"Sonobuoy Use in WWII?" Topic

I read about this recently, and thought that sonobuoys were developed during the postwar period.

I was surprised to find they were in use/testing by the British as far back as Jun/Jul 1942, with Sunderlands in 210 Sqdrn. Apparently, they called their sonobuoys "High Tea".

I also read that 1,000 sonobuoys and 100 receivers were approved for purchase at the end of Oct. of 1942, and were in use fairly early in 1943. Don't have an exact date on the first combat use of them.

Supposedly, long-range Liberators, and TBF Avengers carried them.

So, just curious to see if anyone knows how many sonobuoys these aircraft could carry, and when they were first used?

Presumably the PBYs carried them as well, so would like to know the same info for those, and/or any other patrol planes that carried them.

I know the American planes were using it with FIDO (Mk 24 mine – code name) homing torpedoes. Apparently, some of these were given to the British as well, but use by all aircrews was severely restricted, so they wouldn't tip off their existence to enemy U-Boat crews, or even Allied naval personnel.

I also ran across a reference of sonobuoys being carried by convoy vessels (presumably merchant ships), but am not sure if this was just an idea that was floated, or if the tactic was used operationally. The plan was to toss them over the side, when u-boats were sighted in, or near the convoy, so they would drift astern. Presumably, u-boats forced to submerge after or before an attack would as well, and then they would fall easy prey to the escort vessels which turned back to engage them.

Any info on the subject would be appreciated.

Here some information starting with the 8th paragraph

link

Totally away from my sources referring to a project I have not examined in ages – but …

I met with two aircrew (pilot and ordnance man) of a TBF Avenger from one of our escort carriers who sank an IJN submarine traveling to/from France (like I said, it has been years since I researched this – I'd have to dig everything out but, IIRC, it was I-52).

The attacking aircraft deployed several sonobuoys and the ordnance man still had copies of the sound recordings made during the attack (which I was able to get copied onto a tape which I still have). It was fascinating to listen to it while having the aircrew discussing how they were used to direct what proved to be a successful attack.

Mark

I found a webpage with the recordings from I-52's sinking:

hnsa.org/sound/#i52wire

I assume the sonobuoys are the active variety?

I read a bit of the I-52 sinking, plus some other accounts. Not sure I've seen the whole account though, so will check that out.

From the bit I read, all seemed to state that the sonobuoys were of the passive type, e.g. just hydrophones, and that the one giving off the loudest sound was presumed to be closest to the enemy sub. Seems they were a bit rudimentary at first.

Also, apparently the first sonobuoy had six signal channels, so you could use six of them at once.

Later, but still in WWII, twelve could be used at one time.

I remember posting this on another site about the sinking of the I-52. Robert
"Sinking of I-52

In an extraordinary engagement, Avengers from USS Bogue CVE-9, the top sub-killing CVE of the Atlantic, sank the Japanese transport submarine, I-52. In 1943 the Japanese and Germans worked out a plan to exchange critical materials via specialized cargo submarines: opium, rubber, quinine, tungsten, and molybdenum from the Japanese for German radar, bombsights, vacuum tubes, optical glass, ball bearings, etc.. In March, 1944, I-52 departed Kure, picked up cargo in Singapore and headed through the Indian Ocean, all monitored by U.S. intelligence. It rendezvoused with a German sub U-530 on June 23, in the mid-Atlantic, and picked up a German pilot who would guide I-52 into port at Lorient. There the exchange was planned to take place.

But Allied "Ultra" intercepts had pinpointed I-52's movements and even its cargo. Within hours of I-52's meeting with U-530, this information had been relayed to Bogue. The commander of its Composite Squadron 69 (VC-69), Lt. Cdr. Jesse Taylor, immediately took off in his TBF in pursuit of the Jap sub. As Taylor patrolled in the darkness, his radarman, Chief Ed Whitlock, picked up a blip. They went after it and dropped flares, lighting up the 350-foot long cargo sub. Taylor closed in, dropping two depth bombs. I-52 dived and the TBF dropped a sonobuoy into the water. The newly-developed sonobuoys picked up long-carrying underwater noises and transmitted these back to the carrier. Following the sonobuoy's signal, Taylor dropped a Mark 24 "Fido" acoustic torpedo. The sonobuoy transmitted the crunching sound of explosions back to Bogue. While Taylor thought he had sunk the sub, other Avengers soon picked up propeller beats. Bogue's CO, Captain A. B. Vosseller, ordered a second attack; William "Flash" Gordon flew his TBF to the site and dropped another torpedo. The I-52 swiftly went to the bottom, with a huge hole in her hull. Next morning, U.S. destroyers found I-52's flotsam: a ton of raw rubber, bit of silk, and even human flesh. "
link