DSV Bibby Bibby Topaz – Case Study & Discussion of Lessons Learned
Scope of Work • Water ater depth epth 91m, 1m, Weath eatheer; – Wind NW – Wind gusting up to 30 – 35 kts – Sig wave height 4.0m
• Vessel ssel set up we west of te templa mplate te • 2 x DG DGPS, 2 x HiPap, 1 x ta taut wire online • 3 Gen Genera rato tors rs onlin nline, e, 5 out out of 6 thrusters running & selected onto DP • MOC conducted ted to enter ter template via side • Ventin ting ann annul uluus ga gas pri prioor to to barrier testing
DSV Bib Bibby by Top Topaz az – Bui Build ld 2008 2008
5&6
4
3
2
1
• Propulsion – 2 x Main Propulsion , 2 x Retractable Azimuth, Azimuth, 2 x Tunnel Tunnel Thrusters
Time Line; 20.13 • Dive 047, starboard bell locked off • Bell loc located ted upstre reaam of template structure • Divers umbilical length into template – 27m from bell
Time Line; 20.49 to 22.09 • Diver 1 & 2 located inside drilling template structure carrying out barrier testing activities • ROV mo monitoring
Time Line; 22.09 • Alarm for ‘RBUS’ activated • DP aam mber al alert ac activa ivated • Master & Dive Co Control informed • Dive Su Supervisor instructed divers to leave structure and locate to bell stage • Attempts made to reselect thrusters into DP
Vessel Tracking
Vessel Tracking Vessel heading and approximate position between 22.09.30 and 22.13.00 (30 sec intervals)
Time Line; 22.11 • DP Red alert activated • Vessel ssel drift riftin ingg easte asterl rlyy, all references & thrusters unavailable to DP • 4th generator started, thruster 4 running • Diver 1 & 2 locatin ting on onto top of template
Easterly Direction
Time Tim e Line Line;; 22.1 22.11 1 – 22 22.12 .12 • Diver 2 umbilical snagged on transponder bucket located on side of structure • Bellma llmann pulli ullinng in div diver 1 slack
Easterly Direction
Time Ti me Li Line ne – 22 22.1 .12 2 • Bellman pro provviding sl slack to diver 1 • Bellman atte ttemptin ting to provide slack to diver 2 • Diver 1 pulled off template, returning to bell • Loss of comms to diver 2 • Momentary loss of comm commss to bell bell
Easterly Direction
Time Tim e Line Line – 22. 22.13 13 to 22. 22.15 15 • Diver 2 um umbilical se severed • Dive Diverr 1 made made way way bac backk to to bel belll sta stage ge • OPM OPM re relo loca cate tedd fro from m Dive Dive Cont Contro roll to to Br Brid idge ge • Mode Mode swit switch ch to to manu manual al thr thrus uste terr con contr trol ol • Po Port rt Taut Taut Wire Wire stow stowed ed (wir (wiree par parte ted) d) • Downline and tugger parted
Time Ti me Li Line ne – 22 22.1 .17 7 • Ve Vess ssel el posi positition on 240m 240m NE of Dril Drilliling ng Temp Templa late te • Vessel Vessel being being manua manually lly driven driven using using fwd and aft azimut azimuths hs • Chief Chief Office Officerr on thrus thrusters ters 2 & 3, 3, Master Master on on main main prop propuls ulsion ion thrus thrusters ters 5 & 6 • Dive Diverr 2 loca locato torr bea beaco conn iden identitifie fiedd at temp templa late te 240m
Time Tim e Line Line;; 22.3 22.30 0 – 22 22.34 .34 • ROV back ack at at Dri Drillllin ingg Te Templa mplate te • Dive Diverr 2 loca locate tedd on on top top of temp templa late te • DP co control trolle lers rs powe powerr recy recyccled led • Vessel ssel back ack on full full auto DP
150m
Time Ti me Li Line ne – 22 22.3 .38 8 • Diver 1 left stage, relocated onto template • Recovery of of Diver 2 commenced
Time Ti me Li Line ne – 22 22.4 .40 0 • Vessel ba back at Dri Drillling Template • Recovery of of Diver 2
Time Ti me Li Line ne – 22 22.4 .46 6 Investigation • Diver 2 recovered to bell, unconscious & breathing • 23.13 Be Bell se sealed an and left bottom • 23.38 Bell locked on • 24.00 co commenced transit to port
DP Control System Investigati Investigation on • Determ Determine ine the fault fault whic whichh cause causedd sudd sudden en loss loss of of all all anal analogu oguee and and digital RBUS input / output signals with subsequent loss of DP control; resulting in vessel drift off • Testin Testingg on the system system to try try to recrea recreate te sequ sequenc encee of events events & method for provoking RBUS jamming developed • Test Test proc procedu edure re deve develop loped ed for for demons demonstrat trating ing fault fault mech mechani anism sm
DP Control System Investigati Investigation on • Compon Component entss in DPC-3 DPC-3 cabi cabinet net expose exposedd to earth earth faul faults ts chan changed ged out as precaution & sent back to Kongsberg Maritime (KM), Norway for factory inspection • KM suppli supplied ed equ equip ip inspe inspecte ctedd & modi modifie fiedd accor accordin dingg to ground grounding ing philosophy • KM disass disassemb embled led hard hardwar waree modul modulee by module module to to fully fully sub substa stanti ntiate ate root cause of the failure • DP syst system em pr prov ovin ingg tri trial alss con condu duct cted ed • Ve Vesse ssell assura assurance nce approv approved, ed, return returned ed operat operation ional al (8th Oct) • KM inve investi stiga gatio tionn conc conclu lude dedd end end Nove Novemb mber er • KM Tech Techni nica call Bul Bulle letitinn iss issue uedd – DP-0 DP-02/ 2/20 2012 12
Causal Factors The investigation determined 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-3 cabinet (one of 3 cabinets / central processing units containing DP control system hardware). Faults found included; • Loose Loose / inte intermit rmitten tentt conne connecti ctions ons of fuse fuse in in DPCDPC-33 cabi cabinet net • Ground Grounding ing;; curre current nt was was measur measured ed in in the the boun boundd from from the the RCU RCU unit unitss to ground. • Inner Inner shield shield on field field cabl cables es not not conn connect ected ed to instru instrumen mentt earth. earth. • DPC DPC 3 cab cabin inet et not not ear earth thed ed to to shi shipp hul hulll stru struct ctur ure. e.
Preventative Actions • A perman permanent ent soluti solution on has has been been made made availa available ble as as a RBUS RBUS I/O I/O Modules (RMP20X) Firmware Update kit. • The kit consis consists ts of a CD CD and and an instal installat lation ion & verifi verificat cation ion proc proced edure ure • The watchd watchdog og func functio tional nality ity self self-tes -testt funct function ion allowi allowing ng unit unit to recognise jamming fault (and provide diagnostic coverage for other CPU faults). • Provid Provides es module module isolat isolation ion should should any of thes thesee fault faultss occu occurr & is capable of removing the unit from the network in case of similar malfunction, ensuring that the inbuilt network redundancy can be utilised
HSE Safety Notice • HSE HSE issu issueed Sa Safety fety Noti Notice ce - OSD OSD 1-2 1-20013 • Target Target suppli suppliers ers of of DP syst systems ems,, operato operators rs of offsh offshore ore inst install allati ations ons,, marine ‘type approval’ bodies, classification societies, verification bodies and marine consultancies • Notice Notice will will focus focus on on Duty Duty Holde Holders rs Safe Safety ty Case Case and and the the veri verific ficati ation on of performance and communication architecture of DP systems • Requir Requireme ements nts that that if the the DP functi functions ons are are depe depende ndent nt on a dual dual BUS BUS network the Offshore Installation Duty Holder should ensure that appropriate measures are in place to prevent a single fault causing failure of the dual BUS network. • If not in place place man manufa ufactu cturer rer / sup suppli pliers ers provid providee adequ adequate ate information regarding vulnerability to single point failure
Lessons Learned / Summary TOR • A numbe numberr of engag engageme ement nt sess session ionss condu conducte ctedd with with client client base, base, industry associations (IMCA, OGP DIWG, MSF) • The objec jective be being to; to;
− Present the incident and the investigation findings − Importantly to identify, from the lessons learned, where potential improvements could be made to diving and marine operations and to mitigate the likelihood and consequence of a similar incident was to occur in the future. • IMCA IMCA Sa Safe fety ty Noti Notice ce 02/1 02/133 iss issue uedd 29 29th Jan
Diving & Marine Safety Enhancement Project Discussed with and endorsed by the HSE • Design Design of the the bell bell stagi staging ng to to assi assist st the the recov recovery ery of unco unconsc nsciou iouss diver • The desig designn of of rescu rescuee equ equipm ipment ent and method method of recove recovery ry of unconscious diver back to the bell • The desig designn and and provi provisio sionn of dive diverr transp transpon onder der / locato locatorr beaco beacons ns • The desig designn and and provis provision ion of ther thermal mal protec protectiv tivee unde undersu rsuits its • The The spec specifific icat atio ionn of of div diver er bail bailou outt bot bottle tless • The assess assessmen mentt and and techn technolo ology gy of of dive diverr re re-br -breat eather her units units • Provis Provision ion of addi additio tionn life suppor supportt equip equipmen mentt on the the seabe seabedd for the dive team • ROV ROV int inter erfa face ce to aid aid and and ass assis istt dive diverr reco recove very ry
Diving & Marine Safety Enhancement Project • Review Review of exis existin tingg dive dive mana managem gement ent system system proced procedure uress and and risk risk assessment criteria • DP contro controll syst system em (softwa (software re and hardw hardware are)) iinsp nspect ection ion and verification regime • DP field field entry entry trials trials and and set set up up to enable enable time time for drivin drivingg the vessel vessel in manual mode • Enhan Enhancem cemen entt of the unders understan tandin dingg and and famil familiar iarity ity of manual manual systems and operation • Brid Bridge ge Tea Team m Mana Manage geme ment nt and and the the mana manage geme ment nt of of majo major r emergencies / command and control • Fully Fully inte integra grated ted appr approac oachh to FMEA FMEA / FMEC FMECA A and and the the sched schedule ule and and criteria for FMEA / FMECA review • Compet Competen ency cy sche scheme me perfor performan mance ce criter criteria, ia, trainin training, g, drill drillss and and exercises
