MMS 2001-045
Contents
1. 4 eS m otn epe i ng n o n Vi i e qu ia in t ap n gn s ei e qi t Casing Bed 3 D Powered Attachment 6 Diagram of Casing Bed and Cart Arrangement Attachment 7 Rear Cart Stop Se c Example of Type Positive Locking System Attachment 8 Free wheel indicator light Emergency Stop Ei Button Aft Powered Cart z Brake Button Oye ty Picture of Cart Joystick Panel 5 6 Aft Cart Mechanical Maintenance Figure 5 2 Cart Lubrication Chart Service Lubricant Interval 3 mos Mobilux EP 2 or equivalent 3 mos Marine Moly Paste Lubricant 5 7 Utility Cart Mechanical Maintenance Figure 5 3 Utility Cart Lubrication Chart Attachment 9 Comments Driveshaft brg As required on drive pinion Service Service Lubricant Point Interval A 3 mos Mobilux EP 2 or equivalent Cart Lubrication Charts Comments Driveshaft brg2. BP Exploration amp Production Incorporated ExxonMobil became the designated operator of the lease on September 19 1994 During routine drilling operations on the MODU Marine 700 the riser cart carriage assembly moved forward pinning a drilling floorhand between the riser cart carriage assembly and the iron roughneck on the drillfloor The floorhand received fatal injuries as a result of this accident Findings Weather Conditions Rig Activity at the Time of the Accident At the time of the incident the air temperature was 82 degrees Fahrenheit and the barometric pressure was 30 19 inches The wind direction and speed were south southwest approximately 200 at approximately 10 15 knots The seas were running out of the south southwest approximately 200 heading with a wave height of 4 6 feet The wave period at the time of the incident was six seconds Wave height is the measurement from mean sea level MSL to either the crest top of the wave or trough bottom of the wave Under these weather conditions the rig was experiencing a pitch of 0 1 degrees and a roll of 0 5 degrees Pitch is the pivotal movement up and down of the rig along the centerline axis from the bow to the stern When the bow goes up the stern goes down Roll is the pivotal movement up and down of the rig along the centerline axis from port to starboard sides When the port side is up the starboard side is down The rig also had a heave of appro
3. Manager Marine Offshore Installation Manager ExxonMobil Representatives four present Marine Vice President Operations Marine QA HSE Director Marine QA QC Engineer On September 22 2000 ExxonMobil submitted their report of investigation findings to the panel the report included statements taken by ExxonMobil and Marine from the following individuals the day of the incident Driller Assistant Driller Toolpusher Shaker hand Floorhand Roughneck Halliburton hand The panel received various documents from ExxonMobil Marine and Victoria Machine Works VMW during the course of the investigation Technical information was gathered from Marine and VMW records and from numerous telephone interviews with both Marine and VMW personnel On March 20 2001 the panel received Marine s final incident report On March 29 2001 the panel received ExxonMobil s final incident report The panel members met at various times throughout the investigation and after having considered all of the information available produced this report Introduction Background Brief Description of Accident Lease OCS G 08801 covers approximately 5 760 acres and is located in Mississippi Canyon Block 167 Gulf of Mexico off the Louisiana coast For lease location see Attachment 1 The lease is jointly owned by ExxonMobil Corporation and BP Incorporated The lease was issued effective January 01 2001 to ExxonMobil Corporation and
4. it might have been used to prevent unwanted movement of the cart thereby preventing the accident However the availability of a positive locking device does not guarantee its use 19 Recommendations Safety Alert The MMS should issue a Safety Alert recommending that drilling contractors who use this type of riser and casing handling equipment review the operations and maintenance for the purpose of identifying weaknesses Their review should include but not be limited to the following items e Clearly defined procedures for the use of and storage of the riser and casing cart assemblies e Detailed inspection and maintenance procedures for all critical operating components e Detailed documentation of inspection findings and corrective measures taken e The use of a pin type positive locking device or other method to prevent unwanted movement when the cart assembly is not in use 20 TEXAS BATON ROUGE E e i LAKE CHARLES Pe LAFAYETTE NEW ORLEANS HOUSTON P j HOUMA e ALABAMA MOBILE X APALACHICOLA VERMILION WEST CAMERON EAST CAMERON SOUTH MARSH IS E 1 HIGH ISLAND EUGENE IS SHIP SHOAL GALVESTON MAT MISSISSIPPANYON DESOTO CANYON IS e l i r J EAST BREAKS EN BANKS 7 MUSTANG j IS p 4 Ns NORTH CHRISTI GREEN CANYON FLORIDA MIDDLE GROUND TARPON SPRINGS THE ELBOW ST PET
5. stop button This button will cut electrical power to the system The Aft Cart brake is hydraulic release and spring set Losing electrical power will cause the Aft cart brake to set During a followup interview with VMW personnel one individual stated that with electrical power cut off to the cart the aft cart brake would set eventually as hydraulic pressure bleeds off in the system This may take some time anywhere from two minutes to several hours The aft cart is not equipped with any type of positive locking device such as a pin dog to prevent unwanted movement For an example of a pin type positive locking system see Attachment 7 Utility Cart The purpose of the utility cart is to transport miscellaneous cargo from the riser loading area to the drill floor There is no power to the utility cart The cart can be moved with air tuggers The cart is equipped to handle a safe working load of 67 000 pounds The utility cart is used in conjunction with the aft cart to support the casing bed The utility cart is not equipped with a parking brake or any type of positive locking device to prevent unwanted movement Casing Bed The casing bed is designed to be installed between the Aft Cart and the Utility Cart The purpose of the casing bed is to transport casing to and from the drill floor by utilizing the drive ability of the Aft Cart The casing bed is designed to support Cart Joystick Panel Post Accident Test of
6. the findings from VMW s report Model number for both units 03 530 616 Serial numbers 98c 236 amp 98c 209 1 Pressure tests indicated that 1 600 psi hydraulic pressure was available at the brakes 2 There was approximately 1 16 clearance between the aft brake adjusting screw and the motor housing at the aft brakes and zero clearance between the forward brake adjusting screw and the motor housing 3 A 002 feeler gauge could not be fitted under either caliper pad and the rotor of aft caliper brake when the brake was hydraulically released 4 Inspection of the forward brake caliper found the fixed caliper pad destroyed and all four pad retaining screws broken 5 Inspection of the aft brake caliper found the fixed pad to be intact with exception of elongated mounting holes and broken pad mounting screws 6 There was no obvious reason for the difference in the condition and wear of the two pads of the forward brake as compared with the aft brake 7 The pivot pins for both brakes appeared to be well lubricated and 10 free moving 8 The bearings for the drive shaft appeared to be well lubricated 9 The mounting bolts for the brakes were corroded and difficult to remove 10 The adjustment bolts for both calipers were corroded and very tight 11 Inspection of the brake rotor found no major scoring of the rotor braking surface 12 Inspection of the brake control valve found the solenoid retainer nut missing but found
7. 5 hours floorhand 1 was taken to the rig hospital where he died at 0500 hours For a diagram of the accident scene see Attachment 5 At the time of the incident the equipment was arranged to handle casing with the casing bed The position of the riser cart assembly faces aft to bow directly behind the drill floor For diagram of the casing bed and cart arrangement see Attachment 6 Victoria Machine Works VMW manufactures the cart assembly in Corpus Christi Texas the following equipment descriptions are based on its Operation and Service Manual for the Riser Skate Cart Assembly model number 03 530 616 Aft Cart The purpose of the aft cart is to drive and support the aft end of the casing bed to and from the gantry crane area The aft cart is powered by a hydraulic drive with a rack and pinion The drive has the ability to free wheel There is also a spring set hydraulic release disc brake provided on the aft cart This is a parking brake only and can be set by pushing a button on the cart joystick panel Note The brake on the aft cart consists of two sets of caliper pads One set is located on the front side of the rotor disk and the other set is located on the aft side of the rotor disk Bumping the joystick in either direction disengages the brake The free wheel light will be illuminated when the brake is disengaged In the operation and service manual on page nine VMW states In case of emergency press the emergency
8. Cart Brakes five 30 foot long joints of 18 inch diameter schedule 160 pipe which equals 46 275 pounds equally distributed over any 30 foot length of the casing bed According to Marine s final report the cart was last used on September 07 2000 At 1730 hours the cart s parking brake was engaged and the hydraulic power system was deactivated The approximate elapsed time until the incident was 11 hours The joystick panel for the aft cart is located on the drill floor inside the drill floor wall The joystick panel consists of one joystick three pushbuttons and one signal light The joystick controls the motion of the aft cart The top left button is the emergency stop button The set brake button located in the center of the joystick panel sets the brake on the aft cart The button is lighted to indicate the brake is set The green signal light on the right side of the joystick panel is lighted when the aft cart is freewheeling For picture of cart joystick panel see Attachment 8 ExxonMobil and Marine tested the cart the night of September 08 2000 They hooked up a tugger started to pull very lightly and the cart started to move They detected that the brakes on the cart were not working Post Accident Disassembly and Inspection by VMW Industries Inspection of the failed brake system began at approximately 1900 hours on September 09 2000 VMW representatives conducted the inspection The following is a summary of
9. ERSBURG X PADREIS port _LsaBEL SOUTH ALAMINOS CANYON PADRE IS HENDERSON VERNON CHARLOTTE HARBOR Western Mississippi Canyon Block 167 OCS G08801 U S Department of the Interior Minerals Management Service Gulf of Mexico OCS Region HOWELL HOOK PULLEY RIDGE RANKIN Eastern Location of Lease OCS G 08801 Mississippi Canyon Block 167 c DRY TORTUGAS KEY WEST STATUTE MILES O 50 100 KILOMETERS 0 100 200 juoumgoenyv Attachment 2 lt gt Roll 0 5 ONITHAG C INIAVW a Cart Assembly a LIESS ESL 1 Weather and Sea Effects on Marine 700 lt Ex Point of Contact floorhand 1 Picture of Cart Assembly Point of Contact JUOTIORN VW Attachment 4 n I fo ET 1 TE pret SE 3 Y i f ii i E r n Of i reading this gauge fei na M Ew Floorhand 1 was k standing here Picture of Iron Roughneck Point of Contact VMW Industries Utility Casing Cart 30 000 Ibs jaor AFT Cart pes 54 4 Cart Length Hydo Control Power to Cart EM PUIM 10014 IIA L2 7 ieuea xonsfor weg Drilling Shack Iron One Joint 3 Gauge a Drill Pipe 30 rd Floorhand 1 38 8 Travel Distance Diagram of Accident Scene on 9 8 00 Marine 700 Floorhand 2 Bow quouoLyy g amp I a 8 g 5 b E l p
10. OCS Report MMS 2001 045 Investigation of Fatality Mississippi Canyon Block 167 OCS G 08801 September 8 2000 Gulf of Mexico Off the Louisiana Coast U S Department of the Interior MMS Minerals Management Service Gulf of Mexico OCS Regional Office OCS Report MMS 2001 045 Investigation of Riser Fatality Mississippi Canyon Block 167 OCS G 08801 September 8 2000 Gulf of Mexico Off the Louisiana Coast David Dykes Tom Machado U S Department of the Interior Minerals Management Service New Orleans Gulf of Mexico OCS Regional Office May 2001 Contents Investigation and Report Authority 1 Procedures 1 Introduction Background 4 Brief Description of Accident 4 Findings Weather Conditions 5 Rig Activity at the Time of the Accident 5 The Accident 6 Description of the Cart Assembly 6 Cart Joystick Panel 9 Post Accident Test of Cart Brakes 9 Post Accident Disassembly and Inspection by VMW Industries 10 VMW Maintenance Procedures 13 Marine Cart Inspection and Maintenance Procedures and Records 15 Conclusions Causes 18 Contributing Causes 18 Recommendations Safety Alert 20 Appendix Attachment 1 Location of Lease OCS G 08801 Mississippi Canyon Block 167 Attachment 2 Weather and Sea Effects on Marine 700 Attachment 3 Picture of the Cart Assembly Point of Contact Attachment 4 Picture of the Iron Roughneck Point of Contact Attachment 5 Diagram of the Accident Scene on 9 8 00 Marine 700 Atta
11. chment 6 Diagram of the Casing Bed and Cart Arrangement Attachment 7 Example of Pin Type Positive Locking System Attachment 8 Picture of the Cart Joystick Panel Attachment 9 Cart Lubrication Charts ii The Investigation and Report Authority Procedures An accident that resulted in one fatality occurred on Marine Drilling Companies Incorporated Marine mobile offshore drilling unit Marine 700 located on ExxonMobil Production Company s ExxonMobil Mississippi Canyon Block 167 Lease OCS G 08801 in the Gulf of Mexico offshore the State of Louisiana on September 8 2000 at approximately 0425 hours Pursuant to Section 208 Subsection 22 d e and f of the Outer Continental Shelf OCS Lands Act as amended in 1978 and the Department of the Interior Regulations 30 CFR 250 the Minerals Management Service MMS is required to investigate and prepare a public report of this accident By memorandum dated September 14 2000 the following personnel were named to the investigative panel David Dykes New Orleans Louisiana Chairman Tom Machado New Orleans Louisiana On September 9 2000 an inspector from the MMS New Orleans District visited the rig to assess the situation and began gathering information thereby initiating MMS s investigation of the incident The visit started with a meeting to discuss the incident The following individuals attended the meeting Lead Inspector New Orleans District Marine Operations
12. forward brake assembly was found to be in a failed state The reason the aft brake assembly was not effective was not determined at the time of the inspection and disassembly During a followup interview with VMW personnel one individual stated that the brake rotor and pads were contaminated with grease The 12 VMW Maintenance Procedures inspection and disassembly report does not explicitly identify contamination on the rotor and pads However the report does state that certain factors ought to be investigated as reasons for the brake failure and as possible design improvement Those factors are as follows Possible caliper misalignment issues Possible distortion of the caliper housing Contamination of the caliper pads The effectiveness of the spring assembly The pad material VMW personnel also stated that under ideal conditions with everything functioning properly and with no contamination of the braking surfaces the brakes front and aft set of calipers would hold a maximum load of 60 000 pounds at an incline angle of approximately 4 5 degrees With only one set of brakes front or aft set of calipers functioning properly the brakes could only hold to approximately a 2 degree maximum angle Add contamination to the braking surface and the brake holding capacity is significantly reduced Maintenance procedures of the cart cover five main areas and are listed below Electrical Maintenance e Monthly Check inter u
13. me of the accident are considered to be contributing causes of the accident The loss of brake holding capacity was caused by contamination of the brake rotor and pads with grease and also by the state of disrepair of the forward caliper pads Therefore the contamination of the brake rotor and pads and the state of disrepair of the forward caliper pads are considered to be contributing causes of the accident Marine could not provide this panel with the monthly aft powered riser cart inspection form for the month of August 2000 The monthly 18 inspection identifies checking the brake components for wear and other operational defects It is possible that this inspection would have detected the contamination and the state of disrepair of the braking system At the time of this report the cause of the failed state for the forward caliper pads has not been determined It is the conclusion of this panel that Marine failed to conduct a monthly aft powered riser cart inspection during the month of August The failure of Marine to conduct the monthly aft powered riser cart inspection during the month of August is considered to be a possible contributing cause to this event The failure of VMW to provide a secondary lockout device or a secondary procedure as a backup to the brakes to prevent unwanted movement of the casing cart assembly is considered to be a contributing factor If a positive locking device such as a pin had been provided
14. nit cabling for possible physical damage Correct 13 e Bi Annually Install new moisture absorption material in all electrical enclosures Ensure cabinets are sealed tightly when closed Pneumatic Maintenance e Monthly Check hoses for fatigue cracks and excessive wear Replace if needed Hydraulic Maintenance e Monthly Check hoses for leaks fatigue cracks and excessive wear Replace if needed Mechanical Maintenance General e Monthly Visually inspect the structure for weld integrity loose connecting hardware and general condition Bolted connections should be checked for proper torque by using torque values Welds should be inspected for cracks Should a weld be suspect verify using the dye penetrate method Treat corrosion and paint effected areas Aft Cart and Utility Cart Mechanical Maintenance e Lubrication as per Cart Lubrication Charts Figures 5 2 and 5 3 For cart lubrication charts see Attachment 9 The VMW Operation and Service manual does not identify brake inspections as part of any routine maintenance 14 Marine Cart Inspection and Maintenance Procedures and Records On pages 7 and 8 of the Operation and Service manual the operation procedures make reference to calm sea operations The procedures state in part When setting the Aft Cart brake the green freewheel light should turn off and the red brake light should turn on Also during calm sea operations the brake ma
15. nspect the entire cart assembly for all mounting hardware and any indication of damaged paint Repair as necessary e Visually check all power track components to include covers and hinges Records indicate that monthly inspections occurred on June 26 2000 July 30 2000 Several attempts were made by the panel to obtain a copy of the August 2000 inspection from Marine However at the time of 16 writing of this report the panel has not received any proof of an August inspection The records indicate that the steps identified above were taken however the records do not show the exact process undertaken deficiencies found or any corrective measures taken The records show simply a check v by each step indicating that it was performed 17 Conclusions Causes Contributing Causes The unintentional movement of the riser cart assembly was caused by the movement and list of the rig and the lack of brake holding capacity of the aft powered cart The movement of the rig was caused by the sea conditions at the time of the accident and the relative position of the rig The sea conditions created enough pitch and heave coupled with the list of the rig to cause the cart to move from its stationary position toward the rig floor This movement continued until the cart assembly fatally struck the Marine employee and pinned him against the iron roughneck Therefore the sea conditions and their effect on the rig at the ti
16. the solenoid to be operating properly 13 Visual inspection of the mounting plates indicated that there may be some out of plane misalignment After removal from the drive system the brake parts were photographed and taken to the mechanic shop for further inspection Disassembly and visual inspection of the brake calipers revealed the following 1 Corrosion was apparent inside the aft spring compartments 2 The internal spring parts appeared intact 3 The spring stacking sequence was consistent with the manufacturer s documentation for both brakes 4 The forward springs were found coated with a residue 5 The aft springs were found lubricated 11 The hydraulic piston components appeared to be intact The forward bearings pad piston was slightly tarnished but free to move The aft bearing pad piston was clean and free to move Both caliper housings were found to be wider at the mouth than at the root This was noted to be approximately 3 16 for the aft housing and 1 4 for the forward brake housing After disassembly all components were placed in marked individual bags the individual bags were placed in a box and the box was taken to the rig office and remains in the custody of the Marine Drilling QA HSE Director The following were concluded by the VMW and Marine inspection team 1 A pull test was conducted prior to the inspection and the brake system was determined to be ineffective The
17. ximately linch Heave is the vertical movement up or down of the rig along the surface of the water Rig personnel stated during the initial MMS visit that the rig also had a list of 0 25 0 5 degrees to the bow List is the relative leaning position of the rig with respect to the sea surface For weather and sea effects on Marine 700 see Attachment 2 The rig was conducting drilling operations and at the time of the accident the rig crew was in the process of connecting drill pipe The Accident Description of the Cart Assembly At 0425 hours on September 08 2000 the drill crew was in the process of connecting the last string of drill pipe with the aid of an iron roughneck There were two floorhands operating the iron roughneck Floorhand 1 was watching the torque gauge on the iron roughneck when the toolpusher and floorhand 2 noticed the casing cart rolling towards floorhand 1 The cart hit him pinning floorhand 1 between the cart and the iron roughneck For pictures of the points of contact see Attachments 3 amp 4 The cart rolled back a few feet and floorhand 1 fell to the floor The toolpusher went to the cart control panel and attempted to move the cart away from floorhand 1 The cart would not move so the toolpusher told the driller to turn on the cart hydraulics and then the toolpusher moved the cart away from floorhand 1 The medic arrived on the drill floor at 0430 hours and started tending to floorhand 1 At 044
18. y not be required However rough sea operations require the parking brake to be set VMW personnel defined calm sea conditions during the followup interview as near zero wave height According to Marine personnel on the rig calm sea conditions are determined by the pitch and roll of the drilling rig and not necessarily by wave height Rough sea conditions exist when there is either a pitch or roll of the rig of at least 0 5 degrees Calm seas are therefore determined to be anything less than a 0 5 degree pitch or roll of the rig Marine s inspection and maintenance procedures call for both a weekly and monthly inspection of the aft powered riser cart The procedures for the weekly routine inspection are as follows e Check hydraulic motor and valve and hose connections for leaks e Check power track for loose missing or damaged components e Check saddle and pivot bearings for any damage and 15 operation e Clean any debris from rack and check for missing or damaged teeth Remove any rust or corrosion and coat with taskmaster or equivalent corrosion preventive medium e Check all manual controls for freeness of operation Records indicate that weekly inspections occurred on July 13 2000 July 30 2000 August 11 2000 August 27 2000 The procedures for the monthly routine inspection are as follows e Perform all weekly scheduled checks e Check brake components for wear or other operation defects e Visually i
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