequate and exposed Mr Butcher to a risk to his safety, I find for the same reasons, beyond reasonable doubt, that the prevailing procedure for isolating the power (disengaging the PTO while clearing the rollers) and the limited instructions received by Mr Butcher also failed to ensure his safety. 47 Although not at all clear from the content of the particular that the prosecutor also relies on the absence of an interlock device and the absence of an emergency stop button, the prosecutor in written submissions has informed the Court that reliance is placed on the absence of both devices. Little else is said by the prosecutor in relation to the evidence concerning the two devices. In relation to the absence of an emergency stop button near the in-running nip point the prosecutor makes the following submission: It is submitted that this was something that could have, and should have been fitted to the machine to give a worker who was caught, or at risk of being caught, the chance to protect himself. It is submitted that it is self evident that if such a device was fitted the risk of injury, or more serious injury, would have been lessened. Again, the defence sought to meet this submission by the evidence of Mr Sulman, see e.g. at T 146-147. However, ultimately he agreed in cross-examination, at T 149 ln 18, that an emergency stop would have mitigated the risk to Mr Butcher. 48 Most of the evidence in relation to the absence of an emergency stop button emerged in the defence cases. The prosecutor is entitled to rely upon evidence which emerges in the defence case in order to establish a particular in his or her own case. In Environment Protection Authority v Sydney Water Corporation Limited (1997) 98 ACrimR 481 Gleeson CJ, in the Court of Criminal Appeal, with whom Ireland and Bruce JJ agreed, said on the point (at 485):- Fairness to Sydney Water, however, does not require that the prosecution should be precluded from relying upon evidence which may emerge during the course of the defence case. Nor does it require that a distinction be drawn between the evidence which strengthens the Crown case in respect of a particular that was made out to a prima facie level in chief, and evidence relation to a particular which the Crown did not succeed in establishing to that level in chief. There is no basis in legal principle for such an artificial distinction. 49 According to Mr Sulman's evidence, an emergency stop button like a trip device would not have removed the risk to Mr Butcher's safety created by the in-running nip point. This is because the size and plurality of the Windrower's components would cause significant momentum when the PTO was disengaged resulting in overrun, (a term I referred to earlier in this judgment). Mr Sulman expanded upon this point during cross-examination: Q. 47, you say due to the size and plurality of components in the windrower it is my view significant momentum will be exhibited when the PTO is disengaged causing over run. In other words if Mr Butcher had been able to hit a lanyard or something else or emergency stop device system there would still be a period in which his leg is pulled in? A. That's correct. Q. This over run is not desirable when activating emergency stop device as cessation of components would take too long? A. That is correct. Q. Would you not agree from what you know about the circumstances of this accident that that maybe so but if Mr Butcher had been able to hit an emergency lanyard or emergency stop device however long it took, it would not have taken as long as it did take for the other two then to come and be aware that Mr Petersen turned that PTO off? A. Essentially you are proposing the best of a bad design. Q. Sure but from Mr Butcher's perspective half a second would have been a mercy wouldn't it? A. No. 50 Mr Sulman also identified a further problem with the emergency stop button which he said rendered it ineffective in removing the relevant risk to safety. In his report he explained that the device requires deliberate action by "the operator" to bring the machine to rest when a danger is recognised. This necessarily relies on "human response time". Mr Sulman conducted an analysis in order to calculate the drawing-in velocity of the nip point. Based on his calculation he concluded that taking into account the drawing-in velocity at the nip point and the "inevitable machine overrun", that there would be insufficient response time in order to recognise the danger and take appropriate action to prevent an accident. 51 It follows from this evidence that an emergency stop button, or a trip device would not have removed the risk to Mr Butcher's safety. The requisite causal nexus therefore between the failure to provide an adequate system of isolating the Windrower and the resultant risk to safety has not been made out by the prosecutor. There exists a reasonable doubt that the particular, insofar as it relies on the failure to provide an emergency stop button or trip device, resulted in Mr Butcher being at risk to his safety. 52 The prosecutor also relies on the defendants' failure to provide an interlock device fitted to either the Windrower or the tractor. Mr Sulman's report adopted the definition of the device contained in AS4024.1-1996 at 8.2.31: An interlocking guard is a physical barrier which is interconnected with the power or control system of the machine. Interlocking guards provide an effective safeguard where access to the point of operation is required between each cycle of the machine or where regular access is needed. They are frequently used in combination with stationary guards to provide a total physical barrier safeguarding system. An interlocking guard shall be so connected to the machine controls that - (a) until the guard is closed the interlock prevents the machinery from operating; and (b) either the guard remains locked closed until the risk of injury from the hazard has passed or opening the guard causes the hazard to be eliminated before access is possible. The interlocking system may be either mechanical, electrical, hydraulic, pneumatic or any combination of these. The type and mode of operation of the interlock shall be considered in relation to the process to which it is applied (see Section 10). The interlocking system shall be designed to fail to safety and shall not be defeatable. 53 Mr Sulman in his report explained the term "fail to safety" as a safety device failing to a safe condition, "...where the hazard is no longer present". Mr Sulman recommended the interlock device as the "most suitable" form of protection for the workers working near the nip point area between the main web and the haulm roller on the Windrower. In his oral evidence he said that the device which he referred to as an interlocking guard: [W]ould be the most suitable. Stress this point, if the provision was made by the manufacturer of the tractor to allow the system to be incorporated into the tractor and it most certainly would have been the more desirable option to prevent this accident. And I stand by in my opinion that this would have prevented this accident but only if that operation was available on the tractor which it was not at the time of the accident. 54 The evidence revealed that neither the tractor nor the Windrower had been designed to incorporate an interlock device or interlocking guard. Nor, at the time of the alleged offence was one commercially available. The failure to ensure safety as particularised here is a failure to provide a system of isolation, namely an interlock device. Section 8(1) like its predecessor section, s 15(1) of the 1983 Act, imposes a duty on an employer in absolute terms to ensure safety: see for example Shannon v Comalco Aluminium Ltd (1986) 19 IR 358 at 359. The question is whether the duty or obligation which arises under s 8(1) extends to a failure to provide that which cannot be provided or that which an employer is not capable of providing. In the circumstances the risk to safety was both obvious and known to the defendants. In Morrison v Powercoal Pty Ltd and Another (2004) 137 IR 253 the Full Bench examined the element of causation in relation to an offence under s 15(1) and found that where there is a risk to safety which was impossible to anticipate or unduly remote or speculative then there can be no failure to obviate the risk on the part of the employer. At [109] and [110] of the judgment the Full Bench said: The second point raised in O'Sullivan and Kirk Group Holdings is this issue of whether there is a relevant failure on the part of an employer if steps are not taken to preclude a risk that was impossible to anticipate or that was merely speculative or unduly remote: See also Drake Personnel Ltd (t/as Drake Industrial) v WorkCover Authority (NSW); WorkCover Authority (NSW) v Police Service (NSW) (No 2). We agree with the observation of Walton J in Kirk Group Holdings that: "...[T]here can be no failure on the part of an employer to obviate a risk which was impossible to anticipate may be characterised as an elaboration of the requirement to establish causation. The same could be said of risks which are merely speculative as distinct from those risks which are real and appreciable (see Drake Personnel at 452-453). If a risk is impossible to anticipate or is entirely speculative it will be very difficult to prove causation to the criminal standard." We also agree with the Vice-President's observation in Kirk Group Holdings that: "'Remote' risks must fall within the duty imposed by the Act (otherwise, it would be meaningless to extend risks beyond those which are reasonably foreseeable) and the question then centres upon whether the word `unduly' introduces a qualitative difference to justify exclusion from the broad duties imposed by ss 15 and 16 of the Act or alternatively whether ... the issue would be decided on a case-by-case basis by reference to causation." 55 In the same judgment however the Full Bench considered and rejected a proposition that an inability on the part of the employer to provide the means to ensure the safety of its employees (because, for example, there was no prevailing method or technology to do so) was not causative of the danger (or risk to safety) to the employees. At [128] - [129] the Full Bench found: It is not open to an employer, in answer to a charge under s 15(1), to contend that it was unable to assess whether something was safe because there was no method or technology available to do so (subject, of course, to any available defences). Employees cannot be placed in a situation where the employer is unable to ensure, or make certain, or guarantee their safety. That is not to say that visual inspection and sounding with a metal bar cannot be used in testing the safety of a roof in an underground mine. As long as it is comprehended that in relying on these methods alone is not a guarantee of safety. It then becomes a question of whether the corporate respondent's failure to provide an adequate system for assessing the safety of the roof was causally connected to the risk of the roof falling in whilst employees were working in the relevant area. There will be a causal connection if the corporate respondent's failure to provide an adequate assessment system failed to avert the risk to safety of the roof falling in. Clearly, in this case, it did. Visual inspection and soundings using a metal bar, which was essentially the method used by the defendant to assess the safety of the roof, did not avert the risk of the roof falling in. In fact the roof fell in and killed Mr Edwards, thereby putting beyond any doubt that the corporate respondent failed to obviate the risk to employees working in the relevant area. If there had been an adequate system of assessing the safety of the roof we are satisfied the risk would have been avoided. 56 The facts revealed by the evidence here, together with the application of the principles extracted from the judgment of Morrison v Powercoal compel the conclusion that the defendants failed to ensure Mr Butcher's safety by failing to provide an interlock device on either the tractor or the Windrower. This is so notwithstanding that the machinery was not designed to incorporate such a device and the device was not commercially available at the time of the offences. If the law were otherwise employers could with impunity place their employees at risk of injury on the basis that they cannot ensure, make certain or guarantee their safety. 57 There can be no doubt that this failure resulted in or caused a risk to Mr Butcher's safety when he assisted Mr Willie in cleaning the rollers on the Windrower on the day of the alleged offence. I therefore find that this particular has been made out by the prosecutor beyond reasonable doubt. Whether rollers inadequately guarded 58 The third particular alleges that the defendants failed to ensure that the rollers were adequately guarded. The prosecutor made one very short written submission in relation to this particular: That the rollers were not guarded is not in dispute. The evidence in that regard in the trial was quite clear. 59 The evidence disclosed that the rollers were not guarded. In order to clean the rollers however it was necessary to gain access to them. The rollers were cleared of debris following a blockage by using either hands, a crowbar or some other implement. The risk to safety arose because of the necessity to access the rollers for the purposes of cleaning them. If the defendants had provided a guard to cover the rollers it would have had to have been removed to enable the employees to clear the blockage. Given these causative facts, there can be no nexus between the failure to ensure safety as particularised (the failure to adequately guard the rollers) and the risk to safety to Mr Butcher which arose while he was cleaning the rollers. The procedure would necessarily have required the guard to be removed before access could be gained in order to clear the blockage. 60 The prosecutor therefore has failed to make out this particular to the requisite standard. 61 I find that the defendants failed to ensure the safety of Mr Butcher by first, failing to provide and maintain a safe system of work for the cleaning of the rollers by failing to provide an adequate procedure for performing the task as well as failing to provide adequate instructions for performing the task. Secondly, I find that the defendants failed to ensure the safety of Mr Butcher by failing to provide an adequate system of isolation of the Windrower by failing to provide adequate instruction and failing to provide an interlock device or interlocking guard over the nip point area of the rollers. Both defendants are therefore guilty of an offence under s 8(1) of the Act unless they are able to make out a defence under s 28 of the Act. Defence under s 28 of the Act 62 The defendants rely on both limbs of s 28. The section provides two defences, first, that it was not reasonably practicable to comply with s 8(1) and, secondly that the commission of the offence was due to causes over which the defendants had no control and against the happening of which it was impracticable for them to make provision. The defendants' submissions focus exclusively on the failure to provide an interlocking guard. 63 An interlocking guard on the Windrower would require essentially two things: a guard and an interlock device connecting the tractor and the Windrower. The evidence of Mr Sulman was that at the time of the offences the device was not commercially available. The only avenue that may have been available to the defendants was to have the device specifically designed. According to Mr Sulman this would have incurred substantial costs exceeding $150,000 for the interlock device and $4,000 including GST for the guard cover. Mr Sulman said that a "one-off" device could have been produced by a company of which he is a director, for a cost of $96,000. This figure Mr Sulman derived from a number of necessary development steps including the design of the device as well as the completion, development, testing and final assembly of the device, using a combination of mechanical, electrical and electronic expertise over a minimum 6 month period. Mr Sulman concluded that the "...time, expertise and cost to develop an interlocking device, satisfying AS 4024-1-1996 and the OHS Act 2000, would be extremely disproportionate to the risks surrounding the nip point area". In oral evidence Mr Sulman said that he estimated the costs of the Windrower at between $50,000 - $100,000. 64 The prosecutor, Inspector Jones gave some evidence in terms of the expertise required and the cost, of a one-off guard. He said that such guards were readily available in his experience following the issue of prohibition notices requiring persons to provide guards for machinery and types of agricultural equipment. He conceded in cross-examination that none of the prohibition notices extended to guards on a Windrower or that he had ever seen a guard on a Windrower. 65 The prosecutor's evidence on the point was very general. He demonstrated no technical expertise which might have allowed him to critically assess Mr Sulman's predictions about the complexity, technical sophistication and cost of producing an interlock device for the Windrower. It is not entirely clear from his evidence that he was discussing such a device. Rather his evidence appears to be confined to a guard cover. Indeed the prosecutor did not hold himself out as having any particular expertise in the area. Nor was the prosecutor asked any specific questions as to the details of the "one-off" guards which he says were produced following the prohibition notices. Nor was he asked about the circumstances under which the guards were able to be produced and fitted, and the complexity, practicability and cost involved in their manufacture and design. 66 Mr Tippett said in his evidence that at the time of the accident he was not aware of any available interlocking guard devices for potato harvesters and other agricultural machinery. 67 The proper approach to a consideration of the defence under s 53(a), the predecessor section to s 28(a) of the Act, has been conveniently set out by Walton J, Vice-President in Cleary Bros (Bombo). After considering the authorities his Honour said (at [87] [88]): [87] It is evident from these authorities that what is required by s 53(a) of the Act is a balancing of the nature, likelihood and gravity of the risk to safety occasioning the offence with the costs, difficulty and trouble necessary to avert the risk. At one end of the scale, it could not be reasonably practicable to take precautions against a danger which could not have been known to be in existence: see Jayne v National Coal Board [1963] 3 All ER 220 at 224 and Shannon v Comalco Aluminium Ltd (at 362). Similarly, if the happening of an event is not reasonably foreseeable then it will not generally be reasonably practicable to make provision against that event: see WorkCover Authority (NSW) (Inspector Mayo-Ramsay) v Maitland City Council (1998) 83 IR 362 at 381; WorkCover Authority (NSW) v Kellogg (Aust) Pty Ltd (at 259) and Austin Rover Ltd v Inspector of Factories (at 627) per Lord Goff and (at 635-636) per Lord Jauncey of Tullichettle. [88] At the other end of the scale, there will be cases, such as the present, in which known or obvious risks to safety exist. In these circumstances, the defendant will not have established a defence under s 53(a) of the Act where it was reasonably practicable to have complied with the Act by ensuring that persons were not exposed to those risks. This may be the case because no measures were reasonably available or because measures which were available were not reasonably practicable. As has been discussed, the assessment of the reasonable practicability of those steps requires a balancing of the quantum of the risk with the sacrifice (in money, time and trouble) in adopting the measures necessary to avert the risk. In my view, where there is a known risk which entails the potential for serious injury to persons in the workplace, the defendant will generally have to demonstrate that the costs, difficulty or trouble occasioned by the measures significantly outweigh the risk. This must be done by reference to the charge as brought by the prosecutor. 68 As earlier mentioned, the risk to safety here was both known and obvious, questions of reasonable foreseeability, therefore do not arise. The issue is whether it was reasonably practicable to have complied with the Act. This issue requires a balancing of the severity of the risk against the sacrifice in money, time and trouble in adopting measures necessary to avert the risk. 69 In this regard I make the following findings: (i) the defendants are farmers not engineers, and lacking in the necessary technical expertise which might have facilitated a recognition that employees would not be exposed to the nip point when cleaning the rollers if an interlocking guard had been installed; (ii) the device was not commercially available at the time of the offences; (iii) neither the tractor nor the Windrower were designed to incorporate the device; (iv) incidents of employees being on the Windrower when the PTO was engaged were unknown prior to the offences date; (v) the cost of producing the device is $96,000 plus $4,400 for the cover guard. The estimated value of the Windrower is between $50,000 to $100,000. 70 Balanced against the above factors is the very serious risk to which Mr Butcher was exposed on the day of the accident. In my view, my findings set out above when taken together, significantly outweigh the severity or quantum of the risk. In any event there were other measures including the provision of adequate instructions which were readily available to the defendants, which could have been taken, in order to ensure Mr Butcher's safety. I therefore find that it was not reasonably practicable for the defendants to have had an adequate system of isolating the Windrower by designing and fitting an interlock guard. The defence in relation to this particular has therefore been established by the defendants on the balance of probabilities. 71 It remains to consider s 28 by reference to the defendants' failures to provide adequate instructions in relation to the provision and maintenance of a safe system of work and the adequacy of a system of isolation of the rollers on the Windrower. On the one hand it is beyond doubt that the risk to safety was extremely serious. On the other hand making provision for an adequate system of instructions would have been relatively easy and not at all a burden financially. A system of comprehensive instructions which were consistently checked and monitored to ensure compliance, and which were formulated in order to specifically take into account the cleaning of the rollers by more than one employee, would have been relatively easy to implement and maintain, by further instruction, if necessary as well as by regular supervision and refresher training. The defendants have put forward no submissions in relation to whether a defence can be established in the event a finding of guilt was made in relation to the inadequacy of instructions. Accordingly I find that the defendants have failed to establish a defence under s 28(a) on the balance of probabilities. 72 Nor in my view can the defendants successfully establish a defence under s 28(b). The defendants here rely on the evidence which tends to confirm, they say, that the employees received adequate instructions in relation to the cleaning of the rollers but nevertheless ignored those instructions and knowingly and deliberately placed themselves in a situation of danger. I have already found however that Mr Butcher was not the recipient of adequate instructions in relation to the task of cleaning the rollers and in relation to isolating the rollers while they were being cleaned. The defendants had control in relation to the task. They were responsible for and capable of, as employers, providing suitable instructions to Mr Butcher in relation to the safe performance of the work. I am therefore not satisfied on the balance of probabilities that the defendants have established a defence under s 28(b) in relation to the offence with which each defendant has been charged under s 8(1) of the Act. 73 The defendants are therefore guilty respectively of an offence under s 8(1) by reason of failing to provide and maintain a safe system of work for the cleaning of the Windrower, and by failing to have an adequate system of isolating the Windrower while the rollers were being cleaned. Orders 74 I make the following orders: 1. In Matter No IRC 2587 of 2005 the defendant, JT & LC Tippett Pty Ltd is found guilty of the offence. 2. In Matter No IRC 2588 of 2005 the defendant, RD & LF Tippett Pty Ltd is found guilty of the offence. 3. Both matters are set down for a directions hearing at 10.00am on Friday, 16 February 2007 for the purpose of setting dates for sentence hearings. __________________________ AMENDMENTS HISTORY: 26/02/2007 - Alteration of catchwords - Paragraph(s) Catchwords DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.