Photos/specs needed of rotating hydrophone head

[Mark Sarsfield]

Another little item that the Batfish sorely needs is the rotating hydrophone head on the top of the deck near the bow.  If we have enough pictures and some basic dimensions, we could probably fabricate a replica.

[Tom Bowser]

Which type did the Batfish have? there was a ball looking one later in the war I think and the t or rectangular one.
Tom Bowser

[Travis McLain]

The Batfish had the Rectangular T type head.

[Paul Farace]

I am not a SONAR historian, but I think the ball head was used on S-boats and was one of the two SONAR heads used on the keel of fleet boats. A few of the fleet subs got the FM SONARs for mine deterction in the last months of the war. These were cylinders mounted on the top deck.

Again, I was sleeping in basic SONAR for fleetsub curators classes.


I'll try to get some pictures of our JP hydrophone when I get down to COD next.
-- PF
 

[Mark Sarsfield]

I remember that there were three different types of sonar on the boats and they were operated from at least two different locations.  The sound equipment in the bow torpedo room looks more complicated than the one in the CT.

[AVGWarhawk]

The Torsk's is long gone.  All the listening gear is under the chin and submerged at the moment. Not sure if we have diagrams in the archives for the original set up. 

[Rick]

The batfish was actually equiped with 2 sets of sonar heads.  We had the sed that was located under the hull.  These stuck out and moved up and down.  The heads are not there anymore, but you can still see the hydrolic rams in the FTR on either side of the hatch going into the Forward battery.  The second is the one on the deck that everyone is familiar with and can see.  It is my understanding that the one located under the boat was monitored in the FTR Port/Aft porton of the boat.  The one on the deck was monitored in the Conn.....

[Mark Sarsfield]

That was my understanding, as well.  I have seen models of fleet boats that also had a recessed dome/sphere in the keel aft a little ways from the two retractable heads.

[Tom Bowser]

Here are some photos of our sonar head and basic dimensions.
40" long, 6" wide, 2 1/2 " thick except where rubber type material wraps around that is 3", 35 1/4" from top of deck to bottom of head, the round tube on the side opposite the rubber 2" dia.
do you need measurements on the pedestal also?
Tom

[Mark Sarsfield]

Tom,

  What you gave us is a start.  I noticed that you have a T-Post in the background of one of the photos at the bow for the wire antennas.  Looks like the Union Jack is flying from it.  We could use photos and dimensions of all of the pieces to it, as well, if you don't mind.

  Thank you for all of your help.

[Lance Dean]

Very nice shots there Tom!

Cool old Chevy out behind the dumpsters, too. 

[Paul Farace]

The term SONAR refers to the supersonic spectrum, beyond normal hearing. This system is exclusively on the keel of the fleet sub and is monitored primarily in the conning tower where there are monitors for both the wide beam and narrow beam heads as well as two levers to control them and a telegraph key on the side of the monitoring station to fire an active PING.  The JP hydrophone is the T-shaped device on the deck . This is a sonic-range device, basically a very good underwater microphone. It just listens and can rotate to provide bearing information. This is monitored in the FTR. The monitoring station there probably can also listen in on the SONAR gear, but the station lacks the range readout dials of the SONAR station in the control room. There is ample information on the FLEET SUB MANUAL on the HNSA website, I believe.  The FM SONARs were added to the top deck because they were looking for mines ahead and on the beam while submerged.

BTW:  On BATFISH, how do you know the SONAR heads are missing? Since she is sitting in the mud, they are not visible, are they? They just might be there since it would not have been required to remove them.

PF
 

[Tom Bowser]

Will do,
I just look at that as the jack staff, never did put together that it was the t post also. I will try to get a better photo of the jp head also.
Tom

[Rick]

I have been told this by one of the vets that brought it up here.  unfortunatly I cannot lift the boat to check and the Community servis kids are not to keen on digging me a tunnel to check. 

On a side not Nick Guadliaro (served on the Marlin) was telling me how his sonar techs would use the hydrophone to listen in on conversations behing held on the deck.  He never told me any details though......

[Mark Sarsfield]

I didn't think that it was possible to listen unless the hydrophone was submerged.  I thought it was highly dependent upon water vibrations.  He's probably right, though.