Components redundancy Components redundancy in power and propulsion systems in power and propulsion systems installed onboard platform supply vesselsinstalled onboard platform supply vessels

RISK, QUALITY AND RELIABILITY – RQR ‘07September 20-21, 2007

Technical University of Ostrava, Czech Republic

Dr inż. Leszek Chybowski

Prof. dr hab. inż. Zbigniew Matuszak

Mgr inż. Paweł Pełka

Minutes of presentationMinutes of presentation

Dynamic positioning (DP) systems classification

Platform supply vessels characteristics

Power and propulsion plants characteristics

Propulsion and power plants components redundancy

Final conclusion

Dynamic Positioning Class 1 Dynamic Positioning Class 1 ((IMO MSC/Circ.645IMO MSC/Circ.645))

(A. J. SØRENSEN 2004)

Dynamic Positioning Class Dynamic Positioning Class 22 ((IMO MSC/Circ.645IMO MSC/Circ.645))

(A. J. SØRENSEN 2004)

Dynamic Positioning Class Dynamic Positioning Class 33 ((IMO MSC/Circ.645IMO MSC/Circ.645))

(A. J. SØRENSEN 2004)

Characteristics Vessel of UT 755 Design

Vessel of UT 755 L Design

Main ParticularsLOALPPBreadth MouldedDepth Main DeckMin DraughtMax DraughtDWT (max draught)GRTNet Tonnage

67,0 m61,8 m16,0 m7,00 m4,80 m6,00 m3000 t2237 t951 t

71,9 m66,8 m16,0 m7,00 m3,80 m5,83 m3084 t2401 t1069 t

PerformanceMax speedFuel consumption per day

14, 7 knotsSailing: 18 t @ 14,7 knotsStandby: 4 tIn port: 1 t

14,2 knotsSailing: 18 t @ 10 knotsStandby: 4 tIn port: 1 t

Machinery and Propulsion Main Engines

Auxiliary EnginesEmergency

Generators

Shaft Generators

Main PropellersTunnel Bow ThrustersAzimuth Bow

ThrustersTunnel Stern ThrustersRudders

2 x Rolls-Royce Bergen, 5450 BHP

2 x 250 kW, 450 V, 60 Hz1 x 48 kW, 450 V, 60 Hz2 x 1600 kVA, 380-450 V,

60 Hz2 x CPP1 x 800 BHP1 x 800 BHP1 x 800 BHP2 x HighLift

2 x Rolls-Royce Bergen, 5450 BHP

2 x 320 kW, 450 V, 60 Hz1 x 65 kW, 450 V, 60 Hz2 x 1600 kVA, 380-450 V,

60 Hz2 x CPP2 x 800 BHPN/A2 x 800 BHP2 x HighLift

Dynamic PositioningDP systemDP ReferencesJoystick

DP II – Kongsberg Simrad SDP21

2 x DGPS, 1 x Fan Beam, 1 x IALA Land Station

Fitted

DP II – Kongsberg Simrad SDP21

2 x DGPS1 x Fan Beam, Fitted

Analysed vessels characteristicsAnalysed vessels characteristics

Power and propulsion plants configurationPower and propulsion plants configuration

UT 755 L hull designUT 755 hull design

z(X,t) - complex number plane position for system X is:

where: p(X, t) - number of basic components r(X, t) - number of standby components i - imaginary unit

For a given moment of time t≥0 the total number of components J(X,t) in the system X equals:

where: J(X,0) - size of the system X at t=0 JREST - number of components of the system X that have been failed till the time t.

Redundancy in different DP classesRedundancy in different DP classes

Components redundancy in Components redundancy in power and propulsion plant systemspower and propulsion plant systems

ES1-1 – DP control unitES1-2 – DP supervision stationES1-3 – manual control system ES2-1 – main generator setsES2-2 – main switchboardES2-3 – gensets auxiliary systemsES2-4 – mains switchboard busesES3-1 – ship’s main propulsion unitES3-2 – main propulsion rudderES4-1 – uninterrupted power supplyES4-2 – battery setES4-3 – emergency power plantES5-1 – gyrocompassES5-2 – anemometer

For the subsystem X with a threshold k-out-of-n structure composed of identical components EX the system reliability is:

For the threshold structure k-out-of-n composed of components E1, E2,…En with various reliability characteristics system reliability is:

Reliability calculation based on redundancy modelReliability calculation based on redundancy model

Reliability calculation Reliability calculation for for DPDP thrusters thrusters (for(for exponentional failures distribution and exponentional failures distribution and generic datageneric data))

Final conclusionFinal conclusion

Component redundancy model allows to compare different redundancy classes (DP Classes)

Component redundancy model allows to compare different systems in same redundancy class

Component redundancy model allows to number of transformations and particular measures estimation

There is possibility of application of redundancy model for reliability estimation

Thank you for attentionThank you for attention