+-------------------------+ [2] The naval armed guard is attached only when the ship is in convoy or in an extremely active theater of operations _Figure 3. Organization chart of engineer port repair ship crew showing functional setup of ship’s personnel._] SECTION III SHIP SPECIFICATIONS, EQUIPMENT, AND SUPPLIES 7. SHIP SPECIFICATIONS. =a. General external characteristics.= An engineer port repair ship is similar in external appearance to the average sea-going commercial cargo carrier. Two ready means of identification are the cathead on the ship’s prow and the number and arrangement of the cargo booms. These features are discussed in detail in paragraph 10. (See figs. 4 and 5.) The ship’s superstructure begins at the mainmast and continues aft to the stern. Forward of the superstructure are the two masts, the three hatches, and the forecastle deck. =b. Principal dimensions and capacities.= (1) For principal dimensions and capacities see table I and figure 6. (2) For location and capacities of fuel-oil, fresh-water, and salt-water tanks, see table II and figure 7. [Illustration: _Figure 4. Cathead welded on ship’s prow._] [Illustration: _Figure 5. View looking aft from forecastle deck showing masts and cargo booms._] _Table I. Principal dimensions of engineer port repair ship_ ==================================================== Principal Dimensions ---------------------------------------------------- Length over-all 291 feet, 1 inch. Length between perpendiculars 255 feet, 0 inches. Breadth, molded 42 feet, 6 inches. Depth, molded 25 feet, 3 inches. Gross tonnage 2,483.70 Net tonnage[3] 1,577.15 ---------------------------------------------------- Weights and Volumes Used ---------------------------------------------------- 1 ton 2,240 pounds. 1 ton fresh water 36 cubic feet. 1 ton salt water 35 cubic feet. 1 ton Diesel oil 41.98 cubic feet. ---------------------------------------------------- [3] Net tonnage is gross tonnage less deductions for space occupied by main engines, crew’s quarters, etc. It indicates approximate cargo capacity of the ship. _Table II. Capacities of Diesel-oil, fresh-water, and salt-water tanks_