[Music] this video is the result of a creative sentencing project in partnership with the government of Alberta energy safety Canada and a company that experienced an incident involving a confined space and nitrogen gas [Music] the guys they're down in the cooler sir can you tell me any more information about the situation what should I do sir I'm gonna need you to stay on the line okay we're dispatching emergency services to your location how did this incident occur the facility is divided into two bays this Bay houses large coolers designed to reach temperatures as low as
minus 185 degrees Celsius [Music] in these coolers nitrogen gas is used as a freeze treatment for metal pipes and other equipment so they can be reused the nitrogen is stored as a liquid in a pressurized tank outside the building the nitrogen turns into a heavy invisible odorless gas as it flows from the pressurized tank through supply lines to the coolers this nitrogen gas is intensely cold nitrogen gas is heavier than air so as it fills a cooler it settles at the bottom displacing the air the cooling system includes two large coolers which are connected by
a transfer duct this duct has two gate valves to control the flow of gas between the coolers these valves are controlled manually each cooler is connected to an exhaust duct that runs up the wall and to the rear of the building where the nitrogen vents outside the exhaust ducts also have manual gate valves the nitrogen Supply is automated so the equipment can be cooled overnight during the cooling process nitrogen is supplied to one cooler and its exhaust gate valve is closed the gate valves are open in the transfer duct between the coolers as is the
exhaust duct on the other cooler this flow path exposes the other cooler to nitrogen partially cooling its contents as the gas moves out of the system this pre-cooled pipe is then fully cooled during the next overnight treatment cycle when the nitrogen flow path is reversed when a cooling cycle is complete the nitrogen is purged using compressed air and a gas monitor is lowered into the cooler once a safe level of oxygen is confirmed workers can climb into the cooler to unload the equipment because of the extreme cold fog will form in the open cooler even
when oxygen levels are safe removing the heavy pipes requires slings and a loader when the crew arrived early on that November day cooler one contains three large pipes that had completed an overnight cycle and cooler too contained many smaller sections of pipe that had been pre-cooled to accommodate a high volume of work they need to run an additional cooling cycle in cooler too during the day this had not been done before the work was performed by Carson the supervisor and three workers miles Wayne and James James was new to the company with this being his
ninth day Carson indicated that he and miles would remove the pipes from cooler one while Wayne and James processed other pipes in the yard they purged the cooler and got to work unloading the large pipe miles climbed into the cooler to wrap slings around the pipe and Carson removed two of them with the loader placing them in the yard to warm up the cooler lid was closed to prevent frost buildup on the remaining pipe which they planned to unload later that morning the additional nitrogen cooling cycle was initiated in cooler too however the position of
the gate valves was not adjusted to support this additional cooling cycle this left an open Flow path from cooler 2 to cooler 1. but with cooler one's exhaust gate valve closed the preferred path of nitrogen was through the Open Exhaust duct on cooler II the crew worked steadily on pipes in the yard until noon when they broke for a quick lunch after lunch Carson and Miles returned to unload the large pipe they'd left in cooler one that morning when miles opened the cooler lid nitrogen immediately rushed through the transfer duct as this was now the
preferred flow path Carson waited in the loader while miles climbed into the cooler to attach slings to the remaining pipe the atmosphere in the coolers was not tested after the lunch break and personal gas monitors were not worn it was normal to see fog and frost in the cooler regardless of the atmosphere so fog did not alert miles to the invisible nitrogen gas building in the cooler miles made his way around the pipe and knelt down to pull the sling under the pipe as he did this he was exposed to the oxygen deficient atmosphere and
immediately passed out Carson unaware of what had just happened to Miles called out to see how things were going when miles didn't answer Carson got off the loader to check on him when he saw miles he called to Wayne for help and entered the cooler to assist hearing Carson yell for help Wayne went to assist Wayne climbs the ladder and entered the cooler to help foreign didn't return after a few moments James went to investigate hey say something he climbed the ladder to check inside the cooler where the crew should have been working what's going
on um oh um what should I do for these three workers help could not save them all three lost their lives on November 15 2018 in Leduc Alberta what can we learn from this tragedy there are several actions that can be taken to prevent future fatalities of this nature processes involving hazardous substances must be engineered based on a risk assessment and should include emergency shutoffs alarms and ventilation these engineered systems should have capacity to fail safely if an error or mistake is made by personnel for example if the status of the gate valve is not
checked or air monitoring is not conducted the design and operation of the coolers should have capacity to fail safely confined space entry requires that you identify confined spaces at the work site identify hazards in the confined spaces and develop a written code of practice specific to the workplace that details how these hazards and changes to conditions will be managed cold nitrogen gas can easily displace oxygen leading to asphyxiation it only takes one or two breaths in an oxygen deficient atmosphere to instantly lose Consciousness leading to possible death confined space incidents often result in multiple fatalities
when a response plan does not exist or is insufficient to protect The Rescuers ensure that you are trained in confined spaces and their hazards as well as the seven step initial response strategy reflecting on this incident in relation to your own work is the most effective way to learn from this tragedy is it possible to fail safely with the confined space safeguards you have in place under what circumstances in your work could nitrogen or other asphyxians impact you um what assurances do you have that your confined space emergency response plan is sufficient what can you
do today to prevent a similar tragedy visit energy safety Canada to learn more about what it takes to safely complete work
