SPECIMEN EXAMINATION FOR SECOND MATE 



51 



You are required to supervise the 

 stowage of two consignments of butter 

 contained in cases as sketched. Describe 

 the difference in the manner of stowage 

 required for each lot. 



An oil hose has an inside diameter of 

 8 inches. What is the minimum radius 

 to which the hose should be bent? 



Your reading of a combustible gas in- 

 dicator showed that less than 0.1 per- 

 cent petroleum vapor was present in a 

 tank that had been used for sour crude 

 (containing hydrogen sulfide, H2 S). 

 Would you consider the tank safe as far 

 as toxicity and explosibility are con- 

 cerned ? 



Describe the hazards that may be in- 

 volved when working in tanks that have 

 carried gasoline having a tetraethyl 

 lead content. 



Where shifting boards are rigged for 

 a grain cargo : 



(a) Would you regard wooden 

 shores "A," "B," or "C" as most ef- 

 ficient? 



(b) Why? 



(c) What compensation is made 

 for inefficient positioning of shores? 



'hose dlaneter 



radius of 'bend 



When gas-freeing a tank vessel, what 

 precaution must be taken with respect 

 to vent lines, heating coils, steam 

 smothering lines, and loading and dis- 

 charge piping? 



When a centrifugal pump is operat- 

 ing with a suction lift : 



(a) what care is necessary? 



(b) What is the maximum suction 

 lift possible? 



Describe the proper manner of read- 

 ing the thermometer shown, when deter- 

 mining the temperature of a liquid 

 cargo. 



