Case Studies: Marine Engines

SEMT-Pielstick Marine Propulsion Engines

As a result of accidental damage to the hull of 20,000 tonne ROR ferry while berthing under severe weather conditions, a tear in the port side plates allowed seawater to flood the engine room compartment.

During the process of assessing possible damage to machinery, Visiscope technicians were contacted to assist. As a result of the urgency, Visiscope technicians were on board the vessel within 2 hours of the call. The "brief" for the Visiscope technicians was to try to ascertain as to whether or not sea water had made ingress into the combustion chambers of the two main engines.

Working under adverse conditions & only temporary lighting, the camera inspection equipment was man handled into place and all 2 x 12 cylinder combustion chambers were viewed and recorded on video for the Marine project engineers.

The Visiscope technicians continued to work non-stop on board the vessel and into the night to complete their assigned task. In addition to finding the effects of sea water ingress, several "general wear & tear" defects were also captured on video.

The resulting inspection video and a comments spread sheet was able to be viewed at leisure by experienced marine engineers.

SEMT-Pielstick Marine Engine Inspection
(note the valve face obstructed in right image)

Marine Tug Engine Inspection

Visiscope were invited to demonstrate the application of a RVI camera with a view to the Tug operators considering including NDT as part of their extended engine operation between survey inspections.

The 5 meter length video scope unit was used to inspect two of the port main engine combustion chambers and the compressor inlet end of the P.E. turbo blower. Regretfully the inspection time available was reduced due to a change in port ship movement schedules.

After viewing the video several times, the engines were uncertain as to whether or not a premature exhaust valve failure was about to occur. However rather than remove the cylinder head, Visiscope technicians offered to carry out another inspection of the "suspect" combustion chamber.

The second inspection concentrated in more detail on the exhaust valves in the "open position". This then enabled the engineers to reassess their opinion and fortunately by comparing both sets of images, carbon deposits were determined as being the culprit and not "guttering" as originally thought.

The tug engineers are now considering other possible uses of NDT camera inspection techniques for thier maintenance program.

Marine Tug Engine Inspection
(Note the deposits on the valve seat in the right image)