SPECIMEN EXAMINATION FOR THIRD MATE 



15 



Would you drive in wooden wedges 

 with the smooth grain parallel to the 

 cleat as in Figure "A" or with the 

 smooth grain parallel to the batten as 

 shown in Figure "B"? Why? 



Name three types of pumps used in 

 the handling of liquid cargo. 



When using turnbuckles for securing 

 gear, particularly where the turnbuckles 

 are inaccessible for routine inspection, 

 what precautions should be taken to 

 insure that the turnbuckle does not 

 back off? 



Is a hook or a shackle of the same 

 size stronger? 



Give two good reasons why wire rope 

 cargo falls, topping lifts for booms, and 

 other wire rope gear should be lubri- 

 cated periodically. 



What is the minimum size block you 

 would use with a specified size of ma- 

 nila rope? 



What is the minimum size block that 

 should be used for a 3" manila rope? 



What is the minimum diameter 

 sheave that should be used with a 3" 

 manila rope? 



When a vessel is fitted with sideports, 

 what precautions must be taken to as- 

 sure that they are accessible for being 

 secured, and for inspection at sea? 



How are sideports usually secured? 



If the warranted breaking strength 

 of a wire rope is divided by the safety 

 factor required for a particular applica- 

 tion, the result is known as the 



This question may 



be stated also as follows : 



BS = ? where BS = breaking strength 



FS FS = factor of safety 



Some grades of sisal rope are listed 

 by their manufacturer as having 80 

 percent of the strength of the same size 

 manila. For a certain sling, a 3 inch 

 manila line was necessary. What size 

 sisal would you use for the same sling? 



If the 3 inch manila was used for 

 2000 pounds of weight, what weight 

 would you lift with 3 inch sisal having 

 80 percent of the strength of manila? 



What precautions must be enforced 

 by ship's officers when working cargo 

 at a hatch with only part of the port- 

 able hatch beams or pontoons removed? 



On freight vessels what is the pur- 

 pose of the wooden ceilings under the 

 square of a hatch? 



What precautions should be taken 

 with wet manila rope? 



Does a splice or a knot weaken a 

 manila line more? 



What is a preventer stay and how is 

 it rigged? 



Name at least five factors that make 

 an adequate factor of safety necessary 

 on any wire rope purchases or topping 

 lifts. 



Describe the proper method of open- 

 ing and uncoiling a new manila line. 



Using the formula B = C x 900, 

 where "B" is the breaking stress in 

 pounds and "C" is the circumference, 

 compute the breaking stress of a 3 inch 

 manila rope. 



How is the draft of a vessel affected 

 when passing from salt to fresh water? 

 Give reasons. 



What precautions must be taken with 

 respect to stuffing-boxes and glands on 

 pumps when discharging petroleum 

 cargoes? 



What precautions should be taken 

 when using a spray gun for painting? 



A sling is rigged on a piece of pipe 

 weighing 1,000 pounds. What stress is 

 exerted on each sling leg when the pipe 

 is lifted? See sketch below. 



