NTSB Safety Recommendation P-86-020

NTSB safety recommendation P-86-020.

THE NTSB RECOMMENDS THAT NORTHEAST UTILITIES SERVICE COMPANY: CONSIDER THE ABANDONMENT OF CAST-IRON GAS MAINS PRIOR TO ANY EXCAVATION WORK IN THEIR PROXIMITY. WHERE ABANDONMENT IS NOT PRACTICAL OR FEASIBLE PRIOR TO THE EXCAVATION WORK, ASSIGN INSPECTORS TO THE JOB SITE TO MONITOR THE EXCAVATION WORK.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1986-11-24

Adopted Date: 1986-11-14

Overall Date Closed: 1995-08-01

Synopsis: ABOUT 3:55 P.M., EASTERN STANDARD TIME, DECEMBER 6, 1985, A NATURAL GAS EXPLOSION AND FIRE DESTROYED THE RIVER RESTAURANT AT 268 MAIN STREET IN DERBY, CONNECTICUT. GAS ESCAPING FROM A BROKEN GAS MAIN AT A PRESSURE OF ABOUT 1 POUND PER SQUARE INCH HAD ESCAPED, MIGRATED INTO THE RESTAURANT BASEMENT, IGNITED, EXPLODED, AND BURNED. OF THE 18 PERSONS INSIDE THE RESTAURANT AT THE TIME, 6 WERE KILLED AND 12 WER INJURED; 1 PASSERBY AND 1 FIREFIGHTER WERE ALSO INJURED. AFTER THE ACCIDENT THE STREET ADJACENT TO THE RESTAURANT WAS EXCAVATED WHERE A 24-INCH DIAMETER SEWER SYSTEM HAD JUST BEEN INSTALLED; AN 87-YEAR-OLD, 3-INCH DIAMETER, CAST-IRON NATURAL GAS MAIN WAS FOUND BROKEN.

Probable Cause: None

Ntsbnumber: DCA86FP004

Report Number: PAR-86-02

Addressee Name: Yankee Gas Services Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1995-08-01

Addressee Organization Type: P-Private Industry

Communication Date: 1987-02-10

Communication Type: Official Correspondence

Communication Contents: THE COMPANY HAS A REPAIR/REPLACE POLICY WHICH ADDRESSES GAS FACILITIES IN PROXIMITY TO EXCAVATION PROJECTS. THE GAS FACILITY IS REPLACED (MATERIAL DEPENDENT) WHEN IT IS LOCATED WITHIN THE ZONE OF INFLUENCE OR ANGLE OF REPOSE (45 DEGREES) AND NO OTHER ADJACENT ACTIVE SUPPORTING STRUCTURES EXIST. WHEN THE COMPANY HAS KNOWLEDGE THAT A GAS FACILITY WILL BE EXPOSED AS A RESULT OF CONSTRUCTION ACTIVITY, AN INSPECTOR MAY BE ASSIGNED ON A TEMPORARY OR FULL-TIME BASIS, DEPENDING ON THE TYPE AND EXTENT OF CONSTRUCTION.

Addressee Organization Type: P-Private Industry

Communication Date: 1995-06-14

Communication Type: Official Correspondence

Communication Contents: THE COMPANY REVIEWS ALL CONSTRUCTION PROJECTS TO DETERMINE THE LOCATION OF GAS FACILITIES & ANY POTENTIAL CONFLICTS WITH THE PROPOSED CONSTRUCTION. ANY DIRECT CONFLICT WITH CAST IRON GAS MAIN REQUIRES REPLACEMENT OR RELOCATION. WHERE REPLACEMENT IS NOT PRACTICAL OR FEASIBLE, A MOBILE LEAKAGE SURVEY IS CONDUCTED PRIOR TO, AT TIMES DURING, & FOLLOWING THE CONSTRUCTION PROJECT. INSPECTORS ROUTINELY & RANDOMLY INSPECT THE CONSTRUCTION AREA & REMAIN ON SITE WHENEVER EXCAVATION WORK IS IN CLOSE PROXIMITY TO A CAST IRON GAS LINE.

Addressee Organization Type: P-Private Industry

Communication Date: 1995-08-01

Communication Type: Official Correspondence

Communication Contents: THE BOARD NOTES THAT THE NORTHEAST UTILITIES SERVICE COMPANY HAS BEEN MERGED INTO YANKEE GAS SERVICE COMPANY. WE UNDERSTAND THAT THE YANKEE GAS SERVICE COMPANY REVIEWS ALL CONSTRUCTION PROJECTS AND, THE CASE OF ANY CONFLICT WITH CAST-IRON MAINS, REQUIRES REPLACEMENT OR RELOCATION. WHERE REPLACEMENT IS NOT PRACTICAL OR FEASIBLE, A MOBILE LEAKAGE SURVEY IS CONDUCTED PRIOR, DURING, & AFTER THE CONSTRUCTION PROJECT WHILE AN INSPECTOR IS MONITORING ON SITE. BASED ON THIS INFO P-86-20 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

Addressee Organization Type: P-Private Industry

Communication Date: 1987-05-14

Communication Type: Official Correspondence