WW2 sub radio silence

[OldCoot]

During a WW2 patrol would a submarine maintain rado silence from start to finish, or would they report contacts with the enemy? Specifically, if they experienced problems with the Mark 14 torpedo, would they, at some point, report this by radio, or would they wait until they reached home port?

[Knavey]

Radio was used.

Yamato comes to mind. She was spotted by subs on her final sortie. The subs (Threadfin and Hackleback + 15 other subs) were under orders to transmit the sighting, and get confirmation of the message BEFORE attacking. They were specifically on the lookout for the Yamato at that time. Threadfin actually had a shot at her but could not take it because they did not get their confirmation report back in time.

Source - A Glorious Way To Die by Russell Spurr

[mdiehl]

It depended on the nation.

USN sub doctrine was to report a contact as soon as practical on sighting and then attack the target. Other information was reserved for patrol reports filed upon return to port. Important noncritical information would be radioed in once the submarine was clear of its patrol zone and on its way back to port. Problems with the torpedoes were extensively discussed in after-action reports and patrol reviews, but not reported by radio (for obvious reasons). Things like "We have twenty rescued personnel on board and are proceeding to Midway to debark them" would be reported when clear of the patrol zone. "Convoy of six ships comprised of two transports and four escorts" would be reported as soon as possible, so that ComSubPac could route other boats onto the target.

The German navy (Kriegsmarine) was anally retentive about forcing submarines to report almost daily by radio. The result was that many German subs in 1943-44 were sunk when radio direction finding stations triangulated on the signals and put hunter-killer task forces on top of the German submarine.

The Japanese practice was to communicate sightings of enemy combat ships as these occurred, as soon as was expedient for the sighting sub, and to report attacks by radio as soon as reasonable practical after the attack (and of course file detailed reports on return to port).

[m10bob]

ORIGINAL: mdiehl

It depended on the nation.

USN sub doctrine was to report a contact as soon as practical on sighting and then attack the target. Other information was reserved for patrol reports filed upon return to port. Important noncritical information would be radioed in once the submarine was clear of its patrol zone and on its way back to port. Problems with the torpedoes were extensively discussed in after-action reports and patrol reviews, but not reported by radio (for obvious reasons). Things like "We have twenty rescued personnel on board and are proceeding to Midway to debark them" would be reported when clear of the patrol zone. "Convoy of six ships comprised of two transports and four escorts" would be reported as soon as possible, so that ComSubPac could route other boats onto the target.

The German navy (Kriegsmarine) was anally retentive about forcing submarines to report almost daily by radio. The result was that many German subs in 1943-44 were sunk when radio direction finding stations triangulated on the signals and put hunter-killer task forces on top of the German submarine.

The Japanese practice was to communicate sightings of enemy combat ships as these occurred, as soon as was expedient for the sighting sub, and to report attacks by radio as soon as reasonable practical after the attack (and of course file detailed reports on return to port).

Sub doctrine for the U.S. in the Pacific also depended on when you might refer to.
Many subs never reported after leaving Brisbane or Pearl unless reporting they felt truly important, (like a CV sighting).
They were after all "The Silent Service"

I recommend Clay Blair's excellent books "Silent Victory"..

[rtrapasso]

The Japanese practice was to communicate sightings of enemy combat ships as these occurred, as soon as was expedient for the sighting sub, and to report attacks by radio as soon as reasonable practical after the attack (and of course file detailed reports on return to port).

At least early in the war, the Japanese subs made (almost) daily contact reports... one sub that shelled the west coast was picked off when the contact positions (revealed by ULTRA, iirc, but maybe by triangulation) showed a Great Circle coarse from the site of the shelling back towards a major Japanese base (Kwaj, i think)... the USN sent out its forces and reportedly sunk it... i am trying to look up which one it was.

EDIT: i've read this story several times (and i think in different places), but in trying to actually identify the sub, i think the story is not accurate: either it was NOT the West Coast that was shelled, or the events never took place at all.

I-73 was intercepted and sunk by GUDGEON in the right time frame, but it had been shelling Midway, not the West Coast.

[CaptDave]

Another factor determining what the US subs would call in, and when, was whether doing so would jeopardize their position. While a contact report would be made as soon as possible, this didn't always mean immediately, as it could result in the sub's detection and result in at best foiling the attack and at worst foiling the sub. The same would apply to the post-combat report, if it were deemed worthy of sending (if one or more viable targets were still afloat, then a contact/combat report might be sent).

[morganbj]

ORIGINAL: rtrapasso

The Japanese practice was to communicate sightings of enemy combat ships as these occurred, as soon as was expedient for the sighting sub, and to report attacks by radio as soon as reasonable practical after the attack (and of course file detailed reports on return to port).

At least early in the war, the Japanese subs made (almost) daily contact reports... one sub that shelled the west coast was picked off when the contact positions (revealed by ULTRA, iirc, but maybe by triangulation) showed a Great Circle coarse from the site of the shelling back towards a major Japanese base (Kwaj, i think)... the USN sent out its forces and reportedly sunk it... i am trying to look up which one it was.

EDIT: i've read this story several times (and i think in different places), but in trying to actually identify the sub, i think the story is not accurate: either it was NOT the West Coast that was shelled, or the events never took place at all.

I-73 was intercepted and sunk by GUDGEON in the right time frame, but it had been shelling Midway, not the West Coast.

I think the costal defense installation at Astoria, Oregon was shelled at one point. My father-in-law was in a TBM crew that flew ASW out of there before joining the Princeton to prevent the base from being sheled again.

[morganbj]

Heres a quote from the Astoria website.   http://www.astoriaoregon.com/astoria_japanese_invasion.php
 
"Althought many protective measures were made to secure the coast from a Japanese attack, on the night of June 21, 1941 around 11:30 pm a Japanese submarine attacked Ft. Stevens. The submarine lobbed 17 shells toward Ft. Stevens in a twenty-minute bombardment. Most of the shells landed in swampy terrain, one did fall 300 yards in front of Batteryt Russell and one withing 50 yards of a concrete pillbox. No damage was done, but this was the only bombardment of a fortification within the continetal U.S. since 1812."
 
I think they must mean 1942, not 1941.
 

[morganbj]

Here's the story from another website that has the correct date.  http://www.all-oregon.com/city/astoria/history.htm
 
"Fort Stevens enjoys the distinction of being the only military installation in the continental United States to be fired on since the War of 1812. On the night of June 21, 1942, the Fort was the target of a Japanese submarine which fired 17 shells, causing no damage."

[Howard Mitchell]

ORIGINAL: bjmorgan

Here's the story from another website that has the correct date.  http://www.all-oregon.com/city/astoria/history.htm

"Fort Stevens enjoys the distinction of being the only military installation in the continental United States to be fired on since the War of 1812. On the night of June 21, 1942, the Fort was the target of a Japanese submarine which fired 17 shells, causing no damage."

This incident is, bizzarely, mentioned in the section on the Fu-Go balloon offensive in Special Attack Aircraft and Flying Bombs by Ishiguro and Januszewski. Apparently there was some damage when I-25 shelled Fort Stevens - the net on a volleyball court was damaged!