Strength Of Underwater Fillet Welds

The strength of a completed weld joint may well become the most important factor in the success of an entire salvage operation. The loading on a member, such as a padeye, involves both static and dynamic forces. Dynamic loading may be a combination of tension, compression, shear and bending. Because there is always some doubt concerning the magnitude of loading, a safety factor of six is used in calculating the required length of a fillet weld, which in turn determines the strength of the weld.

The second factor is the overall length of the fillet weld. In many cases, this will be determined by the size of the patch or work in question. However, if in doubt, use the 1,000 pounds per linear inch as a safe guideline. For example, a padeye for a 10-ton load will require 20 linear inches of fillet weld, as shown below: Before going into actual welding procedures, a few word of definition are required. The primary application for wet welding is the fillet weld. Groove welds may also be worked. For best results when welding a groove weld, a backing strip should be used.