Risk Evaluation (Stationary Applications)

In order to support our customers to evaluate the individual risk arising from the turbocharger for their specific application and to provide them with a basis for appropriate decisions about suitable measures to enhance containment safety, we have carried out a risk ananlysis for each individual turbocharger type. The methodology of the risk analysis in hand is on the basis of an analysis that FutureShip (a company of Germanischer Lloyd) has carried out in the authority of MAN Energy Solutions for marine applications.

Methodology of Risk Analysis

The annual fatal risk of an individual operation and maintenance staff member due to a turbocharger containment failure has been estimated. Therefore, the failure probability of the containment is combined by the proportional person’s exposure time in the endangered area where a person is possibly affected (also considering off-times). These values were estimated for each turbocharger type and application within typical engine room arrangements and operational profiles. As each individual containment failure will only affect a part of the endangered area it is assumed that 20% of the person’s time within this area he is located in a position where scattering debris would have fatal impact.

Formula Determination of Risk

Individual risk _{T/C, Appl.} = Failure probability _{T/C, Appl.} x Individual presence rate in endangered area _Appl. x 0.2

Explanation of factors

Individual risk _{T/C, Appl.}

The annual fatal risk for an operation and maintenance staff member, caused by one turbocharger of specific type and application.

Failure probability _{T/C, Appl.}

Annual probability of containment failure of one turbocharger of specific type and application. Number of recorded containment incidents observed in the field for this type and application of turbocharger, divided by the cumulated operating years. In case the annual failure probability of a turbocharger type and application is either zero or the population is too small, the value for the corresponding series is used instead.

Individual presence rate in endangered area _App.

Average time of an individual operation and maintenance staff member in the endangered area, i.e. where fatal injury is possible in case of a containment incident. Off times are considered within the individual presence rate. The underlying individual presence rate for 4-stroke stationary engine is between 6.25% and 12.5%. Please note that a specific turbocharger application might deviate from these values.

0.2

This factor is the fatality rate, i.e. the probability that a person is affected by actual turbocharger destruction scenario, when such failure occurs and when the person is located in the endangered area.

Risk values per turbocharger type and operation and maintenance staff member

The individual risk values for the turbochargers per operation and maintenance staff member consider the average length of stay of a person (favorable case and conservative case scenario) in the hazardous area.

The defined presence rate of the individual person in the endangered area for the stationary engines is:

• 6.25% (favorable case scenario) – 12.5% (conservative case scenario)

Please note that containment tests at MAN’s test facilities have shown a loss of containment in high load situations also for turbochargers with relatively low risk statistics based on observed cases or without any containment incident in the field.