NTSB Safety Recommendation Letter P-90-039

Page 1Official PDFNational Transportation Safety Board Washington, D.C. 20594 Safety Recommendation Date: October 1, 1990 In reply refer to: P-90-39 Mr. Jerome J. McGrath President Interstate Natural Gas Association of America 1660 L Street, N.W. Washington, DC 20036 Mr. G. H. Lawrence President American Gas Association 1515 Wilson Boulevard Arlington, Virginia 22209 Mr. Robert Cave Executive Director American Pub1 ic Gas Association 301 Maple Avenue West Vienna, Virginia 22180 Mr. Charles J. DiBona President American Petroleum Institute 1220 L Street, N.W. Washington, DC 20037 On October 3 , 1989, the United States fishing vessel NORTHUMBERLAND struck and ruptured a 16-inch-diameter natural gas transmission pipeline about 1/2 nautical mile offshore in the Gulf of Mexico, and about 5 1/3 nautical miles west of the jetties at the entrance to Sabine Pass, Texas. Natural gas under a pressure of 835 psig was released. An undetermined source on baard the vessel ignited the gas, and within seconds, the entire vessel was engulfed in flames. The fire on the vessel burned itself out on October 4. Leaking gas from the pipeline also continued to burn until October 4. Of the 14 crewmembers, 11 died as a result of the accident.’ When the accident occurred, the NORTHUMBERLAND was in shallow waters and close to shore, which was normal and usual for its trade. The water depth and the estimated draft of the vessel at the time of the accident were both about 10 feet. Consequently, the bottom of the vessel was close to the sea bottom or slightly penetrating the bottom when it struck the pipeline. ’ A d d i t i o n a l i n f o r m a t i o n T r a n s p o r t a t i o n S a f e t y B o a r d . r u p t u r e o f a n a t u r a l g a s S a b i n e P a s s , T e x a s , O c t o b e r 9 0 / 0 2 . W a s h i n g t o n , DC.) i s g i v e n 1 9 9 0 . F i r e t r a n s m i s s i o n 3 , 1989. i n t h e on b o a r d p i p e l i n e P i p e l i n e a c c i d e n t t h e F / V i n t h e A c c i d e n t r e p o r t . ( N a t i o n a l NORTHUHEERLAND e n d Gulf o f U e x i c o n e a r R e p o r t N T S E / P A R . 5208B#

Page 2I The pipeline, known as t h e High Island l a t e r a l pipeline, was not f u l l y buried when i t was struck by t h e NORTHUMBERLAND. Diving surveys conducted a f t e r t h e accident established t h a t t h e unburied segments of t h e pipeline were not confined t o a limited length, b u t extended f o r a s much a s 400 f e e t i n t h e immediate accident area. The q u a n t i t y and type of marine growth found on t h e p i p e l i n e indicated t h a t t h e p i p e l i n e had been unburied f o r a prolonged period. Damage t o t h e concrete coating a l s o indicated t h a t the p i p e l i n e had been previously s t r u c k by other vessels o r equipment towed by v e s s e l s . When constructed i n 1973, t h e High Island pipeline was placed i n t h e bottom of a trench. The cover, a s indicated on the a s - b u i l t construction plans, was the v e r t i c a l distance from t h e level of t h e sea bottom down t o t h e top of t h e p i p e l i n e ; the cover, however, was not necessarily the same a s t h e actual depth of t h e overburden ( t h e sediment) t h a t may have been over the p i pel i ne. The investigation revealed t h a t t h e operator of t h e pipeline never inspected t h e pipeline a f t e r its construction t o confirm t h a t natural sedimentation had f i l l e d in t h e trench and had returned t h e sea bottom t o its natural e l e v a t i o n ; thus, i t i s not c e r t a i n t h a t t h e trench filled i n and produced an overburden of t h e depth shown on t h e a s - b u i l t construction plans and required by t h e right-of-way permit issued by t h e U . S. Army Corps of Engineers. Because t h e pipeline was supposed t o have been buried a t the time of construction b u t was unburied a t the time of t h e accident, the Safety Board i s concerned t h a t o t h e r submerged pipelines may a l s o be unburied and vulnerable t o damage and rupture. The operator acknowledged t h a t i t did not have a program of r e g u l a r inspections of i t s offshore pipelines t o determine i f they were unburied o r vulnerable t o damage from surface vessels. Instead, t h e operator adopted a r e a c t i v e policy of waiting u n t i l t h e operator was made aware of a hazardous condition before taking any remedial action, r a t h e r than an a c t i v e policy of looking f o r hazardous conditions and correcting them before an accident occurred I Federal regulations (49 CFR 192.613) r e q u i r e t h a t each operator of a gas p i pel i ne have a procedure f o r continuing survei 11 ance t o determi ne unusual operating and maintenance conditions. To have an e f f e c t i v e procedure t h a t will a c t u a l l y determine such conditions, an operator must regularly and a c t i v e l y inspect f o r these unusual conditions. Operators t y p i c a l l y r e l y on a e r i a l o v e r f l i g h t s t o patrol t h e i r offshore p i p e l i n e s . Although a e r i a l o v e r f l i g h t s o r surface p a t r o l s a r e useful t o d e t e c t l e a k s , they do not, i n t h e Safety Board’s view, s a t i s f y t h e needs f o r continuing s u r v e i l l a n c e required under section 192.613--to d e t e c t t h a t a pipeline has become unburied and vulnerable t o damage from surface v e s s e l s . Also, because the operator of t h e High Island p i p e l i n e did not inspect i t , the operator d i d not maintain t h e p i p e l i n e a s required by t h e permit issued by t h e Corps. The p i p e l i n e was exposed and vulnerable t o damage from surface vessels because the operator d i d not have a program f o r continuing s u r v e i l l a n c e t h a t incorporated regular inspections of t h e pipeline. f#

Page 33 The presence of a submerged pipeline, whether i t is offshore o r passes under a r i v e r o r other body of water, i s not obvious t o a vessel operator. Because submerged pipelines t r a n s p o r t natural gas and hazardous l i q u i d s t h a t can endanger l i f e and property i f released, pipeline operators have the primary r e s p o n s i b i l i t y t o construct, maintain, and operate their p i p e l i n e s i n a manner t h a t does not endanger t h e public. The Safety Board is concerned t h a t t h e inspection and maintenance p r a c t i c e s of the High Island p i p e l i n e operator a r e typical of other operators of submerged p i p e l i n e s because o f testimony provided by industry associations before t h e House Subcommittee on the Coast Guard and Navigation. Consequently, many o t h e r submerged p i p e l i n e s may not have been adequately buried and may be s i m i l a r l y vulnerable t o damage. Also, p i p e l i n e s t h a t were never required t o be buried because of regulatory exemptions o r grandfathering provisions are a l s o l i k e l y t o be vulnerable t o damage. The majority of a l l submerged pipelines very l i k e l y have not been r e g u l a r l y inspected. The Safety Board believes t h a t t h e only reasonable long-term s o l u t i o n t o minimize t h e hazard posed t o mariners and t h e environment by unprotected submerged p i p e l i n e s i s t o bury them where t h e depth o f water is comparable t o t h e d r a f t s of surface vessels. The Safety Board a l s o believes t h a t t h e operators of a l l submerged pipelines should be required t o conduct r e g u l a r inspections t h a t will ensure t h e pipelines remain buried and not become vulnerable t o damage from surface vessels. The Safety Board recognizes t h a t t h e l e g i s l a t i v e and regulatory changes needed t o achieve these goals are long-term actions. I n the interim, a l l operators of submerged pipelines should proceed with programs t o inspect their pipe1 i n e s and t o bury them where necessary. Therefore, a s a r e s u l t of t h i s accident, t h e National Transportation Safety Board recommends t h a t t h e I n t e r s t a t e Natural Gas Association of America, the American Gas Association, t h e American Public Gas Association, and t h e American Petroleum I n s t i t u t e : Notify member companies of t h e circumstances of t h e accident involving t h e rupture o f t h e natural gas pipeline i n the G u l f of Mexico and t h e f i r e on board t h e F/V NORTHUMBERLAND on October 3 , 1989, and recommend t h a t members who operate submerged p i p e l i n e s e s t a b l i s h and implement a program t o conduct regular and adequate inspections o f t h e i r submerged pipelines and maintain them i n accordance with a s - b u i l t construction plans and a l l right-of-way permits. (Class 11, P r i o r i t y Action) (P-90-39) Also as a r e s u l t of i t s investigation, t h e Safety Board issued recommendations t o t h e Zapata Haynie Corporation, Natural Gas Pipeline Company of America, U.S. Department of Transportation, Research and Special Programs Administration, U.S. Coast Guard, U.S. Department of the I n t e r i o r , Minerals Management Service, U . S . Army Corps of Engineers, National Oceanic and Atmospheric Administration, National Fish Meal and Oil Association, Louisiana Shrimp Association, and National Council of Fishing Vessel Safety and Insurance.#

Page 44 The National Transportation Safety Board is an independent Federal agency with the statutory responsibility "...to promote transportation safety by conducting independent accident investigations and by formulating safety improvement recommendations" (Public Law 93-633). The Safety Board is vitally interested in any actions taken as a result of its safety recommendations and would appreciate a response from you regarding action taken or contemplated with respect to the recommendation in this letter. Please refer to Safety Recommendation P-90-39 in your reply. KOLSIAD, Chairman, COUGHLIN, Vice Chairman, LAUBER, BURNETT, and HART, Members, concurred in this recommendation. James L. Kolstad Chairman i#