Marine Losses

Vessel Engine Seawater Pump Failure Analysis

 

Background Information: A marine loss required the specific expertise of Forensic Analysis & Engineering Corporation and its subsidiary, Forensic Marine Investigations (FMI), dedicated to this case. When a client’s vessel took on water and became partially to fully submerged, instigating significant property loss, it prompted the subject claim investigation. Once the water pump was identified to have a significant crack in this plastic housing cover, it was removed and forwarded directly to FMI for forensic inspection. The client decided to consult the experts at Forensic Marine Investigations for our specialized knowledge to help ESTABLISH WHY the engine water pump failed.

 

Assigned Task: The assigned task was to examine a supplied marine engine water pump housing and to determine if possible the specific causation(s) of its failure. An FMI expert was readily available to assist in the case.

 

Observations and Findings: The following investigative findings and conclusions are presented based upon our visual and microscopic examination of the subject water pump housing.

 

              1. FMI found that the subject water pump housing was cracked in a rather ‘U’

                  shaped pattern and that it originated near the top of the pump’s molded plastic

                  impeller housing cover.

              2. Our examination of the positioning of the bolt holes in the molded plastic impeller

                  housing cover to what it was mated, found that due to the holes slight

                  misalignment.

              3. Additionally, the repetitive and cyclic vibrations that are developed during the

                  course of the normal operation of the engine would in and of themselves induce

                  additional stresses into the tightly bound casing.

              4. The instigation of cyclic loading into a prestressed molded plastic housing that

                  has by design inherent areas of high stress concentrations resulted in the

                  instigation of a fracture in the one of the square cornered areas within the

                  molded piece.

              5. While the bending stress that was applied to the housing cover when it was

                  bolted down each time added to the strain being applied to the cover, they in of

                  themselves did not cause the fracture. The repetitive stresses instigated from

                  cyclic loading during normal engine operation are also only contributors to the

                  final failure.  In our opinion the primary cause of the subject failure is a design and

                  manufacturing defect that resulted from the use of the subject part with highly

                  stressed square versus rounded surface junctures.

 

Results of the Investigation: Forensic Analysis & Engineering was able to ESTABLISH WHY the engine pump failed, ESTABLISHED WHY each of the damages occurred and whether or not it was attributed to the catastrophe.

 

Contact Forensic Analysis & Engineering Corporation to investigate your maritime loss at (800) 224-3595 or directly submit an assignment online.

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