Duhaime's Law Dictionary

Pennsylvania Rule Definition:

An rule of maritime law that if a ship is in some violation of a navigation statute at the time of a collision, she is presumed to be at fault.

The rule of maritime law and liability was first stated and derived its name from the 1873 United States Supreme Court case, The Pennsylvania, in which the court wrote:

"But when ... a ship at the time of collision is in actual violation of a statutory rule intended to prevent collisions, it is no more than a reasonable presumption that the fault, if not the sole cause, was at least a contributory cause of the disaster. In such a case the burden rests upon the ship of showing not merely that her fault might not have been one of the causes, or that it probably was not, but that it could not have been. Such a rule is necessary to enforce obedience to the mandate of the statute..."

In Dover Barge, Justice Chin offered this summary of the law:

"The Pennsylvania Rule, in other words, shifts to defendants the burden of disproving causation.

"The Pennsylvania Rule originally applied only to cases involving collisions between ships, but has been extended to apply to any statutory violator who is a party to a maritime accident. Because the Pennsylvania Rule places a heavy burden on defendants, it is limited to the violation of a statute intended to prevent the catastrophe which actually transpired. The Pennsylvania Rule will not create a presumption that the violation caused an injury unless common sense or the realities of admiralty prompt that conclusion.

"Three elements must exist for the Pennsylvania Rule to apply: (1) proof by a preponderance of the evidence of a violation of a statute or regulation that imposes a mandatory duty; (2) the statute or regulation must involve marine safety or navigation; and (3) the injury suffered must be of a nature that the statute or regulation was intended to prevent.

"Failure to post a look-out when the conditions require one has been found to warrant invocation of the Pennsylvania Rule."

The presumption is rebuttable. In Wills v. Amerada Hess, Justice Sotomayor did not apply the Pennsylvania Rule because it could not agree with the suggestion that the ship's failure to hang cautionary lights, even though required by law, was the cause of the collision, adding:

"By shifting the burden of proof to establish causation, the Pennsylvania Rule creates a drastic and unusual presumption - albeit a rebuttable one - against the shipowner who has violated his or her legal duties. Nevertheless, such a presumption is appropriate in cases where, in light of wide experience in maritime navigation, the logical probability is that the fault of the ship is the cause of the disaster.

"Collision cases, such as the case that gave the Rule its moniker, most clearly illustrate this principle. Because a collision is rare in which there is not at least some arguable reason for regarding both vessels at fault, it is logical to attribute fault to a ship that at the time of a collision is in actual violation of a statutory rule intended to prevent collisions. Thus, under the Rule, proof that a maritime safety rule was violated creates a presumption that the violation led to the collision, such that the complaining party is relieved of its obligation to show causation, unless the derelict shipowner can prove that the violation was not the cause of the collision....

"[A]pplication of the Pennsylvania Rule has not been limited to cases involving collisions (and has been applied) in the context of allision (and) in the context of ship stranding.

"Nevertheless, we have been cautious not to extend the Rule's application in ways that would unmoor it from its animating principles."

In Evergreen, Justice Hamilton wrote:

"There is no dispute that the Pennsylvania Rule equally applies to allisions such as occurred in this case. Moreover, although the rule speaks of a statutory violation, it is equally applicable to violations of federal regulations. Notably, the Pennsylvania Rule does not establish fault; rather, it shifts the burden of proof on the element of causation to the party who violated the statutory rule or regulation at issue to prove that such violation could not reasonably be held to have been the cause of the collision or allision."


  • Dover Barge Company v. Tug "Crow", 642 F. Supp. 2d 266 (United States District Court, New York, 2009)
  • Evergreen Intern., SA v. Norfolk Dredging Co., 531 F. 3d 302 (United States Court of Appeals, 2008)
  • The Pennsylvania, 86 U.S. 125 (1873)
  • Wills v. Amerada Hess Corp., 379 F.3d 32 (United States Court of Appeals, 2004)

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