'No actions were taken prior to the excavation work commencing to anticipate for an accidental gas release'
An excavator hit an exposed gas line and caused the explosion at the Canadian Forces Base Comox, also known as 19 Wing Comox, on Vancouver Island in November 2021.
This was the finding of Technical Safety BC, an independent, self-funded organization that oversees the safe installation and operation of technical systems and equipment across the province, according to a CBC report.
That was the case even though the contractor working at the site had located, identified, and exposed by hand the gas line in the vicinity of the excavation work.
Read more: Comox blast injures 16 military members in total
The incident happened on Nov. 18 last year and left a total of 28 people injured, including 16 military personnel.
The contracting company was hired to install a new perimeter drain around the exterior of a military barracks building.
“The hazard of hitting the line with the excavator had been identified by the contractor who developed a plan and communicated to employees to keep mechanical excavation over one meter away from the line,” said Technical Safety BC.
However, “no actions were taken prior to the excavation work commencing to anticipate for an accidental gas release or to identify risk factors such as possible gas migration into the building, building occupancy at the time of the work or potential ignition sources in the area.”
Read more: 10 injured in Vancouver Island military base explosion
According to the excavator operator, prior to the explosion, the company had discussed the gas line at the site and planned to expose it by hand while staying one metre away with the excavator. Also, the excavator operator had entirely exposed the gas line 15 feet out from the gas meter by hand and it was entirely visible to them while in the cab of the excavator.
They also had “little perceived risk in working around the exposed gas line,” according to Technical Safety BC. “They stated it was only a small ¾” line at low pressure and not a 4-6” high-pressure line. Other contractors had mentioned to them that when they had hit gas lines that it was a one in a million chance it would cause a problem.”
The supervisor, meanwhile, noted during work preparation meetings they decided they would not be digging with the machine closer than one metre to either side of the gas line; and the excavator operator was a qualified and talented operator with lots of experience on the machine they were using.
“They were the designated spotter for the excavator operator when working around underground services. After the gas line was exposed the job of the spotter was complete and they were not in the trench spotting for the operator when the line was struck,” reported Technical Safety BC, citing the supervisor.
It said that contributing factors that could be considered dangerous manners of excavation work include:
- working in close proximity to an exposed and unprotected gas line with a mechanical excavator
- working in close proximity to an unprotected gas line without a spotter
- misunderstanding of explosion risks when working near live gas lines
- not moderating excavation practices when an increased risk of explosion hazards are present such as occupied buildings, building openings and ignition sources
