104 



UNITED STATES COAST GUARD 



When a passenger vessel is fitted with 

 watertight doors of sliding type, against 

 what list must the power or manually 

 actuated closing mechanism be effective? 



Why must watertight doors which 

 may be opened at sea below the sub- 

 division load line of a passenger vessel 

 be of the sliding type rather than of 

 the hinged type? 



What provisions to maintain water- 

 tightness must be taken when electric 

 cables penetrate a watertight bulk- 

 head? 



What provisions to maintain water- 

 tightness are necessary on passenger 

 vessels bilge piping when the piping is 

 located in a duct keel or within H of the 

 beam from the side of the vessel? 



In case of damage resulting in flood- 

 ing: 



(a) What may be the effect of 

 watertight longitudinal divisions? 



(b) What provisions may be made 

 in longitudinal bulkheads to partly over- 

 come this factor? 



What is a stepped bulkhead and what 

 precautions are necessary where one is 

 installed? 



State the usual minimum bulkhead 

 requirements for a seagoing freight 

 vessel of the United States. 



How could you check inner or outer 

 bottom plating for deflection due to 

 grounding, severe buckling or compres- 

 sive strains, pounding, etc.? 



What precaution is usual to prevent 

 contamination of fresh water double 

 bottom tanks by fuel oil and vice versa? 



What is the name of the first bulk- 

 head aft of the stem and what is its 

 purpose? 



What vessels are required by law to 

 have effective double bottoms? 



For deep tank bulkheads and tank 

 tops: 



(a) What tests are required? 



(b) What other test is sometimes 

 employed to check tightness? 



Where are panting beams or stringers 

 fitted and what is meant by panting? 



What are the functions of partial 

 bulkheads fitted in the cargo spaces of 

 a vessel ? 



What are the functions of pillars or 

 stanchions in a vessel's hold? 



In what part of the vessel may you 

 expect to find deep floors, and floors in- 

 creased in size or thickness to increase 

 their strength? 



When vessels have tanks for the car- 

 riage of bulk liquids, what measures are 

 taken to minimize the dynamic effect of 

 the liquid as the vessel rolls? 



What are the functions of a hold- 

 stringer? 



Why are many modern vessels built 

 without such stringers? 



State why the stringer plate is nor- 

 mally a very important structural part 

 of a vessel's deck which must resist the 

 greatest stresses to the deck structure. 



Why are deep tank bulkheads nor- 

 mally built with the stiffeners inside the 

 tank'? 



What are the three primary functions 

 of bulkheads? 



What advantage is gained through 

 the use of watertight longitudinal di- 

 visions in the double bottom tanks? 



How may fire alarm thermostats be 

 tested? 



How often should such fire alarm 

 thermostats be tested? 



What are the primary functions of 

 the deck or decks of a vessel? 



What protection against damage by 

 cargo or cargo gear should be provided 

 to hatch coamings? 



State what is meant by propeller 

 cavitation. What are the effects of 

 cavitation? 



Where vessels have little or no sheer, 

 what compensation is made to provide 

 extra buoyancy? 



Define boss plate, intercostal floor, 

 margin strake, gusset, and cant frame. 



Why are bilge drain wells located as 

 far outboard as practical? 



What is the purpose of peening the 

 successive beads of weld deposited after 

 each pass when making a weld in heavy 

 plating? 



What is the purpose of preheating 

 heavy sections of steel prior to welding? 



Describe in detail the construction of 

 a portable magazine chest for the car- 

 riage of rockets, flares, lyle gun black 

 powder, and other ship's stores of an 

 explosive nature. 



When vessels are provided with 

 forced-air ventilation for quarters, what 

 provisions are usually made to prevent 

 air-ducts, diffusers, etc., becoming filled 

 with dust? 



If a clinometer in the wheelhouse is 

 used to determine the number of degrees 

 a vessel is rolling, why might it show a 

 greater than actual figure? 



