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Old 08-04-05, 05:22 PM   #2
Rip
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Join Date: Nov 2004
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Default Re: Realism v simulation

Quote:
Originally Posted by The Bellman
Indebted to Blackmuzzle over at Battlefront for the link to unofficial transcript of the USS Greenville incident.

An LA 688 SSN 72 - an officers answer throws some light on how far our sim. has traveled from reality.
The two issues are baffled areas and speed of ascent.

Baffles - ''Sonar baffles are about a hundred -- on this class of submarine was honard sonars about 120 degrees
in the stern sector centered either side of the stern of the ship relative, where you're acoustically deafened
because the sonar is not designed to look in that sector through ownership's machinery and hull noise.
So you turn your ship in the horizontal plane to uncover your previously baffled area.
and you generally turn at least 120 degrees so you now have that previously deafened sector under observation
by your passive sonar system. And you may have new contacts in that sector, and if so you start
to develop your first leg on this new course of information on those new contacts. ''

Why have we got a mere 60 deg. baffled area ?

Ascent - Source believed to be Admiral Griffiths - the sub was at 50 ft and 10 knots prior to going to
periscope depth (DW 63 ft) it took he said '' a minute or so .''
Now the 688 DW takes 2 min. 10 secs to do this - she will go from 150 ft to 83 ft in 53 secs and then takes a huge time to level off.

Could understand if this was periscope deployment and near surface related in order to avoid collision
with surface craft - the transcript reports use of the periscope prior to it breaking the surface to spot 'shadows' etc.
But this slow levelling off phenomena applies at all depth changes.

Quote from Marconi over at Battlefront ''Here're a few musings from a 688/637 class qualified Diving Officer of the Watch:''
''For The Bellman>>The depth change performance in DW isn't unrealistic, it's dreadful.
Take it from a guy with thousands of hours in the center seat. ''

Bellman.

'Never send to know for whom the bell tolls....'
The baffle is less than 120 degrees. They always turn 120 to be safe. You would be suprised how much technical details these guys don't know. I mean crap they have to learn a massive amount of info from the time they join until they ever get to stand OOD.

The depth change data is fairly accurate. Anytime you are going to PD the OOD will constantly spin on the scope while looking for shadows. If one is seen Emergency Deep is ordered to avoid a collision. As soon as the scope breaks the surface the OOD will verbally call out so and make a low power sweep. Reporting any close contacts. Also for ship safety the ESM watch is closely monitoring his recievers for strong close contacts. These can also be picked up slightly below the surface. The EW reciever is the first thing to break the water. Any sign of unexpected close contacts is reson to go deep quick.
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