Barrow sub workers go to hospital after being exposed to significantly high levels of deadly gas

An evacuation of all crew and workers onboard Audacious berthed in Devonshire Dock was ordered after sensors detected significant levels of the toxic and odourless gas inside the boat.

Carbon monoxide monitors taken inside the submarine by fire crew wearing breathing apparatus found the highest levels onboard were 600 parts per million in the switchboard room, close to the engine room.

Such levels of carbon monoxide can result in unconsciousness within two to three hours of exposure if left untreated and any work in confined spaces is usually only permitted when the level is zero.

Anyone who had been on the submarine at the time was advised to attend Furness General Hospital.

With hospital staff typically capable of dealing with around eight patients arriving in A&E per hour, the sudden influx of 18 patients put considerable pressure on the department while blood tests were carried out to determine carbon monoxide levels.

It is understood the high levels of carbon monoxide could have been the result of a fault with the clean air filtration system and its back-up system.

The large amounts of the gas could have been produced by the submarine's back-up diesel generators which had been running overnight on Friday. This led BAE bosses to then contact all those who had worked on Audacious during the night in case they too had been exposed.

One night shift worker had already taken himself to A&E after beginning to feel dizzy. He was due to be kept in hospital overnight to be given oxygen treatment.

Another worker, a non-smoker, claims he was told by doctors that his blood contained levels of carbon monoxide that were the same as if he had just smoked two cigarettes.

A spokesman for BAE Systems said the 23 people were taken to a hospital "as a precaution".

They said: "At 7.15am, on Saturday, there was a controlled evacuation of Audacious after the submarine's monitoring systems detected higher-than-normal levels of carbon monoxide on-board.

"By early afternoon this was resolved and employees returned to work."

BAE has informed the Ministry of Defence and an investigation will now attempt to determine the cause of the incident.

An MoD spokeswoman said: "I can confirm that the Navy is aware of an incident at Barrow. No injury to personnel has been reported and there is no risk to the public."

David Walker, medical director at the University Hospitals of Morecambe Bay NHS Foundation Trust, which runs FGH, said: “The incident at BAE Systems saw 23 patients attend Furness General Hospital’s emergency department over the course of Saturday May 27.

“Patients attending any emergency department will always be prioritised depending on the severity of their injuries. Patients from BAE Systems were treated for minor injuries as quickly as possible.

"However, the patients arrived at a time when the department also received trauma calls. These trauma patients were critically ill and so received immediate medical attention.

“Once BAE Systems declared an incident, the North West Ambulance Service supported the trust by attending FGH’s emergency department with an incident vehicle.”

CARBON MONOXIDE POISONING: THE SYMPTOMS

Concentration

Symptoms

35 ppm

Headache and dizziness within six to eight hours of constant exposure

100 ppm

Slight headache in two to three hours

200 ppm

Slight headache within two to three hours; loss of judgment

400 ppm

Frontal headache within one to two hours

800 ppm

Dizziness, nausea, and convulsions within 45 min; insensible within 2 hours

1,600 ppm

Headache, increased heart rate, dizziness, and nausea within 20 min; death in less than 2 hours

3,200 ppm

Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes.

6,400 ppm

Headache and dizziness in one to two minutes. Convulsions, respiratory arrest, and death in less than 20 minutes.

12,800 ppm

Unconsciousness after 2–3 breaths. Death in less than three minutes.