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Fire May Leave US Nuclear Sub Damaged Beyond Repair
Hugh Pickens writes "AP reports that a fire that swept through a nuclear-powered submarine in dry dock at Portsmouth Naval Shipyard has caused such extensive damage to its forward compartments that the 22-year-old Los Angeles-class attack submarine might have to be scrapped. 'These submarines were designed decades ago. So they're no longer state of the art,' says analyst Loren Thompson. 'If this vessel returns to service, I will be amazed.' The fire broke out while the Miami was on a 20-month stay at the shipyard for an overhaul, and it took firefighters from more than a dozen agencies twelve hours to put out the fire, described as intense, smoky, and a 'hot scary mess.' 'It takes a lot of guts to go into a burning building. But the idea of going into a submarine full of hot toxic smoke — that's real courage,' said U.S. Rep. Chellie Pingree after meeting with the shipyard commander. Firefighters isolated the flames so they would not spread to nuclear propulsion spaces at the rear of the submarine. There was nuclear fuel on board the sub, but the reactor has been shut down for two months and was unaffected. Rear Admiral Rick Breckenridge says an investigation has been launched into what caused the fire, but he expects that investigation to take a long time to complete and wouldn't say if human error has been ruled out as a cause of the fire, or if the focus is on mechanical issues."
Pardon my ignorance here. But I have a question.
I know that fire in a sub is considered one of the most dangerous threats there is (every crew-member is trained in fire suppression on a sub). But since this ship was presumably unmanned and in dry dock, and presumably also still air-tight, why didn't they just close all the hatches in the effected areas and shut off the oxygen? I can't imagine a fire in such an enclosed space would last very long without incoming oxygen.
What political party do you join when you don't like Bible-thumpers *or* hippies?
Well, that's confusing... The article is from a newspaper in Seattle, about a Los Angeles class boat in Portsmouth, Maine named Miami...
Two crew members, three shipyard firefighters and two civilian firefighters were hurt, but their injuries were minor, officials said. Officials were waiting Thursday to begin venting smoke and noxious fumes so workers could go inside the submarine to assess the damage. Workers had to let fire-damaged compartments cool enough for fresh air to be safely introduced without risk of another fire.
My work here is dung.
The USS Miami was my first boat, 1998-2003.
Yes, there is a possibility this was bedding. Usually though, when you go into an overhaul like this, all the bedding is removed. The mattresses may or may not have been removed.
There is a lot of wiring that is bundled together around ships. There is also quite a bit of temporary equipment that is brought on the ships during overhauls like they were doing that could have been the source as well.
There is no "fire suppression system" as you might imagine. Normally all firefighting would have been taken care of by the 130 man crew. Portable extinguishers only go so far, and it seems that this was far beyond a few extinguishers.
I stood my fair share of watches in the engine room. I knew this day would come sooner or later. I'm sure that the nuclear operators stayed at their watch stations during all this. This is a hell of a way for the Miami to go out.
Can do, will do, glad to.
First to fire, twice to fire.
SSN-755
Hi there. Ex-submariner here. One reason was that they likely could not close the hatches. Being in one of these extended dry dock periods usually means that they have all sorts of hoses, wires, etc. going through the hatches making them neigh impossible to close without taking a hatchet to them all. Not to mention, if they were doing any sort of work on the sea water piping, which may be plausible since they were in dry dock, then the fire would still be supplied from the lack of piping that is normally there due to the repair.
My first guess of how this fire happened is that someone had done some welding in a compartment and something caught fire. Usually the Navy is pretty good about removing flamables in the area. They even go so far to have a "fire watch" for several hours after the welding was done to ensure that nothing catches fire. it will be interesting to hear what the root cause is.
Another interesting fact about L.A. class submarines, of which the Miami is included. There is only one water tight door interior to the sub, and that is the one that separates the forward part of the ship to the rear (ie engineering which was apparently not affected). Compare that to the submarine that I was on (Sturgeon Class), there were two water right doors for just the forward part of the ship, and two in the engine room. Basically, if you ever have flooding in an LA class sub, you are going down. At least in a Strugeon class, if 3 of the 5 compartments were completely flooded, you could still survive.
Every ship is manned until it is decommissioned. One third of the crew is on board at all times to stand security watches and maintain the ship. For various reasons listed in other comments, just shutting the hatches was unacceptable - even if you had been able to stop the fire that way, the risk of reflash and the damage would be unacceptable. Submariners do not run from fires.
What will likely happen is what has happened before. The oldest LA class boats are the ones being replaced by the Virginia class, so they'll promote the Miami down the list to be written off against the next Virginia instead of whatever boat was scheduled for scrapping. That boat will then get an overhaul instead of being scrapped.
Been done with destroyers, carriers and subs in the past if my history memory isn't full of holes.
Trying to become famous by taking photos. Visit my homepage please.
When metal burns, depleting it's oxygen supply doesn't always help. When I was in, the SOP for burning metal was to push it overboard and let it sink to the bottom where it could burn out safely.
There is a 250 volt battery with a huge amount of potential energy. You have basically a medium size bedroom full of batteries that are 6 feet tall.
The battery can keep the lights running for about 1.5 hours while also supplying power to move it through the water and power the reactor plant to do a restart.
We calculated one time that if all the energy in the battery was released at once (not possible, we knew that), it would blow the sub 1.5 miles into the air.
I hope that someday we will be able to put away our fears and prejudices and just laugh at people. - Jack Handey
Pardon my ignorance here. But I have a question.
I know that fire in a sub is considered one of the most dangerous threats there is (every crew-member is trained in fire suppression on a sub). But since this ship was presumably unmanned and in dry dock, and presumably also still air-tight, why didn't they just close all the hatches in the effected areas and shut off the oxygen? I can't imagine a fire in such an enclosed space would last very long without incoming oxygen.
I am a former submariner.
1 - A submarine in dry dock is basically a ship on ship. A problem on one constitutes a problem on the other.
2 - There is a lot of piping throughout the boat. It contains either oxygen (@ 10's of PSI) or hydraulic fluid (@ thousands of PSI). If the piping burst, its source is a giant tank containing much more of the stuff in a different location of the boat. There are isolation valves, however, which may mitigate the problem for a while.
3 - There's this thing called a nuclear reactor. It's shut-down while in dry-dock but still requires power to keep it safe.
4 - Separating the reactor and the forward compartment is a giant tank containing thousands of gallons of diesel fuel oil. If it over heats, well, yeah, kiss your asses goodbye.
5 - There's a HUGE battery on the boat for when the boat needs to run off of battery power. It contains an enormous amount of energy - so much so that if it caught fire and exploded, the sub, the dry-dock and the facilities surrounding it would be damn near vaporised. I think anything within a few miles would *easily* have its windows blown out if not flattened.
6 - If the reactor has a problem, you'll basically have Fukushima on your hands.
7 - Submarine fires (when the get large enough) dont stay a single class of fire for long. There is too much hydraulic fluid, electrical line and combustible materials for it to remain one class of fire for long - ergo, one can not simply spray water (seawater, btw) to extinguish it.
So, no. Shuttering the place up and trying to starve the fire isn't exactly a proactive manner to extinguish a fire.
Throw in skeleton crews (most systems shut down), lots of welding, oil and whatnot all over the deck and you have a recipe for disaster on your hands. I'm surprised there arn't more fires of this magnitude more often.
More questions? Guess I'll read below and answer some there, too.
yep, fire is usually considered the #1 hazard aboard space ships and subs. Simply because the first thing you normally do when there's a fire is evacuate, something that's not such an easy option for them.
Evacuating ship is *not* the first thing submariners do. They attack fires with a vengeance. One, it's stealing our oxygen. Two, it's polluting our oxygen supply with *deadly* gases. Three, it can kill you fairly quickly. Some exhaust gases on board submarine cause damn near instant death.
And that's just compounded by the low availability of breathable air.
Actually, you're close. Underway (that means out to sea) subs purposefully keep their oxygen levels low - very low. So low that a cigarette will immediately extinguish when the smoker is not inhaling. It must be re-lit before each puff.
But that's not important. The important part is that whatever is attempting to catch fire would smoulder for a bit before flaming up - thereby catching the eye/ear/nose of the watch or any other passing crew member.
In port, oxygen levels are normal to the atmospheric oxygen levels of the surrounding city. (By the way, Norfolk, VA smells bad. - Norfolk sub sailors know what I'm talking about. ;P )
I don't know on the hatches, I'd expect a sub to have the usual complement of watertight compartments, so as long as the fire didn't get hot enough to melt or deform bulkheads (which it may, which is why they stopped using aluminum for warship superstructure) they should have simply been able to close the doors.
Let me address this. While in dry dock, the boats have all kinds of cabling in the way preventing hatches from being closed. Forgot about that in my first post on this topic. So, no, you typically cant just walk up and close the hatch - not that you'd want to. See my previous post, above.
But maybe they had problems getting the people out first. Subs don't have too many doors on them, and if the fire is between 25 crew and the door and there's no other route, sealing off isn't an option.
I find it hard to come to a conclusion where this would become a problem. There are multiple exits in most areas that are 'dead ends'. There'd have to be a pretty messed up situation that prevented ~25 people from escaping a location without them trying the emergency route *before* the emergency route became blocked.
The ship is never unmanned. There is always people in the engineering spaces except for very few limited special conditions during a defueling of the reactor and there is at least one person forward of the engineering spaces as a roving watchstander.
I'm not sure about the specific conditions while in drydock but normally, any temporary setup (hoses, pipes etc) that passes through a water tight door has to have a quick disconnect or a way to isolate or cut the obstruction away so the door can be shut easily and quickly. I don't recall ANY circumstance where the reactor tunnel water tight door (the door that separates the forward part of the ship from the engineering spaces above the reactor compartment) could ever have anything passing through it and that door had to be shut at all times unless you are actually passing through it.
As for fire and flooding on a sub? I went through one flooding and two fires. The flooding was pretty bad and scary but at least you are "aware". You can still see, hear, and move around freely to isolate and fix it. Any type of fire almost immediately fills the entire compartment with heavy smoke, even small transformers, coils, actuators, etc can have a much bigger bark then a bite. It is scary. In 10 seconds you can't see or breathe and running away is NEVER an option. There is no "fire" department or any safe place to go. You have to immediately respond and act quickly to save you and your shipmates lives. The ship has breathing masks spread out in places and standard air type valves to plug them into all around the ship and you are trained how and where to find them in the dark. It is very scary when you have to unplug your mask, hold your breath and walk 10-20 feet in complete blinding smoke hoping you can find the next place to plug in your mask. All of this while trying to roll out a fire hose in an area about 2.5 feet wide with cabinets and pipes all around and fumbling with your mask and its hose and coordinate with other people you can not see and barely hear. You also have to check and make sure the air is cut off between compartments, luckily, the valves and air pipes can be shut from the adjacent compartments. It's hard to describe in words in a forum post but there is a lot going on. Submariners train for this and other situations over and over and over again. You have to know where every piece of damage control gear is on the ship, every hose, every type of extinguisher, every pump, every locker with breathing masks, know how to find the connections where to plug your mask in, who is in charge when, what information to relay, how to secure your space, how to remove an electrical panel, know what is flooding or on fire and how to get the power off to it etc.. If you give the wrong location of the source and someone shuts that source down, you could be screwed because the fire/flooding will rage on and you lost some other vital capability by shutting down good running equipment. Same extensive training with flooding, reactor "issues", loss of propulsion etc as well. You spend more time training and running exercises than anything else. I was on a submarine for about 10 years. Everyone makes jokes, picks on nubs, did some hazing within new Navy guidelines etc but when the shit hit the fan or something was going wrong, people stepped up and had your back 100% every single time. The option to walk or run away from a threat is not there. Stepping outside for a while is not an option.
Happy Memorial Day to my fellow shipmates and those that have served in the armed forces. I Thank You.
And that's just compounded by the low availability of breathable air.
Actually, you're close. Underway (that means out to sea) subs purposefully keep their oxygen levels low - very low. So low that a cigarette will immediately extinguish when the smoker is not inhaling. It must be re-lit before each puff.
But that's not important. The important part is that whatever is attempting to catch fire would smoulder for a bit before flaming up - thereby catching the eye/ear/nose of the watch or any other passing crew member.
In port, oxygen levels are normal to the atmospheric oxygen levels of the surrounding city. (By the way, Norfolk, VA smells bad. - Norfolk sub sailors know what I'm talking about. ;P )
This is not correct. Actually the atmosphere in the boat while underway is 19-21% oxygen. Atmospheric oxygen levels are around 20% worldwide. The atmosphere on the ship is no different in any way from the atmosphere that you are currently in most likely (gas wise). What IS different is the pressure which changes with the depth the ship is at, the amount of time since the ship has "equalized pressure" by putting the exaust mast up, and the amount of people on the ship (you all breathe out more than you breathe in).
And this is where *your* boat took chances. Our boat kept the oxygen levels at about 13% to 15%. Yes, you read that correctly. Again, the smokers had to inhale *deeply* while attempting to light their cigarettes so they could create enough air-draw across the surface of their *lighters* to get the lighter to even light so they could light their cigarette. Low oxygen levels starve fires.
You say you've been in 3 fires and they were extinguished within 10 minutes? I'm very glad you did. However, wow. Amazing. How many captains did your boat(s) go through? While we had our own scares we only had 1 real fire on board while underway and it was nothing more than a smoking rag. Someone left it on top of the CO2 Candle where it began to smoke. It was amazing. I was one of the few who showed up in an EAB. Three guys showed up in their skivvies. People were on it *instantly*.
The only other time we had a near miss (and the scariest moment of my life, hands down) was when our 4500lbs Hydraulic line ruptured in the engine room. It was spraying 4500lbs PSI hydraulic fluid into the engine room. If the roving watch underway hadn't been standing *right* next to the kill switch when it ruptured I might not be here today. We surfaced and remained surfaced for 3 days drawing circles on nav charts in sea state 3 to sea state 4 seas. If the oxygen levels were any higher AND (I stress AND) the fluid would have sprayed at 4500psi for more than 30 seconds, it would have been a flame-thrower.
It's purely up to the CO on what level of O2 he wants the boat to run around at. Maybe they've enacted some regulation since I got out in late 1996; but, don't sit there and say I'm not correct. Certainly, in port the ship's O2 levels are in keeping with the surround local atmosphere - ~20%. Our boat kept O2 levels low purposefully under-weigh.
But maybe they had problems getting the people out first. Subs don't have too many doors on them, and if the fire is between 25 crew and the door and there's no other route, sealing off isn't an option.
I find it hard to come to a conclusion where this would become a problem. There are multiple exits in most areas that are 'dead ends'. There'd have to be a pretty messed up situation that prevented ~25 people from escaping a location without them trying the emergency route *before* the emergency route became blocked.
Okay so oddly enough there isnt really an "emergency route" on the ship for reasons that I wont detail here (it would take too long to explain). I do have to say that there are contingency plans in place for this kind of thing un