Take off distance CV vs Land

[Brady]

These weapons could only be carried by the B5N2 Kate used as a level bomber. Too heavy for the D3A Val dive bomber. The one such attack on Hornet was by 6 level bombers in the afternoon. Result 5 near misses and a single hit on the aft starboard quarter of the flight deck and passed through to explode in the water. The following is from her damage report.

I. Probable Damage Caused by Bomb Hit, After Starboard Corner of Flight Deck and Near-Misses​

46. Since HORNET was being abandoned at the time of the high level attack, the structural damage as a result of the near-misses and the bomb aft is unknown. These bombs were probably S.A.P. inasmuch as they detonated after traveling underwater and produced an effect similar to that of a mine explosion. If this assumption is correct, then the bomb hit on the after starboard corner of the flight deck must have passed through the flight deck, leaving a small hole, and detonated underwater with the other near-misses. The skin was probably dished in the general area of the explosion. Possibly the hull was ruptured, permitting flooding in some of the after compartments on the second platform or hold.


49. The bombs used by the enemy in the afternoon high-level bombing attack were probably at least 250 Kg. S.A.P. bombs inasmuch as reference (a) reports that the detonation occurred underwater. The cumulative effect of the detonation of the six near-misses was that of a mine explosion. It also appears doubtful that high level bombers would carry bombs of a smaller size than 250 Kg.

https://ibiblio.org/hyperwar/USN/WarDamageReports/WarDamageReportCV8/PlateII.jpg

Note the hit is described on the diagram as being from a "small" bomb.

Full report is here

U.S.S. HORNET (CV8) LOSS IN ACTION SANTA CRUZ 26 OCTOBER, 1942

U. S. S. HORNET (CV8) LOSS IN ACTION SANTA CRUZ 26 OCTOBER, 1942

ibiblio.org

They were defiantly dropping 800 kg bombs.

Just looking at the Zuikaku's Action Report, it's impossible to tell what type of 800kg AP bomb was used. Since the Type 2 bomb was adopted in June 1942, the August consumption was definitely Type 99s, and all I can say is that the October consumption "might have been Type 2s

https://forum.axishistory.com/viewtopic.php?f=65&t=289213#p2594291

 

[Thumpalumpacus]

Yeah, damage reports notwithstanding, Lundstrom on p.448 of First Team and the Battle of Guadalcanal asserts the final bombs dropped on CV-8 being 800-kg.

 

[R Leonard]

And just for the record -

The VB-6 report for Midway, dated 10 June 1942, for the morning attack states:
"The attack group was led by the Enterprise Air Group Commander and consisted of thirty-two SBD's; fifteen from VB-6, loaded with one 1000 lb bomb each, sixteen from VS-6, loaded with one 500 lb bomb and two 100 lb bombs each, and the EAGC plane loaded with one 500 lb and two 100 lb bombs."

For the afternoon attack on Hiryu and its escorts the report shows:
"The attack group was led by Commander Scouting Squadron Six, and consisted of planes of VS-6, four planes of VB-6, each loaded with one 1000 lb bomb, and fourteen planes of VB-3."

The next day, in an evening attack on a destroyer the narrative reports:
"The attack group was led by Lieutenant D. W. Shumway, VB-3, and consisted of a total of 32 SBD's from VB-3, VB-5, VB-6, and VS-6. All planes were armed with one 500 lb bomb."

And for the attack on the Mikuma and Mogami group on Saturday, 6 June:
"The attack group was lead by Lieut. Short, VS-5, and consisted of 31 SBD's from VB-3, VS-5, VB-6, VS-6; 3 TBD's from VT-6 and 12 F4F-4's from VF-6. All VB-6 planes carried 1000 lb bombs as did most of the other SBD's."

The VS-6 report for Midway, dated 20 June 1942, shows:
"The attack group was led by the Enterprise Air Group Commander and consisted of thirty-two SBD's; fifteen from VB-6, loaded with one 1000 lb bomb each, sixteen from VS-6, loaded with one 500 lb bomb and two 100 lb bombs each, and the EAGC plane loaded with one 500 lb and two 100 lb bombs."

For the Hiryu attack in the afternoon, the VS-6 does not mention ordnance loading.

On the 5 June attack on a destroyer:
"The attack group was led by Lieutenant D. W. Shumway, VB-3, and consisted of a total of 32 SBD's from VB-3, VB-5, VB-6, and VS-6. All planes were armed with one 500 lb bomb."

And for the VS-6 Mikuma/Mogami attack of Saturday 6 June, there is no mention of ordnance loading.

Also, neither the VB-6 nor the VS-6 mentions fuse settings for the noted ordnance in their reports.

In the narrative portion of the VB-3 report of 10 June 1942 the following appears related to the Thursday morning attack on the Japanese carriers:

"Thirteen Mk.13, 1000 lb. bombs with Mk.21 nose and Mk.23 tail fuzed were dropped . . ."

Further in the narrative relating to the afternoon attack on Hiryu and its escorts appears:

"Eleven Mk. 13, 1000 lb bombs and 3 Mk. 12, 500 lb bombs were dropped by this squadron at an average altitude of 2,500 ft. Fuses were Mk. 21, nose and Mk, 23, tail, detonating at 1/100 second after impact."

In the attack of 5 June on a Japanese destroyer (universally noted as a light cruiser in all the reports) the VB-3 narrative shows:
"Ten Mk. 12, 500 lb demolition bombs were dropped by Bombing Three. Mk. 21, nose and Mk. 23, tail fuses were used, detonating 1/100 sec. after impact."

And on 6 June in the attack on the Mikuma/Mogami group:
"Ten Mk. 13, 1000 lb bombs were dropped by Bombing Squadron Three from an average release altitude of 2,500 ft. Nose and tail fuses were Mk. 21 and Mk, 23 respectively, detonating at 1/100 second after impact."

VB-5 (temporarily designated VS-5) report dated 7 June 1942 shows for the morning scouting mission:
"Five two plane scout-bomber sections of this squadron were launched at about 1330 ZT +10 to search relative sectors 280° - 20° from the YORKTOWN didtance 200 miles. Each plane was armed with a 1000 lb bomb, fused for 1/100 sec."

On 5 June: "Planes were armed with one 500 lb bomb, fused for 1/100 sec."

And on 6 June: "The attack group with 7 VS-5 planes ere launched about 1245, armed with 1 – 1000 lb. bomb used to 1/100 sec."

The VB-8 report, 7 June 1942, does not mention ordnance until the evening attack on the Hiryu and escorts group where it states: "Attacked out of the sun from 15,000' altitude. Dropped six 500# bombs. Released at 2,500' to 2,000' altitude."

For the 5 June attack on the destroyer: "10 - 500# bombs 1/100 second delay fuses.

For the 6 June attack: "Twelve 1,000# bombs 1/100 second delay fuse."

The VMSB-241 report makes no mention of ordnance loading.

Regret that I do not have a VS-8 report on file.

A quick look at the USN operating statistics shows, without getting too far down in the weeds, the earliest expenditure of semi armor piercing bombs and armor piercing bombs appears in 1943 for both types, so neither were available for the Midway action.

 

[Brady]

A quick look at the USN operating statistics shows, without getting too far down in the weeds, the earliest expenditure of semi armor piercing bombs and armor piercing bombs appears in 1943 for both types, so neither were available for the Midway action.

Thank you for clearing that up!, so despite the 1000 pound AP bomb becoming available in October 42, non were used operationally till sometime in 43, do we know when that was by any chance?

What date? What was the target?

 

[Shortround6]

Thank you very much for that.
Approval or even first issue dates can be a number of months off from first combat use dates.
Approval is usually the date that tests are completed, and the specification/s are finalized for production orders to be issued (contracts signed). Actual production can take several months and issue from depots (in the US) to ships to transport the weapons to combat zones takes how many weeks?

Then there is the issue of training. A 1000lb AP bomb and a 1000lb GP bomb will not follow the same trajectory after dropping. And this "miss" distance will vary with the altitude of the drop. Pilots may train with smaller/lighter bombs with miss distances adjusted but the pilots have to know the different aim off and practice using the different angles and/or altitudes.
This is also going to take either time or accepting a lower hit rate.
As noted earlier, for the AP bomb to penetrate anywhere near the max possible armor thickness the bombs have to dropped at around 3 times the height that the US navy was dropping the 500-1000lb GP bombs from SBDs. in combat. Dropping at lower altitudes and/or lower dive speeds than the testing means less penetration, probably a lot less.

 

[Brady]

600lb AP M62, 800lb AP M61, 900lb AP M60, 1,000lb AP M52/M52A1 and 1,400lb AP M63 were all conversions from US Army coast defence artillery shells of various calibre. They were for use by the USAAF not the USN.

Edit:- you will find details of US bombs on the bulletpicker site.

Bombs

Ordnance, Explosives, and Related Items U.S. Bombs

www.bulletpicker.com

Do we know if and when any of these were used operationally in the Pacific, presumably all were in service in 41?

 

[Shortround6]

Thank you for clearing that up!, so despite the 1000 pound AP bomb becoming available in October 42, non were used operationally till sometime in 43, do we know when that was by any chance?

What date? What was the target?

According to Wiki the last American vs Japanese carrier battle in 1942 was 25 October 1942 at Santa Cruz. There were no carrier battles in 1943 and the first carrier battle of 1944 was 19 June 1944 Philippine Sea.
US air strikes as part of clean up to the mostly destroyer battles of 1943 may have used 1000lb AP bombs but the need for such weapons against anything smaller than a heavy cruiser was minimal. There were only two naval battles in 1943 against the Japanese that involved cruisers of any size.

Perhaps AP bombs were used against bunkers in the late 1943 landings?

 

[EwenS]

Thank you for clearing that up!, so despite the 1000 pound AP bomb becoming available in October 42, non were used operationally till sometime in 43, do we know when that was by any chance?

What date? What was the target?

Production of the AN Mk.33 1,000lb AP for the USN only began in Oct 1942 (numbers of bombs NOT tonnages)

Oct - 44
Nov - 427
Dec - 670
1943
Jan - 1,176
Feb - 1,193

Production for the USAAF began alongside that for the USN in March. I can't give you a date for first use.

 

[EwenS]

Do we know if and when any of these were used operationally in the Pacific, presumably all were in service in 41?

Again numbers of bombs NOT tonnages. No idea of how they were used or when, but they were for the USAAF not the USN.

M-60 900lb - 1,505 produced Oct / Nov 1942
M-61 800lb - 1,532 produced Oct 1942 to Feb 1943
M-62 600lb - 2,691 produced Nov 1942 to March 1943.
M-63 1,400lb - 1,468 produced Oct 1942 to Jan 1943.
M-52 1,000lb - 7,283 produced March 1942 to June 1943 (6,417 -in 1942)

 

[Brady]

Production of the AN Mk.33 1,000lb AP for the USN only began in Oct 1942 (numbers of bombs NOT tonnages)

Oct - 44
Nov - 427
Dec - 670
1943
Jan - 1,176
Feb - 1,193

Production for the USAAF began alongside that for the USN in March. I can't give you a date for first use.

Hugely Helpful thanks.

Interesting the USAAF used the Navy 1000 pounder AP bomb's, or had access to their own supply of them?

 

[Brady]

Again numbers of bombs NOT tonnages. No idea of how they were used or when, but they were for the USAAF not the USN.

M-60 900lb - 1,505 produced Oct / Nov 1942
M-61 800lb - 1,532 produced Oct 1942 to Feb 1943
M-62 600lb - 2,691 produced Nov 1942 to March 1943.
M-63 1,400lb - 1,468 produced Oct 1942 to Jan 1943.
M-52 1,000lb - 7,283 produced March 1942 to June 1943 (6,417 -in 1942)

By the looks of it they were kind of a stop gap measure, suggesting the USAAF actually had no AP or SAP bombs in it's inventory at wars start?

 

[EwenS]

Hugely Helpful thanks.

Interesting the USAAF used the Navy 1000 pounder AP bomb's, or had access to their own supply of them?

Part of efforts to standardise equipment across both services.

 

[Thumpalumpacus]

Relevant to this discussion is this question from Pt2 of Drach's Drydock today, starting @ 37:27 in this vid. If I've done it right it should start at the question:


View: https://youtu.be/G0meGVnREaY?t=2249

 

[Geoffrey Sinclair]

No information on pre war US aircraft bombs beyond there would have been trials with AP and SAP versions.

British Statistical Digest, filled weight of bombs by year, 1940 to 1944, short tons, 51,093 plus an unknown amount of incendiary and smoke bombs, 147,848, 211,048, 223,807, 309,246, the first 9 months of 1945 it was 244,498 tons (all including incendiaries and smoke). Unfortunately it counts AP and anti submarine bombs together.

The Ministry of Aircraft Production goes with weekly averages and the monthly figures jump around a lot. There were 2,000 pound AP and 250 and 500 pound SAP bombs in production in January 1941, in that month the average number per week were 9, 832 and 236 respectively, January 1942 it was 33, 723, 909, January 1943 112, 720, 1,960, the 250 pound went out of production in May 1943, the 500 pound in December, while production of the 2,000 pound AP was paused August to October 1943 before ending in July 1944.

MAP reports Anti Submarine bombs ended production in October 1941. Assuming that is correct than British AP and probably SAP bomb production per the Statistical Digest 1942 to 1944 was 26,798, 19,061, 1,788 tons but as a warning also says 80 tons of AP and AS bombs Q1 to 3/1945.

The useful bomb production figures Ewen is quoting come from the War Production Board Report, available at

World War II Operational Documents

Contains data on actual production by months from July 1, 1940 at the beginning of the War Program, through August 31, 1945, the last month of actual fighting against Japan. Covers aircraft, ships, ordnance and automotive vehicles (guns and small arms, ammunition and bombs, combat and motor...

cgsc.contentdm.oclc.org

Section III pages 217 to 224

In Summary around 2,000 tons of bombs in the second half of 1940, then 40,000, 493,000, 1,005,000 and 956,000 tons 1941 to 1944 then 1,130,000 tons January to August 1945. This hides a major drop in production from 114,000 tons in September 1943 to 45,000 tons in January 1944, then back to 116,000 tons in December, it made the top 7 months of production January to July 1945. The drop is probably due to consumption reports for the North African fighting in particular as well as world wide numbers.

The AP/SAP bomb program started in January 1942 and was wound down to zero for a time in early 1944, by year 52,400, 175,200, 36,500 tons and 29,500 tons January to August 1945. With a 2,000 pound AP SAP bomb produced in 1945. Apart from the small runs the "standard" 1,600 pound AP, 1,000 pound AP, 1,000 pound SAP and 500 pound SAP went in and out of production at least once. The odd weight one offs tended to be repurposed USN shells.

The USAAF Statistical digest reports no usage of AP or SAP bombs in 1943, in Europe it was 1,122x1600 AP, 11,633x1000 SAP and 20,934x500 pound SAP in 1944, 4x1600 AP, 4,587x1000 SAP and 9,981x500 pound SAP in 1945, against Japan again nothing in 1943, 633x1000 SAP in 1944 and 5,675x1000 SAP and 78x500 pound SAP in 1945 (also add 31 torpedoes in 1945)

When it comes to the USN the pre war treaty limits gave it a comfortable superiority in battleships, add the low load carrying capacity of the aircraft but their usefulness as spotters meant the USN carriers were orientated towards destroying enemy air power with a bonus of inflicting damage on enemy lighter warships. Reinforced by the way the IJN was matching USN carrier numbers. From 1935 to 1039 the USN built BG-1, SBU, SBC, SB2U, BT-1 dive bombers and the TBD Devastator torpedo bomber, the RN was the reverse, emphasising torpedo bombers. Early in WWII the submarine threat was upgraded.

Paraphrased from Friedman, US Aircraft Carriers, representative magazine loads. There is a suspicion some of the entries are typos, repeating the previous line The load of course varied according to what sort of opposition the carrier was expecting to face.

Ship

Lexington

Ranger

Essex

Essex

Essex

Essex

Essex

Midway

Midway

CVL

CVL

CVE

CVE

CVE

year

1936​

1941​

1939​

1940​

1942​

1944​

1945​

1942​

1945​

1942​

1947​

1942​

1943​

1944​

100 GP

804​

600​

288​

522​

504​

508​

300​

552​

828​

162​

240​

150​

240​

180​

500 GP

391​

515​

246​

450​

296​

292​

400​

480​

470​

72​

72​

85​

72​

120​

500 SAP

292​

60​

1,000 GP

240​

177​

108​

148​

146​

147​

75​

216​

324​

36​

18​

40​

18​

30​

1,000 SAP

129​

128​

204​

306​

36​

27​

40​

27​

45​

1,000 AP

110​

110​

36​

18​

18​

30​

1,600 AP

19​

18​

120​

180​

9​

24​

9​

15​

2,000 GP

19​

18​

15​

9​

9​

15​

325 DB

200​

296​

292​

48​

480​

720​

36​

72​

110​

72​

120​

100 INC

296​

292​

240​

480​

720​

180​

72​

175​

72​

121​

Torpedo

36​

0​

36​

36​

36​

50​

0​

168​

96​

24​

36​

46​

36​

9​

3.5 AR

366​

300​

486​

132​

132​

5.0 HVAR

4,006​

1,700​

5,324​

1,500​

1,452​

1,188​

11.72 AR

108​

250​

The 1945 Essex also carried 50x250 pound bombs and 300x220 pound F bombs.

 

[Brady]

No information on pre war US aircraft bombs beyond there would have been trials with AP and SAP versions.

British Statistical Digest, filled weight of bombs by year, 1940 to 1944, short tons, 51,093 plus an unknown amount of incendiary and smoke bombs, 147,848, 211,048, 223,807, 309,246, the first 9 months of 1945 it was 244,498 tons (all including incendiaries and smoke). Unfortunately it counts AP and anti submarine bombs together.

The Ministry of Aircraft Production goes with weekly averages and the monthly figures jump around a lot. There were 2,000 pound AP and 250 and 500 pound SAP bombs in production in January 1941, in that month the average number per week were 9, 832 and 236 respectively, January 1942 it was 33, 723, 909, January 1943 112, 720, 1,960, the 250 pound went out of production in May 1943, the 500 pound in December, while production of the 2,000 pound AP was paused August to October 1943 before ending in July 1944.

MAP reports Anti Submarine bombs ended production in October 1941. Assuming that is correct than British AP and probably SAP bomb production per the Statistical Digest 1942 to 1944 was 26,798, 19,061, 1,788 tons but as a warning also says 80 tons of AP and AS bombs Q1 to 3/1945.

The useful bomb production figures Ewen is quoting come from the War Production Board Report, available at

World War II Operational Documents

Contains data on actual production by months from July 1, 1940 at the beginning of the War Program, through August 31, 1945, the last month of actual fighting against Japan. Covers aircraft, ships, ordnance and automotive vehicles (guns and small arms, ammunition and bombs, combat and motor...

cgsc.contentdm.oclc.org

Section III pages 217 to 224

In Summary around 2,000 tons of bombs in the second half of 1940, then 40,000, 493,000, 1,005,000 and 956,000 tons 1941 to 1944 then 1,130,000 tons January to August 1945. This hides a major drop in production from 114,000 tons in September 1943 to 45,000 tons in January 1944, then back to 116,000 tons in December, it made the top 7 months of production January to July 1945. The drop is probably due to consumption reports for the North African fighting in particular as well as world wide numbers.

The AP/SAP bomb program started in January 1942 and was wound down to zero for a time in early 1944, by year 52,400, 175,200, 36,500 tons and 29,500 tons January to August 1945. With a 2,000 pound AP SAP bomb produced in 1945. Apart from the small runs the "standard" 1,600 pound AP, 1,000 pound AP, 1,000 pound SAP and 500 pound SAP went in and out of production at least once. The odd weight one offs tended to be repurposed USN shells.

The USAAF Statistical digest reports no usage of AP or SAP bombs in 1943, in Europe it was 1,122x1600 AP, 11,633x1000 SAP and 20,934x500 pound SAP in 1944, 4x1600 AP, 4,587x1000 SAP and 9,981x500 pound SAP in 1945, against Japan again nothing in 1943, 633x1000 SAP in 1944 and 5,675x1000 SAP and 78x500 pound SAP in 1945 (also add 31 torpedoes in 1945)

When it comes to the USN the pre war treaty limits gave it a comfortable superiority in battleships, add the low load carrying capacity of the aircraft but their usefulness as spotters meant the USN carriers were orientated towards destroying enemy air power with a bonus of inflicting damage on enemy lighter warships. Reinforced by the way the IJN was matching USN carrier numbers. From 1935 to 1039 the USN built BG-1, SBU, SBC, SB2U, BT-1 dive bombers and the TBD Devastator torpedo bomber, the RN was the reverse, emphasising torpedo bombers. Early in WWII the submarine threat was upgraded.

Paraphrased from Friedman, US Aircraft Carriers, representative magazine loads. There is a suspicion some of the entries are typos, repeating the previous line The load of course varied according to what sort of opposition the carrier was expecting to face.

Ship

Lexington

Ranger

Essex

Essex

Essex

Essex

Essex

Midway

Midway

CVL

CVL

CVE

CVE

CVE

year

1936​

1941​

1939​

1940​

1942​

1944​

1945​

1942​

1945​

1942​

1947​

1942​

1943​

1944​

100 GP

804​

600​

288​

522​

504​

508​

300​

552​

828​

162​

240​

150​

240​

180​

500 GP

391​

515​

246​

450​

296​

292​

400​

480​

470​

72​

72​

85​

72​

120​

500 SAP

292​

60​

1,000 GP

240​

177​

108​

148​

146​

147​

75​

216​

324​

36​

18​

40​

18​

30​

1,000 SAP

129​

128​

204​

306​

36​

27​

40​

27​

45​

1,000 AP

110​

110​

36​

18​

18​

30​

1,600 AP

19​

18​

120​

180​

9​

24​

9​

15​

2,000 GP

19​

18​

15​

9​

9​

15​

325 DB

200​

296​

292​

48​

480​

720​

36​

72​

110​

72​

120​

100 INC

296​

292​

240​

480​

720​

180​

72​

175​

72​

121​

Torpedo

36​

0​

36​

36​

36​

50​

0​

168​

96​

24​

36​

46​

36​

9​

3.5 AR

366​

300​

486​

132​

132​

5.0 HVAR

4,006​

1,700​

5,324​

1,500​

1,452​

1,188​

11.72 AR

108​

250​

The 1945 Essex also carried 50x250 pound bombs and 300x220 pound F bombs.

Thank you very much of the effort involved in putting that together, It is extremely useful, very informative.