I just read about the russian navy’s latest misadventure; it seems the freon-based fire extinguisher system trigger-and killed 21 people. My question; was there anybody on watch? Would such a poorly-designed system be safe for the crew? presumably, everybody should be on oxygen masks when the freon is on-comments?
Suffocation on submarines is a longstanding danger. Submarines are sealed tubes filled with many industrial processes that produce (or have the potential to produce, should things go wrong) various gases, fumes, and positive and negative pressure differentials. Industrial processes are generally pretty hazardous to human life, and the crew is trapped in the same airspace with all the machinery and chemicals. Furthermore, a lot of different things are going on all the time on a busy military sub, increasing the chance for human error and mechanical breakdown.
In diesel-electric subs, the danger of carbon monoxide buildup from the diesel engines was real enough, but exceeded by the danger of chlorine gas produced by saltwater leaking into the batteries. There are many historical accounts of accidents or near-accidents with battery compartments in particular.
The only unusual bit of news I have regarding the casualties in the story you’re talking about is that the sub was apparently overloaded, with substantially more people on board than is normally the case. Whether this contributed to the accident (or even possibly to a shortage of oxygen/breathing equipment, which seems like a possible oversight) is unknown, but I wouldn’t be surprised if it factored in .
Whether we’ll ever see a credible accident analysis of this accident is an open question, between military secrecy and Russian national pride.
Reports I’ve read state that the sub was conducting sea trials with a number of shipyard workers on board, and that the shipyard workers were not as familiar with the emergency procedures that are drilled into trained sailors.
One of the first thing submariners are taught is how to find and get a breathing mask on during a casualty–immediately.
That being said, it doesn’t seem like the best idea to put an automatic Halon-type fire suppression system in a berthing area.
Link to BBC article.
A proper Halon system will leave O2 in the space. From what I understand the system failed and completely discharged and displaced all the O2.
The sub did have an excessive amount of civilian engineers on board. Indian engineers. India was financing the sub’s completion in preparation for taking delivery of it (Russia is hard up for cash).
Gotta’ love them Ruskies. Some forty years down the line they still have never instituted a comparable “Sub-Safe” program like the US did in the 60s. Human life just isn’t as valuable to them.
Isn’t the idea of a Halon system, or freon, to remove the O2; so nothing can burn?
Surely if you remove enough O2 to put out a fire, that’s not compatibale with people breathing. I know halon systems in the US have alarms before discharge, and O2 breathing maskes in the area.
Halon systems are quite widely used in mainframe computer rooms, because they put out fires with minimal damage to the machines.
These systems are designed to fill the room with a 5-10% concentration of Halon. At that percentage, fires will be retarded or extinguished, but humans are still able to breathe enough to get out of the room. At higher percentages, there may not be enough oxygen for humans to remain conscious long enough to exit.
Thus computer room Halon systems are generally designed with a limited amount of Halon – so that if the entire supply were released into the room, it would still be a less than lethal concentration. Of course, computer rooms can count on being able to refill that small Halon container the next day from a local source. A submarine doesn’t have that advantage, so maybe they designed the system with enough Halon to be able to be used repeatedly to fight fires.
Or it may be that sub Halon systems are designed to deploy much greater concentrations than datacentre installations. I’m no expert, but a fire in a sealed tube full of humans and explosives several hundred metres underwater might merit more agressive fire control measures than a fire in a room full of electronics at or near ground level.
Hopefully one of the submarining Dopers can give us the scoop on how these things work (at least in western boats - the russians do have a tendency to do things differently).
Part of my job is the installation and service of commercial fire suppression systems. t-bonham has is correct. The target for fire suppression in a mainframe computer room is determined by the cubic area of the room, and a three to five percent concentration of halon 1301 will keep a fire out for about as long as the air balance is maintained. In these applications, the total amont of halon available is just enough to reach this target. The cylinders are designed to empty on demand. Having been at this for a long time, I have been in rooms where the halon has been discharged a number of times. The system discharge does not render the space uninhabitable.
That being said, I have no idea how the system was set up in the Russian sub.
Sorry, I hit post too quickly.
The system in the sub may not have been a halon system as used in computer rooms. I have no idea how the system was set up in the Russian sub. The BBC article says that the fire extinguisher was a freon system and does not mention halon as the specific chemical used. Possibly, this system was not safe for occupied spaces.
The fact that at its largest, the Russian Navy had more subs than the rest of the world; combined, 4 sub losses, versus 2 for the US.
Gotta love them Yanks, never read the fine print.
In all of the U.S. submarines that I have been on, there was very limited use of Halon-type fire suppression systems. I can only recall them in some small closed-off spaces filled with electronic equipment.
Most fires were fought manually with the extensive number of fire extinguishers (foam, CO[sub]2[/sub], and dry chemical, as appropriate), and fire hoses.
Do Russian subs still use the very flammable hydraulic fluid? That was what doomed a Russian sub in the Barents Sea (ca. 1993?)-that fire burned so hot that it melted the electrical cables.
Aren’t materials used in a sub all non-flammable?
At its largest, much of the Russian submarine force consisted of outmoded subs whose every deployment was a crapshoot as to whether or not they’d make it back to port without breaking down. (Which is not to say that they have not also produced some rather capable subs–especially after stealing design ideas from the U.S. via espionage–it’s just that the number of such subs has always made up a relatively small proportion of their sub force.)
The Russians/Soviets have had many, many serious accidents that did not necessarily involve the loss of the submarine.
Note too that the U.S. has not lost a submarine since 1968. Forty years is a pretty good safety record. The sub that was lost in 1968 (USS Scorpion) had not yet been upgraded via the SUBSAFE program that was instituted after the loss of USS Thresher in 1963.
In addition, the U.S. Navy has never had a reactor accident.
And if you want to talk fine print, we’re talking about the same Russian/Soviet Navy whose first submarine reactor design had no backup cooling system, and that later designed a submarine (Alfa-class) with so little reactor shielding (to save weight) that the entire engine room (not just the unoccupied reactor compartment) was a high-radiation area during operation. God help the sailor who had to go aft to repair a piece of broken equipment while underway.
I could also go on about their civilian designs and operation. Chernobyl was an accident waiting to happen with a design that cause the nuclear reaction to actually increase during a loss-of-coolant accident (referred to as a positive temperature coefficient of reactivity), as opposed to the inherently safe western designs. The accident in 1986 then occurred during a safety test in which the operators intentionally disabled all of the automatic fail-safe equipment.
I have seen schematics of Russian/Soviet nuclear reactors, but I have no desire to get near one.
I cannot fathom why the indian navy wants this ship. Maintaining a nuclear sub is extremely costly, and requires very special port facilities. add to this, the fact that russian subs are not the best engineered ones, and you have a potentail accident waiting to happen.
Anybody know why India can’t content herself with diesel-electric subs?
Indian military procurements are often highly politcised, part of the great power ambitions they have. They have one CV which spends most of its time as far east from Pakistan as possible, just in case an exocet or harpoon gets it.
WRT to subs they want a nuclear sub, currently they are outgunned by the Pakistan Navy on this, they Kilos and Foxtrots that they have can apparently be heard in the O Club at Karachi Naval Base.