NTSB Safety Recommendation Letter P-77-009 through P-77-012

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. M r . Louis R. Reif President National Fuel Gas Company 10 Lafayette Square Buffalo, New York 14203 SAFETY RECOMMENDAT I O N (S) P-77-9 through P-77-12 - A t 2 : 4 2 a.m. e.s.t. on March 26, 1977, t h e Buffalo P o l i c e Department reported gas odors i n a telephone company manhole near 1446 South Park Avenue. A National Fuel Gas Company serviceman a r r i v e d a t the scene a t 3 : 1 4 a . m . and checked t h e v a u l t below t h e manhole f o r gas. H i s com- b u s t i b l e gas i n d i c a t o r (CGI) indicated a f u l l - s c a l e reading on its s i n g l e , lower-explosive l i m i t s c a l e , and he radioed f o r a d d i t i o n a l help. A t 4 : 3 O a.m. a three-man, emergency r e p a i r crew a r r i v e d and removed t h e manhole cover t o vent t h e gas from the v a u l t . The r e p a i r crew was composed of supervisory personnel because regular gas company employees were on s t r i k e . The crew foreman walked down the street t o determine t h e location of t h e gas main by examining paving patches over previous r e p a i r s , w h i l e the o t h e r two men remained a t the manhole. A s h o r t t i m e later, t h e foreman heard one of t h e men call f o r help. The foreman found one man on a ladder i n the manhole holding t h e o t h e r man, who was unconscious. The man on the ladder then l o s t consciousness and both f e l l back i n t o t h e manhole. The foreman radioed f o r a n ambulance and t h e f i r e department t o help g e t t h e asphyxiated men o u t of t h e v a u l t . A t 5:OO a.m., firemen, wearing oxygen masks, removed t h e bodies from t h e manhole. The repairmen had not used t h e r e s p i r a t o r y devices which were on t h e gas company truck. The National Fuel Gas Company’s maintenance and operations manual specified t h a t : (a) No one s h a l l be permitted t o e n t e r a v a u l t or manhole unless a test has been made f o r t h e presence of gas and f o r oxygen deficiency. 2107#

Page 2I - 2 - (b) Workmen entering a v a u l t containing gas concentrations o r oxygen d e f i c i e n c i e s s h a l l use an approved r e s p i r a t o r y device and have a l i f e l i n e attached t o t h e i r body. The autopsies on t h e repairmen revealed t h a t the cause of dea asphyxia due t o carbon monoxide (CO) inhalation. Five thousand t o 10,000 p a r t s per million (ppm)(0.5 t o 1.0%) of CO i n air can cause dea i n 2 t o 15 minutes. 1/ A sample of the coke-oven g a s taken t h e day a f t e r the accident was analyzed and was found t o contain approximately percent carbon monoxide. The day a f t e r t h e accident, a 12-inch-diameter, b a r e steel gas main, which transported manufactured (coke-oven) gas und was excavated. A l e a k w a s found i n t h e pipe 200 f e e t away from t h e manhole. The coupling components including many of t h e b o l t s used t o j o i n t h e p i p e lengths had r u s t e d ; t h i s gas main was not protected cathodically i n accordance with 49 CFR 192.457. Gas, escaping a t 1 psig pressure, had entered t h e telephone conduit through a j o i n t i n clay telephone duct located 6 inches from t h e gas main. Gas had traveled through t h i s conduit and i n t o t h e manhole and v a u l t . A mobile flame i o n i z a t i o n leak survey had been conducted over t h e gas main 2 days before the accident, but no i n d i c a t i o n of leaking gas had been detec Therefore, t h e National Transportation Safety Board recommends t t h e National Fuel Gas Company: Reemphasize t o a l l supervisory and operating personnel the importance of c a r e f u l l y following established pro- cedures f o r working i n v a u l t s and manholes. (Class I, Urgent Followup) (P-77-9) Excavate, on a random sample b a s i s acceptable t o t h e New York Public Service Commission, t o determine i f other bolted couplings have d e t e r i o r a t e d on t h i s 12-inc gas main and make t h e necessary r e p a i r s o r replacements. (Class I, Urgent Followup)(P-77-10) Coordinate with l o c a l e l e c t r i c companies, telephone companies, water and sewer departments, and o t h e r s t r e e t f a c i l i t y owners t o i n s t a l l signs a t manholes a l e r t i n g persons t o t h e hazards of entering before c f o r gas content and oxygen deficiency along t h e r o u t e of t h i s manufactured gas pipeline. (Class 11, P r i o r i Followup) (P-77-11) Encyclopedia of Chemical Technology, second e d i t i o n , 19#

Page 3- 3 - Protect cathodically t h i s 12-inch bare steel gas main s o t h a t continuing corrosion w i l l not r e s u l t i n a condition t h a t is detrimental t o public s a f e t y . (Class I, Urgent Followup)(P-77-12) TODD, Chairman, BAILEY, Vice Chairman, McADAMS and HOGUE, Members, concurred i n t h e above recommendations. HALEY, Member, d i d not p a r t i c i p a t e . By: Webster B. Todd, Jr! Chairman#