design considerations for aluminum hull structures - Ship Structure ...

Rudder Assembly -carrier should be madethe following reasons:-72-The rudder and rudder stock of the aluminum bulkof steel, similar to that of the steel ship, for(a)(b)(c)An alwminum stock would have an excessively large diameter, tosuit torsional and bending loads, which wo-dd r=sult in anunfavorable aspect ratio for the rudder. In addition, steelsleeves would be required in way of the bearings to resistabrasion. Therefore a high-strength steel stock is consideredmore practical.The use of a steel stock dictates that the remainder of therudder be steel, to avoid problems of attachments of dissimilarmetals.The use of a steel rudder minimizes abrasion and vibrationproblems.The rudder stock should be isolated from the hull by the use of micarta orphenolic stave bearings. A cathodic protection system is also required,as discussed later. Details of the rudder bearing attachment to the hullwill be similar to Figure 14.//’ /“ /J1‘\ ‘\ \ \\’\ \‘~///“ ‘///////5I“I.=”:” .II!1—-..,— _~—-l 1 —.—FIG. 14 Stern Tube & Propeller Details M. V. C7mZZmgw