Newly Commissioned USS Milwaukee Breaks Down at Sea

By ThinkReliability Staff

On December 11, 2015, just 20 days after commissioning, the USS Milwaukee completely lost propulsion and had to be towed back to port. This obviously brought up major concerns about the reliability of the ship. Said Senator John McCain (R-Arizona), head of Senate’s Armed Services Committee, “Reporting of a complete loss of propulsion on USS Milwaukee (LCS 5) is deeply alarming, particularly given this ship was commissioned just 20 days ago. U.S. Navy ships are built with redundant systems to enable continued operation in the event of an engineering casualty, which makes this incident very concerning. I expect the Navy to conduct a thorough investigation into the root causes of this failure, hold individuals accountable as appropriate, and keep the Senate Armed Services Committee informed.”

While very little data has been released, we can begin an investigation with the information that is known. The first step of a problem investigation is to define the problem. The “what, when and where” are captured in a problem outline, along with the impacts to the organization’s goals. In this case, the mission goal is impacted due to the complete loss of propulsion of the ship. The schedule/production goal is impacted by the time the ship will spend in the shipyard receiving repairs. (The magnitude and cost of the repairs has not yet been determined.) The property/equipment goal is impacted because metal filings were found throughout both the port and starboard engine systems. Lastly, the labor and time goal is impacted by the need for an investigation and repairs.

The next step of a problem investigation is the analysis. We will perform a visual root cause analysis, or Cause Map. The Cause Map begins with an impacted goal and asking “why” questions to diagram the cause-and-effect relationships that led to the incident. In this case the complete loss of propulsion was caused by the loss of use of the port shaft AND the loss of use of the starboard shaft. The ship has two separate propulsion systems, so in order for the ship to completely lose propulsion, the use of both shafts had to be lost. Because both causes were required, they are joined with an “AND”.

We continue the analysis by continuing to ask “why” questions of each branch. The loss of use of the port shaft occurred when it was locked as a precaution because of an alarm (the exact nature of the alarm was not released). Metal filings were found in the lube oil filter by engineers, though the cause is not known. We will end this line of questioning with a “?” for now, but determining how the metal filings got into the propulsion system will be a primary focus of the investigation. The loss of use of the starboard shaft occurred due to lost lube oil pressure in the combining gear. Metal filings were also found in the starboard lube oil filter. Again, it’s not clear how they got there, but it will be important to determine how the lube oil system of a basically brand new ship was able to obtain a level of contamination that necessitated full system shutdown.

While metal filings in the lube oil system is not a class-wide issue, it’s not the first time this class of ship has had problems. The USS Independence and USS Freedom, the first two ships of the class, suffered galvanic corrosion which caused a crack in the Freedom’s hull. The Freedom also suffered issues with its ship service diesel engines, a corroded cable, and a faulty air compressor.

Once all the causes of the breakdown are determined, engineers will have to determine solutions that will allow the ship to return to full capacity. Additionally, because of the number of problems with the class, the investigation will need to take a good look at the class design and manufacturing practices to see if there are issues that could impact the rest of the class going forward.

To view a one-page downloadable PDF with the beginning investigation, including the problem outline, analysis, and timeline, click “Download PDF” above.