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and torsional vibration due to a torsional that’s taught in the classroom. It requires the most satisfaction, and why? business and experience behind us, we coupling which is beyond its service life, a combination of knowledge, training It is rewarding as an engineer to diag- have been able to solve a lot of problems has failed or is about to. and hands-on, real world experience. nosis and solve complex vibration prob- with the resources available to us and lems. It is also very rewarding to mentor improve our customers operations and

Can you describe one problem that Looking back on the ? rst quarter cen- our younger employees. Sometimes it maintenance.

you found most challenging to solve, tury in business, in what do you take takes perseverance, but with 25 years of with insights on how the problem was detected, analyzed and ? xed?

One of my ? rst customers was a large, well-known cruise line. It was their ? ag- ship vessel, the ? rst one they had built, and they had a complaint about a loud high pitch noise coming from the shaft- line, following a dry docking, which they perceived as being a defective shaft bearing. I attended the vessel and was able to immediately diagnose it as a “singing” propeller. The propeller blade resonance was being excited by the vor- tices coming off the trailing edge of the blades. I recommended the divers grind an anti singing edge on the blades, which corrected the problem. However, while

I was there, I noticed an exceptional and extreme vibration coming from the shaft generators which were driven by a pinion shaft which was integral with the propeller shafting. I came to ? nd out that this had been an issue since the vessel was built, and resulted in catastrophic failures of the pinon shaft, rendering the shaftline inoperable and involving costly and time-consuming repairs. Vibration analysis showed a structural resonance problem of the propeller line shaft bear- ings. Further inspection revealed that additional structural reinforcement was needed in the double bottom to stiffen the tank top where the bearings were mounted. We were able to work together with a ship repair ? rm that welded in the appropriate structure while we moni- tored the position of the shaft bearings with precision lasers, so to maintain the shaft alignment and control the welding heat distortion. The result was a signi? - cant drop in vibration of the line shaft bearings and a happy and impressed cus- tomer.

Innovation that shapes tomorrow

What do you consider to be your big- gest challenge in running an ef? cient,

Marine Jet Power is a leading supplier of pro? table business?

We are in a technology intensive busi- waterjet propulsion for small craft and larger ness, using lasers alignment systems ships – the ?rst in duplex steel mixed ?ow jets.

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constantly upgrading and purchasing new equipment to better our services.

It is both challenging and exciting to be on the leading edge, but there is a huge learning curve when becoming pro? - marinejetpower.com cient in the services we provide and equipment we use. It’s not something www.marinelink.com 45

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