. "Chemical mortar battalion"@en . . "The United States chemical mortar battalions were army units attached to U.S. Infantry divisions during World War II. They were armed with 4.2 in (107 mm) chemical mortars. For this reason they were also called the \"Four-deucers\"."@en . "The United States chemical mortar battalions were army units attached to U.S. Infantry divisions during World War II. They were armed with 4.2 in (107 mm) chemical mortars. For this reason they were also called the \"Four-deucers\"."@en . . . . .