School of the boat 4 Mar 09 (underwater log)

[Darrin]

Ok folks it looks like there is 1 more block of instruction that we all can participate in, Torsk doesn't have her origional pitometer log anymore so I will learn right along with you.. EVERYONE is encouraged to get involved in this one to include other School of the Boat instructors

First question: what does it do and where is it located?

Good luck all

[etkfixr]

The pitometer log is in the forward torpedo room starboard aft corner.  It is retractable so you don't ram it into the bottom when entering port.  I am pretty sure it works by sensing the flow of water over the "sword" using electromagnetic interference.  It puts out a magnetic field, and the faster you go the more it distorts.  It is only approximately correct in measuring the vessel's motion since you might be running with or against a current.  Terry

[Darrin]

You are on the mark there Terry,

Now how does the underwater log tell you how many miles that you have traveled in your journey???

[Dave595]

The way it provides distance traveled seems rather complicated, but the below link is to the description of operation in the manual:    
The Fleet Type Submarine Online
Submarine Underwater Log Systems

http://www.maritime.org/fleetsub/log/chap18.htm#18B

[Darrin]

Thanks Dave,  Welcome aboard also if I haven't said so already.  It has and always will be a pain to teach how a submarine or any vessel can tell how many miles it has truly gone, granted you can cheat and calculate off of the charts the distance everytime you go out on a run and you can also you how many miles are shown that the screws have pushed the boat thru.. 

The reason why I have asked this question was because there was a boat that came home under "sail" once because it ran out of gas and ran nearly out of battery power, while it was in safe waters around Hawaii (IF I remember correctly) it was still a unique thing to read about.

[JTheotonio]

It may seem strange but Darrin can actually remember facts and not just some wild sea story.

During a search for the sea-going tug Conestoga  (AT-54) in May 1921. R-14 (SS-91) ran out of fuel southeast of Hawaii. Sails were made from blankets and mattresses, and the submarine arrived at Hilo on 15 May after 5 days under sail.

Here is a link to the story about the search for he missing tug: http://www.pa-roots.com/lancaster/tales/ussconestoga.html

NIce memory Darrin 

[Darrin]

Thanks John,
While I could remember the story I couldn't place the name of the boat and why she ran out of fuel, the story of that happening is in the book "SUBMARINE STORIES" and I am sure in many many more books as a lessons learned and how ingenious our submarine crews can get to bring their boat home

[JTheotonio]

I found it interesting that it was one of the crewmen that suggested sails. 

[Lance Dean]

Man they would have been screwed being at sea without the ability to dive.  But then again, just drifting isn't too great either.

[JTheotonio]

Oh! They could dive.  Manually open vents. blow tanks - it would be harder and not all that safe - but they could dive! 

[Darrin]

Well Lance,
there have been a number of boats that while being submarines were not allowed to dive anymore while coming home from a deployment.. The last was the USS San Francisco (SSN 711) and that was because of her accident where she hit a uncharted mountain on a flank bell, once the temp bow was placed on her she went from GUAM to Bremerton, Wa on the surface without the ability to dive.. Then there were the boats that got depth charged so badly during the war that they were not allowed to dive once they returned home due to being so badly damaged.

[Lance Dean]

Oh yeah, of course.  That would be a tight situation, being in a submarine that wasn't safe to dive.

[JTheotonio]

Lance I have to point out that up until the nuclear submarine all submarines spent a lot of time on the surface.  Submarines could only remain submerged as long as they had adaquite battery power.  They were made to ride out conditions on the surface.

Many boats during storms would ride the surface because it was a lot easier (except to the tossing around we got) to remain surfaced than try to surface during a storm.  Yes some boats did remain submerged. But they could only last so long.

WWII patrols were spent with much of the night time on the surface to charge batteries and to steam to other patrol areas.  At sunrise they would submarge to remain hidden. 

With nuclear submarines that all changed.  There was now never a reason to surface until the end of a patrol and you were back home. 

The inability of a submarine to submerge takes a lot of the purpose of the submarine away.  It's still rather safe to remain sufaced (unless in a war).  USS San Francisco was a prime example.  Baddly damaged that boat made it back to a port.

[Darrin]

The crew of the San Fran did a job that is still unbelievable to those whom have ridden 688's due to the amount of damage to her bow and having served on her it was horrific to see my former boat coming in hull down instead of hull up especially knowing that they were running the low pressure blower and then the diesel to continually pump air in to what remained of the forward balast tanks. When the pictures of her in the drydock emerged I was shocked and in AWE of the crew that did the impossible, it reminded me of seeing pics of the Growler with her bow crushed nearly 90 degrees to port and they still brought her home (Capt Gilmore gave his final order to "TAKE HER DOWN" and shut the hatch knowing that he couldn't make it below)  while the tanks are layed out differently between the classes it showed that todays submariners can still do the impossible in conditions that would appear to be no way out.

Lance with the Skipjack class and the Albacore the rules really changed about how submarines operated, with previous hull designs they were designed to ride on the surface and with the above mentioned classes we were ment to stay underwater and not surface unless we were coming in and out of port and I will be more then happy to tell you that riding a 688 in a typhoon is NOT a nice place to be however I would rather be underwater and getting tossed around then being on the surface and being thrown like a rag doll around..  IF you would like to see basicly what the San Fran went through once she got on the surface fill a water bottle half to 3/4 of the way full of water and then put in your tub and then create a gentle sea state by gently moving the water around in your tub creating small waves to the ever so violent hurricane like waves in the tub.

[JTheotonio]

  Lance takes baths?    What's worse is somehow Darrin you know this fact? LOL

I've been at sea during two hurricanes on the Picuda and we had to spend our time on the surface trying to stay outside of the storms.  What a ride!  I can almost say I know what it would have been like in an old wooden frigate in the 1800's. 

And like Darrin said, I've taken some monster rollers in the North Atlantic in an SSBN.  Stuff flying everywhere until we finally pull the plug and ahead flank to calmer waters.  SSBN's need to be able to launch within x minutes and rolling heavy prevents you from launching your birds.

I too marvel at what the crew of the San Francisco pulled off.