A CATASTROPHIC incident onboard a submarine saw temperatures in the nuclear reactor soar and led to the crew being forced to strip off and use rags filled with ice to cool down, according to a copy of the Royal Navy’s investigation report obtained by the Evening Mail.

In May 2011, Barrow-built submarine HMS Turbulent was on operations in the Middle East when, while berthed at the port of Fujairah in the United Arab Emirates, temperatures onboard the boat began to rise.

According to the investigation report, the boat’s crew believed this had happened for one of two reasons – either the temperature was higher in the port’s stagnant water, or the submarine itself was generating heat and raising the temperature of the surrounding seawater.

At this point, the boat’s senior crew, including commanding officer Ryan Ramsey and the marine engineering officer, had to make a decision.

However, the report goes on to say that “the small drop in seawater temperature that was thought to be all that was needed to improve the performance... never happened” and “the ambient internal temperature and humidity began to rise very quickly”.

The situation was “spiralling out of control”, according to the investigation report, and with temperatures rising to 60 degrees Celsius the boat’s crew had to decide what to do.

The options involved returning to the port and sailing out to a point where the submarine could dive to cooler waters.

“Returning alongside was the least preferred option”, the report says, as it would take up to five hours and, by that point, the temperature could have caused severe casualties and perhaps even worse. The commanding officer ordered the submarine to sail and dive, a procedure that would take up to two hours.

At this point, as things continued to deteriorate, and while the submarine was speeding towards a position to allow it to dive to cooler water, the commanding officer ordered “all ship’s equipment not crucial to safety to be shut down”.

Throughout the report, references are made to what is understood to be the core temperature of the submarine – effectively the temperature inside the nuclear reactor. This was no doubt at the forefront of all decisions made, as an overheating of the nuclear reactor could have resulted in an international incident.

The report says: “People were beginning to lie down... stripping down to the waist... The petty officer medical assistant gave people rags filled with ice”.

The report also reveals that the first severe casualty was the marine engineer officer who was “essentially incapacitated from this time onwards”. His deputy was forced to take over.

Submariners began succumbing to the heat quickly from this point on, with a total of 23 casualties – eight of which were considered to be severe. The boat’s medical assistant started handing out drinks of squash but at this stage the commanding officer realised the situation “was becoming out of control”.

The commanding officer attempted to call the duty submarine controller – essentially the North Atlantic Treaty Organisation’s equivalent of air traffic control, to request permission to dive the submarine but “could not get through”. He then took the decision to dive anyway, having realised there was no time to wait for assistance as there were no other submarines operating in the area.

Around seven hours after the temperature began soaring, the submarine was finally able to dive to cooler waters at a depth of around 200 metres. The report says that “from this point personnel started to recover, with the worst of the casualties being cooled off with hoses and showers”.

Following a meeting of the submarine’s senior crew, decisions were taken to put “physical exercise off limits for one week” and that the crews should “eat and regain strength, gain plenty of rest and sleep”.

However, the report adds that “the total ban on physical exercise was only in force for three days as it was becoming a negative focus of a team who were used to training regularly”, and the report states that the commanding officer allowed this in order to “restore a degree of normality after this catastrophic situation”.

The report’s conclusion goes into detail to highlight the actions of certain individuals who had undoubtedly prevented the situation from becoming any worse.

In particular, the petty officer medical assistant was highly praised in the investigation, with the report’s author stating that his experience with heat-related injuries “definitively made the difference” and “his leadership was exceptional”.

In the report’s conclusions, the author refers to a number of recommendations – many of which have been blacked out for reasons of national security.

It was later revealed, after publication of the investigation report, that the problem was likely to have been caused by a blockage of barnacles in the coolant inlet pipes.

It is clear from the report, however, that the navy was keen to learn from the incident in a bid to prevent a repeat of the disastrous situation, which could easily have led to some of the 100 lives onboard the submarine being lost.

AN assessment of the incident onboard Turbulent, by a former submariner who served on other Trafalgar-class boats:

“THE report makes it clear that the crew were concerned about two things – the manpower to control the reactor and the reactor itself,” the former submariner said, speaking under the condition of anonymity.

“The big problem with the submarine, which is made clear by this incident, is that the Trafalgar-class submarines were designed for a completely different type of war; they were built to fight in the cold waters of the Arctic, and not built to deal with Middle Eastern temperatures.

“In my opinion, the commanding officer made the right decision to continue to a diving position. It would have taken them five hours to return alongside and in that time, someone could have died”.

“I’ve been in a situation myself, where you’re onboard a submarine and the potential threat of death is there, and these men would have been thinking the same but ultimately, and although it sounds harsh to members of the public, the ethos of the Royal Navy and the training the men would have had is that the priority is that of the boat first and then the crew second.

“This ability to override fear proved that the boat was taken from an incident with possible fatalities to a safe controlled area where the situation was managed and a normal state of operation was adopted.”