Nakajima B6N Tenzan (Jill)

[windhund116]

Were there any accurate accounts of a Jill sinking a US ship using a torpedo? Not suicide victories.

Thanks!

 

[fubar57]

This is all I could find using this book

 

[windhund116]

This is all I could find using this book

View attachment 657501

View attachment 657500​

No names sited for those ships? Must have been an escort carrier, as I would think a main battle group one would have been reported?

 

[DarrenW]

No names sited for those ships? Must have been an escort carrier, as I would think a main battle group one would have been reported?

View attachment 657505

You are right in your assumptions. According to this article the only naval vessels lost in the Pacific on that date were of Japanese origin:

https://en.m.wikipedia.org/wiki/List_of_shipwrecks_in_June_1944#15_June

Also, every account I've read were that the B6N was a complete failure as a combat machine. Most if not every claim its crews made turned out to be a distortion of the truth, with the agenda of the Japanese high command having a lot to do with this.

 

[windhund116]

You are right in your assumptions. According to this article the only naval vessels lost in the Pacific on that date were of Japanese origin:

https://en.m.wikipedia.org/wiki/List_of_shipwrecks_in_June_1944#15_June

Also, every account I've read were that the B6N was a complete failure as a combat machine. Most if not every claim its crews made turned out to be a distortion of the truth, with the agenda of the Japanese high command having a lot to do with this.

I remember a report on a New Guinea based IJN torpedo Tenzan bombers sinking two aircraft carriers. The only report on the US side was two landing crafts attacked by "Kates(?)" Damaged but not sunk.

 

[Acheron]

No idea if this list is complete:

List of sunken aircraft carriers - Wikipedia

en.wikipedia.org

As for the B6N, my understanding is that torpedo bombers were quite sensitive to enemy air power. The death ride of the Devastators at Midway is famous, but I read that the much more modern Avengers didn't fare better either, so the B6N might have suffered from becoming active when the USN outclassed the IJN in the air?

 

[BlackSheep]

Wasn't the USS Grayback sunk by a Jill?

Edit: Apologies, the Grayback was sunk by a B5N Kate with a bomb to the tower in the open sea. Still a great piece of detective work, in combing through and cross referencing old records by the Lost 52 Project.

 

[EwenS]

Looking through the Osprey Combat Aircraft book on the Nakajima B5N "Kate" and B6N "Jill" reveals the following B6N non kamikaze successes.

17/6/44 LCI(G) 468 sunk in a dusk attack by 5 Jills. 3 shot down by other craft.
12/10/44 cruiser Canberra torpedoed
13/10/44 cruiser Houston torpedoed and again on 16/10/44
Both these ships had to be towed to safety but survived. They did not however return to service until Oct 1945.

By this time Japanese tactics had evolved into using dusk attacks with targets silhouetted in the last remaining light with attackers coming from out of the dark.

5/12/44 SS Antoine Saugrain torpedoed twice by B6N. It sank next day. Other B6N made unsuccessful attacks on other ships in the convoy.

I would hardly call it a failure. Its entry to service was delayed until mid-1943, so it missed the big carrier battles of 1942. Only some 1,300 were produced. It suffered from the usual Japanese problems like unprotected fuel tanks. It had a high landing speed so could only operate from land bases or the ever diminishing number of large carriers. And by 1944 it was having to fight its way through ever increasing numbers of USN fighters (the Big Blue Blanket) and light AA to reach its targets. And USN levels of radar guided night defence also increased in 1944, with NF flights on every fleet carrier and specialist night carrier air groups being deployed from Aug.

Edit. Had the Canberra/Houston incident happened in 1942/43 then the ships would probably have had to have been scuttled. They were saved by the much higher standard of damage control displayed by the USN in 1944 and by the USN's ability to keep a sufficient level of airborne protection over them during the 2 weeks it took to tow these ships back to Ulithi for temporary repairs.

 

[cherry blossom]

The torpedoes which hits on Houston were probably dropped by P1Y1 Gingas

USS Houston CL81 War Damage Report No. 53 has:
At about 1841 a twin engine plane was detected visually to starboard at a distance of 2,000 yards, approximately 150 feet off the water. The forward starboard automatic weapons took the plane under fire and scored numerous hits. The plane then turned directly towards HOUSTON. At about 1,500 yards from the ship it dropped a torpedo and crossed over the bow. The Commanding Officer ordered full right rudder in an attempt to parallel the torpedo's course and at the same time to present the smallest possible target. The helmsman, either misunderstanding the order or failing to hear the order correctly due to the firing of all guns of 5-inch and smaller caliber, started the rudder left. The error was discovered immediately and corrected; however, due either to this delay or to the short torpedo run, the ship was hit amidships on the bottom at about frame 75.

and

49. At about 1348, several ships astern opened fire with 5-inch batteries in a direction away from HOUSTON. In the vicinity of their bursts a twin-engine plane, later identified as a NICK, was sighted bearing 300 degrees true heading directly for HOUSTON down the oil slick in her wake. When the plane had closed to about 5,000 yards, all 40mm guns that could bear opened fire. At about 3,000 yards, the plane dropped a torpedo at an altitude of 75 feet and continued on toward the ship, under heavy fire. The 20mm battery opened fire at about 2,000 yards. Many hits were observed and the plane flew up the starboard side at about 200 yards range, crossed ahead, lost altitude, and without burning, crashed into the sea about 3,000 yards ahead.
50. The torpedo struck the starboard side at frame 145, having approached on a line parallel to No. 2 shaft.

Canberra's damage report does not try to identify its attackers.

 

[cherry blossom]

On the other hand, USS Pennsylvania was torpedoed by a Jill on August 12th 1945 in "Buckner Bay" off Okinawa and might have been in difficulties out to sea. She was towed into shallow water but did not need to be beached.

 

[DarrenW]

I remember a report on a New Guinea based IJN torpedo Tenzan bombers sinking two aircraft carriers. The only report on the US side was two landing crafts attacked by "Kates(?)" Damaged but not sunk.

I read that too. Another unsubstantiated report which was accepted at face value due to its great propaganda potential.

 

[DarrenW]

I would hardly call it a failure...

Everything you mentioned contributed to its failure as an effective torpedo bomber. It may have been a fine aircraft in every other respect but it's combat record is dismal at best so IMHO that classifies it as a failure in its intended combat role.

 

[GregP]

The Aichi B7A Ryusei was the airplane that SHOULD have been their torpedo bomber.

It was big, powerful (1,825 hp), fast (352 mph; 567 km/h), and it had great range (1,888 mi / 3,038 km).

The only problem with it was the fact that it came out when the big carriers had been sunk or would soon BE sunk (first flight May 42), so it didn't have any ships to operate from, only land. They only built 114 of them, but it was a formidable machine that never got a chance to show what it could do. Considering the speed it had, we are perhaps lucky it didn't get produced in numbers.

 

[windhund116]

Looking through the Osprey Combat Aircraft book on the Nakajima B5N "Kate" and B6N "Jill" reveals the following B6N non kamikaze successes.

17/6/44 LCI(G) 468 sunk in a dusk attack by 5 Jills. 3 shot down by other craft.
12/10/44 cruiser Canberra torpedoed
13/10/44 cruiser Houston torpedoed and again on 16/10/44
Both these ships had to be towed to safety but survived. They did not however return to service until Oct 1945.

By this time Japanese tactics had evolved into using dusk attacks with targets silhouetted in the last remaining light with attackers coming from out of the dark.

5/12/44 SS Antoine Saugrain torpedoed twice by B6N. It sank next day. Other B6N made unsuccessful attacks on other ships in the convoy.

I would hardly call it a failure. Its entry to service was delayed until mid-1943, so it missed the big carrier battles of 1942. Only some 1,300 were produced. It suffered from the usual Japanese problems like unprotected fuel tanks. It had a high landing speed so could only operate from land bases or the ever diminishing number of large carriers. And by 1944 it was having to fight its way through ever increasing numbers of USN fighters (the Big Blue Blanket) and light AA to reach its targets. And USN levels of radar guided night defence also increased in 1944, with NF flights on every fleet carrier and specialist night carrier air groups being deployed from Aug.

Edit. Had the Canberra/Houston incident happened in 1942/43 then the ships would probably have had to have been scuttled. They were saved by the much higher standard of damage control displayed by the USN in 1944 and by the USN's ability to keep a sufficient level of airborne protection over them during the 2 weeks it took to tow these ships back to Ulithi for temporary repairs.

The large Landing Craft sinking (LCI 468, on 12/6/44) must have been what I read in another book. Though that book stated two crafts were attacked by "Kates(?)", one severely damaged and one moderately damaged. The pilots of the torpedo bombers reported the landing crafts as aircraft carriers. The number of US troops killed or injured was not reported. I must try to find that source.

I suppose the offset control tower could be mistaken as an aircraft carrier. If one is under intense anti-aircraft fire and flying zig-zag maneuvers during the initial mid-altitude approach to the target at high speed.

Thanks, for the follow-up and citation!

 

[BlackSheep]

The Aichi B7A Ryusei was the airplane that SHOULD have been their torpedo bomber.

View attachment 657571

It was big, powerful (1,825 hp), fast (352 mph; 567 km/h), and it had great range (1,888 mi / 3,038 km).

The only problem with it was the fact that it came out when the big carriers had been sunk or would soon BE sunk (first flight May 42), so it didn't have any ships to operate from, only land. They only built 114 of them, but it was a formidable machine that never got a chance to show what it could do. Considering the speed it had, we are perhaps lucky it didn't get produced in numbers.

Looks like a bird in flight, with that wingspan

 

[EwenS]

The large Landing Craft sinking (LCI 468, on 12/6/44) must have been what I read in another book. Though that book stated two crafts were attacked by "Kates(?)", one severely damaged and one moderately damaged. The pilots of the torpedo bombers reported the landing crafts as aircraft carriers. The number of US troops killed or injured was not reported. I must try to find that source.

I suppose the offset control tower could be mistaken as an aircraft carrier. If one is under intense anti-aircraft fire and flying zig-zag maneuvers during the initial mid-altitude approach to the target at high speed.

Thanks, for the follow-up and citation!

View attachment 657572

The superstructure was on the centreline on the LCI and its various gunboat derivatives, as in the lead ship in your photo.

NavSource Landing Craft, Infantry Photo Archive

The trailing ship in the photo is an LSM where the bridge structure was offset to starboard to ensure a clear tank deck. The first of these only began completing in May 1944, so too late to participate in the Mariana invasions in June.

NavSource Landing Ship, Medium Photo Archive

 

[DarrenW]

The Aichi B7A Ryusei was the airplane that SHOULD have been their torpedo bomber.

Rare footage of a "Grace" getting shot up by an F6F Hellcat (starts around 20 second mark):

 

[Clayton Magnet]

Fleet carriers loaded with B7N and A7M air wings, with a few C6N recce birds would have been a problem.
Thankfully it is only a "what-if" scenario

 

[windhund116]

More complete film of that Grace getting shot up (3:33 mark). Scrolling on the time line gives the types of planes involved.
Best seen in HD1080 mode.

 

[DarrenW]

More complete film of that Grace getting shot up (3:33 mark). Scrolling on the time line gives the types of planes involved.
Best seen in HD1080 mode.

Man that Japanese crew had to be seriously soiling themselves from that particular encounter!