to the difficulty of handling gear and, most important of all, hampers the conduct of even the 

 most routine scientific work. In addition it might be mentioned that for certain types of work 

 it would be a great advantage to be able to control the heading of the ship at speeds below 

 steerageway and even while lying to. 



Precise criteria for satisfactory performance do not exist, but there is obvious benefit 

 in a vessel which will permit operations which have previously been prevented by a state 5 sea. 



PROPOSED HULL DESIGN 



A hull which has been proposed to meet the many and diverse requirements of ocean- 

 ographic research was designed by CDR R.T. Miller, USN. The lines and outboard profile are 

 shown in Figure 1 and several views of a 5-foot model of this vessel are shown on Figure 2. 

 Pertinent design particulars are listed in Table 1. 



TABLE 1 



Design Characteristics of the Oceanographic Research Vessel 



Length, overall, feet 





181 



Length, waterline, feet 





170 



Length between perpendiculars, feet 





163 



Draft (design waterline), feet 





14.75 



Displacement (design waterline), tons 





1000 (salt water) 



Design speed'(still water), knots 





12 



Longitudinal prismatic coefficient C p 





0.53 



Coefficient of maximum sectional area 



°x 



0.80 



Block coefficient C B 





0.423 



Ratio of ship length to maximum beam 



L/B 



5.2 



Ratio of maximum beam to draft B/H 





2.2 



The values of C x , C B , L/B, and B/H are typical of tugs and trawlers of the same 

 approximate size as the proposed ship; the same is true of the deadrise. 



The level of the forecastle deck terminates farther forward on the starboard side than 

 on the port side; see Figures 2a and 2b. This affords 100 feet of clear working space on the 

 starboard side for streaming equipment. The rubrail on the starboard side is faired into the 

 hull down to the waterline, starting at the after end of the deck house and extending forward 

 some 14 feet. This arrangement preserves the function of the rubrail without offering an 

 obstruction to gear being worked overside. 



The model was ballasted to the design waterline to give a radius of gyration of 0.22 L, 

 resulting in a pitching period (determined experimentally) of 0.738 seconds or 4.3 seconds 

 full scale. The figure 0.22 L for the radius of gyration is somewhat smaller than that usually 



