124 Given Mr Thiedeke's evidence that the risk of slipping identified by Mr Nicholson, had never been identified as a risk and had never manifested itself at this yard, when considered together with Mr Underwood's evidence as to his experience in industry, this note of caution needs, in this case, to be kept in mind.
125 It was the plaintiff's case that there was a duty to ensure safety in the yard imposed on United Concrete by the Occupational Health and Safety Act and the Regulations. Failing to conduct formal risk assessments and safety audits had resulted in a risk which ought to have been known, not being identified, with the result, Mr Willet's injury when the hazard posed by the sand and aggregate in the yard materialised in 2004. While no breach of statutory duty was alleged, the failure to conduct formal risk assessments and safety audits was pleaded. It followed that negligence had been established.
126 It must be observed that while such failures were pleaded, they could not of themselves establish the existence of the risk in question. That was sought to be established by the expert evidence called from Mr Nicholson.
127 The experts had each inspected the place at which the accident occurred in 2009, some five years after the accident, at a time when the site was no longer operated by United Concrete. The plaintiff's expert Mr Nicholson had also seen the workplace in 2007, but only from the street, at a point where he could not see the place where the accident had occurred. The experts had conferred in order to identify what they disagreed about, with almost no success. In their evidence, however, their disagreements were somewhat resolved and the difficulties with the plaintiff's case was revealed.
128 The place of the accident was at a yard with a concrete floor, sloping at 3 degrees, where trucks came to deposit loads of sand and aggregate 10 to 12 times a day. Mr Thiedeke confirmed that in 2004, the yard was configured in a similar way to that which the experts saw in 2009. In 2004 the concrete had lain on the yard for quite a number of years and was worn by the activity which took place there. There was no doubt that by 2009 it was more worn, by then having been affected by water, but nothing much seems to turn on that, because the slipping hazard was not claimed to have arisen from the presence of worn concrete.
129 There was no evidence as to how the yard was cleaned in 2009. Mr Thiedeke explained that in 2004 sand and aggregate was dumped at the yard by truck in open bins, then removed by front-end loader and taken elsewhere in the plant. Throughout the day, sand and aggregate escaped from where it was stored in the open bins and was deposited on the concrete floor of the yard. This escaped material was regularly cleaned up throughout each day by use of a front-end loader. The front-end loader could not pick up all of the sand and aggregate from the ground. Every two or three days, the concrete yard was also swept clean by use of a brush attachment on the loader.
130 It was Mr Willett's evidence that on the day that he was injured, there was more sand and aggregate on the ground, than when he visited the site with Mr Nicholson in 2009. As was submitted for Mr Willett 'there was clear evidence of significant quantities of sand (and some aggregate) in the vicinity'.
131 From Mr Willett's evidence, that of Mr Thiedeke and the photographs taken by the experts, there can be no question that the sand and aggregate lying on the ground when Mr Willett was there in 2004, was obvious. While Mr Willett claims that he did not see what he slipped on until after he fell, it was apparent that nothing obstructed Mr Willett's view of the yard, either when he entered, or when he got out of his truck. What, on his evidence, he could not see, was what was lying on the ground, on the other side of the draw bar, when he stepped across it, but after he fell, he saw both sand and aggregate underfoot.
132 It was the plaintiff's case that Mr Willett could not have stepped onto any sand which had fallen there, when he brushed off the back of the tipper and the drawbar, given where the airlines lay at the back of the truck and on the draw bar. That was both Mr Willett's evidence and that of Mr Nicholson. It follows that on the case advanced, this sand cannot have been what Mr Willett slipped on, it can only have been what was generally lying on the ground, after having escaped from the bins, or been brushed to the ground from another truck, or what had otherwise been spread around by the movement of trucks, loaders, people, weather and the like.
133 On Mr Nicholson's assessment, a loader would remove some 80% of what lay on the ground. In 2004, this occurred several times a day. More was removed, when some three times a week, the sweeper attachment was used. On the evidence, when the accident occurred in 2004, the yard could not have recently been swept clean, by sweeper or loader, given Mr Willett's evidence as to the amount of the sand and aggregate which he then saw lying there.
134 Given what they each saw at the yard in 2009, Mr Nicholson was of the view that the sand on the concrete floor presented a risk and Mr Underwood, that it did not. Mr Underwood saw even less sand and aggregate underfoot than Mr Nicholson. Neither of those opinions was based on scientific testing of the coefficient of friction between what was found lying on the concrete where the accident occurred and work boots of the kind worn by Mr Willett and others who accessed the yard. There was no question that such testing could have been done. Mr Nicholson was qualified and experienced in such testing and could have undertaken it. He even had a work boot with him, but conducted no such test. Nor did Mr Underwood. He, however, was wearing such a boot and tested whether it would skid on what he found on the ground. It did not. Mr Nicholson did not attempt such an exercise.
135 Mr Nicholson's evidence was that a coefficient of friction of less than 0.45 presented a risk to a pedestrian walking across the yard. On the measurement which he did undertake, inadequate as that test undoubtedly was, the coefficient which he found ranged from 0.30 to 0.45. On his own assessment, if the place where Mr Willett stepped had a coefficient of 0.45, it would have been safe. That it did not have such a coefficient was not established, firstly because Mr Nicholson's test was directed only to a fine layer of sand on the ground, that being what he understood Mr Willett had slipped on. Mr Willett's evidence was that there was more sand underfoot in 2004 than was there in 2009. More sand would have been less slippery. Secondly, on Mr Willett's evidence, there was both sand and aggregate underfoot when he slipped. The presence of aggregate would also have reduced the risk of slipping. Mr Nicholson conducted no tests as to the coefficient of friction presented by both sand and aggregate. Thirdly, Mr Willett was wearing a work boot. That, too, would have reduced any risk of slipping, but to what degree, is not known, because there was no testing undertaken in the context of a work boot.
136 Finally, it must be considered that the test which was conducted by Mr Nicholson was not directed to the action undertaken by Mr Willett, when he stepped across the draw bar. Mr Nicholson agreed that the action of stepping across the draw bar was different to the action of walking across the yard. The action of swinging the leg over, while standing facing the rear of the truck, no doubt would have been another action entirely, but not one put to Mr Nicholson, presumably because it only arose as a possibility in later submissions.
137 As Mr Nicholson explained, the co-efficient of friction which he found was established by rubbing a slider across the sand which he found in 2009 at a spot which he thought replicated the conditions underfoot where Mr Willett fell. Mr Nicholson acknowledged that this was a simple test, not undertaken in accordance with the Australian Standard. Mr Underwood conducted no such test, Mr Nicholson not having revealed this testing until shortly before the hearing, when the joint statement was prepared. Mr Underwood thought the test unreliable.
138 That it was an unreliable basis upon which any conclusions could rest, was confirmed by Mr Nicholson in cross-examination. What the coefficient of friction between the sand and aggregate which Mr Willett described to have been underfoot and the work boots which Mr Willett was wearing, was not established. It was not shown that the coefficient was unsafe, that is, less than the 0.45 coefficient which Mr Nicholson postulated as being safe.
139 The only test Mr Underwood undertook was a subjective test, namely trying to make his foot skid, while wearing safety boots. He could not do so, which confirmed him in his opinion that the yard was not slippery. That accorded with Mr Thiedeke's evidence as to United Concrete's experience of the yard and Mr Underwood's experience in industry.
140 Plainly, the expert evidence led in this case was of more limited assistance in a resolution of this controversy than it would have been, had other available tests been undertaken.
141 The experts agreed that a fine layer of sand on concrete could be slippery and that a variable surface could also increase slipperiness, if walking across the yard. They also agreed that more sand on the ground, would have made this concrete surface less slippery, as would the presence of aggregate.
142 Commonsense accords with the expert evidence that a fine layer of sand on a concrete surface can pose a slipping hazard and that whether there is in fact a risk, depends on the footwear being worn by a person who accesses that surface, whether there is anything else underfoot and what action the person is taking on that surface.
143 There was no evidence, however, that it was a fine layer of sand which was underfoot when Mr Willett fell and no evidence that the coefficient of friction between the surface on which Mr Willett said he slipped, contaminated as it was by a substantial amount of sand and aggregate, was slippery, given the work boots which he was wearing.
144 While it follows from the evidence that in theory, there might have been a potential risk of slipping present at this site, it was most likely to exist, after this yard was swept clean of sand and aggregate, by the sweeper attachment, several times a week. That there was then a risk that a fine slippery layer of sand might develop, was theoretically a possibility. Whether it ever materialised, depended on the coarse sand delivered to this site spreading and being ground fine, by the movement of vehicles across the sand, without sufficient aggregate being also present, to obviate that slipping risk for those walking across the yard while wearing safety boots, before more coarse sand covered the fine sand so created. This scenario seems most unlikely to have ever developed, on the evidence. The expert evidence did not address itself to such a situation developing and it was not one consistent with Mr Willet's evidence as to the state of the yard as he found it, in 2004.
145 That this condition ever existed was not established, or sought to be. That it was not the condition of the ground when Mr Willett fell, was clear on his own evidence.
146 It is in this context that Mr Thiedeke's evidence that he did not find the yard slippery and that this was United Concrete's experience in the six years that he had worked there, has to be considered. That evidence may not be ignored.
147 In Makita, itself a slipping case, there was evidence led from an expert as to the slipperiness of the stairs in question. While the expert concluded that the stairs were slippery, on the evidence there, the only other occasion when there had been a slip on those stairs, was one other occasion, quite a number of years beforehand. This was considered by Powell J to 'cast more than a shadow of doubt over any assertion that the stairs were slippery and that the Respondent ought to have taken steps to obviate that risk of injury to its employees arising from that fact' (at [10]). For his part, Heydon J observed that there was a collision between the expert's evidence that the stairs were slippery and the lay evidence that there had been no problems experienced with slipperiness. At [99], Heydon J observed that resolution of that collision depended on satisfaction as to the validity of the expert's approach.
148 Plainly, a similar collision here arose between Mr Thiedeke's evidence and that of Mr Nicholson. Mr Underwood's impression that there was no risk of slipping in this yard, when work boots were worn, also had to be considered. Like in Makita, the expert evidence led in this case for the plaintiff, was not convincing, for the reasons which I have explained.
149 While the argument put for Mr Willett, that a risk, even a slight one, could not be ignored until there had been catastrophic consequences such as those which befell Mr Willett, has obvious force, of itself, an injury cannot establish that the risk alleged existed, or that it caused the injury.
150 In terms of what the Civil Liability Act requires to be established, the question of whether, in the circumstances existing at the United Concrete yard in 2004, it was foreseeable that there was a risk of slipping and that the precautions in place would not prevent a slip, must be answered in the negative.
151 That there was a risk of slipping, given the sand and aggregate on the ground, as described by Mr Willett, was not established by the expert evidence, such as it was. Nor was it shown that the precautions taken by United Concrete, namely, of removing the bulk of the sand and aggregate off the yard several times a day by front end loader, sweeping it several times a week with a mechanical sweeping attachment and requiring those who accessed the yard to wear safety boots, would not prevent someone working in the yards from slipping. Nor was it shown that a reasonable person would have taken additional precautions. That additional precautions could have been taken, as I have noted earlier, of itself takes the matters which must be established under s 5B and 5C of the Civil Procedure Act no further.
152 In coming to a conclusion on whether a reasonable person would have taken additional precautions, account must be taken of: