THE HARNESS DID NOT ARREST THE PLAINTIFF'S FALL
36 In light of that background, and those competing contentions, I turn to the evidence of the plaintiff as to his practice, and as to what he recalled of the accident; and to the expert evidence concerning the harness and the matters that need to be taken into account for its safe use.
37 The plaintiff gave evidence that he always wore the harness, when working from the cherry picker, once it was acquired. This followed upon the general instruction from his father, following the earlier prosecution, to all staff, that anyone who went up in the bucket without wearing the harness would be dismissed. He said that he was not given any specific advice by anyone in respect of the way in which the harness was to be attached, save for some general instructions from his brother as to the way in which it was to be buckled up and adjusted. He also said that he did follow the instructions printed on the indelible label of the harness.
38 He said that he was never warned of the possibility of imperfectly securing the hook to the D ring or webbing, or of the integrity of the hook being interfered with by clothing, or of the need to have a co-worker check the connection, or as to the advisable sequence of attaching the lanyard to the harness and the fixed point.
39 He said that it was his practice to place on the harness first, and then to hook the lanyard onto the D ring, with his right hand behind his back at waist level. He also said that it was not possible for the wearer to visualise the connection being made between the hook and D ring, when following this procedure.
40 In chief, he said that he had no particular recollection of how it was that he fitted the harness, and effected the connection, on the day of the accident. However, I see no reason to believe that he followed other than his usual practice, particularly in the light of the two pieces of evidence previously mentioned. The first was his own evidence that he recalled, before the accident, feeling the weight of the lanyard dragging on his back, and "collecting" him when he moved about. The second was that of his brother Marco, who said that he saw the lanyard hanging down from the harness before the plaintiff fell from the bucket.
41 The plaintiff conceded, in cross examination by Counsel for Fallright, that he could not recall whether he tugged on the harness after he attached it. When cross examined by Counsel for Kuba he said, initially, that he checked the attachment by moving the hook to see if it would shift around inside the D ring. He later corrected this by saying that the check consisted of pulling on the cable, rather than moving it from side to side. "It felt right so I kept working".
42 He made it clear, in cross examination, that he connected the lanyard to the harness after putting it on and that this occurred after he got into the bucket.
43 It was his recollection that, immediately before the bucket tipped, he had crouched down to pick up the welder, which was in front of him in the bucket. The controls were behind him, he agreed in cross examination, when he did this. He was not aware whether the back of the harness was touching the bucket, but he believed it "would have been fairly close". He was also not sure whether, in the dynamics of the bucket tilting, his back was struck by it before he fell out, although he thought that may have occurred.
44 It was established that he had been wearing a jumper and jeans positioned beneath the harness, in the way that was recommended. Moreover, he said that the exercise with the cherry picker occupied 5 to 10 minutes, a period of sufficiently short duration as to have made it unlikely that he would have deliberately disconnected the lanyard from the harness, between the time of the initial connection and the fall.
45 It is possible that the plaintiff was in error in his recollection that he bent down to pick up the hand piece to the welder. His brother Marco thought that he was looking instead for a spanner to remove some bolts from the purlins which were in the way. Nothing, however, turns on this difference in their accounts, it being common ground that the plaintiff did crouch down facing the open doorway and beam, just before the fibreglass rod snapped, and that when he did so, his shoulders went below the rim of the bucket.
46 I turn next to the expert witnesses who were called in relation to the likely reason for disengagement of the hook, and in particular in relation to the question whether it was due to roll out or to an unrealised but imperfect connection. In the course of their evidence some attention was given to the development of the Australian Standard, to industry knowledge, to alternative forms of hook and lock, to alternative ways of connecting the lanyard hook to the D ring, and to alternative ways of checking the integrity of that connection.
47 It became clear from their evidence that the problem of roll out had been well recognised, in relation to single action hooks, leading to the introduction of double action hooks. The Australian Standard 1891.1.1995, that was published in March of that year, ie prior to the supply of the subject harness, gave recognition to this so far as it called for double action hooks rather than single action hooks, and so far as it replaced the 1983 standard.
48 In the plaintiff's case, Dr John 0lsen, an occupational health, safety and rehabilitation consultant, was called. It became clear that he had no substantial complaint in relation to the design of the harness, which he thought complied with the 1995 standard. He also thought it was the right harness for the kind of work which Yoogali undertook. His principal concern, it appeared, was with the hook design, which he said "was such that to disengage the two locks of the double action, compression only was required. This is unlike some double action hooks where tension is required on one side." One such hook, that was available in 1998, was demonstrated in a Fallright catalogue which was an attachment to his report. Another was the Karabiner type hook.
49 The hook used in the present case did not, in his view, comply with clause 3.3.2 of the 1995 Standard which specified that the springs of the snap hooks are to "be loaded so that when the latches are closed the springs rest in position and are constrained from any movement until deliberate pressure is applied to engage or release the latch"; and further specified that "in order to reduce the probability of involuntary opening, snap hooks and karabiners should be capable of being opened only by at least two consecutive deliberate actions."
50 He said that he had been able to simulate an accidental opening by applying pressure, in a single direction, on the side of the locking plate of the hook when attached to the harness, ie in a way not requiring two consecutive deliberate actions. He demonstrated this event in the witness box, although not without considerable difficulty.
51 It became apparent that this could only occur in the rare circumstance where the D ring and hook were so configured that, pressure applied directly inwards against the locking plate would generate a reciprocal pressure outwards, when the hook was pressed against the shock absorbing part of the harness. That, he said, would then activate the locks, and allow the D ring to slide out of the hook.
52 In the manner first demonstrated by Dr Olsen, the curve of the D ring was in the uppermost position, the hook was allowed to sag slightly to the left with the eye toward the body of the wearer and the pressure was applied to the safety latch. The same event was demonstrated with the hook reversed, ie with the eye pointing outwards. In this configuration pressure from the wearer's side activated the safety latch, permitting the hook to snap off, provided it swivelled sideways.
53 The force required to open the main latch, Dr Olsen explained was one of 2kgs, a force which had to be applied in exactly the correct direction, differing according to the way in which the hook was positioned.
54 Dr Olsen conceded that "roll out" occurring in either of these ways would be "necessarily rare" although each was "a possibility". He regarded the exercise undertaken as one involving a simultaneous action, in the sense that it depended upon the generation of simultaneous, reciprocal but opposing forces.
55 He acknowledged that he had not endeavoured to simulate roll out by a blow to the hook as distinct from a sustained pressure upon it. He also acknowledged that the safety catch had to be depressed for some distance before the hook would open, and that there had to be a sideways movement for the open hook to come off the D ring. He further agreed that the natural tendency of the hook and lanyard was to follow the forces of gravity to the floor, thereby pulling the D ring downwards, and that it was also the natural tendency of the hook, once slipped into the D ring, to lie to one side or another, rather than to sit perpendicular to the back.
56 It follows that the second simulation of roll out that he demonstrated was less likely to occur since the optimum circumstances for it required the hook to be as close as possible to 90 degrees to the wearer's back. Although, for the first simulated roll out that he demonstrated, the D ring was at an angle, he acknowledged that it also could not occur where the D ring was flat against the wearer's back.
57 Apart from the double acting tension and compression hook that he thought appropriate, Dr Olsen said that a Karabiner would have been a better option since it could not be opened by a single pressure. He did, however, acknowledge that the Karabiner would be more fiddly to use, particularly if secured to a D ring behind the wearer's back, because of the need to twist the screw that brings it to a closed position. Moreover, he conceded that a user may not be able to tell whether the screw gate was fully closed, that Karabiners are able to work themselves undone through vibration and possibly through rubbing against clothing, and that some wearers may not bother to screw up a knurled mechanism of the kind deployed in a Karabiner.
58 The double acting tension and compression hook he thought would be easier to use than the Karabiner, but "slightly more difficult" to operate than the one used on the plaintiff's harness.
59 Another alternative means of connection that was explored, in cross examination of this witness, was the one that employed a mechanism permitting permanent, or at least semi permanent closure, and that can only be undone, once fixed, with an implement such as a screwdriver, spanner or pair of pliers. One that Dr Olsen spoke of was a shackle. Another, that was identified in the evidence of Dr. Turner, was a tube nut connector, normally referred to by its brand name, Maillon, that can be made even more secure by application of Lock Tight glue.
60 The other aspect of the case explored by Dr. Olsen related to the method of attachment of the hook to the D ring. One possible solution for improvement that he offered, involved a small extension of the D ring strap, by about 300 to 400mm, to improve the ability of the wearer to visualise the connection. Another solution was to make that connection before donning the harness, or to have someone else make the connection.
61 The problem of effective connection that he identified in this regard, was that previously mentioned, namely the difficulty, if not the impossibility, of the wearer being able to see the D ring on the harness when attempting to attach the hook to it, with the risk of incomplete closure due to some impediment, or due to connection to the webbing or some part of the harness other than the D ring.
62 In cross examination, he admitted that the provision of an extended D ring strap would cause the lanyard and ring to hang lower on the body of the wearer than the preferable mid back point of attachment. This, he conceded, could present its own dangers, so far as the attachment may become more prone to compression through leaning against or pushing against other objects, if worn at waist level, and in so far as there would be a greater likelihood of snagging. His evidence in relation to this aspect of the case is best encapsulated in the following answer:
"If you look at the purposes that you might put this harness to, it is probably better to have it the way it is. For use in a cherry picker, I would rather have the extension."
63 Finally, Dr Olsen was of the view that it would have been desirable for the harness to contain an indelible instruction, in respect of the security of the connection of the lanyard onto the D ring. That, he said, might also include instructions to the effect that the connection ought to be made before the harness was donned, and/or that its integrity should be checked by a co-worker, and/or that the connection should be made by the co-worker. He agreed, in cross examination, that it was not possible to warn against every possible mishap, and that warnings should be confined "to the main risk associated with the use of the equipment".
64 Dr Olsen made it clear that he was unwilling, if not unable, to determine which of the possible competing causes of detachment identified, had occurred in this case, regarding this as a matter for the Court.
65 Dr Turner, an engineer employed by Workcover New South Wales and Chairman of the Standards Australia Committee for Industrial Belts and Harnesses, was called in the case of Fallright. He was asked to examine the subject harness and lanyard after the accident, in order to report on the suitability and condition of its components. The effect of his report was that the hooks used were properly to be regarded as double action hooks, within the intent of the Standard. He also said that the signage and markings on the harness conformed with clause 5.2 of the 1995 Australian Standard. He found no fault with any of the individual components.
66 He agreed that, while the 1995 standard had led to a great improvement, double action hooks were not infallible, and that, dependent upon them being placed in a particular orientation, they were still susceptible to simulated roll out.
67 So far as the 1995 Standard dealt with the need for deliberate pressure to engage and release the latches, he said that he regarded this as directed to the need for the spring not to be in tension when the lock is closed; and also to the need to ensure that when the device was closed, the spring was contained and not vulnerable to being activated accidentally by a side load or by some external object pushing against it.
68 His evidence in relation to this aspect of the case, and in particular the likelihood of there having been a roll out through compression, is best encapsulated in the following passage of his evidence:
"Basically to achieve a roll out you need the hook and the connection to be in a particular orientation with respect to each other to actually achieve that and most of the orientations are difficult to maintain other than by holding them tight, tightly by your hand. If you were to hold them by the lanyard you may not be able to achieve that orientation because the components would naturally tend to move away from that orientation."
69 He regarded the Fallright (SSE) hook as safe to use in relation to fall arrest equipment, and added that he was unaware of any problem with its use in the workplace. In a letter to the plaintiff''s solicitors dated 25 March 1999, he said that it was acknowledged that some double acting hooks were susceptible to simulated roll out, and that the hooks involved in the accident "were one of the easiest to demonstrate this potential". In the course of his cross examination he explained that he was speaking of simulated roll out. He accepted that while roll out with a hook of the kind used here was extremely rare, that could occur if both sides of the locking mechanism were compressed by an action in a single direction, ie if it could be held and retained in the correct orientation, and the necessary movement of the hook on the D ring could be achieved.
70 He agreed that there were locks available in 1995, including those in the Fallright catalogue that could not suffer hasp unlocking as the result of pressure in a single direction, and required separate and consecutive movements for that to occur. However, he said, they could also be shown to roll out in a different circumstance, ie if the lanyard was twisted in a particular way, albeit that it would be "very rare and very difficult to achieve" the necessary orientation, and "in real life virtually impossible "to do so".
71 Karabiners, he said, were appropriate for use with fall arrest equipment. They had advantages in terms of their light weight and flexibility of use; and disadvantages so far as they may not meet the standard for strength when loaded across the gate, so far as they depend on the worker winding the knurled nut up tight to secure a lock, so far as they tend to go missing in the workplace (because of their other potential uses), and so far as they can become undone by rubbing up against another surface or object (if done up finger tight) or through vibration. He pointed out that they can also give a false positive if screwed up tight against some obstruction in the gate, especially if done up out of sight.
72 The semi permanent or permanent connectors, such as the maillon, he said could overcome this problem but they could also cause problems in certain applications, for example, where the worker had to move around because of the risk of having the lanyard caught or snagged. Additionally, he said the use of a permanently fixed lanyard could be uncomfortable if the worker was required to get into a vehicle, in which event it might dig into his back. The risk of tube nut connectors coming undone through vibration or friction, he said could be overcome by the application of Lock Tight glue, and to that extent they had an advantage over karabiners.
73 It was his experience that wearers of harnesses of the kind used in this case made the D ring connection by going over the top rather than from below (the way that the plaintiff did it). He had not seen any difficulty with this, and he did not regard it as a dangerous or inadvisable practice to hook up after the harness was donned.
74 He also did not see any difficulty in the way of a worker making a physical check himself to confirm proper connection. This he said was normally done by giving the hook a wiggle to check that it was moving freely within the D ring.
75 He did, however, agree in cross examination, that any form of safety equipment that involved a worker attaching something behind his back, had inherent dangers arising out of the fact that the worker could not see the precise point of attachment and that in the hustle and bustle of work, a mistake could genuinely be made when effecting the attachment. He also conceded that if the hook had been firmly attached to the webbing or clothing of the worker, then a pull on the lanyard may leave the worker with the incorrect belief that he was properly attached. He did, however, indicate that it would be more likely, if there were an imperfect connection, for the hook to pull off whatever it was attached to, when tugged. Another false positive that could appear to an operator, in the event of the hook being enmeshed in the clothing or webbing, he accepted, was the reassurance of the weight of the lanyard.
76 In relation to the provision of additional instructions upon the harness, Dr. Turner pointed out that there was a limitation, in a practical sense, in that there was not a large amount of room available.
77 By reason of his belief that there was nothing inherently unsafe in connecting the hook to the D ring after the harness was in place, he did not think, subject to one qualification, that there was any point in placing upon it any additional instruction or warning of the kind that Dr. 0lsen had identified. The qualification was expressed in the following terms:285
"If it was not possible to do a physical check I would agree there should be some sort of instruction to get another person to check it or to put it on first or to do something else that removes that problem, yes."