## Facts

- During U.S. neutrality in World War I, two major incidents occurred involving munitions-related facilities in the United States:
- On July 29–30, 1916, a large explosion destroyed or damaged property at the Lehigh Valley Railroad terminal in New York Harbor (“Black Tom”).
- On January 11, 1917, a fire destroyed the Kingsland, New Jersey plant of the Agency of Canadian Car and Foundry Company, which produced munitions.
- The United States, on behalf of Lehigh Valley Railroad, the Canadian Car and Foundry agency, and various underwriters, alleged the incidents were caused by German sabotage agents acting within U.S. territory.
- Under the bilateral claims framework creating the Mixed Claims Commission, Germany could be financially responsible for damage to U.S. nationals during neutrality if caused by acts of Germany’s authorized agents.
- In an October 16, 1930 merits award, the Commission dismissed the claims, finding the evidence insufficient to prove that German agents caused the specific Black Tom and Kingsland incidents.
- In January 1931, the United States sought rehearing, asserting factual errors, legal errors, and procedural irregularity based on the umpire’s participation in deliberations and drafting.
- In March 1931, the Commission rejected the procedural-irregularity argument and denied rehearing on the existing record, but reserved decision on whether to reopen based on genuinely new evidence.
- On July 1, 1931, the United States filed a supplemental petition for rehearing supported by newly submitted evidence; the December 3, 1932 decision addressed whether that new material warranted reopening the final 1930 dismissal.

## Issues

1. Whether the Commission had authority, after a final merits award, to entertain a supplemental petition to reopen based on newly discovered evidence.
2. What standard governs rehearing on new evidence in an international arbitral claims process, particularly the required weight and potential effect of the evidence.
3. Whether the United States’ newly submitted evidence was sufficient to justify reopening the 1930 dismissal of the Black Tom and Kingsland claims.

## Decision

- The Commission held it could consider a supplemental petition based on new evidence despite the prior award’s final character, but only within narrow limits.
- The Commission applied a demanding threshold: reopening is warranted only if the evidence is genuinely new and of such probative force that it could reasonably lead to reversal or material modification of the prior decision.
- The Commission found the United States’ newly submitted evidence did not satisfy that threshold.
- The Commission denied the supplemental petition and refused to reopen the October 16, 1930 dismissal; the claims remained dismissed at that stage.

## Legal Principles

- Finality is a central feature of international arbitral adjudication; rehearing is exceptional rather than routine.
- A tribunal may reopen a final award on new evidence only where:
  - the evidence is genuinely new (not merely cumulative or a repackaging of prior arguments), and
  - the evidence is sufficiently weighty that it could reasonably change the outcome or materially modify the award.

- Rehearing procedures are not a vehicle to relitigate factual findings on the original record or to challenge ordinary internal deliberative practices of the tribunal absent a cognizable procedural defect.

## Conclusion

The Commission declined to reopen its final dismissal of the Black Tom and Kingsland sabotage claims because the United States’ supplemental evidence, though new, was not strong enough to justify reconsideration; the decision confirms a stringent standard for rehearing that protects the finality of international arbitral awards.


Lehigh Valley R.R. Co. v. Germany (Sabotage Cases) (U.S. v. Ger.), 8 R.I.A.A. 104 (Mixed Cl. Comm’n U.S.-Ger. 1932)