Monday, January 31, 2005
Remember the San Francisco
Gentleman, this is what happens when steel meets rock at high speed.
A few answers I can give for anticipated possible questions:
Q: What's that blue tarp doing there?
A: The Navy wants to provide as much information as possible, consistent with our nation's history of openness, without giving away classified information. Under that tarp is one of the ship's sonar arrays. I'm sure it is extremely mangled as well, but there is no reason to provide open source photographs to whomever may be interested in its shape, size, configuration, wiring, placement, etc.
Q: It says they hit a sea mountain. Why didn't they detect it before they hit?
A: The ship was reported to be traveling at Flank speed (i.e. maximum speed). I will assume the reader understands that submarines (except research vessels) are not outfitted with visual ports as they are of minimal value and degrade watertight integrity. I will also assume the reader understands the principles of active sonar (i.e. ping and listen). Above certain speeds the utility of active sonar is degraded by the fact that the water rushing over the hull is so loud you can't hear the echo anyway. Additionally, fathometers (i.e. depth finders) are tuned assuming a certain speed range. If you go too fast you basically pass the reflected sound before it reaches you. Short answer: there was no way to detect it given the operting parameters.
Q: Well, isn't it on the chart.
A: The reports have emphasized it was an uncharted sea mount, but it is important to understand this in context. Some places in the world have been traversed so much and the depths of the water have been sounded so often that the charted soundings have been checked and verified to the point of near absoluteness (for example, the Mediteranean Sea). Other bodies of water, however, have been relatively seldomly traveled and sometimes not by ships well equipped to accurately determine the soundings. In the Arctic Ocean, for example, the Navy posesses several classified charts since the line of soundings visible clearly indicate the paths our submarines have traversed. Likewise, in parts of the South Pacific an entire chart may have a couple of dozen clear lines of soundings, some literally from Capt. Cook, and the rest of the chart will simply be blank. I haven't looked at the location the accident occurred, but it would not surprise me to see a low sounding density.
Q: If that's the case, what were they doing going so fast? Wasn't it dangerous?
A: I don't know specifically what they were doing other than conducting a high speed transit, a fairly routine activity. If there were circumstances that should have advised against the chosen course and speed the investigation should reveal them. And yes, it was dangerous, but submarining is itself a dangerous and often thankless profession. Comparatively speaking, running at a Flank bell in open ocean is so much safer than any number of other, more fun, things that submarines do it hardly merits mention. My assumption at this point, absent further information, is that the dice just came up wrong for the San Fran on that particular day.
CDR Mooney and his crew lived up to the history of the force, brought everybody home but one and did it on their own power. The Captain has been reassigned during the investigation, as is customary in these cases, but regardless of any possible errors leading up to the event (and I've seen nothing so far to indicate there were any), his peformance in crisis was second to none. One thing that has always defined the submarine force is its brotherhood and cohesion. Chief among the reasons for this is the increadible interdependence of each crew member of every other. Too often when there is a casualty abord a submarine it is an all-hands evolution. While all submariners share the loss of MM2 Ashley, they also know how close San Fran came to going three section with Thresher and Scorpion.
A few answers I can give for anticipated possible questions:
Q: What's that blue tarp doing there?
A: The Navy wants to provide as much information as possible, consistent with our nation's history of openness, without giving away classified information. Under that tarp is one of the ship's sonar arrays. I'm sure it is extremely mangled as well, but there is no reason to provide open source photographs to whomever may be interested in its shape, size, configuration, wiring, placement, etc.
Q: It says they hit a sea mountain. Why didn't they detect it before they hit?
A: The ship was reported to be traveling at Flank speed (i.e. maximum speed). I will assume the reader understands that submarines (except research vessels) are not outfitted with visual ports as they are of minimal value and degrade watertight integrity. I will also assume the reader understands the principles of active sonar (i.e. ping and listen). Above certain speeds the utility of active sonar is degraded by the fact that the water rushing over the hull is so loud you can't hear the echo anyway. Additionally, fathometers (i.e. depth finders) are tuned assuming a certain speed range. If you go too fast you basically pass the reflected sound before it reaches you. Short answer: there was no way to detect it given the operting parameters.
Q: Well, isn't it on the chart.
A: The reports have emphasized it was an uncharted sea mount, but it is important to understand this in context. Some places in the world have been traversed so much and the depths of the water have been sounded so often that the charted soundings have been checked and verified to the point of near absoluteness (for example, the Mediteranean Sea). Other bodies of water, however, have been relatively seldomly traveled and sometimes not by ships well equipped to accurately determine the soundings. In the Arctic Ocean, for example, the Navy posesses several classified charts since the line of soundings visible clearly indicate the paths our submarines have traversed. Likewise, in parts of the South Pacific an entire chart may have a couple of dozen clear lines of soundings, some literally from Capt. Cook, and the rest of the chart will simply be blank. I haven't looked at the location the accident occurred, but it would not surprise me to see a low sounding density.
Q: If that's the case, what were they doing going so fast? Wasn't it dangerous?
A: I don't know specifically what they were doing other than conducting a high speed transit, a fairly routine activity. If there were circumstances that should have advised against the chosen course and speed the investigation should reveal them. And yes, it was dangerous, but submarining is itself a dangerous and often thankless profession. Comparatively speaking, running at a Flank bell in open ocean is so much safer than any number of other, more fun, things that submarines do it hardly merits mention. My assumption at this point, absent further information, is that the dice just came up wrong for the San Fran on that particular day.
CDR Mooney and his crew lived up to the history of the force, brought everybody home but one and did it on their own power. The Captain has been reassigned during the investigation, as is customary in these cases, but regardless of any possible errors leading up to the event (and I've seen nothing so far to indicate there were any), his peformance in crisis was second to none. One thing that has always defined the submarine force is its brotherhood and cohesion. Chief among the reasons for this is the increadible interdependence of each crew member of every other. Too often when there is a casualty abord a submarine it is an all-hands evolution. While all submariners share the loss of MM2 Ashley, they also know how close San Fran came to going three section with Thresher and Scorpion.
