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COMSUBBBS
Posts: 2561
Location: Rapid City, SD | Subject: A bunch of questions...
This is from the Official War Patrol Reports of the USS Sterlet. I will first type it out in it's entirety; then break it down to ask several questions.
"Installed .50 cal. guns, twin 20 mm on bridge aft, Voycal (yes, this is how it was spelled) voice modulator, APR-1 radar detector and radar-TBT true bearing repeator."
1. "Installed .50 cal. guns, twin 20 mm on bridge aft."
Are 50 cal. guns and 20 mm one and the same guns? How many guns were installed on the bridge aft?
Or - were they all installed on the bridge aft?
Or - were only the twin 20 mm guns installed on the bridge aft?
If so, where were the .50 cal gun(s) installed?
All these guns were installed after the boat had sailed down the east coast; through the Panama Canal; and through much of the Pacific before reaching Pearl Harbor. It would seem to a land lubber like me, that if the boat didn't have these guns for the six weeks that it took for them to reach Pearl, they must have been very vulnerable. Why wouldn't they have had the guns installed before they left New London?
2. What's a 'voycal' voice modulator? Or, was this a typo, and the yeoman meant to type 'vocal'?
In any case, what is this 'modulator,' and what does it do?
What's an APR-1 radar detector?
What's a radar-TBT true bearing repeater?
Shouldn't the initials be 'TBR' true bearing repeater?
I have many more questions, but will hold them until I get answers for these.
Cora |
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Plankowner
Posts: 9165
Location: Upper lefthand corner of the map. | Subject: RE: A bunch of questions...
Cora. A picture worth 1000 words. Guns were added, removed, changed and replaced at the will of the commanding officer based on the boats experience and circumstances.
.50 caliber machine guns looked like this.
20 MM guns looked like this. You can see it isa much bigger gun.
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COMSUBBBS
Posts: 2561
Location: Rapid City, SD | Subject: So, Ric...
How many guns and where were they placed?
Cora |
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Master and Commander
Posts: 1324
Location: Oxnard, CA | Subject: RE: A bunch of questions...
A .50 CAL M-2 (The Ma Deuce) machine gun has a bore diameter of .500 inch (1/2 inch) and was designed by John Moses Browning. It fires 50cal linked ammunition. While it is heavy, one man can carry a .50 cal Browning machine gun.
The 20mm anti-aircraft machine gun has a bore diameter of 20 mm ( .79 Caliber or .790 inch (8/10 inch)) and is made by Oerlikon of Switzerland. It fires 20mm drum fed ammunition. The 20mm is too heavy to be carried by one man, and may require the use of some type of crane to move it.
The next size larger would be the 40mm Bofors gun (Sweden) (1.58 inch dia.) It fires 40mm 4-round clip fed ammunition. The can be single mount, twin mount or quad (4) mount. (These were the so-called "Pom-Pom" guns.
After that would be the 3 inch, then the 5 inch guns. Surface navy would go up to the 8 inch, 10 inch, 12 inch and 16 inch guns. There might have been 14 inch guns on WWI battleships, but I don't know.
Where they were installed on the Sterlet (per your post) is "on the bridge -aft" which would mean exactly that, on the bridge, but having the ability to also point rearward. Had they said on the bridge forward, would have meant pointing to the front.
The difference between a "twin 20," and "two 20" is twin 20mm is two 20 mm guns mounted side by side on the same turret arrangement, aimed and fired by one person. Two 20mm would be two individual 20mm guns on their own turret arrangements, amed and each fired by different people. As the report indicates a "twin 20" I would surmise it was mounted on the center line of the ship, and positioned to be able to fire on either side of the ship and points aft.
As there was no entry as to how many .50 cal guns were installed, I can't say how many there were. But for the twin 20, there was two guns mounted together on one turret arrangement.
A .50 cal mounting can consist of a braced vertical pipe onto which the .50 is placed. You can mount .50 cal machine guns as close as (say) 3 feet apart. You can also twin-mount the .50's, but from what I can gather, these were all single mounts. As they indicate "50 cal gunS"... I would surmise these were mounted on both sides of the bridge so as the ones on the left would cover the port side of the ship to a point directly aft, and the ones on the right would cover the starboard side of the ship, to a point directly aft. There may have been some over lap directly aft.
Note I use the words "turret arrangement" only for clarity. A true turret is something completely different.
Below the 50 cal Ma Duce, would be the Browning 30 Cal machine gun, firing a U.S. .30 CAL (civilian 30-06) linked round. Other weapons firing the (30-06) were the M-1Garand rifle (8 rounds clip fed) and the M-?? Browning Automatic Rifle (BAR) (20 rounds box magazine fed).
The next one down from the M-1 Garand was the 30-M1 Carbine (15 to 30 rounds box magazine fed), which used the same diameter bullet, but a different shell casing, and was for close range only. It was SUPPOSED to be for officers to supplement the .45 pistol.
Firing the .45 pistol round was the M-1911 and the M-1911A1 Browning pistols, AND the M1928 Thompson Sub Machine gun (Tommy gun). This was supplemented by a cheaper stamped metal parts "Grease Gun" (designations escape me).
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COMSUBBBS
Posts: 2561
Location: Rapid City, SD | Subject: Jon, the report says, . . .
"Installed .50 cal. guns..." The plural was used.
Cora |
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Plankowner
Posts: 9165
Location: Upper lefthand corner of the map. | Subject: RE: Jon, the report says, . . .
They could ahve been installed on the railing around the after smoking deck or maybe on the railings on the deck level. Boats had them both places
Picture shows the Balao with her deck mounted guns.
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Master and Commander
Posts: 1107
Location: Tucson AZ | Subject: RE: A bunch of questions...
Corabelle wrote: '... All these guns were installed after the boat had sailed down the eastcoast; through the Panama Canal; and through much of the Pacific beforereaching Pearl Harbor. It would seem to a land lubber like me, that ifthe boat didn't have these guns for the six weeks that it took for themto reach Pearl, they must have been very vulnerable. Why wouldn't theyhave had the guns installed before they left New London?'
The submarine guns we're talking about here were used primarily for defense from air attacks, and against very small/lightly armed surface craft. There simply wasn't any real danger from either during the transit down the east coast, and through the eastern Pacific to Mare Island, Pearl, or whatever their eventual destination was. There was no significant enemy surface or air power in the transit regions; there were submarines, but sub vs. sub action used either torpedoes or the main 3" or 5" deck gun.
In addition, small caliber tactics for subs was constantly evolving through the war, so the folks in command at SUBPAC and regional levels wanted to get the new boats on scene as fast as possible and take care of the 'small caliber details' when they got 'on site' at Pearl, or Perth, or Brisbane, etc.
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Senior Crew
Posts: 141
Location: Seattle, WA | Subject: RE: A bunch of questions...
"What's an APR-1 radar detector?"
I don't have the specific information on the APR-1 series, but in general it was a receiver for picking up radar signals (the books say from 40-1000 MHz) to provide the sub with a warning that someone nearby (within Radar line of sight) was using active radar.
The APR-1 would have been originally designed for use on airplanes (in standard Navy system desigantions the A at the start stands for aircraft, the P is for pulsed radar, and the R is for receiver), but was probably small enough to fit nicely on a sub.
"What's a radar-TBT true bearing repeater?"
This just would have been a device that transmitted the bearing information from the radar or TBT (Target Bearing Transmitter) to some other device, such as the Torpedo Data Computer (TDC).
Hope that helps.
Dave |
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A bunch of questions...
