Margin Management and Procedures for U.S. Navy Small Craft
Abstract
Weight and center of gravity margins are included in a weight report by the designer to cover the inherent limits of precision in initial weight estimates. Powering and hump/speed margins are included to account for inaccuracies in design calculations. Service Life allowances are for additions that will take place in the life of the craft. Other allowances are for items that lack a high degree of definition and are usually based on past experience. It is incorrect to omit an item from the weight estimate with the belief it will be covered by margins. These items should be accounted for. This report is intended as a guide for selecting and using margins in the design and construction of U.S. Navy craft under the Jurisdiction of NAVSEACOMBATSYSENGSTA. Guidance is provided to assure the craft will meet the structural, stability and mission requirements. The values outlined in this document can be violated only with the written authorization (waiver) from NAVSEACOMBATSYSENGSTA, Code 60, and shall be included in the design history. This document differs from past formal and informal policy by the more precise definition of margins and the incorporation of the Service Life Allowance for future growth of the craft in service. The readers are assumed to have a thorough understanding of the boat design process and are aware of the need for integrity and accuracy of the weight estimate. Each design requires individual consideration of its unique features, unknowns and complexities.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1988
- Accession Number
- ADA387757
Entities
People
- E. G. Hatchell
- R. C. Wilson