[OT] Navy releases photos of U.S.S. San Francisco

Peter Stickney wrote:

Derek, did you ever play the game of suspending a spoon on a string
stretched across the Missile Compartment and guesstimating the depth
by how much the string sagged as the hull contracted?



I still want to know if he's got those submariner propellors* tattooed
on his butt.

* I was going to say "screws", but thought that that might be going too
far. :-D


Pat

Herb Schaltegger wrote:

He could tell you . . . but then he'd have to kill you. ;-)



With a spoon, no less....they showed another game on television- a race
of soapbox derby model "cars" made from mechanical odds and ends down
the missile room via gravity from getting the sub in a bit of a bow-up
position. It looked like a lot of fun.

Pat

"Derek Lyons" wrote in message
...
"Mr Jim" wrote:
As a former crew member of two 688 submarines, from two of the 4 different
"flights" (the Portsmouth was the same flight as the San Francisco), I can
tell you that by design, there is no "hump" on this part of a 688 boat.
The
appearance of one in the referenced photo appears to be an optical
illusion,
enhanced by the curved shadows of the lifelines. Laying a ruler along the
joints (the joints running fore to aft) between the anechoic tiles, one
can
see that there is no evidence of deformation.

Take a look at the high res photo[1], and note the straight lines of
the individual lubber boards and the decidely unstraight line of the
total run of boards, and one can plainly see the deformed section.
(For reference, compare the lubber boards in way of the sail.)

D.
[1] http://www.navy.mil/view_single.asp?id=21183, click on 'download
high res'.

I agree that it looks very much like the deck is bulged. However, I feel
confident in stating that the capstan (sitting right in the middle of the
"bulge") could not have been rigged out if the hull had been so damaged. The
hydraulically-actuated piston and capstan motor are mounted inside the
pressure hull directly below it, connected via a rod through a gland, and
the capstan itself must be free to rise along guides from a flush-mounted
stowage position, so the system wouldn't likely be operable if the main deck
had been distorted. Though the cleats have generous tolerances, I don't
think the three visible sets would have rolled to the in-port position if
the deck was deformed - they often jam due to small foreign objects,
hardened grease, etc, even under normal circumstances. Also, the tiles in
that area are not disturbed - no visible gaps in the seams, or broken tiles
in that area. The tiles (and the adhesive used to affix them) aren't
flexible enough to stretch - they tend to break like linoleum under any
stress that doesn't entirely remove a tile - note the area forward and along
the side where the tiles are torn and/or missing. The elastomeric "grout"
between them is more fragile than the tiles, yet it too seems undisturbed.
The lubber boards appear to have been set up to enclose a narrow walkway
just wide enough to include the cleats, widening to accomodate the entire
non-skidded area of the main deck walkway, plus some extra space on either
side.

Jim H.

"Pat Flannery" wrote in message
...
I'm still trying to figure out how you cave in the side of the sub's bow
when hitting a submerged mountain; the thing must have been shaped like
Devil's Tower with near vertical sides.

Well, there might easily have been some local vertical face, while the rest
of the mountain could still be shaped like Mt Fuji. My question is why
didn't they see it? All that technology, and they can't detect what's right
in front. At 500 feet I suppose we can rule out a Japanese fishing boat this
time.

Peter Stickney wrote:

An addition to the list of Possible Submarine Predators:
The Cookie Cutter Shark:
http://www.amonline.net.au/fishes/fi...sh/ibrasil.htm



That's the one! I was digging around in my "Deep Atlantic" book trying
to find it, I knew there was a reference to some sort of shark biting
sonar domes, but couldn't find it. The damage on the destroyer was
supposed to be pretty much over the whole front of the dome, with long
cuts in the rubber as opposed to small craters like this critter makes;
but if it were me, I'd say that the Manta Ray is the best suspect; it's
got a skin rough enough to cut the rubber covering, and a mass high
enough to really knock things out of whack during a collision- over 3000
pounds in the biggest specimens.

A most fascinating beast - among other tings, it glows in the dark,
and seems to hunk by luring larger predators into range by masking
itself as a Sardine.
While they're more a hazard to the Sonar Dome than to the boat itself,
you've got to admire the chutzpah of an 18" (50cm) shark taking on a
400' (125m) Steel Ocean Behemoth.
At least the Swordfish that speared Alvin looked like it had a chance.



It did punch a hole in the freeflood conning tower at least. They never
did figure out what torqued it off so- but it made good eating for the crew.

(Hmm. since a Megalodon was/possibly is a 100' Great White, just think
of what a 50' Cookie Cutter could do. I think I'll get on the horn to
Scaramanga and No, CIvile Engineers, to see about enlarging teh
Aquarium)



Ever hear of pliosaurs? Another pleasant group of prehistoric sea
creatures; here, one meets a Giant Squid:
http://www.oceansofkansas.com/Varner/varner09.jpg
.....so...exactly how big is this sucker? Oh, about this big:
http://www.oceansofkansas.com/images2/krono2.jpg

I've also noted that some of the Giant Squid references are breaking
them down still further, into the Giant Squid and Colossal Squid
categories.



The Colossal Squid has been known for a while, it's just now that
they're getting around to studying it in detail and trying to estimate
just how big it gets...unlike the Giant Squid, which appears to be
pretty fragile and sedate, this one appears to be one tough and vicious
mother that you wouldn't want to run into. Divers near antarctic waters
take note. They think it lives deep down...they used to think that about
the Giant Squid also, but every now and then they find one swimming
around near the surface.
Looking for divers, no doubt... ;-)

Pat

Neil Gerace wrote:



Well, there might easily have been some local vertical face, while the rest
of the mountain could still be shaped like Mt Fuji. My question is why
didn't they see it? All that technology, and they can't detect what's right
in front. At 500 feet I suppose we can rule out a Japanese fishing boat this
time.



They never turn on their active sonar unless they have to; if they are
in what they think is unobstructed water they will maintain silence if
at all possible for the sake of stealth.
One odd thing though; the first-hand account stated that they were going
pretty fast- he said something like "as fast as we can at 500
feet"...which might suggest that the were going at the maximum speed
they could without their propellor cavitating and producing
sound....given that the water pressure increases with depth, I wonder if
cavitation vacuum bubbles are less prone to occur at depth than near the
surface, and the deeper you go the higher your propellor RPM (and speed)
can be?
In the book "The Hunt For Red October" they mention a "mass detector"- a
device that picks up gravitational anomalies near the sub and allows
navigation around subsurface obstacles without the use of sonar. This is
probably the thing that didn't get put into the movie at the insistence
of the Navy as part of the deal to get their aid in making the movie
(there was something they didn't want on those control room sets that
was in the book from what I've read) we were playing with this gear
clean back in the late 1950's when the Triton made her submerged
round-the-world cruise, as it gets mentioned in her skipper's (Capt.
Edward L. Beach) book on the voyage; and if San Francisco was equipped
with such gear, then it should have shown something as they approached
the seamount. Maybe by the time they realized it was there it was too
late to turn sharply enough to completely avoid it, like the iceberg in
the case of the Titanic

Pat

In article ,
Neil Gerace wrote:
...My question is why
didn't they see it? All that technology, and they can't detect what's right
in front...

Trouble is, all that technology doesn't change the fact that it's pretty
damn dark 500 feet down. There basically isn't any way you can detect
what's right in front without illuminating it yourself -- with light,
sound, or whatever -- and it's hard to do that and still remain stealthy.
So subs emit only when they have urgent reason to.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

In article ,
Pat Flannery wrote:
...given that the water pressure increases with depth, I wonder if
cavitation vacuum bubbles are less prone to occur at depth than near the
surface, and the deeper you go the higher your propellor RPM (and speed)
can be?

Basically correct. Cavitation occurs because the pressure on the
"suction" side of the propellor blade goes below the vapor pressure of
water. The higher the ambient pressure, the faster the blade can move
without causing this to happen. (The same thing happens in rocket pumps;
this is why propellant tanks are pressurized even in pump-fed rockets.)

In the book "The Hunt For Red October" they mention a "mass detector"- a
device that picks up gravitational anomalies near the sub and allows
navigation around subsurface obstacles without the use of sonar.

Not quite -- the device in the book detects small changes in the local
gravitational field, which can be compared against a gravity *map* to
navigate accurately in a *mapped* *area* without sonar. It's a navigation
system, not a way of sensing what's ahead; it wouldn't help you avoid an
unmapped obstacle.

(Such devices really do exist, but whether they are useful and practical
for submarine navigation is not obvious.)
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"Peter Stickney" wrote in message
...
The Reactor and Engine Room stuff aren't rigid;y mounted to the hull.
They're attached to a "raft" that's somewhat free to move within the
hull.

So a barrel roll would be right out then, eh?

"Pat Flannery" wrote in message
...
Maybe by the time they realized it was there it was too
late to turn sharply enough to completely avoid it, like the iceberg in
the case of the Titanic

I rather doubt that particular iceberg would have been a problem in the
Pacific Ocean. :P