Attn: Navy or ex-Navy people. Question for you

[JRNYMAN]

This video shows a US submarine and a tug boat that has somehow gotten tangled up in some way or another. Then after what seems like the tug is able to pull away, it gets high centered (I think...) on the stern planes (?) and then, all of the sudden the tug just sinks, ass-first for seemingly no reason. Could someone please explain what the heck happened here 'cause I don't get it.

http://www.youtube.com/watch?v=UrKHLQMA_5U

[Don]

The tug got stuck on one of the sub's tail fins? When it pulls away that opens the hole the fin was clogging and the tug floods and sinks.

[The Sushi Hunter]

Don's right, the tug hit the aft portion called the stern planes of the sub and sustained enough damage to send it down, and tugs aren't designed with much if any water tight integrity since they aren't designed to be used in combat situations. That's some really old footage, not sure I even remember hearing about it, but they usually keep sub news under wraps. Tug didn't break away fast enough to clear the aft of the sub, could have been because the sub was moving faster than protocol, which did not allow the tug to pull away quick enough. In the video you can see the sub was making a hard starboard turn trying to get the stern of the sub away from the tug. The sub was moving forward too fast though and the tug was stuck on it.

In the image below, you can get a general idea of what it is the tug hit that was under the water line that you couldn't see in the video.

[JRNYMAN]

Don's right, the tug hit the aft portion called the stern planes of the sub and sustained enough damage to send it down, and tugs aren't designed with much if any water tight integrity since they aren't designed to be used in combat situations. That's some really old footage, not sure I even remember hearing about it, but they usually keep sub news under wraps. Tug didn't break away fast enough to clear the aft of the sub, could have been because the sub was moving faster than protocol, which did not allow the tug to pull away quick enough. In the video you can see the sub was making a hard starboard turn trying to get the stern of the sub away from the tug. The sub was moving forward too fast though and the tug was stuck on it.

In the image below, you can get a general idea of what it is the tug hit that was under the water line that you couldn't see in the video.

Okay I get it now. Thanks to both.
So, the tug was actually assisting the sub and that's why it was so close to it or did the sub surface and the tug just happened to be right where it surfaced? If it's the former, I didn't realize subs needed assistance from tugs the way ships do to maneuver in close quarters and what not.

[The Sushi Hunter]

The sub and tug were conducting what is called underway replenishment detail (unrep). That is when two or more vessels "meet up" and transfer people and/or supplies from one vessel to the next. Notice when the tug was sinking you can hear someone make a joke "There goes the mail"? This is the way subs received their mail. I was reading some of the comments on that youtube vid and apparently there are some guys who posted information about what was going on there. A guy was moved from the sub to the tug, which is most likely his tour was over and he was PCS'ing off to another duty station. Watching the video I see a guy in his summer dress whites on the tug waving to the sub as they depart one another, which leads me to believe he's the one who was the one leaving the sub. This is one of the methods they use to transfer guys off vessels, other way is transferring them off at the next available port of call, or flying them off if they are on a carrier or other such vessel that has birds. Vertrep (Verticle Replenishment) is another method of transferring people and/or supplies from one ship to another via heli.

[JRNYMAN]

The sub and tug were conducting what is called underway replenishment detail (unrep). That is when two or more vessels "meet up" and transfer people and/or supplies from one vessel to the next. Notice when the tug was sinking you can hear someone make a joke "There goes the mail"? This is the way subs received their mail. I was reading some of the comments on that youtube vid and apparently there are some guys who posted information about what was going on there. A guy was moved from the sub to the tug, which is most likely his tour was over and he was PCS'ing off to another duty station. Watching the video I see a guy in his summer dress whites on the tug waving to the sub as they depart one another, which leads me to believe he's the one who was the one leaving the sub. This is one of the methods they use to transfer guys off vessels, other way is transferring them off at the next available port of call, or flying them off if they are on a carrier or other such vessel that has birds. Vertrep (Verticle Replenishment) is another method of transferring people and/or supplies from one ship to another via heli.

Interesting. I didn't read the comments but did read the description in which it said 2 people were lost in that incident.
Speaking of transferring stuff to and from subs... one of my brothers was career Navy and while out on a mission, our Dad's health took a turn for the worse and wasn't expected to make it much longer. My mom made a call (I was really young at the time so I have no idea the specifics) and the Navy sent a helicopter out to renz de vous with the sub somewhere in the Indian ocean where it surfaced, transferred my brother to the chopper then on to a carrier. A transport plane was waiting to fly him to whichever airport and he was home from the middle of the ocean in less than 36 hrs. Amazing!

I guess the part of the situation I still don't get is how the sub got punctured by the stern plane when it's lateral to the bottom of the tub. If it was sticking up I could understand. I'm not being thiick-skulled, I promise!

Thanks for taking the time to explain this in such detail for me.

[Rick]

It didn't take long for that boat to sink. I imagine those little tug boats being extremely heavy, with all the horse power they have to generate.

[JRNYMAN]

It didn't take long for that boat to sink. I imagine those little tug boats being extremely heavy, with all the horse power they have to generate.

Yeah, it definitely went down in a hurry. When I first saw the vid I thought that the combination of the tug's captain giving it full throttle (which you can see right before it starts to sink from the thick black deisel smoke) and its bow being hung up o the sub that the stern somehow dropped below the surface just long enough to take on enough water to sink it which would have made more sense to me seeing as how it's the bow that's hung up and apparently where the hole was made. If that's the case, then why did it sink ass-first? I guess I'm just ignorant on this one.