Case study

Investigation of ship propeller shaft vibration related failures

We provided our client with insight and understanding to inform its investment decisions on maintenance of propeller shaft components.

Our expertise across a wide range of technical disciplines provided our client with the insight and understanding necessary to make key investment decisions on maintenance, to reduce risks and cost of ownership of propeller shaft components on its ship.

Our customer had been experiencing an increasing frequency of defects and failures of a wide range of components along the ship’s propeller shaft systems. We quickly got to grips with the complex shaft dynamics and provided the customer with a range of options to resolve its issues, catering for its operational and budgetary constraints.


Our systems engineers assisted in the collection of  data relating to the failures and defects associated with the  plummer bearings, ‘A’ bracket bearings, Prime Movers, propellers, couplings and bulkhead penetrations. Our noise and vibration experts then set to work to define and execute multiple trials to measure shaft dynamic behaviour whilst alongside, underway and in dock.


We generated a simple but effective shaft dynamic response model using our proprietary AUSRAT software tool. This enabled a wide range of model permutations to be analysed rapidly. The AUSRAT model was validated initially against a more complex finite element analysis model, until  trials data was available to corroborate the predicted dynamic behaviour of both models.

We used both the dynamic models and analysis of the trial data, including modal analysis measurements, to develop an understanding of the dynamic response behaviour of the shaft systems, and the sensitivity to numerous parameters relating to various components of that shaft system.


We identified the likely causes of the problems experienced and set out a range of remedial design measures’ options, as well as providing operational advice for mitigating the risk of further defects.

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