PILLARS AND GIRDERS
1. What is the function of a pillar?
2. What is the relation between the load on a pillar and pillars' number?
3. What determines the dimensions of the pillars?
Every ship of large size is provided with pillars and generally with (longitudinal) girders for the purpose of supporting the deck under which they are fitted. A pillar is accordingly subjected to a buckling load, which increases with a lower position of the pillar or an increase of the cargoes weight. This load is further dependent on the number of rows of pillars and the ship's breadth. The greater this number, the breadth remaining the same, the smaller the load a pillar has to bear, and, conversely, the larger the ship's breadth, with an equal number of pillars, the more the load allotted to each pillar will increase. Finally, the pillars will take up heavier loads in the proportion in which their spacing as well as their length are increased.
Consequently, the ruling factors in the determination of the dimensions of the pillars are:
1) the type of deck;
2) the weight of the total load above the pillars;
3) the number of rows of pillars and the ship's breadth;
4) the spacing of the pillars;
5) the length of the pillars.
Pillars may be distinguished as pillars having a small spacing and the ones being widely spaced. Large vessels are often provided with widely spaced pillars. The head and heel of a pillar are designed so that they can be securely bolted or welded. In association with the pillars the deck beams are supported by longitudinal girders, passing along the lower sides of the beams.
Exercises and assignments
элементы одинарного дна включают флоры, кильсоны-стрингеры и киль.
III. Study the general arrangement drawing of a cargo vessel.
IV. Find on the diagram the items given in the unit vocabularies and give their definitions:
double bottom tanks
double bottom tanks
tank top (inner bottom)
|| machinery space
V. Get ready to speak of general arrangement of a ship.
Date: 2014-12-28; view: 1345