Supreme Court of Canada
Carl M. Halvorson, Inc. v. Robert McLellan & Co. Ltd. et al., [1973] S.C.R. 65
Date: 1972-06-29
Carl M. Halvorson, Inc. (Plaintiff) Appellant;
and
Robert McLellan & Co. Ltd. (Defendant) Respondent;
and
Wrights’ Canadian Ropes Ltd. (Defendant) Respondent.
1972: May 17, 18, 19; 1972: June 29.
Present: Judson, Ritchie, Hall, Pigeon and Laskin JJ.
ON APPEAL FROM THE COURT OF APPEAL FOR BRITISH COLUMBIA
Negligence—Aerial tramway project—Contract for erection engineering services—Modifications of winch designed by engineer—Failure of winch—Liability for negligent performance of contract.
The major operation to be performed on an aerial tramway project was to put in place four heavy cables on which two tram cars were to run up and down a mountain more than two miles to a top altitude near 10,500 feet. The cables were 13,000 feet long, about 1¾″ in diameter and weighed more than 50 tons. The erection plan was to haul up the high end some 3,000 feet by means of a tractor and pull up the remaining 10,000 feet by means of a hauling cable attached to a winch to be installed at the top. On taking over this work, the appellant company (H) made arrangements to have erection engineering services provided by the respondent M, personnel and equipment, by the respondent W. A suitable winch could not be located and one originally designed for 3,000 feet of 1⅜″ cable was purchased by W on instructions from H, and modified as directed by M to accommodate 10,000 feet of 1¼″ cable adding 24″ to the drum length and 6″ to the flange diameter.
The first two cables were hauled up without incident but the winch drum broke on the gear side when the third cable was near the top, the flange separating from the drum barrel at the weld. After repairs, the drum broke again before the hauling of that cable was completed. It also gave way on the brake side before the hauling of the fourth cable was completed.
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H’s action in damages against M and W was dismissed by the trial judge whose decision was affirmed in appeal. H then appealed to this Court.
Held: The appeal should be allowed against the respondent M and the case remitted for assessment of damages. The appeal should be dismissed against the respondent W.
Under the circumstances, the repeated breaks that occurred when the stresses on the drum were admittedly nearing the maximum, went far towards showing that those mishaps were due to M’s negligence in altering the design of the winch drum, without proper consideration being given to all the stresses to be expected in the altered drum, particularly in the flanges. He just assumed the changes would be negligible although, on his admission, he was incapable of figuring it out. A clear preponderance of the evidence showed that the failure of the winch was traceable to negligence on the part of M.
Accordingly, H’s claim against M succeeded, it having been established that there was negligence on M’s part that is a failure to reach the necessary standard of professional competency in the performance of the contract for erection services.
The evidence supported the conclusion of the Courts below that W acted as agent to obtain the winch and to have it modified, and not as seller or as contractor. No liability could be imposed on W for the failure of the winch.
APPEAL from a judgment of the Court of Appeal for British Columbia, affirming a judgment of Mclntyre J. Appeal allowed.
W.G. Burke-Robertson, Q.C., and J.G. Alley, for the plaintiff, appellant.
W.J. Wallace, Q.C., and Marshall Bray, for the defendant, respondent, Wright’s Canadian Ropes Ltd.
Harvey Grey, Q.C., for the defendant, respondent, Robert McLellan & Co. Ltd.
The judgment of the Court was delivered by
PIGEON J.—This case arose out of difficulties experienced in the erection of an aerial tramway for Jackson Hole Ski Corporation at Jackson, Wyoming. The respondent Robert McLellan & Co. Ltd. (McLellan & Co.) is a firm of consulting
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engineers specializing in work of this kind. As such, they designed the aerial tramway that was to be erected by Williamette Construction Company (Williamette) and also undertook to provide to the latter erection engineering services. In July 1965, Williamette had to withdraw from the project and, on July 26, 1965, the appellant Carl M. Halvorson Inc. (Halvorson Inc.) undertook to complete the work ready for testing by November 1, 1965.
The major operation to be performed was to put in place the four heavy cables on which the two tram cars were to run up and down the mountain more than two miles to a top altitude near 10,500 feet. Those cables, manufactured in Switzerland, were 13,000 feet long, about 1¾″ in diameter and weighed more than 50 tons each. The erection plan was to haul up the high end some 3,000 feet by means of a tractor and to pull up the remaining 10,000 feet by means of a hauling cable attached to a winch to be installed at the top. Willamette had expected to obtain from the respondent Wrights’ Canadian Ropes Ltd. (Wrights’) some skilled personnel and the special equipment needed for that difficult task. When Halvorson Inc. took over, it promptly made arrangements to have erection engineering services provided by McLellan & Co., personnel and equipment, by Wrights’. A suitable winch could not be located and one originally designed for 3,000 feet of 1⅜″ cable, known as the “Drenka hoist”, was purchased on instructions from Halvorson Inc., and modified as directed by McLellan & Co. to accommodate 10,000 feet of 1¼″ cable adding 24″ to the drum length and 6″ to the flange diameter.
The first two cables were hauled up without incident but the winch drum broke on the gear side when the third cable was near the top, the flange separating from the drum barrel at the weld. After repairs, the drum broke again before the hauling of that cable was completed. It also gave way on the brake side before the hauling of the fourth cable was completed.
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Halvorson’s action in damages against McLellan & Co. and Wrights’ was dismissed by the trial judge whose decision was affirmed in appeal. Towards Wrights’, the reasons of the trial judge that were adopted in appeal, were essentially the following:
I cannot find on the evidence that Wrights recommended the use of this winch… I cannot find that Wrights took any part in the design or completion of the modifications… I find that the modifications were designed and their execution supervised by McLellan and Wrights had no part in this.
In acquiring the winch, the plaintiff Halvorson was not, in my opinion, relying on Wrights who played more or less a passive role in the winch selection. Halvorson acted upon his own initiative in getting the winch and upon McLellan’s advice that the winch as modified would serve its purpose…
I find as well that Wrights were not a seller of the winch to the plaintiff. Therefore, no question of any warranty under the Sale of Goods Act can arise… I find therefore that the defendant Wrights in the matter of winch acquisition were merely agents of Halvorson for that purpose and the sale took place between Drenka as the seller and Halvorson as the purchaser. I am unable to impose any liability on Wrights for the failure of the winch.
In my view, these findings are fully supported by the correspondence between the parties. This was expressly intended to record their arrangements and clear evidence of a subsequent intention to depart therefrom would be needed to establish a different legal position. Nothing is to be found in the depositions of the witnesses from which such an intention could be deduced. On the contrary, everything, in my view, supports the conclusion of the trial judge on that point.
The correspondence above mentioned starts with a long letter by W.S. Aman, secretary of Halvorson Inc., to John Clark, Wrights’ sales manager, dated July 30, 1965, in which one finds the following:
…This letter will serve to confirm the understandings reached between yourself and Mr. Halvorson as follows:
1. Wrights is interested in providing the technical know-how, including the on site supervision, and
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the equipment other than what we have already on the project or available, for the pulling of the cables and related work, and has available as required the experienced person or persons for the work.
2. Halvorson holds a contract with Jackson Hole Ski Corporation for completion of the project, and is interested in having Wrights perform the cable installation and related work.
3. It is agreed that Wrights will immediately proceed to prepare for the performance of the cable installation and related work by fabricating or causing to be fabricated the necessary hardware and special equipment or tools, and have the same ready by September 1, 1965. Wrights will have their technician, Mr. Pacey, visit the project within the next two weeks to acquaint himself with jobsite conditions and to communicate to the job supt. the information he may require in preparation for the cable installation.
4. Mr. Pacey will be in charge of the installation, and will be present on the jobsite during the entire operation.
5. Wrights does not wish to quote a price for the installation on a lump sum basis, but agrees to have prepared within approximately two weeks an estimate of the time and cost required for performance of the work, including the acquisition, modification, and fabrication of special tools and hardware, and a presentation of their proposed basis of compensation for their contribution to the work.
6. Halvorson agrees that he has authorized and instructed Wrights to proceed as set forth herein, and expects Wrights to be prepared to perform the work on or about September 1, 1965 at the project site.
7. Halvorson and Wrights have agreed that upon Mr. Halvorson’s return from Europe, in approximately two weeks, they will meet to conclude an agreement for actual basis of compensation to Wrights, and to conclude an agreement on actual methods being employed by Wrights.
8. The instruction to immediately proceed with the planning and arrangements, given by Halvorson to Wrights and confirmed herein, is not a conditional instruction even though the final agreement is yet to be consummated. Both Wrights and Halvorson after lengthy discussion are satisfied that they are in complete agreement as to the basis for such an
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agreement, and Wrights are to proceed diligently with the planning and preparation and are so authorized and instructed.
9. Mr. Robert McLellan is already performing work for Halvorson in planning methods of cable erection and installation, and will continue with this work. All work performed by McLellan for Halvorson, and for Williamette Construction Co., is available to Wrights, and Mr. McLellan has further been instructed to provide any additional information or assistance which Wrights may require, at the request of Wrights. Mr. McLellan’s compensation for these services will be the direct obligation of Halvorson.
…
Clark’s reply dated August 2, read:
We have your letter of July 30th recording points discussed with Mr. Halvorson on the night of Wednesday, July 28, 1965. We agree with the points outlined with the exception of paragraph No. 4.
It is our understanding and we agree that we are to propose a plan of cable erection and to get the necessary equipment together to carry this out. Also, we are to estimate the time required to implement this plan.
It is understood that the Carl M. Halvorson, Inc. resident superintendent will run the operation and Mr. Pacey will act in an advisory capacity to the superintendent and will co-operate fully with him at all times. That Mr. Pacey be free to leave the job for a short time if necessary due to prior commitments.
Then came the letter to Clark, dated August 16, in which one reads:
Carl returned from Europe over the weekend, and we received the status of the hoist acquisition yesterday. Today we have talked with Vic Hamblin of Bob McLellan’s office, and learned of the results of his further conversations with the Burard people in their estimating department. As you are no doubt aware, he now has a ceiling price from them of a little less than $5,000.00 Canadian for their work.
After consideration of this information, Carl could not see any choice but to proceed immediately with all dispatch to modify the Drinka (sp) hoist. Even under the most favourable time table taking this route we will be delayed on the job, and any attempt to build a new hoist would undoubtedly
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require a month longer even than modifying the existing hoist.
Every day being most important to us, we have instructed Vic to have Burard pick up the hoist from your yard and proceed immediately with the modifications. Inasmuch as you have handled all discussions with Drinka personally, we are reluctant to interfere and thought it best to await your return and have you confirm to him that we are purchasing the hoist. If you will please take care of that, and also issue an order to Burard for the modification work, we will of course reimburse you these costs or remit directly to the parties as you may prefer.
On September 24, 1965, a letter sent by Clark to Halvorson Inc. recorded the agreement for actual basis of compensation as follows:
Confirming our discussions of August 23, 1965 it was agreed that:
…
(3) Carl M. Halvorson would pay Wrights Canadian Ropes Ltd. a 15% commission on all machinery and equipment purchased in Canada for the installation of the Jackson Hole cables.
…
(5) All wire ropes, and slings, and fittings required for the pulling in of the tramway cables will be purchased from Wrights Canadian Ropes Ltd.
Wrights’ invoice for the winch, dated September 7, 1965, included “15% commission” in accordance with the understanding in that letter.
In view of all this and specially of the last-quoted paragraph of the letter of August 16, I fail to see how one could differ from the conclusion of the Courts below that Wrights’ acted as agent to obtain the winch and to have it modified, and not as seller or as contractor.
It was strenuously contended in argument that McLellan & Co. acted for Wrights’ rather than for Halvorson Inc., in designing the modifications to increase the cable carrying capacity of the winch. The only basis for this contention is that McLellan said so. However, he failed to state any facts
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from which it could properly be concluded that he was so acting. He admitted that, having received his statement of account dated September 21, 1965, Clark phoned him saying that he thought he was acting for the account of Halvorson Inc. and the matter was not pressed further. It is clear that McLellan & Co. was generally acting for Halvorson Inc. concerning the erection engineering of the Jackson Hole tramway. At the same time as he was sending to Wrights’ a letter so stating, Aman wrote McLellan under date July 30, 1965, saying:
This will confirm my verbal instruction to you of this date to provide Wrights Canadian Ropes with any and all information you may have, and the results of all design and research you may have performed, relative to installation of the cables on the Jackson Wyoming aerial tramway.
…
We have advised Wrights that this service and information is available to them without cost.
McLellan himself says he received this letter on August 2. The record shows that on the same day the first calculations were made by his employee Hamblet in view of using the “Drenka hoist”, then called the “Checkamus winch”. Other calculations are recorded on August 4, August 9 and August 10, including one showing that by increasing the flange radius by three inches and widening the drum two feet, the drum capacity would be 11,000 feet of 1¼″ cable. These were just calculations of the available space and torque not involving design or stress calculations. In his own testimony, McLellan related that on August 11 he asked Aman to go with him to Wrights’, “Because I was concerned that the decision which winch to use should be expedited”. During that meeting, as he also said himself, “there was a discussion… about winches and I believe about other aspects of the erection…” In the end he said, “We were instructed to go ahead with the ideas of the design changes”. But the instructions to go ahead and proceed with the modification came direct to his firm from Halvorson on August 16 as stated in Aman’s letter above quoted. Only then did McLellan proceed with actual design changes and
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related stress and deflection calculations, these being dated August 18. Under date September 15, a letter was sent by McLellan & Co. to Halvorson Inc. in which the following is to be found (emphasis added):
Enclosed is our invoice for erection engineering and expenses since January 31st, 1965. This work included the preparation of the following drawings:
| 1020—3C |
Rigging Socket Details |
| —5 |
1¾″ Rope Clamp |
| —6 |
Erection Spreader Bars & Hardware |
| —9 |
Rigging Details—Lazy Bar |
| —A1 |
1¾″ Rope Socketing Clamp |
| —A2 |
1¾″ Rope Clamp |
| 1243—E— 2 |
Erection Sheave Details |
| G— 6 |
Erection Profile |
| E—SK–41 |
Tower No. 1 Cable Erection |
| –42 |
Tower No. 2 Cable Erection |
| –43 |
Tower No. 3 Cable Erection |
| –44 |
Tower No. 4 Cable Erection |
| –45 |
Tower No. 5 Cable Erection |
| –47 |
Drenka Hoist |
In the absence of any precise evidence that a definite part of the work on the “Drenka hoist” was specifically agreed to be done for the account of Wrights’, which evidence is totally lacking, the only possible conclusion is that all this work was done for the account of Halvorson Inc. Of course, Wrights’ was entitled to rely on such data in the performance of its duties as agent and cannot be found negligent for having done so.
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This means also that Halvorson’s only possible claim is against McLellan & Co. for negligent performance of its contract for erection services, not in tort as was contended. This gives rise to a difficulty because, while counsel for Wrights’ denied that there ever was any contract with McLellan & Co., counsel for Halvorson Inc. relied to the end on McLellan’s assertion of the existence of such a contract and, therefore, claimed against McLellan & Co. only in tort although the action was in contract also.
In view of the pleadings, I do not think that this erroneous position in argument is sufficient to prevent appellant from succeeding against McLellan & Co. if, in fact, negligence on its part was established that is a failure to reach the necessary standard of professional competency in the performance of its contract for erection services. The findings of the trial judge on that issue were as follows:
Professor Hooley and Professor Holt are men of great learning and great experience and men who have worked in this field for many years. The other engineers called are all men of reputation and standing. Referring particularly to the evidence of Hooley and Holt, I can say that neither of these gentlemen gave evidence dogmatically. Each seemed to be willing to consider and deal objectively with other theories than their own. I refer again to the comments of Professor Holt that I referred to earlier and I must ask myself whether I can hold or should hold McLellan, a consulting engineer, to such a high standard in this situation when men of the stature of Hooley and Holt confess to confusion and uncertainty in these matters. Is it right for me to visit upon a professional engineer all of the consequences of a judgment against him for negligence upon such uncertain ground?
The plaintiff is under a burden of proof. Can I say, on all the evidence before me that I am satisfied on a balance of the probabilities that the cause of the failure of this winch is to be found in the modifications made by the defendant McLellan? On the whole of the evidence, if engineers of the stature of Professor Holt expressed doubt, I think I may be
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forgiven for entertaining one myself, I refer to Owners of S.S. Australia and Owners of Cargo of S.S. Nautilus, [1972] A.C. 145, where Lord Sumner said at page 155 in discussing the treatment of the advice of assessors in Admiralty cases which I take to be analogous to the proper treatment of expert evidence in cases such as I have before me:
“If, as may happen, a judge cannot decide in his own mind whether or not the advice he receives is sound, his position is simply that the point is not proven, and the loss falls upon the party, who bears the burden of proof on that issue. It is just as if necessary proof had failed.”
This case was mentioned in an article on expert evidence in the Modern Law Review of January, 1947 at page 35 by H.A. Hammelmann, in which he made the following apt comment:
“If, in a case involving complicated scientific or technical details which the Court is unable to resolve without expert assistance, the Court cannot come to any conclusion whether the expert opinion or opinions it has received are sound or not, or if it does not feel capable of overcoming the confusion created by contrasting expert evidence, ‘the position is simply that the point is not proven and the loss falls on the party which bears the burden of proof on the issue’ (per Lord Sumner in Australia v. Nautilus, [1927] A.C. 153.)” (My underlining)
I have delayed giving judgment in this matter to enable me to examine and re-examine all of the evidence that was taken before me, to give the fullest consideration to the questions which are raised. Having weighed all the expert testimony, I feel I must adopt the course chosen by Lord Sumner and hold that the plaintiff has not discharged the burden of proof with regard to his claims in respect of the winch and on that aspect of the case the claim against McLellan must fail.
This part of the learned trial judge’s reasons was in effect adopted in appeal. I agree with counsel for the appellant that it is not a finding of fact. Faced as usual in such cases with conflicting scientific opinions, the trial judge declared himself incapable of overcoming the confusion created by constrasting expert evidence. Under such circum-
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stances, justice requires that an effort be done to overcome the confusion.
In my view, the issue of negligence against McLellan can be decided without going deeply into any scientific theories.
McLellan himself said:
There are a lot of subtleties to designing drums and I don’t profess to be an expert in designing drums, and I think the only people who are are the people who are manufacturing them. I don’t know any consulting engineer who is an expert on the designing of drums…
I couldn’t calculate the exact stresses in the drum barrel; I couldn’t calculate the exact stresses in the flanges and components of that nature.
However, he took a winch designed for a capacity of 3,000 feet of 1⅜″ cable and proceeded to have it modified so that the drum would hold 10,000 feet of 1¼″ cable.
On the other hand, the witness H.A. Brown said:
I would like to make a comment if I could about the additional wrap or layers on a hoist, being a hoist engineer, it is my practice to accept a customer’s requirements for a hoist and design from that, and we design a hoist for a specific rope capacity in length of rope which that hoist will hold. If the hoist is to be, to deviate any way from that, then our figures have to be recalculated, our hoist then is not warranted. It goes beyond the rated capacity of the hoist.
While the design criteria used by this witness were criticized as excessive, the above statement stands unchallenged. It is moreover supported by the following statement from another hoist expert, S. Ward:
in my opinion a flange extended out you have got to be awful careful about extending and welding it, because in my practice I don’t do that.
Counsel for McLellan & Co. contended that an engineer is entitled to rely on a manufacturer’s specifications. Assuming this is so, the fact is that
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this winch was not being used according to the specifications. It was not being used as designed but with important modifications. When McLellan undertook to give advice to Halvorson Inc. concerning the use of this winch for the erection of the aerial tramway, he clearly assumed a duty to ascertain whether it would be adequate as modified. He did not fail to appreciate that such was the situation because he made some calculations of some of the stresses and deflections to be expected in the altered winch drum and he also figured out bearing pressure. However, he made no calculation of the stresses on the flanges, although he was having their diameter increased 6″ and intended to pull 15 layers of cable instead of the 9—or 10 at the most—that were contemplated in the original design and specifications of 3,000 feet of 1⅜″ cable. His explanation was that the alterations to the main drum would change the stress pattern “negligibly”.
At this juncture it is appropriate to indicate what those alterations were. In order to lengthen the drum it was found necessary to cut through the 6¼″ drum shaft because it could not be pressed out of the 10″ hubs to which the drum ends, or flanges, and their twelve 6″ deep stiffeners were welded. Nothing was put in to reconnect the two shaft ends when an additional two-foot barrel section was welded in the middle. This new section was merely made somewhat thicker (1½″ v. 1¼″). To hold the cut shaft ends in place, 1″ steel plate diaphragms were welded inside the cut barrel ends before welding in the new section. On the gear side, the flange was extended by welding around a 1″ X 3″ ring. As this was impossible on the brake side, an extra 1¾″ circular plate of the required outside diameter was welded to the barrel inside the old flange. All those changes, it should be noted, were not made by the Vancouver manufacturer of the winch, but in a shipyard.
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As previously mentioned McLellan, as he admitted, was not experienced in winch drum design and he was unable to calculate “the exact stresses in the flanges and components of that nature”. Yet, he took the responsibility of directing the changes above described which changes resulted in turning a drum of proven design built around a rigid shaft into a larger drum of unproven and unusual design with a discontinuous shaft. Ward, an engineer with experience in hoist design, said:
I say here the most danger of a hoist—when it is designed for nine wraps and you jump it up to fifteen wraps and you leave the flanges about the way they are, I think you are asking for trouble.
Under the circumstances, the repeated breaks that occurred when the stresses on the drum were admittedly nearing the maximum, went far towards showing that those mishaps were due to McLellan’s negligence in altering the design of the winch drum, without proper consideration being given to all the stresses to be expected in the altered drum, particularly in the flanges. As we have seen, he just assumed the changes would be negligible although, on his admission, he was incapable of figuring it out.
Professor Hooley, a consulting engineer specializing in the stress analysis of structures, endeavoured to justify McLellan on the basis that the load put on the flanges by the rope under tension in the actual conditions at Jackson Hole was less than the maximum load contemplated in the winch specifications. These were for a normal working load of 44,000 lbs. while the line tension at Jackson Hole according to accepted figures, started at 24,000 lbs. He contended that the total force on a flange with fifteen layers wound under the actual tensions was only 250,000 lbs. while the force due to ten layers wound at a constant 44,000 lbs. tension would be 350,000 lbs. Those figures were in extremely sharp contrast with those submitted by Ward and Brown. They were conclusively shown to be erroneous.
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Professor Holt, who testified as a witness for Wrights’, did not hesitate to say of the results of Hooley’s method of flange force computation: “this is ridiculous”. He is an expert in mechanical engineering specialized in “the proper design of engineering hardware”. He explained why some of Hooley’s assumptions that are valid in many structural problems, are invalid in machine design. He demonstrated that, even on his own assumptions, Hooley’s calculations were erroneous and the actual force on the flanges at Jackson Hole on that basis was greater, not smaller, than with either nine or ten layers wound as per the specifications. Then, he proceeded to explain how Hooley had greatly underestimated the load on the flanges:
The big point is that Professor Hooley only considers the residual line tensions or residual line loads for the retention of compression effect. In fact, he only takes into account the tension loads are the only ones that are applying load to the flange, whereas in mine I say that it isn’t the residual stress left in the coils that applies the load to the flange but it is those loads transmitted from layer to layer by the coils that applies the load against the flange. And this is the basic difference and the big difference between Professor Hooley’s work and mine; that I am taking into account the actual loads transmitted as against his taking into account the residual stress being, in the coils, the only load imposed.
On that basis, Professor Holt submitted two calculations comparing the flange force as a result of fifteen layers under Jackson Hole conditions with ten layers at the specified load. The first calculation making no allowance for friction gave 1,710,000 lbs. at Jackson Hole against 1,230,000 lbs. under specification conditions. The second, assuming a 0.2 friction coefficient gave 1,275,000 v. 954,000 lbs., that is in both cases an increase of approximately one-third or something between 300,000 and 500,000 lbs. for just one of the factors that McLellan considered negligible. The barrel circumference being about 80 inches, this meant an additional stress of some 4,000 to 6,000 lbs. per inch of a weld for
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which the allowable stress was said to be as little as 12,000 lbs. per inch. Not precisely negligible.
The correctness of Professor Holt’s theory and calculations was strikingly confirmed by the results of an experiment made by one Harlander and put in evidence in rebuttal. Properly extrapolated these gave for fifteen layers at Jackson Hole tension, 1,500,000 lbs. and for ten layers at rated load, 1,000,000 lbs., an increase of 50 per cent. These results are pretty close to the average of Professor Holt’s computations. They also confirm his severe criticism of Hooley’s absurdly low figure of 250,000 lbs., that turned out to be just one-sixth of a proper figure for the flange load under Jackson Hole conditions. The close correlation between Professor Holt’s figures and the test results which became known to him subsequently, is such a strong confirmation of the latter’s validity that it appears unnecessary to say much of the objection that the test was made on a reduced scale and with a rigid flange and a short barrel. It is sufficient to say that the evidence of Professor Harlander and of Professor Holt shows clearly that this objection is ill-founded.
Something more, however, needs to be said concerning the extremely high figure of 3,700,000 lbs. given by hoist expert Brown, and the still higher figure resulting from Ward’s formula. It was strenuously contended that the evidence of those witnesses was worthless because if they had been right as to the high flange pressure which they calculated and the low allowable stress on the drum weld, the winch would have failed on the first haul, not the third. This reasoning is unscientific, it ignores the effect of the safety factor in design and of the yield point in actual operation under excessive stress, coupled with temperature variations. Prof. Holt said:
I believe that Mr. Brown, for instance, is a manufacturer of winches and design(er) of winches and
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he is thinking in terms of design. If he uses his analysis this means that his winches are over designed; they will give good service and last for a great, long while; there is more material there than is necessary, but it would be a safe, satisfactory piece of machinery; heavy, but reliable.
This was said in the course of discussion of the proper coefficient of friction. Some of the high figures for the flange load were obtained by formulas making no allowance for friction. Of course, this overstated the load. However, Hooley assumed a friction coefficient of 1.0 which as obviously tends to understate it. When challenged on this in cross-examination, his answer was that it was based on his experience. Apparently, it was not realized that this meant it was based on nothing because his experience was in structural engineering, not in mechanical engineering.
Near the end of the trial, during Harlander’s cross-examination, the trial judge said:
The significant evidence in reply, that is, in rebuttal, was that part of the evidence, in my opinion, which went to the point at which the failure would be attributable, if it was to be attributable to that, to the compression, and I agree that it is on almost all fours and supports Professor Hooley.
In view of that observation, some further comments on Hooley’s evidence appear desirable. In short, his theory was that the failure of the drum was due to the insufficient rigidity of the barrel which he called marginal. He pointed out that the compressive force of the rope wound under tension on the barrel puts a stress on the weld joining the barrel to the flange, in addition to the stress caused by the axial load due to the cable layers resting on it and the torsion load due to the torque applied through the gear to pull the cable by turning the drum. As we have seen, he minimized the flange load and contended that it was actually lower with fifteen layers at Jackson Hole tension than for nine or ten layers at rated pull. The result of the test effectively rebutted
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that theory, by showing that the axial flange load at Jackson Hole was six times higher than he figured. However, the test also included a measurement of the compression load on the barrel and the result of such measurement did show that the compression force reached its peak at nine layers and did not increase when fifteen were put in. Apparently, this was taken as a confirmation of Hooley’s theory when, in fact, it was a confirmation of a single factor and in no way established the correctness of the other factors involved in that theory. For one thing, it did not prove that this compressive force resulted in a stress of the magnitude that Hooley had figured. But, even at that, the fact that the stress from the compressive force was not increased did not minimize the effect of the increase in the axial force and in the torque load. If the weld was already overloaded as a result of the compression force, it was that much more imprudent to load it further by a substantial increase of the stresses due to flange load and torque.
Much was made at the hearing in this Court of the fact that a witness for the plaintiff, one Barlow, submitted a calculation, for the total axial flange load under Jackson Hole conditions, of only 208,900 lbs., that is somewhat less than Hooley’s figure of 250,000 lbs. Under this result there is the following notation:
While this figure is based on a lot of assumptions, at least it is an indication of the magnitude of the force.
It is not easy to understand why the plaintiff thus weakened its case by having a structural design engineer put in figures so completely at variance with those of the hoist experts Brown and Ward who were both mechanical engineers. This may well explain why, at the conclusion of the trial after a long adjournment during which the test was made, the trial judge remained confused even after allowing the test results to be given in evidence in rebuttal. However, I must say with respect that he failed to appreciate how completely Hooley’s theory was conclusively
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shown to be false by Prof. Holt’s testimony and the results of the test.
Counsel for McLellan & Co. relied in argument on the answer given by Hooley to the following question in cross-examination:
Q. In other words, let me put it this way: Are you saying that you did not give equal weight to all the manufacturer’s notations?
A. Perhaps I could put it otherwise: I look at the 3,000 feet and I do not know from that number, unless I do some calculations, how much of the drum is full of cable, but I can look at the specifications and notice that it will carry 0510 wraps, that is about two thirds full. I can read those numbers directly from the specifications and I would conclude that if it will carry 180 kips two thirds full it will certainly carry 40 kips full. So there is my logic.
Now the specifications read:
Normal working load 44,000 lbs. Winch parts will not fail on accidental shock load to 90 tons—i.e. failure of 1⅜″ rope. Capacity 3,000′—1-⅜ line.
It will therefore be observed that the 180 kips (90 tons) is accidental shock load only, but what the winch will carry (normal working load) is 44 kips with 3,000 feet of 1⅜″ cable. The logic that equates accidental shock load with working load is strangely in contrast with the careful analysis made by Prof. Holt and is not to the credit of a man in a responsible position.
This is not a matter in which the impression created by the demeanour of a witness in the box can be a criterion in the appreciation of the evidence. An exhaustive analysis has driven me to the conclusion that a clear preponderance of the evidence shows that the failure of the winch is traceable to negligence on the part of McLellan & Co.
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The appeal should be allowed against respondent Robert McLellan & Co. Ltd. with costs throughout and the case remitted to the Supreme Court of British Columbia for the assessment of the damages. The respondent Wrights’ Canadian Ropes Ltd. is entitled to its costs in this Court on the main appeal, but, under the circumstances, I would dismiss its cross-appeal without costs.
Appeal allowed with costs.
Solicitors for the plaintiff, appellant: Davis & Company, Vancouver.
Solicitors for the defendant, respondent McLelland: Harper, Grey, Eaton & Company, Vancouver.
Solicitors for the defendant, respondent Wrights’: McMaster, Bray, Moir, Cameron & Jasich, Vancouver.