92 



UNITED STATES COAST GUARD 



In checking a sliding watertight door 

 for closeness of fit in the closed posi- 

 tion, how would you make the check and 

 what should be regarded as the maxi- 

 mum allowable clearance? 



How should the wedges be adjusted 

 on a watertight door? 



When vessels are fitted with flat- 

 plate keels, how are they fitted inter- 

 nally so that they have vertical rigidity 

 in the keel structure? 



Describe briefly the causes of the 

 stresses that frames must withstand. 



What section of the Regulations con- 

 tains the minimum strength require- 

 ments for a vessel's framing? 



Where bilge piping of a passenger 

 vessel runs through a box or a duct 

 keel as illustrated, what provisions are 

 required to prevent flooding of the 

 holds in case of bottom damage? 



When testing bottom on new con- 

 struction or repairs, why must a slight 

 leak or "weep" be regarded as more 

 serious in a welded vessel than in a 

 riveted vessel? 



In drydocking a vessel not in level 

 trim, what stability and local pressure 

 problems may be encountered in: 



(a) a graving dock 



(b) a floating dock 



What is meant by the "faying" flange 

 of a frame in riveted construction? 



How has welded construction changed 

 the methods of constructing ship fram- 

 ing? 



On the sketch shown, identify "A" 

 and "B." 



What is the purpose of bilge keels? 



Do bilge keels affect a vessel's 

 stability? 



In repairing broken cleats for bat- 

 tens, what is the preferred method of 

 attachments to frame, "A" or "B"? 



A. 



Why is it important that the dock- 

 master of a floating drydock be in- 

 formed of a vessel's trim when the 

 vessel is being drydocked? 



What is the function of side keelsons 

 or longitudinal intercostals in the double 

 bottom of a vessel? 



Why is longitudinal framing usually 

 employed for tank vessels and trans- 

 verse framing used on freighters? 



Why are frames usually welded to 

 shell plating with intermittent rather 

 than continuous welds? 



In the illustration below is a deep 

 web frame with longitudinal frames 

 passing through the slots. Why should 

 the corners of the slot be rounded in 

 one case and holes drilled in the other 

 case? 



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How are the frames of a vessel num- 

 bered in usual practice? 



Where is the spacing between frames 

 measured, i.e., does the distance along 

 the shell plating between frames neces- 

 sarily represent the frame spacing? 



Describe the reasons why vessels con- 

 structed with welded frames are more 

 susceptible to impact damage in dock- 

 ing, etc., than vessels of riveted frame 

 construction. 



