Design Data Sheet: Calculation of Surface Ship Endurance Fuel Requirements

Abstract : A major consideration in the design of any Naval ship or craft is its ability to meet the endurance requirements. This Design Data Sheet outlines the procedure to determine the minimum necessary fuel tankage for non-nuclear surface ships and operational presence. These conditions represent three different operational scenarios. Economical transit minimizes the consumption of fuel under normal transits. Surge to theater requires a ship to rapidly travel a specified distance, (such as to an operational area) without having to refuel. Operational presence requires a ship while deployed to remain on station for a specified period of time. The mobility requirements of these scenarios in conjunction with sustained speed requirements can drive the choice of prime movers and their ratings. Historically, the U.S. Navy has specified only the economical transit condition for an endurance speed of 20 knots. Assuming sustained speed requirements can be met, a lower endurance speed of 16 knots could result in a Combined Diesel (electric) and Gas Turbine (electric) plant. An operational presence profile heavily weighted for low speeds with high mission electrical loads will favor selecting power plants with a high degree of load sharing. For auxiliary and amphibious warfare ships with a lower sustained speed, diesel or diesel electric plants will likely be selected. This document uses metric units with the exception of distance which is measured in nautical miles, ship speed which is measured in knots, and temperature which is measured in degrees Fahrenheit. Conversion factors are provided to convert the units used to traditional units (long tons, pounds, and horsepower). This document is organized in a task oriented approach. The General Requirements section details the input and outputs of the Endurance Fuel Calculation Process. The Specific Requirements section provides details on the method to calculate the process outputs based on the inputs.