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| Why the USS San Francisco Ran Aground |
| 2005-01-12 |
| January 12, 2005: The American nuclear submarine USS San Francisco hit an uncharted seamount on January 7th, killing one sailor and injuring 23 others. Facts about the incident were slow to emerge. It appears that the sub was traveling on a course it was ordered to follow, at a depth of 500 feet and a speed of about 56 kilometers an hour. This was the first time the navy had given the speed of a Los Angeles class sub as anything but "25+ knots" (45 kilometers an hour.) It has long been believed that these subs could make more than 55 kilometers an hour. The visible damage to the sub indicated that the sonar dome at the front of the sub was partially collapsed, and, according to information released by the navy, some of the forward ballast tanks were damaged. The pressure hull was not compromised. The submarine immediately surfaced after the collision, which was apparently a glancing one. The crew had some trouble getting to the surface, because of the damaged forward ballast tanks (which hold water, that is rapidly pumped out, and replaced with air, to give the sub buoyancy and bring it to the surface.) The impact, of course, caught everyone unawares, which is why there were so many injuries. The sailor who died, had been thrown forward, hitting his head on a pipe. He died of that injury two days later. The captain usually losses his command after accidents like this, although in this case, that might not happen. If the captain was following all procedures correctly, and there was no way the seamount could be detected, the incident might not destroy his career. There are many uncharted underwater features, especially 500 feet underwater. The technology does not yet exist to economically chart all of the ocean bottoms to that, and greater, depth. Most waters are charted sufficiently to protect surface ships. But there are only about two hundred subs that normally operate at the depth this accident took place. There may be a call for the navy to change its procedures, and have the sub use more active sonar devices when traveling in certain waters. But this will generate protests, because active sonar disturbs the fish. There are also technical issues regarding how effective such sonar would be in avoiding all types of underwater collisions. Moreover, in wartime, you avoid using sonar as a navigation aid, as it gives away your position. Actually, traveling at high speed gives away your position, because of the noise generated by the propulsion system and water rushing over the sub. In wartime, the sub might have been moving at 10-20 kilometers an hour, which would have caused less damage and fewer injuries. If the Navy adheres to maritime tradition, that calls for the naming of previously unknown underwater features after the vessel that "discovered' them, even if by running into them, the uncharted seamount will now be known as the "San Francisco seamount". Accidents like this are rare, but there will probably be a review of the charts, of underwater geography, that are used by American subs. This review process is standard whenever there is a major underwater earthquake or volcano eruption. For example, the December 26, 2004 earthquake off Aceh is known to have seriously rearranged the ocean bottom in that area, and efforts are already underway to update charts. But now an effort will be made to try and determine where there may be other potential "San Francisco seamounts". |
| Posted by:Steve |
| #19 hitting anything at 30kts and being able to bring back the boat and all souls but 1, that is more a cause for commendation instead of a career ender (like I first assumed). If this was truly an unknown seamount, and the boat was under orders to mvoe the way it was , then there is no holding the skipper accountable as long as all the regs and procedures were properly followed. This one goes in my book along with the shuttle disaster as "deaths caused by eco-fascists" (no using the active sonar for the sub, and that cheesy insulation that fell off the booster tank due to "environmentally friendly propellant" changes for the shuttle) |
| Posted by: OldSpook 2005-01-12 10:53:25 AM |
| #18 hitting anything at 30kts and being able to bring back the boat and all souls but 1, that is more a cause for commendation instead of a career ender (like I first assumed). If this was truly an unknown seamount, and the boat was under orders to mvoe the way it was , then there is no holding the skipper accountable as long as all the regs and procedures were properly followed. This one goes in my book along with the shuttle disaster as "deaths caused by eco-fascists" (no using the active sonar for the sub, and that cheesy insulation that fell off the booster tank due to "environmentally friendly propellant" changes for the shuttle) |
| Posted by: OldSpook 2005-01-12 10:53:25 AM |
| #17 It was just a snarky comment. Forget about it. It was classified!!! ;) |
| Posted by: Bomb-a-rama 2005-01-12 10:34:33 PM |
| #16 ... and get some dedicated survey ships--like the USNS John McDonnell and USNS Mary Sears mentioned in previous posts--out there to update their navigational charts. In the area involved, probably. Maybe a bit larger area too - one doesn't want to draw too much attention to one's survey ships. As a rule, surveying and re-surveying areas is time consuming and expensive. Not every place needs to be surveyed either. The areas affected by the tsunami that are high-traffic regions will be done. The rest will probably go decades, if not centuries, before a survey is done. I've used charts of regions in the South Pacific and Middle East that had the bulk of the hydrographic data compiled in 19th century (even some late 18th century) with occasional updates since then. |
| Posted by: Pappy 2005-01-12 8:12:32 PM |
| #15 :) Done that G5. |
| Posted by: Shipman 2005-01-12 6:34:52 PM |
| #14 It was just a snarky comment. Forget about it. |
| Posted by: G5 2005-01-12 4:58:41 PM |
| #13 Good to see you visiting here, Mr. Den Beste. |
| Posted by: Brett_the_Quarkian 2005-01-12 4:25:55 PM |
| #12 Are they Haliburton Command and Control Vessels now? Has it gone that far? This is what happens when you build the big pontoon boats. |
| Posted by: Shipman 2005-01-12 4:17:50 PM |
| #11 G5, *whose* training vessels were used as party boats? By *which* "current leadership?" Don't throw something out there you |
| Posted by: Seafarious 2005-01-12 2:59:45 PM |
| #10 I can say no more. |
| Posted by: G5 2005-01-12 2:54:41 PM |
| #9 Explain please, G5. |
| Posted by: Seafarious 2005-01-12 2:53:46 PM |
| #8 what do you expect when the hydrographic training vessels were used as party boats by the current leadership? |
| Posted by: G5 2005-01-12 2:48:21 PM |
| #7 Actually, what the protesters have been bitching about is their claim that active sonar negatively affects dolphins and whales. Regarding underwater speed, the propeller can be turned faster at depth because the higher water pressure prevents cavitation on the back side of the prop. |
| Posted by: Steven Den Beste 2005-01-12 2:13:54 PM |
| #6 I don't think you can blame the eco-nuts for this--submariners don't want to use active sonar unless it's an emergency because it broadcasts their position way beyond its effective range. It's like shining a flashlight in the dark--you can only see the stuff immediately lit up in front of you, but EVERYONE now knows where you are. I think rather than using active sonar they'll have to restrict depths and speed in areas that are not sufficiently charted and get some dedicated survey ships--like the USNS John McDonnell and USNS Mary Sears mentioned in previous posts--out there to update their navigational charts. As I understand, active sonar on subs is only employed when under attack. The logic being that the enemy knows where you are already so you activate your sonar to locate him and any other boats out there. Additionally, you'll be twisting and turning at high speed to evade torps which will make your passive sonar useless. |
| Posted by: Dar 2005-01-12 11:27:00 AM |
| #5 Sailors versus fishes, employ the sonars, damn it! |
| Posted by: Captain America 2005-01-12 11:16:07 AM |
| #4 The decision to reveal the submarine's speed is indeed unprecedented, though very high underwater speeds have been reported for many years. Submarines designed after the late 1950s use the spindle-shaped "Albacore" hull form, which gives higher speed submerged than surfaced. It has consequently been relatively easy to conceal their actual speeds. Contrary to common assumptions, the real advantage of nuclear power is not endurance at sea (which is limited by factors other than fuel) but sustained underwater speed. In water, power requirements increase in proportion to the cube of the speed. 30 knots would require 64 times as much power as 7 1/2 knots, for example. Some conventional submarines are capable of very high speeds as well, but only for very short bursts, typically an hour or less at full power before the batteries run flat. OTOH, they can run submerged for a week or more at lower speeds. The nuclear submarine, with its enormously higher energy density, can run at high speed for days or even weeks on end. |
| Posted by: Atomic Conspiracy 2005-01-12 10:57:38 AM |
| #3 hitting anything at 30kts and being able to bring back the boat and all souls but 1, that is more a cause for commendation instead of a career ender (like I first assumed). If this was truly an unknown seamount, and the boat was under orders to mvoe the way it was , then there is no holding the skipper accountable as long as all the regs and procedures were properly followed. This one goes in my book along with the shuttle disaster as "deaths caused by eco-fascists" (no using the active sonar for the sub, and that cheesy insulation that fell off the booster tank due to "environmentally friendly propellant" changes for the shuttle) |
| Posted by: OldSpook 2005-01-12 10:53:25 AM |
| #2 Say what you want, but the sub hit the seamount at ahead flank and they were able to get her back to Guam. This says quite a bit for the design and construction of a 688. It also says a hell of alot about her crew. |
| Posted by: Penguin 2005-01-12 10:24:45 AM |
| #1 But this will generate protests, because active sonar disturbs the fish. You have got to be shitting me. But, of course, you're not... |
| Posted by: tu3031 2005-01-12 10:01:42 AM |