This Manual is intended primarily for use by foundry personnel aboard repair ships and tenders. The recommended practices are based on procedures proved workable under Navy conditions and are supplemented by information from industrial sources. The Manual is divided into two general sections. The first section, chapters 1 through 13, contains information of a general nature, such as "How Metals Solidify," "Designing a Casting," "Sands for Molds and Cores," "Gates, Risers, and Chills," and "Description and Operation of Melting Furnaces." Subjects covered in these chapters are generally applicable to all of the metals that may be cast aboard ship. The second section, chapters 14 through 21, contains information on specific types of alloys, such as "Copper-Base Alloys," "Aluminum-Base Alloys," "Cast Iron," and "Steel." Specific melting practices, suggestions for sand mixes, molding practices, gating, and risering are covered in these chapters. This manual has been written with the "how-to-do-it" idea as the principal aim. Discussions as to the "why" of certain procedures have been kept to a minimum. This manual contains information that should result in the production of consistently better castings by repair ship personnel.
The United States Department of the Navy (DoN) was established by an Act of Congress on April 30, 1798, to provide a government organizational structure to the United States Navy, the United States Marine Corps and, when directed by the President (or Congress during time of war), the United States Coast Guard, as a service within the Navy, though each remain independent service branches. The Department of the Navy was an Executive Department and the Secretary of the Navy was a member of the President's cabinet until 1949, when amendments to the National Security Act of 1947 changed the name of the National Military Establishment to the Department of Defense and made it an Executive Department. The Department of the Navy then became, along with the Department of the Army and Department of the Air Force, a Military Department within the Department of Defense: subject to the authority, direction and control of the Secretary of Defense.