The opinion of the court was delivered by: BECKER
This suit was brought to recover damages occasioned by the malfunction of a large machine known as a tubular strander, which twists together seven or eight wires of aluminum or steel into wire rope.
The malfunction occurred on January 23, 1964 and was caused by the failure of a cradle casting which supports the large bobbins of wire that feed the machine. Plaintiff Southwire Company (Southwire), a firm engaged in making electrical wire and cable for distribution in the South, is the owner of the malfunctioning strander which was located at its wire mill in Carrollton, Ga.
Defendant Beloit Eastern Co. (Beloit) manufactured and cast the cradles at its Downingtown, Pa. foundry. Beloit supplied them to third-party defendant Syncro Machine Co. (Syncro) which manufactured and assembled the stranders at its Perth Amboy, N.J. plant.
Southwire is the plaintiff in C.A. 42129. The Travelers Indemnity Co. (Travelers) was, at times relevant here, the products liability insurer of Syncro. By reason of damage claims made by Southwire against Syncro, Travelers entered into an agreement on June 15, 1966. Under this agreement, Travelers advanced $95,000 to Southwire in return for Southwire's covenant not to sue Syncro; Southwire also assigned to Travelers the right to sue any person it considered to be liable. Travelers is the plaintiff in C.A. 42130, which it brought in its own name.
Beloit is the defendant in both actions and it has joined Syncro as third party defendant in both.
The central question in the case is the cause of the failure of the casting. When the casting fractured, the reel and cradle in the No. 6 bay of the strander were thrown through the window of the tube in which they were installed, causing the damage complained of. Plaintiffs contend that the casting failed because it was defective, porous, weak, and improperly cast. Beloit contends that the failure was caused by: (1) the weakening of the casting which occurred when Syncro welded a counterweight to the casting during the course of assembling the machine; and (2) the inordinate and unanticipated stresses to which the casting was subjected because of improper design and maintenance of the machine. In terms of legal theory, the plaintiffs seek recovery under § 402A of the Restatement of Torts,
and alternatively, on the theory of negligence.
Beloit defends on the grounds that: (1) the casting which it furnished was in accordance with specifications and was not defective; (2) there was a substantial change in the casting between the time it was sold and the time of the accident, because of the effect on the casting of the counterweight weld; (3) there was no negligence in the manufacture of the casting; and (4) plaintiffs have failed to prove proximate cause. In particular, Beloit contends that the causes of the accident were: (1) the welding which materially weakened the casting at its most critical area; (2) the stresses and vibrations to which the casting was subjected by (a) the misalignment and excessive vibration of the machine and (b) frequent tangles in the wire.
Our detailed findings of fact and conclusions of law now follow. We note that it is the factual and not the legal issues which are crucial in this case. We have made extensive findings of fact in the wake of which the legal issues become relatively simple and straightforward. Suffice it to say at this juncture that, after careful consideration of all the evidence, we have concluded that plaintiffs must be denied relief since they failed to carry their burden of proving their claim by a fair preponderance of the evidence.
The strander in question was sold to Southwire by Syncro pursuant to a purchase order dated February 2, 1962, and Syncro's acceptance dated February 5, 1962. This was one of two wire stranders purchased by Southwire in order to take care of its top product range, the production of electrical wire and cable. Southwire and Syncro jointly designed the strander; however Southwire's part in the design consisted merely in prescribing the sizes of the parts in order to be sure the strander would fit in the space that was available.
The strander had the capacity to make seven or eight wire strands of either aluminum or steel and was composed of seven bays, each of which received a bobbin of wire through an opening. The bobbins for the strander in question were 31 inches in diameter. The bobbins were carried by shafts which rested on the cradles. The shafts had bobbin locks which prevented the bobbin from coming off in the event it rotated or turned over. The locks or bars were secured through blocks which were bolted to the side of the cradle. The bearings provided a means of supporting the cradle without a friction grip between the cradle and the spiders which were connected to sections between the tubes or bays and constituted the main support for the tube. The bobbins were held in the same plane by the cradles while the tube rotated at approximately 500-550 r.p.m.'s. The rotation of the tube gave a pre-twist to the wire as it came off the machine onto the capstans which were two grooved wheels or drums. The tube and capstan were geared together so that as the tube revolved the capstan moved a pre-determined distance.
The strander was operated on a 24-hour, 7-day a week basis, except for down-time to change spools and except for one 8-hour shift per week during which the strander was serviced and maintained. It produced stranded wire at a rate of 130 to 500 feet per minute, depending on the product and size of cable being produced. For the first few months of its operation, the strander was realigned several times to compensate for vibration. As soon as vibration was detected, the machine was shut down for realignment and service. Although the gross misalignment problem was thus corrected, the problem of misalignment remained to some degree -- at least 7/64ths of an inch. Dr. Talbot so testified, although he concluded that misalignment did not cause the accident in question.
Each cradle was keel-weighted on the bottom so that it would stay in the same plane with a bearing at each end of the cradle and not rotate with the rotation of the barrel and spider. Occasionally a wire would cross over so that it would be pulled off center and tend to either swing the cradle or turn it around. The bobbin shaft had a rod (called a bobbin lock) that prevented the bobbin from coming out in the event it did rotate or turn over. The strander frequently had tangles which could pull the bobbin completely over and rotate the cradle and bobbin; tangles could be and often were caused by improper wrapping of the wire on the spool or reel.
B. The Casting and The Counterweights
The cradle casting in question was manufactured by Beloit. Its dimensions were 51 3/4" in overall length with an overall depth of approximately 10 inches. It can best be described as a flat slab of cast iron, tapered and curved at each end, with a semi-circular depression referred to as a "saddle" in the top side of the middle of the casting. Two mating castings were used in each tube or bay, bolted together at either end and forming a hollow, roughly oval, bottomless cradle which could be likened to a bottomless hammock. Between the sides of the cradle sat the reel or bobbin which contained the wire rope. This bobbin turned on an axle, the ends of which were seated in the saddles. Each end of the axle was held in place by a locking bar. To avoid the lateral rotation of the bobbin and cradle, which would tend to snag the wire as it was pulled off of the spool, the ends of the cradle fitted over bearings installed in the revolving main shaft which turned the spider and tube.
The casting was poured by Beloit at its foundry in Downingtown, Pennsylvania. The casting was made in accordance with Beloit's usual procedures. Each pour was tested so as to avoid the dross which collects at the surface in the early part of the pour and to avoid the sludge and sediment which is found toward the end. Certification of the test results were sent to Syncro from each ladle from which the castings were poured; if any report indicated deficiencies, the castings involved were to be sent back to be re-melted.
As it was manufacturing the strander, Syncro welded metal balance weights to the side of the casting which tended to rise due to the rapid turning of the main shaft of the strander (500-550 rpms.). A large rectangular balance weight was welded directly under the saddle, and a somewhat smaller square balance weight was welded to the left. The counterweights were not of a uniform configuration; instead they were individual to the cradle they were intended to balance. The procedure was done by means of arc welding. In the arc welding process, a piece of metal made of iron and nickel (known as a bead) is melted along with the adjacent surfaces of the casting and the balance weight so that all three flow together and harden. The molten metal is then cooled by conduction of the heat into the metal of the casting. The heat transfer is primarily into the metal; a small part of the heat, perhaps 10%, radiates into the atmosphere. Depending on the cooling rate, either a ductile or an extremely brittle zone results in the casting; the more rapid the cooling, the more brittle the zone. This welding procedure had been utilized by Syncro for many years without any known adverse effects. The welding was done by Syncro without the knowledge of Beloit. Syncro was aware of the fact that the welding of the counterweight to the cradle could weaken the casting. However, it was expected that, by virtue of the stability of the strander, the casting would hold the weight of the spool in an almost static condition so that the deep casting section would be subject to only limited stress. The safety factor which Syncro took into consideration in specifying the cradles was "five," which meant that the cradle could accept a stress five times the maximum stress expected to be applied. In view of these facts, Syncro did not deem it necessary to order that the casting be tested by x-ray or magnaglow,
or by the "destruct" type method
to determine any defects in the casting including subsurface porosity.
After the accident, the casting in question and all other castings in the strander were x-rayed and magnaglowed so that the interior of the castings could be susceptible to visual inspection. In addition, the fractured casting was subjected to additional tests by Dr. Talbot. The visual inspection and the other tests revealed numerous defects therein. While there was substantial dispute between the experts as to whether the tests were properly conducted, and as to the type of fracture involved, the most significant testimonial dispute between Drs. Talbot and Grosvenor related to the cause of the accident and the role played by Syncro's welding of the ...