Japan’s Ministry of Defense has suspended Kawasaki Heavy Industries from bidding on ministry projects after investigations confirmed falsified test data for submarine engines and improper gifting tied to ship repair and procurement practices, according to Japanese and industry reporting.
The ministry said fuel-efficiency test data were manipulated for engines fitted on 23 of Japan’s 24 active submarines, with only the most recently delivered boat unaffected. Reports said the falsification involved using target figures—rather than measured results—in trial documentation for items such as fuel efficiency, and authorities stated the issue did not undermine safe operation but meant contractual fuel-consumption requirements were not met.
Japan’s penalty is a 2.5-month bidding suspension, Japanese outlets reported. Maritime industry reporting said officials initially considered a five-month suspension but reduced it in light of the company’s notification, admission, and cooperation.
In a detailed notice dated 26 December 2025, Kawasaki Heavy Industries said internal investigations found misconduct spanning submarine repair work, marine-engine testing, and related governance controls, describing the situation as “very serious” and outlining measures to prevent recurrence. The company’s disclosures include efforts to strengthen controls, including work to increase the use of automation in inspection and verification processes.
The ministry’s actions also followed findings on inappropriate benefits provided to some naval personnel. Reports said items included consumer electronics and leisure goods, with authorities estimating $7,400 in gifts over the past six years, while disciplinary steps were taken against sailors involved in overseeing repair and supply contracts.
The case sits within a broader scrutiny of marine engine test integrity in Japan. A separate disclosure by IHI Power Systems in 2024 described improper alterations to fuel-consumption records, and Hitachi Zosen (now Kanadevia) also disclosed misconduct in 2024 related to shop-trial fuel-consumption data.
