Underwater Welding: Joint Fit-Up

Since most underwater tasks are more cumbersome than similar topside work, the proper positioning of large members or plates underwater for welding is also quite difficult. Understanding properly the skill of underwater welding joint fit-up is therefore important. Positioning and fitting must be done with thoroughness and care to ensure a satisfactory weld. In underwater … Read more

Underwater Welding Overview

In underwater welding, the installation of large patches, as well as the attachment of suitable pad-eyes presents a more complicated problem to the diver than does the underwater cutting. Considerable practice is necessary to achieve a consistently good standard of underwater welding for salvage work. As a result, the diver’s underwater welding techniques must conform to … Read more

Underwater Welding: Shipbuilding Materials

The underwater welding diver should be familiar with the different types of steel used in shipbuilding in order to select the appropriate welding electrodes. Today shipbuilders have a wide range of steels that are used in the construction of ship’s hulls and superstructures. Quite often, ship hulls are comprised of more than one type of … Read more

Underwater Cutting Oxygen Purity: Grounding the Work

Underwater Cutting Oxygen Purity The oxygen purity for all underwater oxygen cutting should be 99.5 percent or greater. As the oxygen purity is reduced, so is the cutting efficiency. A one percent decrease in oxygen purity will result in a 25 percent reduction in cutting speed. In addition, the quality of the cut decreases, and … Read more

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 … Read more

Conditions Adverse To Underwater Welding

Before welding operations are started, the job should be inspected to determine whether or not the welding can be performed effectively at the worksite. Satisfactory underwater welds are more difficult than welds laid down topside. The following factors make underwater welding difficult: a. Diving apparelb. Where a steady platform cannot be provided from which to … Read more

Underwater Welding Shielded Metal Arc Welding

There are two basic techniques used today in shielded metal arc wet welding: the self-consuming technique and the manipulative or weave technique. With the self-consuming technique, the electrode is dragged across the work and a significant amount of pressure must be applied by the diver. With the manipulative technique, the arc is held as it … Read more

Underwater Welding

Although underwater welding does not have as many applications in marine salvage operations as underwater cutting, underwater welding is an extremely important and useful process. By substituting welding for mechanical methods of joining, the overall cost and time spent on the job can be reduced considerably. Historically, most underwater welding was done for the purpose of making … Read more

Underwater Cutting & Welding

Oxygen arc cutting Steel-Tubular Electrodes  Oxygen arc cutting Steel-Tubular Electrodes The oxygen arc cutting steel-tubular electrode consists of a steel tube with a waterproofed  flux coating which is applied during the manufacturing process. The electrode is 14 inches long with a 5/16-inch outer diameter and a bore diameter of slightly less than 1/8 inch. The… Read … Read more