Before MEDINA, WATERMAN and MOORE, Circuit Judges.
On February 15, 1951 the M/S Christer Salen, one day out of Yokohama, bound for Vancouver, B.C., was proceeding at a speed of approximately 12 knots into a heavy sea, when without warning and for no apparent reason she suddenly split in two at about the middle of No. 3 hold.
The forward part, after being jammed by a sea into the after part, floated off and sank with the consequent loss of all cargo therein. The after part returned without incident to Yokohama. The cargo in No. 4 and No. 5 holds sustained only slight damage.
The cargo owners filed the libels in which the interlocutory decrees here appealed from were entered. The vessel owners filed cross-libels against the owners of the saved cargo, claiming contribution for general average, and petitioned for a limitation of liability.
Subsequent tests revealed that the break was "a brittle fracture" originating in the starboard sheerstrake, i.e., the uppermost longitudinal hull plating on the starboard side, somewhere in its 7 1/2" extension above the main deck.
The M/S Christer Salen, a general dry cargo ship, 405 feet long, 56 feet wide, with a gross tonnage of 4,900 tons, was one of a class of nine ships built at the Eriksberg Yard, Gothenburg, Sweden. The steel for the ship was rolled in Germany in 1943 and her construction was completed in 1944. Her hull was all welded and riveted to the frames. She began operating in 1945 at which time she obtained the standard ship classification of Lloyd's Register of Shipping, namely, 100-A-1. She retained this classification until she split in two.
In January 1950 she ran aground in the Philippines; permanent repairs were made in the Swedish yard, and in May 1950 a certificate of seaworthiness was issued by Lloyd's, continuing her 100-A-1 classification. In November-December 1950 while the Christer Salen was en route from Vancouver, B.C. to Kobe heavy weather caused a crack at the top of its portside bulwark welded to the port sheerstrake where the bulwark joined the bridge front. This crack was v-ed out and welded. Between January 6 and January 8, 1951, only a month before the disaster, the ship was drydocked at Hong Kong for normal maintenance purposes, viz., cleaning, scraping, and painting, and inspected by a Lloyd's surveyor who found that her "shell plating" was "in good condition" and recommended continuance of its classification (Exh. NN).
Were it not for the forceful arguments advanced by the appellant cargo owners, we would have thought it a foregone conclusion that no liability could attach to the carrier under the Carriage of Goods by Sea Act, 46 U.S.C.A. section 1304(2)(p) and (q), which provides that "Neither the carrier nor the ship shall be responsible for loss or damage arising or resulting from * * * (p) Latent defects not discoverable by due diligence; and (q) Any other cause arising without the actual fault and privity of the carrier and without the fault or neglect of the agents or servants of the carrier * * *." To understand the appellants' argument a brief description of the physical phenomena producing the fracture is necessary, which phenomena were explained in great detail at the trial by experts called by the parties.
In the 1940s disasters similar to that which befell the Christer Salen occurred in some other classes of cargo ships having all-welded hulls. Liberty ships seemed particularly prone to this affliction and in fact were the only class of dry cargo ships which displayed any such affinity. Some tankers having allwelded hulls, most notably T-2's, also had a tendency to fracutre. This tendency to fracture was not and never has been present in ships having riveted hull seams.
The first explanation for major fractures not attributable to external forces, such as extremely heavy weather, occurring in welded ships was that they were monolithic structures, which owing to their lack of elasticity possessed locked-in stresses. On the other hand, on riveted ships there is a certain amount of play between the plates, and, while the plates may be sprung when subjected to sudden and extreme stress, the riveted seams will generally absorb the internal stresses which cause the major fractures on welded hulls. This explanation is now hotly disputed by protagonists of the welded hull. They claim that poor steel and poor design will produce as many fractures in riveted ships as they do in welded ones. What prevents major fractures in riveted ships is that the break will stop at the first riveted seam in place of running all the way down the hull.
The fact that a fracture will stop at a riveted seam prompted the superimposition of riveted bands, called crack arresters, on those welded ships, such as T-2's and Liberties, having a tendency to fracture. There are two varieties of crack arresters; in one type longitudinal slots are made in the hull or deck, with riveted straps then fitted over the slots; the other type consists of riveted gunwale bars inserted between the stringer plates and sheerstrakes.*fn1 The evidence conclusively shows that crack arresters do the job which they were designed to do. The arguments advanced by the shipowner based on the testimony of Murray, a representative of Lloyd's, to justify Lloyd's failure to require crack arresters on the vessel were that the fitting of crack arresters might have caused notches which could have been the starting point of fractures and that crack arresters do not stop cracks.
The theory that crack arresters might have done more harm than good is pure speculation contrary to scientific facts and conclusively disproven by actual experience with crack arresters.Commenting upon the efficacy of crack arresters the report of the United States Navy Ship Structure Committee published in 1948 - three years before the accident here - stated that "The evidence that cleavage fractures do not pass riveted seams is now based on 15,000 shipyears service" (Exh. 21, p. 4). There is no evidence of any major fracture originating at crack arresters, and good workmanship would prevent the occurrence of any notches. Furthermore, in 1950 Lloyd's could not have been overly impressed by this fancied danger, since in 1947 it required crack arresters on sixty T-2's classified by it.
The claim that crack arresters are ineffective is also at odds with established fact. The sole support in the record for this position is the fact that two T-2 tankers fitted with crack arresters broke up in a severe storm off Cape Cod in February 1952. Even accepting as true the proposition that the cracks were not stopped at the crack arresters on these two ships, it is difficult to see how Lloyd's could rely on this fact in 1950 and 1951 since the accidents did not occur until 1952. But the proposition is not true. Lieutenant Commander MacCutcheon, one of the foremost authorities on structural failures in welded ships, had knowledge of the crack-ups of these two T-2's and testified that the fractures on these two vessels did not pass through the arresters, but actually stopped at ...