SPECIMEN EXAMIXATIOX FOR MASTER 



89 



22. SIGNALING BY INTERNATIONAL CODE FUGS, 

 FLASHING LIGHT!; 

 LIFESAVING, STORM, AND SPECIAL SIGNALS. 



What are the signals for vessels and 

 aircraft in distress on the water which 

 are provided by the International Rules 

 of the Road? 



Describe the care necessary when 

 using the ship's whistle for sending 

 Morse Code messages by sound. 



Show precisely how you would signal 

 the following: 



(a) Bearing due North. 



(b) Five minutes past midnight. 



(c) Latitude 3° North. 



(d) Longitude 86°-07' West. 

 What signals are provided by the In- 

 ternational Rules of the Road for an 

 aircraft to indicate that she is in dis- 

 tress and requires assistance? 



What information should be included 



in a distress message sent by radio? 



Who is responsible for control of dis- 

 tress traffic over the airwaves when a 

 distress message has been sent? 



What are the signals used in radio- 

 telegraphy and radiotelephony for dis- 

 tress, urgency, and safety traffic re- 

 spectively; and what is the purpose of 

 these types of signals? 



What is the duty of a vessel's officers 

 upon encountering any vessel or air- 

 craft at sea displaying or transmitting 

 any of the distress signals provided by 

 the International Rules of the Road? 



How is accurate reception assured 



when numbers are transmitted by flash- 

 ing light? 



23. STABILITY AND SHIP CONSTRUCTION. 



Given the following data : 



Weight 

 Tons 



Light Ship (including crew 



and stores) 4,000 



No. 1 hold 1,000 



No. 2 hold 2,000 



No. 3 hold 1,000 



No. 4 hold 2,000 



No. 5 hold 500 



Fuel oil and water 500 



Displacement: 11,000 Tons. 



Vertical distance from keel to meta- 

 center at displacement of 11,000 tons is 

 26 feet. 



Moment to trim one inch at displace- 

 ment of 11,000 tons is 1,000 ft/tons. 



Mean draft at displacement of 11,000 

 tons is 25 feet. 



Longitudinal Center of Buoyancy at 

 displacement of 11,000 tons is 223.6 feet 



from the forward perpendicular 

 level trim). 

 Free surface correction is .7 foot. 



(at 



Required : Metacentric 

 rected for free surface. 



height cor- 



The forward and after draft, (as- 

 suming the tipping center is located at 

 the mid-length of the vessel). 



How are double bdttom tanks tested 

 for tightness? 



What is the total upward force on a 

 double bottom manhole cover of 200 

 square inches of area when fresh water 

 to a height of 20 feet above the tank 

 top is standing in the sounding pipe? 



Note : Fresh water weights .433 pounds for a 

 column one foot high and one inch in area at 

 the base. 



A vessel concerned with her stability 

 at departure checks it by lifting with 

 her booms a total of 40 tons, with the 

 boom heads 50 feet from the center line. 

 The clinometer is then carefully read 

 and shows a list of 5°. At the same time 



the ship's displacement is 8,000 tons 

 including the suspended weights. 



(a) What is her GM corresponding 

 to this condition? 



(b) If the 40 tons is stowed 25 feet 

 below the boom heads, what will the GM 

 be? 



Why is it desirable that the valve 

 operating rods on tank vessels be made 

 of solid rod rather than of pipe or 

 other hollow material? 



How are the decks of tank vessels 

 fitted to prevent leakage of gas or 

 vapor where valve operating rods pass 

 through? 



690-515 O - 63 - 7 



