Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation P-71-009
Details
Synopsis: ON SEPTEMBER 9, 1969, A 14-INCH PIPELINE CARRYING NATURAL GAS AT A PRESSURE OF MORE THAN 780 P.S.I.G. RUPTURED IN A RESIDENTIAL SUBDIVISION 3 1/4 MILES NORTH OF HOUSTON, TEXAS. ALL RESIDENTS WERE EVACUATED, AND ABOUT 8 TO 10 MINUTES LATER, THE ESCAPING GAS EXPLODED VIOLENTLY. THIRTEEN HOUSES, RANGING FROM 24 FEET TO 250 FEET FROM THE RUPTURE, WERE DESTROYED BY THE BLAST. THE LEAKING GAS CAUGHT FIRE AND BURNED FOR 1 1/2 HOURS UNTIL VALVES ON EITHER SIDE OF THE LEAK WERE CLOSED BY MOBIL WORKMEN. IN ALL, 106 HOUSES WERE DAMAGED, AND PROPERTY DAMAGE WAS ESTIMATED AT $500,000. MIRACULOUSLY, THERE WERE NO DEATHS, BUT 9 PEOPLE WERE INJURED, 2 SERIOUSLY.
Recommendation: NTSB RECOMMENDS THAT THE MOBIL OIL CORPORATION TAKE THE FOLLOWING ACTION: RECALCULATE THE PRESENT MAXIMUM ALLOWABLE OPERATING PRESSURE ON THIS PIPELINE, UTILIZING A JOINT FACTOR OF O.85 FOR THE ERW SECTIONS OF THE LINE, AND REDUCE THE PRESSURE AT WHICH THE LINE IS OPERATED, WHERE NECESSARY, TO COMPLY WITH THESE NEW CALCULATIONS.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Pipeline
Location: Houston, TX, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: 80255
Accident Reports:
High Pressure Natural Gas Pipeline
Report #: PAR-71-01
Accident Date: 9/9/1969
Issue Date: 7/1/1971
Date Closed: 9/10/1976
Addressee(s) and Addressee Status: ExxonMobil Corporation (Closed--No Longer Applicable)
Keyword(s):

Safety Recommendation History
From: NTSB
To: ExxonMobil Corporation
Date: 4/30/1973
Response:

From: ExxonMobil Corporation
To: NTSB
Date: 11/12/1971
Response: IN A LETTER FROM MOBIL, NEW INFORMATION WAS SUPPLIED ALONG WITH A "TECHNICAL REVIEW." MOBIL REQUESTED THAT BASED ON THIS NEW DATA, THE RECOMMENDATION BE WITHDRAWN. THE TECHNICAL REVIEW IS BEING STUDIED AND A REPLY WILL BE PROPOSED. 5/30/72 - MOBIL SUBMITTED ADDITIONAL INFORMATION CONCERNING MANUFACTURING SPECIFICATIONS AND TESTS PERFORMED AND RENEWED ITS REQUEST THAT THE RECOMMENDATION BE WITHDRAWN. CORRESPONDENCE DOCUMENTATION INCOMPLETE.