Model Boat Mayhem
Mess Deck: General Section => Chit-Chat => Topic started by: polaris on December 12, 2012, 08:22:09 pm
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... well... what do you think?............?
http://www.youtube.com/watch?v=UrKHLQMA_5U (http://www.youtube.com/watch?v=UrKHLQMA_5U)
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Hard to tell for sure but it seemed to me that the sub was moving ahead before the tug was clear. Although the sub's rudder was over it either wasn't swinging the stern fast enough or the tug was being sucked in behind it.
Sad that two people died due basically to impatience. (But then again, most of the several thousand deaths a year on the roads are down to that - ho hum.)
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Hi,
In my opinion,
When you pass water between two parallel surfaces the tendency is to draw the surfaces together… remember the experiment in 1st year science …
So the surface tension kept the tug & sub together nicely…
In power boating we taught to power out of the situation not drift back. The tug seems to have drifted back being sucked into the prop of the sub.
I used to teach this exercise (the right way ;) ) to 'profesional' powerboat users but they deemed it to dangerous an exercise (this and emergency stop) so now they need to find out the hard way... good old stealth & safety...
Regards,
Kim
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An old well viewed video,....
At any moment after the tug became pinned on the stern elevator, any
of the 12 crewman on the deck of the submarine could have called for an emergency stop.
{:-{
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Yes Umi this video was put on the forum and very well discussed a couple of years ago
Geoff
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Dear Geoff,
My apologies, didn't know this had been on before.
Whatever be the case, and in great brief, there was startling negligence by the Upper Bridge commander - there being more than enough time to have corrected the situation. I am sure a Court of Enquiry would have dismissed someone over such a neglect of duty. The whole run of the disastrous event is so very plain to see... no defence.
Again, apologies for putting something on that has been on before... I didn't know.
Regards, Bernard
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However , it was a few years ago, posts have been lost and there are quite a few new members, I have been on for a few years and had not seen this link, that I recall..
No apoloigies due really..(if the post had been in the last few months fair enough)
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Dear Longbuild,
Thankyou for that. Good to see there are more Gents. on here than I realised.
I judge people - rightly or wrongly - as they do to me you see.
Kind Regards, Bernard
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USS Secota (YTB-415) was a harbor tug that served in the United States Navy from 1945 to 1986.
The Secota was assigned to the Pacific Fleet soon after delivery to the Navy. She was at Okinawa in August 1945; visited Tsingtao, China in July 1946; and replaced USS Anamosa at Yokosuka, Japan, on 20 August 1947.
During 1950, Secota visited Hungnam and Pusan, Korea; her last recorded port of call was Sasebo, Japan, apparently returning to Japan from Korea during the waning days of 1950. After that time, Secota was continuously assigned to advanced American bases in the Pacific. In February 1962 she was redesignated a medium harbor tug, YTM-415.
On 22 March 1986, near Midway Island, Secota had just completed a personnel transfer with the USS Georgia when the Secota lost power and collided with the Georgia. From amateur video taken of the incident, it appears Georgia increased speed before the tug was clear causing an impact with the sub's stern dive planes. Secota sank, ten crewman were rescued but two drowned. Georgia was undamaged.
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Whatever be the case, and in great brief, there was startling negligence by the Upper Bridge commander - there being more than enough time to have corrected the situation.
I'm not quite sure what qualifications you have to make a statement like that Bernard. Things can happen very quickly in these sort of situations and unless you are a professional seaman with practical experience then I don't really think you should be expressing an opinion. The tug's hull was pierced by the sub's aft hydroplane and after that the consequences were inevitable.
Colin
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When you pass water between two parallel surfaces the tendency is to draw the surfaces together… remember the experiment in 1st year science …
So the surface tension kept the tug & sub together nicely…
I don't know how good your first year science teacher was, but there is a big error in there.
The passing of water (or air) between surfaces which draws moving ships together is the venturi effect (Bernoulli's principle) which creates a low pressure between the vessels. This is a big effect - jumbo jets would fall out of the sky if you wished it out of existence.
Surface tension is a molecular level thing that gives a meniscus to (eg.) liquid in a tube regardless of whether it is moving and lets pond-skaters, er, skate on ponds. This is a small to microscopic effect.
These two effects are unrelated and surface tension was not in play during the sub-tug accident.
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Thanks for posting it up Bernard and I hadn't seen it before today.
Dave
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Dear Dave,
Thankyou.
Well, I state nothing really, just the blatant facts that have, seemingly, been on here before, do not presume maybe to challenge, the facts are glaringly obvious before you...... eh.................... I just simply show.
Regards, Bernard
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Found this on the web:
Several items to note: This was a medivac from USS Georgia at Midway Island. The Tug was a Navy Service Craft with a USN crew (no contractors involved). This was the first ever BSP of a T-hull at Midway, the tugcrew was not familiar with the below-water configuration of the sub.
At time 30 you hear an alarm go off...this is the tug losing power. At time 45 you see an enlisted man running to the aft door of the tug to get to the engineroom and get the engine going again (this man was trapped below and died). At time 1 minute the tug stats sliding aft. At this point the tug is pinned to the side of the sub by suction forces. Their is nothing the sub could do in the time remaining to get the tug away from them. An Ohio's surface manueverabilty is akin to an 18 wheeler with 17 flat tires.
At time 1:20 the video shows the subs rudder hard over. The OOD is doing the only thing he can, trying to kick the stern around to break the suction from the tug. At 1:29 the crew on deck realize the tug is having a problem..."come on man,back out of their." At T 1:31 the tug hits the stern plane upright.
The sub continues the turn attempting to kick the tug off the sternplanes so it does not get dragged into the prop. No one realizes the tug was holed upon contact with the stern-planes. The sub is actually keeping the tug afloat at this point.
About T 2:04 you start seeing diesel smoke from the tug, the engine was restarted and the craftmaster is trying back off the sub...he does not know his hull is compromised.
T 2:53 you can now see the tug visibly lower in the water. She is starting to slide off the sternplane...and sink.
T 3:10 the tug is off the plane and you can see the rudder now passing by the tug. The tugs stern is almost underwater at this point.
T 3:21 the tug rolls to port (the side with the hole) and starts to sink. T 3:56 the tug is fully under, sinking stern first. The tug crew is seen in the water.
Time stamp on the film is 2:47. Film cuts out and restarts at time stamp 3:01. This is T4:01 on the video. It took this long (about 14 minutes) for the sub to come back around and get in position to rescue the tug crew without them getting caught on the open side of the sub (where waves and current will smash the crew into the side of the sub causing further injuries/death).
The remaining video is a standard sub man-overboard drill scenario.
In short, from the time the OOD realized the tug was in distress to when the tug hit the planes and was holed was about 9-11 seconds. Had the OOD ordered any level of backing bell it is impossible to bring the shaft to a stop and put on a backing bell in that amount of time, much less for the sub to overcome 18,000 tons of inertia and start moving in reverse. The ONLY option the OOD had was to try and get the subs stern away from the tug and not let the tug run through the subs prop.
IIRC the tug craftmaster was faulted for trying to back away from the sub (the engine shut down as soon as he put a backing bell on) rather than the normal (accepted) way of powering forward and driving away from the sub arcing clear. Contributing to this was the unfamiliarity of the tug with submarine ops due to the isolated location of the transfer.
I don't know if it is true but the writer seems to be looking at it from a professional viewpoint rather than jumping to unqualified conclusions.
Colin
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It's all there in the visual isn't it. Begs the question who is right and and who is wrong...
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They could have stopped the prop from spinning, if anything.
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Ummm...
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no one is right or wrong if they had of stoped the prop the sub would still drift the tug couldnt do anything as was dissabled by mechanical faults i am interested why the sub turned into where the tug was woulve thought he would turn away the tug cap obs new what he was doing to manage to get 10?12 crew off is good considering how quick a time it was between them relising they were going to sink and them sinking and the subs ood/co/xo was good to react so quickly and perform a man overboad and get the 10 that got off the boat out safly anywho thats just my opinion
kk
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It's all there in the visual isn't it.
Well, considering that all of the damage was being done below water, no it isn't.
It's always tempting to rush to judgement - and frequently completely wrong, especially if you have no practical experience or expertise.
They say that ignorance is bliss.....
Colin
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I can only sight the poor tug was doing it's best to get away... you only have to look at the engine exhaust... it was on max. power to get away. I have just now passed this matter to an ex RN nuclear sub Commander, and I await his consideration in the matter. B.
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I can only sight the poor tug was doing it's best to get away
If you read the reports you will see that the tug had actually lost power and slid down onto the sub's projecting hydroplane. It wasn't trying to get away, it was impaled! The smoke was due to them attempting, unsuccessfuly, to restart the engines, possibly unaware at the time that their vessel had been ripped open.
Do pay attention! In these situations things happen in a matter of seconds. Hindsight is a wonderful thing but at the time it is not always apparent exactly what the problem is or what is the best method of mitigating the situation. For example, the captain of the tug may not have been immediately aware that his vessel had been fatally holed. He may just have felt a bump. A SSN is a big ship and will not instantaneously respond to helm or engine commands while surfaced. it's all very well to say 'well, if it was me I would have done such and such' but in practice you would have probably made a complete cock up of it yourself.
Colin
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Before I have any answer, wouldn't any body have heard "She has caught the bow plain", it is so asydestinct as to be damning? My determination in a Court Martial would have been easy? Yes???
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I think the tug was caght on the stern plane Bernard - as the video clearly shows.
Colin
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The Sub., for whatever reason, was going on hard Port. Once the prob. started, well, look to the vid.. B,
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Yes, she indeed she was... the Port bow plane
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Sorry, starboard plane of sub.
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The reason in this is, isn't it not somewhat easy to decide? Logic determines same???
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Dear Colin,
Before I have proper professional opinion, am I right or am I wrong do you think???
Regards, Bernard
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Bernard............one question???.............WHAT DOES IT MATTER?!!!!
It happened years ago, you cannot change the incedent, you cannot change any enquiry, you cannot change the outcome....
WHAT DOES IT MATTER?????
The rest of this argument is just superfluous!!
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Indeed true, indeed right, but little satisfaction to those and those familys' who lost? B.
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I AGREE WITH NEIL woops that was in caps
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The y needs only to be left to a RN nuclear Sub. Commander (Rtd.). His opinon will be posted once obtained. As we all know, what better opinion and from what better source.
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As Neil says, it was years ago. An enquiry was held and lessons learned. No point in revisiting it now and I doubt very much whether an ex RN Captain would be prepared to second guess the situation purely based upon an online video.
The Americans have a phrase 'S**t happens' and I think this is a classic example. You can analyse it to your heart's content but it will not change the outcome. People do their best in these circumstances and the outcome is not always what you might wish. That's life I'm afraid.
You have to ask yourself, if you were in that situation would you have done better?The answer is almost always no.
Colin
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I think this has gone a bit far guys, I think we should say that whatever happened and whoever was to blame (if anyone) it was a tragic accident and leave it at that.
Andrew
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I don't know how good your first year science teacher was, but there is a big error in there.
The passing of water (or air) between surfaces which draws moving ships together is the venturi effect (Bernoulli's principle) which creates a low pressure between the vessels. This is a big effect - jumbo jets would fall out of the sky if you wished it out of existence.
These two effects are unrelated and surface tension was not in play during the sub-tug accident.
I do apologise, it is more than possible that I was day dreaming during that lesson…
Did I get any marks for remembering part of what I was taught … thought not … just as well I didn’t become a scientist lol
Regards,
Kim
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Yet again the Mayhemers are at WAR.
Mods I personally think this has run it's course as it will end in tears simply as Members are trying to gert the upper hand over each other and it WILL END IN TEARS
Dave
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Dear Dave,
No, that would be wrong. Just on my way out and had to reply to yours since it is only right I feel.
It's just that on seeing that footage (that I had not seen before), I was astounded that such a thing could happen... my intention was not to start anything contentious.... and if it is heading that way it must stop - as you rightly hint.
I have asked an ex career RN sub. Commander his opinion (a friend of many years standing), so it will be interesting to see what he thinks.
Please all, Dave is right, and the last thing I would want to see is argument over this. As another said, it is in the past, but I didn't know about it so it was new to me! You get my drift.
Kind Regards to All, Bernard
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Thread now closed