NTSB recommends new measures to end pipeline anchor strikes

The US National Transportation Safety Board has recommended a range of actions that it hoped would prevent any repeat of the 2021 Orange County oil spill off the coast of California. That spill was caused by an anchor strike on a pipeline, although the unusualness of the incident was that, while the spill occurred in October 2021, the fundamental cause occurred nine months earlier, in January.

NTSB has recommended new notification alarms and procedures for potential incursions on pipelines, as well as a change to an anchorage off the California coast,

NTSB investigators determined that the oil leak, which began on Oct. 1, 2021, in San Pedro Bay, resulted from an anchor strike on the pipeline when anchors from the containerships Beijing (IMO 9308508, 109,149 gt) and MSC Danit (IMO 9404649, 153,092 gt) dragged and contacted the pipeline during high winds and seas caused by a cold front.

The proximity of the anchorage positions to which the vessels were assigned did not give the crews sufficient time or space to heave in their dragging anchors before contacting the pipeline. The NTSB determined the MSC Danit anchor’s contact with the pipeline was the initiating event that led to the crude oil release.

Subsequent to the anchor strike, an estimated 588 barrels of oil leaked from the pipeline, resulting in about $160m in damage, including clean-up costs.

The NTSB recommended the US Coast Guard implement a proposed change to the anchorage where the Beijing and MSC Danit were located when they began dragging their anchors. This would move the boundary of the anchorage farther away from the pipeline. The NTSB also recommended the Coast Guard develop and implement audible and visual alarms for Vessel Traffic Services (VTS) watchstanders when an anchored vessel was encroaching on a pipeline, and to develop procedures for VTS to notify pipeline and utility operators following potential incursions on submerged pipelines and utilities.

NTSB Chair Jennifer Homendy said that “anchorages need to be designed to account for the size of vessels using them and the time it takes for these ships’ crews to react when anchor dragging occurs. Potential damage to a pipeline needs to be reported immediately because the consequences of a pipeline leak are so great. NTSB investigators identified instances where this leak could have been avoided or mitigated, including making the pipeline operators aware of potential anchor dragging so damage could be identified and repaired before an oil release. Investigators also found that the controllers were not adequately trained to handle abnormal operating conditions, which delayed shutting down and isolating the pipeline.”

The NTSB said that factors in the leak were the undetected damage to the pipeline, the pipeline operator’s insufficient training of the pipeline controllers, and the pipeline controllers’ inappropriate response to the leak alarms due, in part, to frequent previous communication-loss alarms.

It took eight total leak alarms before controllers shut down and isolated the line. Had the San Pedro Bay Pipeline controllers responded in accordance with company procedures and shut down and isolated the line at the first alarm, says NTSB, it would have significantly reduced the volume of crude oil released and the resulting environmental damage.

The NTSB found insufficient training of the pipeline controllers contributed to the 14-hour delay in stopping the pipeline’s shipping pumps, which consequently increased the volume of crude oil released.

The NTSB also issued recommendations to the Pipeline and Hazardous Materials Safety Administration, or PHMSA, the Marine Exchange of Southern California, and owners and operators of pipelines regulated by PHMSA.

​The final report will be published on the NTSB’s website in a few weeks’ time.

https://www.ntsb.gov/investigations/Pages/DCA22FM001.aspx