The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.
ALT1: ... that the Helmover torpedo was powered by an internal combustion engine and needed a tank of high-pressure air to supply it while under water? Source: [2] page 135