The marine industry can improve its performance in designing systems, subsystems and components on which its operations depend on by using risk-based methods and tools. In an environment of increasingly complex engineering systems and structures, the concern about the operational safety of the latter continues to play an important role in their design, construction and operation procedures. A rational and quantitative approach for assessing the failure probabilities and the impact of failure of the structure on its environment (human beings, natural environment) is needed. [Read more…]
Ship’s Geometry and Hull Definition
February 9, 2012 by 3 Comments
The form of a ship’s hull can determine the majority of its attributes; stability characteristics; resistance etc. As a result the power needed for a certain speed can also be determined along with the ship’s seaworthiness; maneuvering capabilities and load carrying capacity.
Figure 1 – Ship’s Principal Dimensions
Aluminum Alloys MIG Welding Procedure Instructions
February 8, 2012 by 2 Comments
1. Base-metal preparation:
To weld aluminum alloys, operators must take care to clean the base material and remove any aluminum oxide and hydrocarbon contamination from oils or cutting solvents or NC machines coolants. Aluminum oxide on the surface of the material melts at about 2035o C while the base-material aluminum underneath will melt at 650o C. Therefore, leaving any oxide on the surface of the base material will inhibit penetration of the filler metal into the work piece. To remove aluminum oxides, use a stainless-steel bristle wire brush (and/or grinding) or solvents and etching solutions. If grinding is used for cleaning/preparing weld areas it should be paid attention to the brand used since some grinding wheels use an organic binder that leaves a residue behind, that will possibly cause weld porosity. Thus, it is recommended to test the particular brand of grinding wheels before actual use, in a welding test work piece
Officer of the Watch 