Connector Drilling Pty Ltd v Equigold Nl - [2003] WASCA 78

JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA

TITLE OF COURT : THE FULL COURT (WA)

CITATION: CONNECTOR DRILLING PTY LTD -v- EQUIGOLD NL [2003] WASCA 78

CORAM: MALCOLM CJ
MURRAY J
WHEELER J

HEARD: 10 MARCH 2003

DELIVERED : 11 APRIL 2003

FILE NO/S: FUL 120 of 2002

BETWEEN: CONNECTOR DRILLING PTY LTD
Appellant (First Defendant)
AND
EQUIGOLD NL
Respondent (Second Defendant)

Catchwords:

Negligence - Mine site accident - Contribution proceedings

Legislation:

Mines Safety and Inspection Act 1994 (WA)

Occupier's Liability Act 1985

Result:

Appeal allowed

Category: A

Representation:

Counsel:

Appellant (First Defendant) : Mr D R Clyne
Respondent (Second Defendant) : Mr R J L McCormack

Solicitors:

Appellant (First Defendant) : Crisp Civitella Smith
Respondent (Second Defendant) : Srdarov Richards Burton

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

Achron Pty Ltd v Serco Water (WA) Pty Ltd [2001] WASCA 141
Crombie v Uniting Church in Australia (1997) 17 WAR 291
Electric Power Transmission Pty Ltd v Cuiuli (1961) 104 CLR 177
Haileybury College v Emanuelli [1983] 1 VR 323
Hamersley Iron Pty Ltd v Robertson, unreported; SCt of WA; Library No 980573; 2 October 1998
Kondis v State Transport Authority (1984) 154 CLR 672
McLean v Tedman (1984) 155 CLR 306
Wyong Shire Council v Shirt (1980) 146 CLR 40

Case(s) also cited:

Nil

MALCOLM CJ: I have had the advantage of reading in draft the reasons prepared by Wheeler J. Her Honour has set out the relevant facts in some detail. In my opinion, the first issue which arises in the appeal is whether, and to what extent, the appellant was entitled to recover contribution from the respondent in respect of an award of damages against the appellant in favour of a Mr Olive, an employee of the appellant who was injured in a mining accident at the mine site of the Dalgaringa Mines Joint Venture near Mt Magnet ("the mine").
Mr Olive had brought an action for damages for negligence in the District Court against the appellant as first defendant and the respondent as second defendant. The appellant conceded liability to Mr Olive and consented to judgment in his favour. The appellant then claimed an indemnity or contribution from the respondent on the ground that the negligence of the respondent caused or contributed to the harm suffered by Mr Olive.
As Wheeler J has recounted the facts, there is no need for me to repeat them. Suffice it to say that I agree entirely with her Honour's account of the facts and the relevant evidence. The trial Judge found that, following the abandonment of a drill hole and the commencement of drilling a second hole close by, there was a blow-out from the first hole. At the time, Mr Olive, acting on the instructions of the senior driller employed by the appellant, was holding a pipe which was fitted to the first hole under circumstances which clearly placed him in a situation of danger in the event of a "blow-out". The blow-out which in fact occurred, resulted from the intersection of the old and new holes.
The immediate cause of the injury to Mr Olive was the adoption by Mr Enfantie, who was a senior driller employed by the appellant, of what the learned trial Judge found to be an inherently dangerous solution. The use of a pipe with a bend in it to direct water away from the second drill site increased the pressure resulting from the drilling operation with the consequences that the bent pipe was blown off with considerable force at a time when Mr Olive was attempting to hold it down, as a result of which he suffered injury.
There was undisputed evidence that it was generally considered desirable in the mining industry to drill a subsequent hole at least five metres away from any pre‑existing hole. It was, however, industry practice to drill closer to an existing hole in certain circumstances, but there was no evidence given by anyone in the present case to explain why it was necessary or desirable for the second hole to be drilled in the chosen location. As Wheeler J has explained, there was undisputed evidence before the trial Judge dealing with alternative methods which could be adopted to deal with difficulties which could arise if a new hole intersected an old hole. One possibility was that a hole could be plugged with foam prior to the commencement of drilling the new hole. Another was to plug the first hole with concrete, but there was a danger of injury if the concrete plug was blown out by pressure. There was always a risk of danger in the use of compressed air in drilling, particularly in combination with water.
The learned trial Judge found that the appellant was an independent contractor. The immediate cause of Mr Olive's injury was the method adopted by Mr Enfantie by which water was diverted by the pipe affixed to the old hole. His Honour held that, in accordance with the general common law rule, a principal was not liable for the negligence of an independent contractor and that the appellant was solely liable for the damages suffered by Mr Olive.
I agree with Wheeler J that the finding by the learned trial Judge that the accident was caused solely by the negligence of the appellant's foreman, Mr Enfantie, in causing a bent piece of PVC pipe to be placed over the collar of the existing hole to redirect water and mud from it, was wrong. First, as contended by the appellant, the learned Judge should have found that the primary cause of the accident was the siting of the second drill hole too close to the first hole, with the result that it was likely that the first hole could "blow‑out". While it was conceded that Mr Enfantie was negligent in the method adopted, the accident was caused primarily by the respondent's employee, Mr Prussner, who had created the risk of blow‑out by directing the appellant's employee, Mr Enfantie, to drill the second hole too close to the first, with the result that there was a foreseeable risk of a blow‑out.
Secondly, it was contended that the learned trial Judge was in error in concluding that the respondent was not liable to the appellant for the injury suffered by Mr Olive because "no liability applied to the [respondent] on the basis that it was not liable for the negligent conduct of the appellant as an independent contractor". As Wheeler J has clearly demonstrated, this conclusion failed properly to take into account s 9 of the Mines Safety and Inspection Act 1994 (WA), which was pleaded.
Thirdly, it was contended that the learned trial Judge was wrong in law in failing to properly apply the provisions of s 9.
In my opinion, the evidence detailed by Wheeler J shows that the respondent was at all material times aware of the potential hazard in siting the second hole where it was and the actual hazard that subsequently developed, namely the discharge of water and mud from the old bore hole. These hazards were caused by the respondent in circumstances where reasonable precautions could or should have been taken to avoid the hazard both before and after it was created and subsequently. In the circumstances, there was an obligation on the part of the respondent to ensure, as far as reasonably practicable, that the appellant, its independent contractor, took reasonable care in circumstances in which employees (including, in this context, employees of both the appellant and the respondent) might reasonably be expected to be exposed to harm: cf Hamersley Iron Pty Ltd v Robertson, unreported; SCt of WA; Library No 980573; 2 October 1998 at 19. Such an obligation is clearly imposed by s 9(1) and (3) of the Mines Safety and Inspection Act 1994 (WA). Section 9(1) imposes on an employer carrying on mining operations a non‑delegable duty of care in respect of the employer's employees. Section 9(3) imposes on the miner the same duty in respect of the employees of an independent contractor. Section 9(3) provides that:
"For the purposes of this section, where, in the course of mining operations carried on by a person (in this section called 'the principal'), the principal engages another person (in this section called 'the contractor') to carry out work for the principal ‑
(a)the principal is deemed, in relation to matters over which the principal has control or, but for an agreement between the principal and the contractor to the contrary, would have had control, to be the employer of ‑
(i) the contractor; and
(ii)any person employed or engaged by the contractor to carry out or to assist in carrying out the work;
and
(b)the persons mentioned in paragraph (a)(i) and (ii) are deemed, in relation to those matters, to be employees of the principal."
Section 9(4) provides that nothing in subsection (3) derogates from the duty of the principal to the contractor or the duties of the contractor to persons employed or engaged by the contractor.
It follows that at all material times, Mr Olive was deemed to be an employee of the respondent with the consequence that the respondent was under a duty to take reasonable care to provide and maintain a safe working environment in which he was not exposed to injury or hazard: cf Hamersley Iron Pty Ltd v Robertson, unreported; SCt of WA; Library No 980573; 2 October 1998 at 19 per Steytler J; Wyong Shire Council v Shirt (1980) 146 CLR 40 at 47 – 48 per Mason J (with whom Stephen and Aickin JJ agreed); and Haileybury College v Emanuelli [1983] 1 VR 323 at 332 – 333 per Murphy J.
In Crombie v Uniting Church in Australia (1997) 17 WAR 291 at 300 in a judgment with which Franklyn and Owen JJ agreed, I said in reference to Wyong Shire Council:
"In Wyong Shire Council Mason J (with whom Stephen and Aickin JJ agreed) held that the existence of a foreseeable risk of injury did not in itself dispose of a question of breach of duty. The magnitude of the risk and its degree of probability remained to be considered with other relevant factors. As his Honour said in Wyong Shire Council at 47-48:
'In deciding whether there has been a breach of the duty of care the tribunal of fact must first ask itself whether a reasonable man in the defendant's position would have foreseen that his conduct involved a risk of injury to the plaintiff or to a class of persons including the plaintiff. If the answer be in the affirmative, it is then for the tribunal of fact to determine what a reasonable man would do by way of response to the risk. The perception of the reasonable man's response calls for a consideration of the magnitude of the risk and the degree of the probability of its occurrence, along with the expense, difficulty and inconvenience of taking alleviating action and any other conflicting responsibilities which the defendant may have. It is only when these matters are balanced out that the tribunal of fact can confidently assert what is the standard of response to be ascribed to the reasonable man placed in the defendant's position.
The considerations to which I have referred indicate that a risk of injury which is remote in the sense that it is extremely unlikely to occur may nevertheless constitute a foreseeable risk. A risk which is not far-fetched or fanciful is real and therefore foreseeable. But, as we have seen, the existence of a foreseeable risk of injury does not in itself dispose of the question of breach of duty. The magnitude of the risk and its degree of probability remain to be considered with other relevant factors.' "
It is clear that each of the appellant and the respondent owed Mr Olive a duty of care in the circumstances. A reasonable person in the position of Mr Enfantie, and in the position of Mr Prussner, should each have foreseen that the drilling of the second hole so close to the first ran the risk of the holes intersecting with the result that, having a person in the position of Mr Olive holding the pipe in the manner described, exposed him to a risk of injury. In the circumstances, steps should have been taken to ensure that the second hole was sufficiently apart from the first so that it could be drilled in safety.
In the context of this case, both the appellant and the respondent were in the position of employers. Their obligations were not only to provide a safe system of work but to enforce it: McLean v Tedman (1984) 155 CLR 306. Consistently with the approach adopted by Mason J in Wyong Shire Council (supra), Taylor J said in Electric Power Transmission Pty Ltd v Cuiuli (1961) 104 CLR 177 at 103: "… the duty of the employer does not extend to guarding against every conceivable risk, however remote or fanciful." In the present case, however, it is clear that the magnitude of the relevant risk and the likelihood of its occurrence was such that it required both Mr Enfantie and Mr Prussner to take reasonable care to prevent injury to Mr Olive against what was a clearly foreseeable risk. In both cases, the duty was non‑delegable: Kondis v State Transport Authority (1984) 154 CLR 672 at 686 per Mason J (with whom Deane and Dawson JJ agreed).
As to the points raised by the respondent's notice of contention, I agree with Wheeler J that neither of them succeed for the reasons stated by her Honour.
It follows that the appeal should be allowed. On the issue of the apportionment of liability to contribute as between the appellant and the respondent, I agree that each of them should be held equally responsible for the accident and the damages suffered by Mr Olive so that the

respondent should contribute an amount of 50 per cent in respect of the appellant's liability to him.

MURRAY J: I agree with the reasons now published by Wheeler J and with her Honour's conclusion that the appellant and respondent should contribute equally to the judgment obtained by Mr Olive. There is nothing that I need to add.
WHEELER J: This appeal arises out of a notice of contribution issued by the appellant against the respondent in relation to an accident in which Mr Olive, an employee of the appellant, was injured at the site of the Dalgaringa Gold Mines Joint Venture near Mt Magnet ("the mine"). The appellant was the first defendant and the respondent the second defendant in proceedings brought by Mr Olive in the District Court. The appellant had conceded that it was liable to Mr Olive in respect of his injury, and had consented to judgment against it in favour of Mr Olive. It then claimed an indemnity or alternatively contribution from the respondent.
Mr Olive was a driller's offsider. The appellant carried on business as a drilling contractor and at the relevant time was engaged by the respondent to perform exploration drilling at the mine. The respondent was the manager of the mine. Mr Prussner was an exploration geologist employed by the respondent. His role included implementing exploration programmes. No earlier than the evening before the accident, he had instructed the appellant's drilling crew to drill an exploration hole. He instructed them as to its location and its direction. It was to be located about 3 metres from a pre‑existing drill hole. The fact that the pre‑existing hole existed was plain from the fact that a PVC collar inserted in that hole was clearly visible.
It is not unusual, when holes are drilled so close together, for the holes to intersect and for there to be a "blow‑out" of material from the old hole. On the day of the accident Mr Prussner observed that a 6 metre length of PVC pipe had been slotted over the collar of the old hole and that there was a spray of water and mud being blown into the air from the end of that pipe which was carrying onto machinery and personnel on site.
Mr Prussner considered that the spray was uncomfortable and untidy, but not unsafe. There was a difference in the evidence between Mr Prussner and Mr Enfantie, a senior driller employed by the appellant, about a conversation which he then had with Mr Enfantie. His Honour did not find it necessary to determine precisely what was said, so as to ascertain whether Prussner merely enquired whether Enfantie considered

that method for venting water and mud suitable, or whether he gave some more positive direction that the spray should be redirected.

As a result of the conversation, whatever its content, Enfantie suggested that a pipe with an elbow might be used so as to direct the spray along the ground away from the equipment. Enfantie had apparently tried to block the old hole with foam once the blow‑out had commenced, but this method was unsuccessful. The evidence, which was not referred to by his Honour but which appears not to have been in dispute, was that the foam method may well have been more successful had it been attempted before water and mud commenced to flow out of the old hole.
His Honour considered that it was what occurred following the discussion between Prussner and Enfantie which was relevant in determining the contribution of the respective parties. Prussner and one Mr Scott went off to look for an elbow, and Scott returned with one. That apparently was unsuitable. His Honour found that Enfantie could have called Prussner on the two‑way radio or driven around to locate him to discuss other options but that he did not do so. His Honour considered that the fact that he did not do so was consistent with "the fact that any supervision or direction of the drilling crew by the [respondent] was limited to drilling location, depth and conduct generally and was not in relation to the operation of the drill rig".
The solution in fact adopted by Enfantie was to fashion a bend in the existing pipe and to tie the long end of the existing pipe down so that the material being vented was close to ground level. It was clear that there would be vertical pressure up the pipe at the bend. Enfantie admitted that it was obvious to him that that vertical pressure may have caused the pipe to lift off the collar. He did not attempt to glue it down since he considered that that would cause a greater hazard. Rather, he instructed Mr Olive to hold the pipe above the bend so as to prevent it from being blown off if possible, instructing him at the same time that if it did begin to blow off he should "get out of the road".
His Honour found that it was quite clear both from the evidence and as a matter of common sense, that the solution adopted was a dangerous one. Because the bend in the pipe increased the pressure of the material being blown out and also, apparently, because of some increase in pressure resulting from the commencement of a new stage of the drilling operation, the bent pipe was blown off with considerable force when Mr Olive was attempting to hold it down and Mr Olive suffered injury.
There was some dispute in the evidence as to how dangerous the pre‑existing situation was, prior to Enfantie's intervention. Certain of the evidence suggested that there was a risk in any event of material disturbed during the drilling, such as rock, being blown from the hole and injuring a person, and certain of the witnesses suggested that the spraying of mud and water around the site would cause other hazards such as slipperiness and obstructed vision. However, his Honour appears to have found that "the fact that the site and equipment was being made untidy or that it may have been uncomfortable for the drillers is not to say that it was dangerous or that drilling should have ceased".
There was also evidence, which was not in dispute, that it was generally considered desirable to drill at a distance of at least 5 metres away from pre‑existing holes. It was the industry practice on occasions to drill closer than 5 metres to an existing hole, and there was no exploration in the evidence as to why the precise location for the new hole was chosen in this case.
Although his Honour made no detailed findings about alternative methods of dealing with difficulties which could arise from the intersection of old and new holes, there was evidence dealing with this issue which appears not to have been in dispute. One possibility was that holes could be plugged with foam prior to the commencement of drilling. On occasion, it appears that holes had been plugged with concrete, but there would be, depending upon the circumstances, a danger that such a plug could become a lethal projectile in the event of pressure build up in the hole. Other methods to prevent a spray of material from the holes had been used from time to time, which included parking a vehicle with a tyre on the hole so that the mud and water oozed rather than sprayed out.

In its accident report, compiled after the injury to Mr Olive, the respondent noted that methods to block holes, other than foam, should be the subject of a risk assessment prior to their use and that "stopgap measures" should not be carried out. The accident report suggested that the use of an elbow could be considered after checking with manufacturer's specifications to ensure that it was appropriate to the task and could be installed properly. The report also recommended that the dangers of compressed air and of the combination of compressed air and water should be conveyed to all employees.
His Honour found that the appellant was an independent contractor. He found that the immediate cause of Mr Olive's injury was a consequence of the method devised and implemented by Mr Enfantie, who was an employee of the appellant. His Honour, in conclusion, noted the long established and general rule at law that a principal is not liable for the negligent conduct of an independent contractor, and found that he was satisfied that the accident giving rise to Mr Olive's injuries arose "solely as a result of the negligence attributable to [the appellant]. Responsibility for causation of [Mr Olive's] injuries rests with his employer the [appellant]".
The appellant has a number of criticisms of this finding. In my view, the ground which must be successful is that which complains that his Honour failed to properly apply the provisions of s 9 of the Mines Safety and Inspection Act 1994. Although in the course of his reasons, his Honour did set out the passages of the appellant's pleading in which it was pleaded that the provisions of s 9 of the Act were applicable, it is in my view clear that at the point of his Honour's findings and conclusion, he was proceeding solely on the basis of the general law relating to the liability of employers for the actions of independent contractors.
That "general rule" is subject to a number of exceptions in any event, and an exception may be found in the case of the employment relationship: Kondis v State Transport Authority (1984) 154 CLR 672. Those exceptions are cases in which the principal is considered for one reason or another to have a "non‑delegable" duty to take care for the safety of another. A non‑delegable duty is essentially one in which there is a departure from the basic principles of liability and negligence, by substituting for the duty to take reasonable care one to ensure that reasonable care is taken: Kondis at 686.
In my view, the whole point of s 9(1) and (3) of the Mines Safety and Inspection Act is to impose on a person who is carrying out mining operations a non‑delegable duty of care for that employer's employees and for the employees of independent contractors, as if the contractor and the contractor's employees were the employees of the person carrying on the mining operation. Subsection (1) of s 9 provides that an employer must, so far as is practicable, provide and maintain at a mine a working environment in which that employer's employees are not exposed to hazards. Subsection (3) provides, relevantly:
"For the purposes of this section, where, in the course of mining operations carried on by a person (in this section called 'the principal') the principal engages another person (in this section called 'the contractor') to carry out work for the principal -
(a)the principal is deemed, in relation to matters over which the principal has control or, but for an agreement between the principal and the contractor to the contrary, would have had control, to be the employer of -
(i)the contractor; and
(ii)any person employed or engaged by the contractor to carry out or to assist in carrying out the work."
Subsection (4) provides that nothing in subs (3) derogates from the duties of the principal to the contractor or the duties of the contractor to persons employed or engaged by the contractor.
As a result of s 9 of the Act, Mr Olive was deemed to be an employee of the respondent. The respondent owed him a duty to provide and maintain a working environment in which he was not exposed to hazards.
In considering s 9(1), Steytler J observed that in requiring an employer so far as practicable to provide a safe working environment it "imposes a duty, personal to the employer, not only to do what is reasonably practicable for the purposes of attaining that objective in the course of its own activities but to ensure, where that is reasonably practicable, that reasonable care is taken by subcontractors whose assistance is necessary in circumstances in which their failure to take such care might expose employees of the employer to hazards": Hamersley Iron Pty Ltd v Robertson, unreported; SCt of WA; Library No 980573; 2 October 1998 at 19. I would respectfully agree with that observation.
The question which his Honour should have asked, then, was not whether the accident was attributable to the negligence of the appellant or of the respondent but rather, whether the respondent had so far as reasonably practicable ensured that reasonable care was taken by the appellant in the course of its drilling activity. Although his Honour did not ask that question, and therefore made no specific findings in relation to it, it seems clear from the findings which his Honour did make and from so much of the evidence as was common to the parties that the following conclusions should be drawn.
It was known to the respondent and its employee Mr Prussner that drilling a new hole closer than 5 metres to an old drill hole carried a risk of the holes intersecting. It was known that a "blow‑out" could occur which would require steps to be taken, at least in some circumstances, to prevent the spray of materials from the old hole. It was known, and was in any event obvious as a matter of common sense, that certain steps to avoid blow‑out, such as the blockage of the old hole with foam, would be more likely to be successful if they were taken prior to drilling and at a time when the old hole had not been recently contaminated by the blow‑out of water and/or mud. There was an obvious danger, given the use of compressed air and the combination of compressed air and water in blow‑outs from old holes, if inappropriate measures were taken to block or deflect the material being blown out.
In the circumstances of the present case, it was known to the respondent that the new hole to be drilled would be within three metres of an old hole. Shortly before the accident in question, it was known to Mr Prussner that Mr Enfantie was proposing to take some sort of steps to attempt to deflect the material being blown out.
In circumstances where it had overall control of the site, knowledge of the risks involved, and knowledge that Mr Enfantie proposed to take some steps with respect to the old hole, the respondent took no steps either prior to drilling or during the course of drilling to ensure that reasonable care was taken by Mr Enfantie or any person under his direction to avoid injury to those at the site. It seems to me that in those circumstances there is a clear breach of the duty of care imposed on the respondent in relation to its deemed employee, Mr Olive.
If the respondent should be unsuccessful, as in my view it is, in upholding his Honour's original finding, the respondent by its notice of contention argues that the claim for contribution must fail in any event. It raises two matters, each of which can I think be readily disposed of.
The first is the effect of the consent judgment by which the appellant admitted its own liability to Mr Olive. That consent judgment would prevent the appellant from alleging in any later proceeding that the appellant was not negligent. But it cannot preclude the appellant from alleging that some other person was also in breach of that other person's duty, so as to give rise to a claim for compensation. So much was accepted by counsel for the respondent, but it was argued that the effect of the consent judgment was to "constrain" the respondent in relation to the types of allegations of negligence which it could make against others. I am not convinced that the respondent's submissions were correct in this respect, but in any event it was conceded on behalf of the respondent that some of the particulars of negligence pleaded against it by the appellant were open, including what is in effect a pleading of a failure to carry out "appropriate planning" of the drilling programme so as to ensure that an appropriate system was developed to handle safety issues where a new hole was drilled in close proximity to the old. As I have indicated, it is my view that on the evidence in this case there clearly was a failure on the part of the respondent to take such steps.
The second matter raised by the respondent in its notice of contention is that pursuant to s 6 of the Occupier's Liability Act 1985, the respondent as occupier could avail itself of the defence pursuant to s 6(1) of that Act. That defence, broadly, is to the effect that an occupier is not liable for damage due to the negligence of an independent contractor engaged by the occupier, provided that the occupier exercised reasonable care in the selection and supervision of the contractor and it was reasonable that the contractor was engaged to undertake the task in question. That submission overlooks the effect of s 8(2) of the same Act which provides:
"Nothing in this Act shall be construed to affect the rights, duties and liabilities arising from an employer and employee relationship where it exists."
Having regard to s 9 of the Mines Safety and Inspection Act, nothing in the Occupier's Liability Act could affect the rights, duties and liabilities arising between the respondent and Mr Olive.
It is my view that this appeal should succeed. The question then arises as to the appropriate degree of contribution between the appellant and the respondent.
It is clear that the immediate supervision of the drilling was in the hands of the appellant, that it had a greater degree of skill and experience in relation to drilling than the respondent, and that the hazard which was encountered was precisely the sort of hazard that one would expect a contractor in the appellant's position to deal with appropriately on a regular basis. However, the respondent not only had overall control of the mine site, but was responsible for the detail of the drilling programme; that is the location and depth of holes. The hazard which was encountered was not an obscure one, but was readily apparent to a miner in the position of the respondent. Further, the respondent's employee Mr Prussner had actual knowledge of the fact that Mr Enfantie proposed to take some ad hoc measure to deal with the blow out, and did not concern himself with ascertaining how that measure was to be undertaken. In "evaluating the respective contributions made by each negligent party to the harm suffered" (Achron Pty Ltd v Serco Water (WA) Pty Ltd [2001] WASCA 141 at [39]) it appears to me that each of the appellant and the respondent should be considered to have contributed equally to the accident, and that a contribution of 50 per cent would be appropriate.
I would therefore allow the appeal, set aside the orders of the District Court, and in lieu thereof order that the respondent contribute to the appellant's liability to the amount of 50 per cent.