Hanwha Ocean (then Daewoo Shipbuilding & Marine Engineering) has discovered defects in the pipes of the Daegu-class (3,100 tons) patrol vessel, with efforts underway to determine responsibility. The problematic pipe was made of stainless steel instead of the previously designed copper-nickel alloy, and there are conflicting claims about whether Hanwha Ocean consulted with the Defense Acquisition Program Administration (DAPA) when changing the design.
According to military and defense industry sources on the 21st, the defect in the Daegu-class patrol vessel arose from a hole in the pipe that penetrates the fuel tank. This pipe developed a hole due to the passage of a large amount of seawater, and the leaked seawater is reported to have entered the fuel tank, causing the issue. Similar problems have been reported in several of the eight Daegu-class patrol vessels.
Daewoo Shipbuilding & Marine Engineering, the predecessor of Hanwha Ocean, had specified the use of copper-nickel alloy in the design, but it was changed to stainless steel during construction. One of the patrol vessels with problems used a different type of stainless steel (SUS304L) instead of the stainless steel (SUS316L) that Daewoo Shipbuilding & Marine Engineering had chosen when altering the design.
Hanwha Ocean referred to the use of a different type of stainless steel as a "mistake by a partner company"; however, both types of stainless steel failed to withstand seawater, resulting in holes and the mixing of seawater with fuel. The reason for not using the copper-nickel pipe was noted as a choice made to prevent contamination of the fuel.
The emergence of the same problem in patrol vessels not constructed by Hanwha Ocean has raised the issue of who will bear the repair expenses. To determine precise responsibility, DAPA, which oversees the project, is examining whether the process of changing to stainless steel was carried out properly. Approvals from DAPA are required when altering the design of weapon systems. The agency responsible for managing the configuration of defense items is DAPA. Configuration management refers to identifying the characteristics of defense items, controlling technological changes, and maintaining various records.
Hanwha Ocean claims that it received approvals from the Defense Technology Quality Assurance Agency (DTQA) and DAPA when changing the original design's copper-nickel alloy pipes to stainless steel. A Hanwha Ocean representative stated, "We submitted all materials related to the change of pipe material to DTQA and DAPA at that time and received approval." However, a military representative noted, "No separate consultations took place when changing the pipes."
Generally, the scope of changes in materials is defined during the design contract process; however, industry sources explained that projects do not always proceed as per the initial agreement, leading to consultations with DAPA. DAPA is also reported to be reviewing past contracts made with Daewoo Shipbuilding & Marine Engineering for clearer judgments. A DAPA representative commented on this matter, stating, "We are making a legal judgment regarding the cause of liability."