Bibby Topaz Incident, 18th September 2012

Dynamic Positioning (DP) Control System

Scope of Work• 18 September 2012

• Working 262ft underwater at the Huntington oil field(in the United Kingdom's central North Sea area) ; on a Drilling template.

• Vessel set up west of template.

• Pressure testing.

• Christ Lemons & Dave Yuasa were the divers involved.

Key Details• A series of alarms sounded; amber and red.

• Red alarm was activated and vessel had to abandon its current position.

• Divers were instructed to get back to the bell stage.

• Mr. Lemons had his umbilical snagged on a transponder bucket and eventually severed, losing air and hot water.

• Mr. Lemons managed to climb onto a platform and sustained with emergency bailout bottle.

• Mr. Lemons was eventually recovered by Dave Yuasa and regained consciousness.

Underlying Causal FactorsBased on investigations carried out, it is determined that RBUS jammed as a result of a rare sequence of events involving the combined effects of faults in one or more RBUS I/O modules in the DPC cabinet.

Faults found included;

• Loose / intermittent connections of fuse in DPC cabinet.

• Grounding; current was measured in the bound from the RCU units to ground.

• Inner shield on field cables not connected to instrument earth.

• DPC cabinet not earthed to ship hull structure.

Contributing Causal factors Failed to piroritise the usage of Cjoy joystick systems when the DP System failed.

cJoy control system - It shall be possible to control the thrusters by the independent joystick in the event of failure of the DP control system.

• At 24:08 – 24:33 of the video, Mr. Eric Strand, the chief officer mentioned that the team had tried to reset the DP system, they went from manual to DP control, and repeated the process 2-3times( it would take about 10mins) , and the next natural step would be to go to the independent joystick system.

• He asserted that no one would be able to confirm that the system was not affected by the fault they got from the DP system and eventually went straight to manual control.

• Therefore , the contributing factor would then be the failure in prioritising the usage of the joystick system, and they had wasted their time restarting the DP system initially. In addition , they could have restarted the DP system while controlling the joystick system.

Preventative Measures• The watchdog functionality self-test function allowing unit to recognise jamming fault (and provide diagnostic coverage for other CPU faults).

• Provides module isolation should any of these faults occur & is capable of removing the unit from the network in case of similar malfunction, ensuring that the inbuilt network redundancy can be utilised.

• Drills should be planned and conducted for DP 2 run-offs while diver(s) are outside of the bell.

• All operations should be performed with ROV monitoring.

• Review FMEA of the DPC.

Lesson Learnt • As a result of the incident, Bibby offshore is leading diver safety, making sure that they had learnt from the incident.

• Lowering the risk of the divers that they are exposed to.

• Initiate projects to look into enhancement of diver safety using experiences from this incident. (http://www.km.kongsberg.com/ks/web/nokbg0238.nsf/AllWeb/6FB042654824C048C1257B2D004992B3?OpenDocument)

KONGSBERG Dynamic Positioning (DP) simulator in Mumbai

References http://www.km.kongsberg.com/ks/web/nokbg0240.nsf/AllWeb/C03BD1E52C6E8B02C1256A4900282075?OpenDocument

http://www.km.kongsberg.com/ks/web/nokbg0397.nsf/f8aa365e2cee6bd2c125693f003f6ee2/f219737029dfc7d7c125723e002ce4a5/$FILE/304039C-low-res.pdf

http://www.bibbyoffshore.com/media/554/bibby_topaz_v1.pdf

https://www.scribd.com/doc/125194960/Bibby-Topaz-Incident-Case-Study

http://www.slideshare.net/arturovillazongranda/incident-summary-081012-bibby-topaz

http://cdn2.shipspotting.com/photos/middle/5/8/3/1164385.jpg

http://www.km.kongsberg.com/ks/web/nokbg0238.nsf/AllWeb/6FB042654824C048C1257B2D004992B3?OpenDocument