After some research

After some research

Joined: October 10th, 2005, 8:42 pm

March 23rd, 2009, 5:35 am #1

The Gun Fire Control System on the LST 325 in its current configuration consists of:
2 Mk 51 Gun directors

2 Twin 40 mm mounts

4 Single 40 mm mounts

Forward battery consists of mounts 41 (twin), 42, 43 and Director 41
Aft battery consists of mounts 44, 45, and 46 (twin)and Director 42
with 43 and 45 being on the starboard side and
42 and 44 being on the port side.

Gun director 41 is the forward director with Gun director 42 the aft director.
Gun director 41 controls the forward battery while Gun director 42 controls the aft battery.
The forward director can not control the aft battery and vice versa.

Rotary selector switches at each director and each 40 MM single mount enable a director to control either or both of the single mounts in its sector. The director is connected directly, without switching, to its sector 40 MM twin mount for control.

The rotary switch in the forward director selects 42, 43 BOTH OFF.
The rotary switch in the aft director selects 44, 45 BOTH OFF.

Examples: Gun Director 41 in OFF position controls the twin mount only.
In the 42 position it controls the twin mount and mount 42.
In the 43 position it controls the twin mount and mount 43.
In the BOTH position it controls the twin mount, mount 42 and mount 43.
Gun director 42 works in the same fashion.

Firing cut outs prevent the mounts from firing when the gun is pointed at any part of the ship.

The mounts themselves could select to be controled by mechanical hand cranks (in the event of power failure) or by electrical control using the control yoke at the pointer's station and AUTO utilizing the Gun directors.

Although each 40 MM mount has its own Mk 14 gyro gun sight to assist in aiming, there was an advantage in using a gun director away from the mounts. The Gun director tub is higher than the mounts, which presents a better all-around view as well as being up and away from most of the gun smoke. By being able to control more than one mount, a whole lot more fire power could be directed at a target more accurately.

AS an added note, the person manning the gun director had to do his best to make smooth movements with the gun director. Any sudden or abrupt movements or jerks could cause one of the loaders or other mount personnel to loose their balance and fall. This might later result in the director operator being invited to a blanket party on the fantail.

Pointer
FTG2








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Joined: December 22nd, 2008, 3:07 pm

March 23rd, 2009, 12:57 pm #2

Great info Bob, your gun numbers match Navy film/photos with gun numbers 41, 42 and 43 visibly stamped on the bow gun tubs. Thank you for the related drawing! One would presume the 20MMs were sequentially numbered 21, 23, 25, 27, 29, 31 for starboard etc. I was fortunate to recently receive a copy of the 783 Night Order Book that each O.O.D. initialed daily. The 3rd standing order for each day was "Ready gun #1, #6, Sky 9 and Sky 10." Sky what? I've also seen notations for Sky 3. It seems that no one can identify the location or usage of "Sky" locations. Not enough elevated guns so I'm cornfused. Bob, can you or anyone please explain? Thanks!
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Joined: August 24th, 2003, 10:08 pm

March 23rd, 2009, 9:56 pm #3

Teach.. between you and Bob Wilder, I am actually starting to understand some of this. Very much appreciate the detailed information you both have given me... and explained the numbering system! I start to feel better.. and then see Joey's questions and think.. Oh my! Here's another set of puzzles!
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Joined: October 10th, 2005, 8:42 pm

March 23rd, 2009, 10:08 pm #4

Great info Bob, your gun numbers match Navy film/photos with gun numbers 41, 42 and 43 visibly stamped on the bow gun tubs. Thank you for the related drawing! One would presume the 20MMs were sequentially numbered 21, 23, 25, 27, 29, 31 for starboard etc. I was fortunate to recently receive a copy of the 783 Night Order Book that each O.O.D. initialed daily. The 3rd standing order for each day was "Ready gun #1, #6, Sky 9 and Sky 10." Sky what? I've also seen notations for Sky 3. It seems that no one can identify the location or usage of "Sky" locations. Not enough elevated guns so I'm cornfused. Bob, can you or anyone please explain? Thanks!
I think the term SKY 1, SKY 2 etc. was related to lookout positions where spotting binoculars were mounted to a pedestal. A lookout scanned the horizon for enemy aircraft (or sometimes surface targets) and when he observed something he would train the binoculars on it. These special binoculars had cross hairs in them much like a hunting riflescope.
On the pedestal an observer could read relative bearing and position angle of the target. The range to the target was estimated by the observer (with lots of practice and training) On the older ships this information was passed on to the Gun Director and/or the gun mount most available to acquire the target via sound powered phones. On newer ships and ships with gun fire control computers this information was fed electronically via syncromotors.
If the ship did not have the special mounted binoculars a freestanding lookout would still identify the target and pass on the information via the battle sound powered circuit.

The SKY lookout, upon identifying a threat would call the command "ACTION STARBOARD" (or action port, starboard quarter, abeam etc.) This alerted the gun crew and Director operator that a target had been identified and more information was following. While waiting for this information the gun crew could already be training the mounts or gun director to the proper general direction of the bogie.
The SKY observer would then pass a three-part target acquisition command giving bearing, position angle and range to target. It might sound something like this:
"ACTION STARBOARD" "ACTION STARBOARD" "TARGET INBOUND BEARING 095 DEGREES RELATIVE, POSITION ANGLE THREE ZERO DEGREES, RANGE NINE THOUSAND"
The weapons officer would then assign a mount(s) and/or gun director to acquire and track the target.
When the report was heard "TARGET ACQUIRED" that meant the gunner or director had the target in the sights and were ready to fire. The command was then given to commence firing.

In the log when it was reported "Ready gun 1, 6, director 41 and SKY 1, it meant that these positions were ready to be put in operation quickly if needed. That is, the weather covers were removed or secured in such a way they could be removed very quickly, the power was turned on in standby mode and the position could be manned and operational in a very short notice.
The earlier ships may not have had gun directors and relied on the SKY observers for target bearing information.



Disclaimer: This is from memory so don't shoot me if something is incorrect.

Pointer FTG2




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Joined: October 10th, 2005, 8:42 pm

March 23rd, 2009, 10:16 pm #5

Teach.. between you and Bob Wilder, I am actually starting to understand some of this. Very much appreciate the detailed information you both have given me... and explained the numbering system! I start to feel better.. and then see Joey's questions and think.. Oh my! Here's another set of puzzles!
SeaBat, your homework assignment (should you choose to accept it) will be to find out what is meant by "shooting a star with a borescope" for "battery alllignment".

Hint, battery allignment does not mean putting all the batteries aboard ship with their positive posts facing the same direction.

BP

P.S. I have your needle gun cleaned, polished and ready to go for work week.


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Joined: December 17th, 2005, 10:55 pm

March 23rd, 2009, 11:00 pm #6

but it make's good since to do it that way and check it again 1 hour later to see if changed by 15 deg. That is if the ship is properly orented.
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Joined: December 17th, 2005, 10:55 pm

March 23rd, 2009, 11:03 pm #7

I think the term SKY 1, SKY 2 etc. was related to lookout positions where spotting binoculars were mounted to a pedestal. A lookout scanned the horizon for enemy aircraft (or sometimes surface targets) and when he observed something he would train the binoculars on it. These special binoculars had cross hairs in them much like a hunting riflescope.
On the pedestal an observer could read relative bearing and position angle of the target. The range to the target was estimated by the observer (with lots of practice and training) On the older ships this information was passed on to the Gun Director and/or the gun mount most available to acquire the target via sound powered phones. On newer ships and ships with gun fire control computers this information was fed electronically via syncromotors.
If the ship did not have the special mounted binoculars a freestanding lookout would still identify the target and pass on the information via the battle sound powered circuit.

The SKY lookout, upon identifying a threat would call the command "ACTION STARBOARD" (or action port, starboard quarter, abeam etc.) This alerted the gun crew and Director operator that a target had been identified and more information was following. While waiting for this information the gun crew could already be training the mounts or gun director to the proper general direction of the bogie.
The SKY observer would then pass a three-part target acquisition command giving bearing, position angle and range to target. It might sound something like this:
"ACTION STARBOARD" "ACTION STARBOARD" "TARGET INBOUND BEARING 095 DEGREES RELATIVE, POSITION ANGLE THREE ZERO DEGREES, RANGE NINE THOUSAND"
The weapons officer would then assign a mount(s) and/or gun director to acquire and track the target.
When the report was heard "TARGET ACQUIRED" that meant the gunner or director had the target in the sights and were ready to fire. The command was then given to commence firing.

In the log when it was reported "Ready gun 1, 6, director 41 and SKY 1, it meant that these positions were ready to be put in operation quickly if needed. That is, the weather covers were removed or secured in such a way they could be removed very quickly, the power was turned on in standby mode and the position could be manned and operational in a very short notice.
The earlier ships may not have had gun directors and relied on the SKY observers for target bearing information.



Disclaimer: This is from memory so don't shoot me if something is incorrect.

Pointer FTG2



I was thinking the samething. You know "Great Minds" think alike.....(grin)
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Joined: August 24th, 2003, 10:08 pm

March 24th, 2009, 12:53 am #8

If you two think alike... we Gator Gals are in big trouble...

Don't get Jim and Chris in on this or it really WILL be something...
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Joined: August 24th, 2003, 10:08 pm

March 24th, 2009, 1:04 am #9

SeaBat, your homework assignment (should you choose to accept it) will be to find out what is meant by "shooting a star with a borescope" for "battery alllignment".

Hint, battery allignment does not mean putting all the batteries aboard ship with their positive posts facing the same direction.

BP

P.S. I have your needle gun cleaned, polished and ready to go for work week.

http://www.visionscopetechnologies.co.u ... copes.html

If you read this article and scroll down, it talks about Hartzell Propeller of Piqua... Want to bet me there is an Adams that works there?

The borescope allows inspection of the bore.. on the Ship, I'm guessing it would be the bore of the gun.

My GUESS is that you'd use the scope on the ship to help aim the guns by using the scope to assess the source of the incoming fire by following the tracers? Don't laugh.. I SAID it was a guess...
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Joined: December 17th, 2005, 10:55 pm

March 24th, 2009, 1:54 am #10

SeaBat, your homework assignment (should you choose to accept it) will be to find out what is meant by "shooting a star with a borescope" for "battery alllignment".

Hint, battery allignment does not mean putting all the batteries aboard ship with their positive posts facing the same direction.

BP

P.S. I have your needle gun cleaned, polished and ready to go for work week.

Bob, Cut SeaBat no slack!
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