43 F.3d 754
1st Cir.
1995
CYR, Circuit Judge.

Defendant and third-party plaintiff Master Unit Die Products, Inc. (“MUD”), appeals from an adverse judgment dismissing its cross-claim for contribution against appellees P.H. Trueblood Corporation and Trueblood, Inc. (collectively: “Trueblood”). As the findings of fact and conclusions of law entered by the district court do not permit reliable appellate review, see Fed.R.Civ.P. 52(a), we vacate its judgment and remand for further proceedings.

I

BACKGROUND

In 1966, Trueblood designed, manufactured, and sold a plastic-molding press designed so that end-users could affix to its movable shuttle table two “quick-change” frames. Once the press was equipped with the required quick-change frames (not manufactured by Trueblood) and each frame was fitted with a die containing an injectable mold, the press would inject liquified plastic into one die-mold; and after the shuttle table shifted the first frame off to one side, the press would inject liquified plastic into the die-mold on the second frame. From recessed holes in the shuttle table surface, the press triggered a “knockout” plate built into the sidelined frame which thrust up through the filled die-mold, thereby ejecting and purging the hardened plastic part from the work area. After the ejection was completed, the shuttle table shifted the frame containing the empty die-mold back into a central position for the next injection of plastic, while the press shifted and “knocked out” the twin die-mold in the same manner.

The console which housed the controls for the Trueblood press was located within arm’s length of the press operator and had three settings. In the “off’ mode, the press would not operate. In “automatic” mode, the press automatically repeated the entire cycle of functions described above, but the press operator was required to use both hands to push two widely-spaced buttons on the console, which meant that the operator’s hands could not be inserted into the injection or ejection areas while the press was in operation. In the “hand” mode, however, the press operator could perform each function in the cycle by manually depressing one console panel button for each function, leaving the operator with one free hand. Moreover, when first switched from “off’ to “hand,” the press automatically “recycled,” thereby thrusting into the ejection area any knockout plate then in position. The “hand” mode was designed to allow the press operator to insert an implement through an opening in the quick-change frame to dislodge a jammed knockout plate or plastic part, while manually triggering the “eject” button located on the control console.

By early October 1989, an unaltered True-blood press had come into the possession of Styletek, Inc., in Lowell, Massachusetts, fitted with two quick-change frames designed and manufactured by appellant MUD. On October 11, 1989, Styletek employee Nan Touch was operating the Trueblood press in the “automatic” mode when one of the MUD frame’s knockout plates became jammed in the “up” position. With his left hand, Nan Touch reached through an opening (1.4" high x 5.25" wide) in the front of the jammed frame to dislodge a part stuck in a die-mold, at the same time using his right hand to change the press from “automatic” to “off’ to “hand” mode. At this point, the jammed knockout plate “recycled” and amputated portions of two fingers on Nan Touch’s left hand.

In June 1992, Nan Touch instituted this diversity action against MUD in the District of Massachusetts, alleging negligence, breach of warranty, see Mass.Gen.L.Ann. ch. 106, § 2-314, and unfair trade practices, see Mass.Gen.LAnn. ch. 93A, in the design, manufacture, and sale of frames incorporating an opening large enough to permit a press operator to insert a hand into the ejection area during operation. MUD impleaded True-blood as a third-party defendant, Mass. Gen. L.Ann. ch. 231B, § 1 (contribution among joint tortfeasors), alleging that the “one-handed” design of the press and its automatic recycling of the knockout mechanism upon transition into “hand” mode contributed to Nan Touch’s injury. Prior to trial, Nan Touch settled with MUD.

MUD’s third-party complaint for contribution against Trueblood was tried to the court. The district court found for Trueblood and entered the foEowing findings of fact and conclusions of law:

As to the defectiveness of the molding press, MUD has faded to establish that two-hand operation was the industry standard for the manufacturing of mechanical power presses in 1966. While Trueblood’s molding press may very well violate current day OSHA regulations, it would be unfair to impose modem standards on the practices of nearly thirty years ago. Accordingly, the Court finds that the molding press was not defective when manufactured. ...

Nan Touch v. Master Unit Die Prods., Inc., No. 92-11493-EFH, slip op. at 3 (D.Mass. June 8, 1994) (emphasis added).

II

DISCUSSION

We review interpretations of state law de novo, see Salve Regina College v. Russell, 499 U.S. 225, 233-35, 111 S.Ct. 1217, 1222-23, 113 L.Ed.2d 190 (1991), and findings of fact for clear error, see Interstate Commerce Comm’n v. Holmes Transp., Inc., 983 F.2d 1122, 1129 (1st Cir.1993). MUD maintains that the district court misapplied the Massachusetts law governing claims for breach of warranty based in tort, or relied on impHcit findings of fact unsupported by the evidence. We do not reach the merits of these contentions, for we conclude that the district court ruling is insufficiently clear to enable effective appellate review. See Fed. R.Civ.P. 52(a) (“In aH actions tried upon the facts without a jury ... the court shaU find the facts speciaUy and state separately its conclusions of law_”).

Under applicable Massachusetts product liability law, negligence-based claims differ markedly from tort-based claims for breach of warranty. The factfinder confronted with a negligence-based product liability claim focuses on whether the conduct of the designer or manufacturer reveals a faEure “to use reasonable care to eliminate foreseeable dangers which subject a user to an unreasonable risk of injury.” Colter v. Barber-Greene Co., 403 Mass. 50, 525 N.E.2d 1305, 1313 (1988). Consequently, evidence that the defendant designer or manufacturer met the pertinent industry safety standards prevailing at the time of manufacture would be material, albeit nondispositive, evidence that the defendant was not negligent, even though its product’s design might not comport with safety criteria later embraced by the industry.

By contrast, a breach of warranty claim arising under Massachusetts tort law is founded on strict liability principles, see Mass.Gen.LAnn. ch. 106, § 2-314; Restatement (Second) of Torts § 402A cmt. e. (1965), and focuses exclusively ‘“on whether the product [is] defective and unreasonably dangerous and not on the [actual] conduct of the user or the seller.’ ” Colter, 525 N.E.2d at 1313 (citation omitted) (emphasis added); see Back v. Wickes Corp., 375 Mass. 633, 378 N.E.2d 964, 968-70 . (1978). Because the breach of warranty inquiry is not concerned with the reasonableness of the designer/manufacturer’s conduct, see Correia v. Firestone Tire & Rubber Co., 388 Mass. 342, 446 N.E.2d 1033, 1040 (1983) (explaining that defendant may be liable for breach of warranty even if he “[took] all reasonable measures to make his product safe”), compliance with “state of the art” safety standards at the time the product was designed or manufactured is usually immaterial. See, e.g., Hayes v. Ariens Co., 391 Mass. 407, 462 N.E.2d 273, 277 (1984). Instead, the factfinder may rely on the faEure of the product to conform to present-day safety standards in determining whether it is “unreasonably dangerous,” under a breach of warranty analysis, even though the risk against which the post-design or post-manufacture safety standard was intended to protect was unknown or not reasonably discoverable by the defendant prior to the sale of the product. See id. (defendant may be liable for breach of warranty “regardless of the knowledge of risks that he actually had or reasonably should have had when the sale took place”).

Moreover, although nonconformance with a present-day safety standard would be relevant evidence, it would not compel the trier of fact to find the product “unreasonably dangerous” per se, see, e.g., Pedraza v. Shell Oil Co., 942 F.2d 48, 52 (1st Cir.1991) (OSHA regulations do not preempt state tort law principles), cert. denied, — U.S. -, 112 S.Ct. 993, 117 L.Ed.2d 154 (1992). Indeed, even the incorporation of a design feature currently perceived as a dangerous condition might be found “reasonable” in the circumstances, based on the factfinder’s application of the traditional risk/utility balancing test to the particular product. See Back, 378 N.E.2d at 970 (listing the factors to be weighed in determining whether particular product is unreasonably dangerous, including “ ‘the gravity of the danger posed by the challenged design, the likelihood that such danger would occur, the mechanical feasibility of a safer alternative design, the financial cost of an improved design, and the adverse consequences to the product and to the consumer that would result from an alternative design’”) (citation omitted).

Viewed against the applicable principles of Massachusetts law, the findings entered by the district court are plainly deficient. The equivocal observation' that “Trueblood’s molding press may very well violate current day OSHA regulations” proscribing one-handed presses, coupled with the court’s negligence-based assessment that “MUD has failed to establish that two-hand operation was the industry standard for the manufacturing of mechanical power presses in 1966,” strongly suggest that the district court viewed any such OSHA violation as simply immaterial to Trueblood’s liability. On the contrary, a finding that the Trueblood press contravened the 1992 OSHA standards, a matter all but conceded by the parties, clearly would be material to the ultimate factual determination whether the press was “unreasonably dangerous,” and hence gave rise to a breach of warranty.

On the other hand, such a finding would not compel the conclusion that the Trueblood press was “unreasonably dangerous” per se. Yet the district court’s observation concerning the “unfairness” of applying the 1992 OSHA standards to a product manufactured in 1966, see supra p. 757, strongly suggests that the district court perceived a need to forefend against just such a “compelled” conclusion. But see Cosme v. Whitin Mach. Works, Inc., 417 Mass. 643, 632 N.E.2d 832, 835 (1994) (contrasting Connecticut’s ten-year statute of repose after sale, and noting that Massachusetts breach of warranty claims are not rendered defeasible simply by the passage of time). In addition, the district court’s free-form “unfairness” exception, especially in reference to a durable product like the Trueblood press, is out of step with the purpose and policy of the strict product liability principles upon which breach of warranty liability is founded. See Colter, 525 N.E.2d at 1313 n. 13 (‘“[Pjublic policy demands that the burden of accidental injuries caused by products intended for consumption be placed upon those who market them, and be treated as a cost of production against which liability insurance can be obtained; and that the consumer of such products is entitled to the maximum of protection at the hands of someone, and the proper persons to afford it are those who market the products.’” (quoting Restatement (Second) of Torts § 402A cmt. c. (1965))).

Finally, we can discern no indication in the district court ruling as to how, or whether, the required risk/utility balancing was performed to determine if the one-handed control feature made the press “unreasonably” dangerous. The court neither cites to apposite Massachusetts case law, nor adverts to any risk/utility balancing test component, even though MUD introduced evidence that Trueblood had available — -at slight additional cost — feasible, “safer” design alternatives. Trueblood countered with evidence that one-handed control was essential to permit a press operator to insert an implement into the work area to unjam a knockout plate, and that it was a “reasonably” safe design provided the manufacturers of quick-change frames did not incorporate an opening large enough to accommodate the operator’s hand. We in no sense suggest which (if either) evidentiary proffer should be credited, but simply emphasize that appellate review is utterly impracticable when neither the conclusions of law which guided the district court ruling, nor the findings of fact essential to a principled decision under the applicable law, are discernible from its decision.

As we have stressed repeatedly in the past, the Rule 52(a) requirements that facts be .stated specially, and conclusions of law separately, impose on the trial court an obligation to ensure that its ratio decidendi is set forth with enough clarity to enable a reviewing court reliably to perform its function; namely, to review the conclusions of law de novo and the essential findings of fact for clear error. See, e.g., Thermo Electron Corp. v. Schiavone Constr. Co., 958 F.2d 1158, 1160 (1st Cir.1992); Peckham v. Continental Casualty Ins. Co., 895 F.2d 830, 842 (1st Cir.1990); Applewood Landscape & Nursery Co. v. Hollingsworth, 884 F.2d 1502, 1503 (1st Cir.1989); Pearson v. Fair, 808 F.2d 163, 165-66 & n. 2 (1st Cir.1986) (per curiam) (explaining that Rule 52(a) is “mandatory, not precatory”) (citing Commissioner v. Duberstein, 363 U.S. 278, 292, 80 S.Ct. 1190, 1200, 4 L.Ed.2d 1218 (1960)); Boston and Maine Corp. v. First Nat'l Bank of Boston, 618 F.2d 137, 143 (1st Cir.1980); see also 9 Charles A. Wright & Arthur R. Miller, Federal Practice and Procedure § 2571, at 679 (1971) (collecting cases).

The parties urge us to salvage the present appeal. Each proposes plausible interpretations of the evidence and conclusions of law favorable to itself. But neither has met with notable success in divining the district court’s essential findings of fact and predicate conclusions of law. We note, further, that although all responsibility under Rule 52(a) rests with the trial judge, and the burden is not an onerous one, see Fed.R.Civ.P. 52(a) advisory committee’s note (1946 amendment) (requiring “brief, definite, pertinent findings” with “no necessity for over-elaboration”), counsel might have avoided the unnecessary expense and delay occasioned in this case simply by submitting a timely request for reconsideration based on the need for adequate findings of fact and conclusions of law as required by Rule 52(a). As neither party sought reconsideration under Rule ■ 52(a), each shall bear its own costs on appeal.

The district court judgment is vacated. The case is remanded for further proceedings consistent with this opinion. Each party shall bear its own costs.