New South Wales Supreme Court CITATION : RTA & Welling v Comerford [2000] NSWSC 163 CURRENT JURISDICTION: Equity Division Construction List FILE NUMBER(S) : SC 55034/98; 55035/98 HEARING DATE(S) : 10.12.99, 11.2.00, 8.3.00 JUDGMENT DATE : 15 March 2000 PARTIES : 55034/98 Roads and Traffic Authority of NSW v William Kevin Comerford & 3 Ors 55035/98 Gerhardus Hendrikus Welling & Anor v William Kevin Comerford & 4 Ors JUDGMENT OF : Hunter J M G Rudge SC & D A C Robertson for Roads & Traffic Authority of NSW COUNSEL : N A Cotman SC & M R Pesman for Messrs Comerford M L Williams SC for Messrs Welling I V Knight (State Crown Solicitor) for Roads and Traffic Authority of NSW SOLICITORS : John F Griffin for Messrs Comerford Carroll & O'Dea for Messrs Welling CATCHWORDS : Practice and procedure - adoption of referees' report - leave to adduce additional evidence - conduct of reference - court to consider aspect of negligence issue not addressed by referees - decision of court on evidence taken before referees and additional evidence. LEGISLATION CITED : Pt 72 r2 & r13 Supreme Court Rules Ghantous v Hawkesbury City Council matter number S69/1999 CASES CITED : Brodie v Singleton Shire Council matter number S44/1999 Hill v The Commissioner for Main Roads (1989) 68 LGRA 173 McDonogh v The Commonwealth (1985) 73 ALR 148 DECISION : 1. Pursuant to Pt 72 r13, I grant leave to the parties to adduce additional evidence to that taken before the referees, limited to the issue of the Authority's alleged negligence and consistently with the findings of the first report as adopted by the judgment of Einstein J of 30 March 1999 2. The parties are notified that, in deciding whether the second report should be adopted, varied or rejected, the Court will have regard to that additional evidence and the evidence taken before the referees 3. Costs reserved IN THE SUPREME COURT OF NEW SOUTH WALES EQUITY DIVISION CONSTRUCTION LIST HUNTER J WEDNESDAY 15 MARCH 2000 55034/98 ROADS & TRAFFIC AUTHORITY v WILLIAM KEVIN COMERFORD & 3 ORS 55035/98 GERHARDUS HENDRIKUS WELLING & ANOR v WILLIAM KEVIN COMERFORD & 4 ORS REASONS FOR JUDGMENT 1 On 3 September 1998 an order was made pursuant to Pt 72 r2(1) of the Supreme Court rules in each of the subject proceedings referring to the late Mr Geoffrey Verge (the referee), the question "of the cause of the collapse of the Wellington Bridge on 6 January 1989." 2 The "collapse" of the Wellington bridge, had resulted from a collision between overhead elements of the bridge and an excavator being transported across the bridge on a low loader attached to a prime mover driven by William Kevin Comerford (Comerford), one of the parties to the litigation. The excavator was the property of Gerhardus Hendrikus Welling (Welling) another party to the litigation. 3 The issue of causation required consideration of the question whether the load being carried was too high for its safe carriage across the bridge or whether some other circumstance brought the excavator into contact with the bridge. 4 In the referee's report of 14 December 1998 (the first report) he answered the question referred in the following terms: "On the balance of probabilities the collapse of the bridge was caused by a buckling failure of the bridge deck in accordance with the contentions of the defendant." 5 The significance of this finding lay in its rejection of a contention that the load was too high for safe carriage across the bridge and its acceptance of the case that the concrete slabs forming the bridge decking buckled under compressive lateral forces which forced the low loader up, bringing the excavator into contact with overhead sections of the bridge. The anatomy of the ensuing collapse of the bridge was described in the first report as follows: "The vehicle was travelling generally in a southerly direction from Dubbo to Wellington. When it entered the first main span of the bridge the top of the dipstick of the excavator on the low loader struck the lower chord of the entry portal truss. The top of the dipstick maintained contact with the portal truss massively deforming it and pulling the first diagonal and the top chord of each main truss inwards and along in the direction of travel. At a point about 5 m beyond the initial contact the dipstick disengaged from the portal truss and at about this point the excavator landed on the bridge deck. The prime mover and low loader continued along the first span; the low loader came to rest tilted down with its rear end (triaxle) on the exit end of the first span and its front end (gooseneck) on the deck of the second span. The prime mover separated from the low loader and continued on about half way along the second span. The initial impact and bending of the portal truss applied a lateral force to the ends of the main trusses causing the end diagonals to pull in at the top and spread apart at the bottom. At the right hand (downstream) side the bearing plate failed and the bottom chord bent outwards clear of its supporting pier No. 8. At the left-hand side the bottom chord jumped forward off its bearing and clear of the pier. The destruction of the top of the truss caused the end of the bottom chord to act as a beam; in this mode it was overloaded. The bottom chord of the truss bent at about the junction of the second and third diagonal being some 7.3 m from its end. In doing so the truss shortened so that its end was no longer supported by the pier. Consequently the entry end of the truss fell back into the river. As it fell the far end of the truss struck the central pier (No.7) and caused it to collapse. This removed the support of the second span and allowed this span to fall to the river. In doing so the southern end of the second span came off its bearings and slid down the face of pier No. 6 on the southern bank of the river." 6 The first report was adopted by the Court in the judgment of Einstein J on 30 March 1999. The nature of the subject proceedings is conveniently outlined in that judgment. 7 In referring the limited question to the referee I had anticipated that his report would expose any liability for the damage associated with the bridge's collapse in the expectation that complex technical issues could be expeditiously resolved and the proceedings brought to a speedy conclusion. That has not been the case. 8 Following upon the adoption of the first report, a further order pursuant to Pt 72 r2 was made by Einstein J on 21 May 1999 which, in substance, referred the question of liability for the subject damage to the Hon. John Brownie QC and the referee, sitting as joint referees (the referees). The referees' report is that of 30 September 1999 (the second report) which found that neither the driver of the prime mover nor the Roads and Traffic Authority (the Authority) was liable. On 10 December 1999 I heard argument from the interested parties on the question whether the report should be adopted, varied, or rejected in whole or in part. In reserving my judgment on that day I made the following observations: "I wouldn't anticipate there to be any lengthy time required to deal with it… if I come to the conclusion that the report should not be adopted, I would, before deciding what was the best course to adopt, take submissions from the parties, particularly having regard to the possibility that leave might have been granted in the meantime in the High Court on the related matter." 9 The reference to the "related matter" concerns applications for special leave in Ghantous v Hawkesbury City Council matter number S69/1999 and Brodie v Singleton Shire Council matter number S44/1999 heard in the High Court on 10 December 1999, which resulted in the High Court referring both applications to a full bench of the court to argue the applications as if on appeal. Both applications involve an invitation to the High Court to revisit the non-feasance rule in relation to highway authorities. 10 Before the referees the reference was conducted on the basis of Comerford's concession that it was not open to the referees to found any liability of the Authority on non-feasance. Welling made no express concession to that effect but did not dissent from that course of conduct of the reference. The issue of negligence as raised against the Authority was restricted to the immediate physical effect of particular bridge repair works performed by the Authority. It was asserted that the works had exacerbated a dangerous condition of the bridge which had existed for some years as a result of its design and the deterioration of the bridge structures, for neither of which the Authority was responsible. 11 The central finding of the referees on that issue was that "on the balance of probabilities we consider that this repair work is unlikely to have appreciably altered the performance of the bridge deck compared with its condition prior to the work." 12 The condition of the bridge immediately preceding its collapse was described in the first report in the following terms: "According to the RTA maintenance file Ex.D41, the bridge has a history of movement and distress requiring repairs for many years. The piers and abutments supported on timber piles had settled and rotated towards the river. The movement joints and gaps at the steel spans had closed so that the deck slabs were compressed. The abutments and wingwalls had cracked and some piers flexed and cracked. Some approach span beams and headstocks had cracked and moved to act as expansion joints." 13 These findings were adopted by the referees in the second report. It is clear from the two reports that an expansion joint in the middle of the bridge deck and rotation joints at each approach to the bridge had, in substance, ceased to function with closure of the rotation and expansion gaps. Consequently, movements in the bridge were only accommodated by cracks which had occurred in various elements of the bridge structure. In layman's terms, this condition had arisen mainly as a result of a settlement of the bridge supports in a direction, on either side of the river, towards the river. This led to the closure of these expansion and rotation gaps and the imposition of compression forces on the concrete slabs which formed the bridge deck. What is of central importance, in this context, is the fact that the concrete slabs were free-lying slabs: that is, they were not attached or fixed in any way to the supporting bridge structure. 14 The finding of the referee which attributed the collapse of the bridge to a "buckling failure" was based upon this aspect of the deck design. In sec 10 of the report the referee expressed the following opinions: "10. Analyses of slab buckling The phenomenon of buckling or lateral instability is well known in structural engineering. It can occur in slender compression members, plates and shells when a very small increase in lateral load causes a large increase in deflection and sudden collapse of the member. The possibility of such a collapse is clearly undesirable so in practice compression members are designed and built to avoid buckling. Nevertheless buckling failures have occurred in slender structures usually caused by unexpected events. And in roads and concrete slabs on ground "blow ups" similar to the buckle postulated in this case are not unusual if thermal expansion is not controlled by means such as compressible joints. There are two sides to the buckling equation - the force required to cause a buckling failure and the source of that force. The bridge deck is unusual in that each main span comprises ten slabs 200 mm thick, 6.3 m wide and 3.7 m long and unconstrained except at the ends of the span where the slab edge is enclosed by a steel channel. Thus there are nine joints where the plain concrete faces abut. There seems little doubt that the slabs were subjected to high compressive forces during hot weather when the slabs expanded against the bridge abutments. Under this condition the slabs act as a series of plates subject to an in plane compressive force and also a bending moment arising from the eccentricity of this force with respect to the centroid of the cross section. Some eccentricity of the force is inevitable in practice and the eccentricity has an important effect on the critical buckling load of a slab. (In theory if there were no eccentricity the slab would not buckle; it would fail by crushing of the concrete.)" 15 In the second reference the negligence action against the Authority relied upon two acts of negligence, namely: "(a) injection of Megapoxy into cracks (in the piers); and (b) inserting Set 45 into the gaps in the deck over piers 6 and 8" 16 In relation to the first alleged act of negligence, the referees noted the following: "The experts agree and we concur that cracks in the piers would reduce their stiffness and increase their flexibility thus more readily accommodating the movements. [The Authority's engineer] proposed that the cracks should be sealed with a flexible epoxy to maintain the status quo; in the event the pier cracks were sealed with a rigid epoxy. If the cracks were sealed with a flexible material this would permit the cracks to move so that the flexibility of the cracked piers would not alter in any significant way. …we are of the view that sealing the pier cracks with rigid epoxy probably had only a marginal and temporary effect on the behaviour of the bridge. The fundamental defects in the original design and construction of the bridge led to the excessive compression of the bridge deck and its ultimate failure. Any change to the flexural rigidity of the piers arising from sealing the cracks was not significant compared with the movement of the Wellington end abutment, the closing of the gaps and temperature expansion of the deck." 17 Dealing with the second alleged act of negligence, the referees concluded that both the rotation joints and the expansion joint had ceased to operate as a result of them being "practically closed". The Authority's repair work was described by the referees as follows: "Apparently the steel cover plates to the rotation joints had worked loose under the traffic and t the edge of the concrete had broken away to form an irregular space at the top of the concrete s slab. The joints were repaired by the following procedure: remove the steel cover plates; insert a temporary timber spacer at the top of the joint and against the steel protection angle at the end of the steel span; provide a temporary filler to close the bottom of the gap between the slabs; fill the space with Set 45 a rapid setting mortar; remove the timber spacer and insert a compressible seal in the space at the top of the joint; and replace the steel cover plate and fix to the steel span with chemical anchors. Clearly this work was intended to cure problems arising from the loose cover plates, the spalling of concrete at the edge of the concrete approach spans and the ingress of deleterious matter into the joints. It did not attempt to address the long-term problems in the design and construction of the bridge." 18 The referees reached the following conclusion: "Considering all the evidence regarding the repair of the rotation joints, we are not able to determine the precise effect of this work on the likely behaviour of the joint if it were subject to in-plane compressive forces. However, on the balance of probabilities we consider that this repair work is unlikely to have appreciably altered the performance of the bridge deck compared with its condition prior to the work." 19 As a result of the way in which the second reference was conducted, the referees did not address any responsibility of the Authority in performing repair work on expansion and rotation joints which was ineffective in restoring the function for which those joints were designed and which aided serviceability of the bridge deck for traffic. The significance of that omission, in my view, is reflected in the following opinion of the referees in the second report: "The expert evidence of Dr Ivering and Mr Kell is conflicting in part on the issue of foreseeability. Dr Ivering's opinion is that a structural analysis as suggested by Mr Kell if carried out prior to 1988, was not warranted and in any event would not have predicted a buckling failure. And further that no reasonably competent bridge engineer could have foreseen that the bridge would suffer the catastrophic collapse as found in the previous reference. Mr Kell's opinion is that an investigation should have been undertaken to assess the condition of the abutments and the probable compressive force induced in the deck. And that if this disclosed a force in excess of any value for which the bridge may have been designed, the unrestrained deck slabs should have been examined to check their susceptibility to buckling failure. This apparently prudent approach advocated by Mr Kell may have been coloured by hindsight. Nevertheless we concur with his view that similar buckling failures have occurred in slabs on ground and that the construction of the Wellington bridge deck is unusual in that the concrete slabs are not restrained by the supporting steel beams. We do not accept the inference from Dr Ivering's comment that because there was no visible distortion of the concrete slabs, a structural analysis was not warranted. Unfortunately a buckling type failure is especially dangerous; (a) it may be difficult to predict and (b) if it occurs it does so often without any warning. An engineering investigation of the bridge structure if carried out in 1988, probably would have disclosed a large compressive force in the deck and the vulnerability of the unrestrained concrete slabs to a buckling or pop-up failure. Although a structural analysis of the slabs probably would not have been conclusive it should have raised the possible risk of a deck failure. If a deck slab were to pop up this would pose some danger to a vehicle traversing the bridge at that time. But it would require a highly imaginative and risk averse engineer to predict the possibility of a catastrophic collapse such as occurred." [emphasis added] 20 In my view, those opinions of the referees call for consideration of a negligence issue which was not addressed in the second report. I raised these concerns with the parties by re-listing the matter on 11 February 2000 and invited further submissions from the parties which were heard on 8 March 2000. In light of those submissions I have decided that, in determining whether the second report should be adopted, varied or rejected, Comerford and Welling should be afforded the opportunity of having a wider issue of negligence considered than that addressed by the referees. The wider issue of negligence is of the kind examined in Hill v The Commissioner for Main Roads (1989) Aust. Torts Reports ¶80-260; (1989) 68 LGRA 173; and McDonogh v The Commonwealth (1985) 73 ALR 148; (1985) 9 FCR 360. 21 Clearly, the outcome of this litigation is of considerable importance to the parties, especially, I think is that true of the personal litigants. Where any prejudice to the parties arising from my decision to consider this wider question of negligence may be adequately compensated for in an appropriate order for costs, I am of the view that the litigants seeking to argue that question should not be deprived of that opportunity. 22 In view of the submissions by the parties that they would seek to adduce additional evidence if this aspect of negligence was considered, it is clear that any leave given to Wellings and Comerford to adduce additional evidence would have to be accompanied by a costs penalty that they pay any costs of the Authority wasted by the limitation of the negligence issue before the referees. I do not understand counsel for those litigants to dissent from that proposition. However, I think the precise form of such an order should await the final determination of outstanding issues. 23 Accordingly: 1. Pursuant to Pt 72 r13, I grant leave to the parties to adduce additional evidence to that taken before the referees, limited to the issue of the Authority's alleged negligence and consistently with the findings of the first report as adopted by the judgment of Einstein J of 30 March 1999. 2. The parties are notified that, in deciding whether the second report should be adopted, varied or rejected, the Court will have regard to that additional evidence and the evidence taken before the referees. 3. Subject to the opinion as to costs expressed in these reasons, costs are reserved. 4. These matters are listed for further directions at 9.30am, 16 March 2000. ********** Last Modified: 09/25/2000 DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. 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