NTSB Safety Recommendation Letter P-71-003 through P-71-004

Page 1Official PDFUNITED STATES OF AMERICA L ~~~~~~ WASHINGTON, D.C. I S S U E D : March 15, 1 9 7 1 Adopted by the N A T I O N A L TRANSPORTATION SAFETY BOARD a t its o f f i c e i n Washington, D. C . on t h e 18th day of February 1 9 7 1 FORWARDED TO: 1 Honorable W i l l a r d J . Smith ) A s s i s t a n t S e c r e t a r y of 1 T r a n s p o r t a t i o n ) Department of T r a n s p o r t a t i o n ) Washington, 1). C . 20590 ) SAFETY RECOMMENDATIONS P-71-3 Cy 4 T h i s i s i n r e g a r d t o a p i p e l i n e a c c i d e n t which o c c u r r e d near Farmington, West V i r g i n i a , on October 29, 1970. I n t h i s a c c i d e n t , which was i n v e s t i g a t e d by t h e N a t i o n a l T r a n s p o r t a t i o n S a f e t y Board, a 16-inch p i p e l i n e o p e r a t i n g a t a p r e s s u r e of 378 p . s . i . g . r u p t u r e d , c a u s i n g a crater 30 f e e t long, 10 f e e t wide, and 25 f e e t deep. An e a r t h q u a k e - l i k e rumble was heard and f e l t by r e s i d e n t s i n t h e area. Mud and s t o n e s were thrown up on t h e highway, houses shouk and t h e n o i s e was deafening. V e h i c l e s being d r i v e n on a nearby highway were h i t by t h e f l y i n g s t o n e s and mud, and f o u r c a r s were s t a l l e d . One of t h e d r i v e r s s t a r t e d h e r car and d r o v e from t h e scene. A t t h i s time, about 10 minutes a f t e r the i n i t i a l r u p t u r e , t h e e s c a p i n g g a s i g n i t e d a l o n g t h e ground, and f l a s h e d back t o t h e break, r e s u l t i n g i n a f i r e 100 f e e t h i g h which was v i s i b l e 1 0 m i l e s away. The occupaints of t h r e e cars remaining on the highway r a n from t h e i r v e h i c l e s as they s t a r t e d t o burn. The f i r e burned f o r about 45 minutes, d i e d down, and went o u t a s t h e v a l v e s one-half mile n o r t h and 5 miles s o u t h of t h e r u p t u r e were manually turned o f f by the toorlcmen o f t h e E q u i t a b l e Gas Company (EquiLable). The cars were demolished b u t t h e r e were no f a t a l i t i e s o r i n j u r i e s . E q u i t a b l e , which o p e r a t e s t h e l i n e d e s i g n a t e d H-557, i n d i c a t e d t h a t t h e a c c i d e n t was caused by c o a l mine subsidence. On .June 3, 1970, a similar type f a i l u r e occurred 766 f e e t s o u t h o f t h e s i t e of t h e October 29, 1 9 7 0 , f a i l u r e . Both a c c i d e n t s occurred a t overbends i n t h i s API 5J.Z 4 6 p i p e . No m e t a l l u r g i c a l a n a l y s i s was made o f the first f a i l u r e . A t t h e Board's s u g g e s t i o n , a n a n a l y s i s is now being conducted o f t h e October 29 f a i l u r e by t h e Battelle Memorial I n s t i t u t e . E q u i t a b l e h a s exposed p o r t i o n s of t h e l i n e near t h e two f a i l u r e s and d i s c o v e r e d o t h e r s i g n s of p i p e movement. About ZOO feet of p i p e has been r e p l a c e d , a n d a n 11-mile s e c t i o n o f t h i s l i n e has been 71816#

Page 2- 2 - The line has a maximum allowable operating pressure of 1,000 p.s.1.g. retested hydrostatically at pressures ranging from 1,500 to 1,678 p.s.i.g. Based line to service. on the tests and pipe replacement, Equitable has now returned this The value of the hydrostatic test as an indication of future safety determined. If the line had failed because of excessive gas pressure, such is suspect at this time, since the type of failure has not as yet been a test would be desirable. If the line failed because of earth movement, as it now appears, the type of test performed would not be meaningful. Equitable indicates that the earth movement caused by the subsidence should continue in this area. Board considers that a continuing hazard probably exists, due to the threat Based on a preliminary investigation of this accident, the Safety of further earth movement, and recommends that 1. The Department of Transportation take the necessary steps to determine whether there is a hazard within the meaning of Section 3(b) of the Natural Gas Pipeline Safety Act of 1968; and 2. The Department review the overall problem of safety of pipelines in areas where mine subsidence exists. Our staff would be pleased to provide you with additional information developed. Mr. Barry M. Sweedler, Associate Chief of our Railroad/Pipeline Safety Division is the contact. This recommendation will be released to the public on the issue date should be made prior to that date. No public dissemination of the contents of this document the above recommendations. Burgess, Member, was absent, not voting- Reed, Chairman, Laurel, McAdams, and Thayer, Members, concurred in Reed Chairman#