On the Transverse Strength of Oil Tanker

under the Heeled Cordition

Abstract

In our previous paper, we had examined the strength of hull structure of an oil tanker under the several load conditions. These results are all coresponding to those under the upright conditions. While the ship is exposed to the various waves and winds generally in her service conditions. Consequently, live load due to the motions both of the water particles of the waves and of the ship is acting on the hull structure in addition to dead load. It is, therefore necessary that the strength of a ship is to be examined under such the load condition mentioned above.
The authors try to examine the strength of an oil tanker under the heeled condition applying the statical load for the basic study of this problems, that is,
(1) to deduce the method of the three dimensional strength calculation under the heeled condition,
(2) to compare the state of deformations and stresses under the heeled condition with heel angle of 20 degrees to those under the upright conditions, both in the still water.
(3) to compare the state of deformations and stresses under the Tank Test Condition to those under the Normal Ballasted Condition with heel angle of 20 degrees.
From this study we obtained the following results.
(1) Stresses under the heeled condition are greater than those under the up right condition in the lower part of the Trans. Ring at the immersed side. The ratio of increment of stress is about 1.21.3 times in the case of this study.
(2) The Tank Test Condition gives the stress in the Trans. Ring almost equal to those under the Normal Ballasted Condition inclined with heel angle of 20 degrees in still water. But the axial forces in the Struts of the Trans. Ring becomes 1.2 and 2 times larger than those under the Tank Test Condition.