kevon.felmine@guardian.co.tt
In-Corr-Tech president Zaid Khan says Land and Marine Contracting Services (LMCS) air-blowing method of clearing oil from Paria Fuel Trading Company Ltd Sealine No.36 is one of the main factors that caused the deadly Delta P event which contributed to the deaths of four divers.
Khan gave his expert opinion on Tuesday to the Commission of Enquiry (CoE) into the Paria/LMCS tragedy at the International Waterfront Centre, Port-of-Spain,
He presented models of Paria’s berths No.5 and No.6 in the Pointe-a-Pierre harbour. Khan also showed simulations of the line clearing, installation and removal of the inflatable plug, which triggered the Delta P event on February 25, 2022.
This event sucked LMCS divers Christopher Boodram, Fyzal Kurban, Kazim Ali Jr, Yusuf Henry and Rishi Nagassar into the 30-inch pipeline.
The simulation also showed the vortex that lone survivor Christopher Boodram previously described. Khan added that the diver who got sucked in first suffered a free fall down the 60ft vertical part.
The CoE saw how a gaseous void in a line combined with the downward force on the plug and vacuum created behind the plug by the air-blowing method used for line clearing contributed to the incident. Khan, a registered engineer and Failure Analysis Consultant authored a report for the Occupational Safety and Health Authority. In-Corr-Tech does inspections, metallurgical design and quality control engineering services.
Khan explained that when LMCS used air-blowing from Berth No.5 to push the oil back to shore, it pumped air into the pipeline and created a pressurised system when it installed the flange.
While LMCS sought to remove enough oil to create a 35 foot clearance from where it cut the pipeline at Berth No.6, the pressurised air at Berth No.5 held the liquid up, giving the contractor a false reading of how much oil was inside the pipeline. He found that the contractor removed too much content from the pipe, leaving it approximately 80 per cent empty.
He said LMCS only needed to remove 40-60 barrels to achieve the correct clearance. Even the 300 barrels mentioned in the LMCS Method Statement were enough to create the gaseous void.
Khan said there was a way to calculate how many barrels of oil to remove to reach the required clearance. He said LMCS could have measured the levels at both berths after draining the vertical topside pipe to achieve the correct level.
He said LMCS initially planned to pump the oil out of the line, which would have been the correct method. He could not understand why they changed the method.
“High school students know that, so why engineers could not calculate that, I do not know,” Khan said.
It created a latent Delta P hazard before LMCS installed the hyperbaric chamber around the pipeline for the divers to begin working. However, when another team opened the flange at Berth No.5 on February 25 to conduct a carber test, it released some of the pressure, causing the oil level in the pipeline to drop at Berth No.6.
LMCS Managing Director Kazim Ali Snr previously said that the workers installed the inflatable plug against a liquid surface. However, when the oil level in the pipe dropped at Berth No.6, it created a vacuum between the inflatable plug and the remaining liquid.
When the divers removed the inflatable plug, the vacuum sucked in the plug, along with water, equipment and the divers.
Khan maintained and explained why the pipe was stable enough to rescue the divers before the lone survivor, Christopher Boodram, escaped the line that afternoon.
On Monday, Offshore Technology Solutions Ltd (OTSL) executive director Antonio Donawa said there would have been more Delta P in the pipeline and was no way to determine the severity.
Khan explained that Delta P exists in many places, from flying on an aeroplane to standing next to a tank. He said something must trigger a Delta P event, such as creating a hole that pressurised or depressurised one area.
CoE counsel Ramesh Lawrence Maharaj asked if the pipeline was stable and if divers entering could have triggered another Delta P event.
Khan said no, noting that another diver entered following the event.
However, he said opening the flange at Berth No.5 or shutting down the compressor that supplied air to the hyperbaric chamber would be a trigger.
Khan agreed with Paria’s counsel, Jason Mootoo, that LMCS should not have removed the inflatable plug on February 25 as no Permit-to-Work specified that job. He said there should be a permit for all major work in the industry.
CoE chairman Jerome Lynch, asked Khan if Paria had called him on the night of the incident and provided him with the details if he would have known what had happened. Khan said he would have known the men got sucked into the pipe because of a Delta P event.
He also said he would have been able to express whether there was a latent Delta P event in the pipeline.
Mootoo said that because Khan did not know the state of the plug, he could not determine another latent Delta P hazard, saying it could have lodged somewhere.
Khan said that was impossible, and the plug travelled down the vertical and through the elbow. He said the line remained static for two hours, and if anyone asked on the night of the incident, he could have told Paria officials this.
