Hitachi Zosen Altered Fuel and Emissions Test Data on Engines Over 25 Years

Japan’s Hitachi Zosen is issuing an apology to its worldwide customers reporting that it discovered the marine business unit was altering test and emissions data on engines during their shop tests to ensure they met customer requirements. While emphasizing that there are no safety issues, the company became the second major Japanese marine engine manufacturer to confirm that engineers had routinely altered data to ensure it met contract specifications.

Hitachi Zosen reports that it has discovered over 1,350 instances of data being overwritten during shop tests for engines both from its plants and involving engines from IMEX. It is saying its internal investigation shows the practice started in 1999 and involves 950 Hitachi Zosen engines, including 903 non-Japanese flag vessels and 47 Japanese-flagged vessels. In addition, 416 engines from IMEX are involved, including 395 supplied to non-Japanese vessels and 20 Japanese ships. The number of NOx emission verifications is reported to involve 28 engine types for Hitachi Zosen Marine Engine and 11 engine types for IMEX.

The practice came to light after another Japanese engine company, IHI Power Systems Company, confirmed that it was being investigated for alerting test data. The company’s facilities were raided by inspectors from Japan’s Ministry of Land, Infrastructure, Transport and Tourism in April to gather details of the fraud. IHI said it discovered the practice dated back to the 1980s at one of its plants and 2001 at a second facility.

The Ministry issued a reminder to engine manufacturers after the IHI case went public emphasizing the importance of complying with environmental and safety regulations. Hitachi says in its review after that it discovered “fuel consumption rate” data recorded in the “test results of shop trial” submitted to customers was being altered so that the recorded results reflected different values from the actual values from the test. NOx emission data was also being calculated at the same time and could have been impacted.

Blaming it on “lack of awareness regarding compliance,” Hitachi Zosen in its statement says, “Through the interviews to relevant personnel, it was confirmed that the data was altered at the time of shop trial test to keep the fuel consumption rate within the permissible range required in the customer’s specification and to reduce data variability.”

Currently, the company says it is verifying whether there have been violations of laws, regulations, or standards, related to the subject engines. The company said it “will promptly establish a special investigation committee composed of external experts and will thoroughly ascertain the facts and investigate the cause while also committing all efforts to prevent recurrence including a reassessment of our business operation structure and to restore trust.”

Hitachi Zosen Marine Engine is today owned by Hitachi Zosen (65 percent) with an investment from Imabari Shipbuilding Co. (35 percent). The business dates to 1950 and holds licenses from both MAN Energy Systems and WinGD, It was spun off from the parent in 2022 to its current ownership. Hitachi Zosen set up IMEX in 1987 and merged it into its current structure in 1999.