United States Coast Guard Report of Investigation into the Circumstances Surrounding the Explosion, Fire, Sinking and Loss of Eleven Crew Members Aboard the MOBILE OFFSHORE DRILLING UNIT DEEPWATER HORIZON In the GULF OF MEXICO April 20 – 22, 2010 Volume I MISLE Activity Number: 3721503 Table of Contents Volume I (Systems and responsibilities within U.S. Coast Guard purview under the U.S. Coast Guard-Minerals Management Service Memorandum of Agreement dated March 27, 2009) Table of Contents i Prologue iii Executive Summary viii Chapter 1 | Explosion 1 Chapter 2 | Fire 34 Chapter 3 | Evacuation / Search and Rescue 46 Chapter 4 | Flooding and Sinking 72 Chapter 5 | Safety Systems (Personnel and Process) 89 Chapter 6 | Summary of Conclusions 112 Chapter 7 | Safety Recommendations 120 Chapter 8 | Administrative Recommendations 127 Appendices Appendix A | List of Abbreviations A-1 Appendix B | Lists of Figures and Tables B-1 Appendix C | Parties in Interest C-1 Appendix D | Crew Data D-1 Appendix E | Vessel Particulars E-1 Appendix F | Weather Information F-1 Appendix G | Final Action Report on the SAR Case Study into the Mass G-1 Rescue of Personnel off the Mobile Offshore Drilling Unit DEEPWATER HORIZON i Appendix H | Critical Events Timeline H-1 Appendix I | Potential Legal Issues Associated with Vessels Employing I-1 Dynamic Positioning Systems Appendix J | Synopsis of Audits and Surveys J-1 Appendix K | Examples of Transocean’s Non-compliance with the K-1 International Safety Management Code Appendix L | Post-sinking Analysis for DEEPWATER HORIZON L-1 Appendix M | Operational Risk Assessment M-1 Appendix N | BP DEEPWATER HORIZON Follow Up Rig Audit, Marine N-1 Assurance Audit and Out Of Service Period, September 2009 Appendix O | Results of Inspections & Surveys of Deepwater Horizon O-1 (2009-2010) Appendix P | Convening Order Joint Department of the Interior and P-1 Department of Homeland Security Statement of Principles and Convening Order Regarding Investigation into the Marine Casualty, Explosion, Fire, Pollution, and Sinking of Mobile Offshore Drilling Unit DEEPWATER HORIZON, with Loss of Life in the Gulf of Mexico 21-22 April 2010 Appendix Q | USCG Investigation Team Members Q-1 ii PROLOGUE On April 20, 2010, the Mobile Offshore Drilling Unit (MODU) DEEPWATER HORIZON was dynamically-positioned at location 28o-44’ North 088o-21’ West in the Mississippi Canyon Block 252 of the U.S. Outer Continental Shelf (OCS). The MODU was performing drilling operations on the Macondo Well, which had been previously started by another vessel. That evening, a series of events began that would ultimately result in an explosion and fire, taking 11 lives, injuring 16 others, and ultimately causing the MODU to become severely crippled and sink. The casualty resulted in a continuous flow of hydrocarbons into the Gulf of Mexico for 87 days before the well was capped, causing the largest oil spill in U.S. history and significant environmental damage to the Gulf of Mexico. The tragedy affected the lives of hundreds of thousands of people who live along the Gulf Coast or rely on the various economies associated with the Gulf of Mexico. Within six days of the incident, the Department of Homeland Security and the Department of the Interior determined that a joint investigation of the DEEPWATER HORIZON’s explosion, sinking, and the associated loss of life was the best strategy for determining the events, decisions, actions, and resultant consequences of this marine casualty. The joint investigation was conducted by the U.S. Coast Guard (USCG) and the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE). The Joint Investigation Team (JIT) used the combined investigative powers and authorities afforded to the USCG and BOEMRE. Personnel from each agency were specifically assigned to the JIT to accommodate the collection of evidence, conduct public hearings and inquiries, and coordinate forensic testing. The agencies operated under the 2009 Memorandum of Agreement (MOA) that identifies responsibilities of the Minerals Management Service (MMS) (predecessor to BOEMRE) and the USCG. The USCG and MMS entered this agreement under the authority of Title 14, United States Code (U.S.C.) § 141 – USCG Cooperation with other Agencies; 43 U.S.C. §§ 1347, 1348(a) – the Outer Continental Shelf Lands Act (OCSLA), as amended; 33 U.S.C. § 2712(a)(5)(A) – the Oil Pollution Act of 1990 (OPA); 43 U.S.C. §§ 1301-1315 – the Submerged Lands Act (SLA), as amended; and the Energy Policy Act of 2005. Per its Maritime Regulations, the Republic of the Marshall Islands (RMI), the flag state for DEEPWATER HORIZON, is also responsible for investigating casualties that are categorized as “Serious Marine Casualty” under the International Maritime Organization’s (IMO) Casualty Investigations Code. The DEEPWATER HORIZON casualty falls in this category. To avoid duplication of efforts, the USCG and RMI investigators shared data and coordinated requests for information. Upon conclusion of the investigations, both countries are required to submit their reports to the IMO for distribution of lessons learned and possible enhancement of safety standards. Regulatory Structure The Outer Continental Shelf Lands Act (OCSLA), Title 43, United States Code, Chapter 29, Subchapter III, provides regulatory authority over activities on the outer continental shelf (OCS) iii to the Secretary of the Interior, Secretary of Homeland Security, Secretary of the Army, Secretary of Labor, Secretary of Transportation and Secretary of Energy. The Secretary of the Interior and the Coast Guard (which has received a delegation of the relevant authorities from the Secretary of Homeland Security) are responsible for requiring, wherever practicable, the best available and safest technologies that are economically feasible, wherever failure of equipment would have a significant effect on safety, health, or the environment. The Coast Guard also promulgates regulations or standards applying to unregulated hazardous working conditions related to activities on the OCS when such regulations or standards are necessary. OCSLA specifically requires the Secretary of the Interior and the Coast Guard to individually or jointly enforce these safety and environmental regulations at least once a year. Such enforcement should include inspecting all safety equipment designed to prevent or ameliorate blowouts, fires, spillages, or other major accidents, and performing a periodic onsite inspection without advance notice to the operator. To meet these requirements, the Coast Guard and MMS signed a memorandum of understanding (MOU) to delineate inspection responsibilities between both the agencies. The MOU is further broken down into five memoranda of agreement (MOAs): OCS-01 Agency Responsibilities, OCS-02 Civil Penalties, OCS-03 Oil Discharge Planning, Preparedness and Response, OCS-04 Floating Offshore Facilities and OCS-05 Incident Investigations. OCS-01 established responsibilities for each agency and clarified overall responsibility where jurisdiction overlapped. Based on these memoranda of agreement, the Coast Guard performs annual inspections on U.S.- flagged MODUs/floating offshore installations and annual examinations on foreign-flagged MODUs. These visits focus on the safe manning and operation of MODUs and include inspection of: lifesaving, fire-fighting, hull integrity, vessel stability, means of egress, locations containing hazardous electrical equipment, machinery systems, electrical systems, helicopter facilities, cranes, navigation and occupational health and safety. In the case of foreign-flagged MODUs, the flag state has primary responsibility for ensuring compliance with applicable international standards. However, the United States can set requirements and conditions for conducting activities on the U.S.OCS, including those that are applicable to foreign-flagged MODUs. Pursuant to Coast Guard regulations specified in 33 C.F.R. § 146.205, foreign-flagged MODUs engaged in OCS activities must comply with one of three regulatory schemes, one of which is the International Maritime Organization (IMO) MODU Code, which contains recommended design criteria, construction standards, and other safety measures for MODUs. DEEPWATER HORIZON was a foreign-flagged MODU that engaged in oil drilling activities on the OCS. It was built and operated in accordance with the 1989 IMO MODU Code. Its flag state, RMI, used the American Bureau of Shipping and Det Norske Veritas as recognized organizations to conduct its required surveys and audits. The USCG periodically performed a limited safety examination, which included verifying statutory certificates, testing of safety devices, and witnessing emergency drills. At the time of the casualty, DEEPWATER HORIZON possessed all required valid documents certifying compliance with applicable international, RMI and USCG requirements. iv The Investigation Under the MOAs, BOEMRE is responsible for investigating incidents related to systems associated with exploration, drilling, completion, workover, production, pipeline and decommissioning operations for hydrocarbons and other minerals on the OCS. The USCG is responsible for investigating marine casualties involving deaths, injuries, property/equipment loss, vessel safety systems, and environmental damage resulting from incidents aboard vessels subject to U.S. jurisdiction. The MOA assigns responsibility in joint investigations according to these responsibilities. Volume I addresses the areas of USCG responsibility and Volume II