Ron, what kind of examples do you want, ships actually sunk by near-misses or examples of a different way of weapon and armor systems interaction compared with direct hit?
Bomb near-misses and gravity of the shock was a hidden problem that no one fully realized before the world war 2. This issue only became apparent with the magnetic mines used in 1939 and when the ships started taking bomb near misses. Interesting fact is that initially naval air attack doctrine was based on near-miss tactics tested by general Mitchell and his provisional air brigade in 1921.
“Mitchell took command on May 27 after testing bombs, fuzes, and other equipment at Aberdeen Proving Ground and began training in anti-ship bombing techniques. Alexander Seversky, a veteran Russian pilot who had bombed German ships in the Great War, joined the effort, suggesting the bombers aim near the ships so that expanding water pressure from the underwater blasts would stave in and separate hull plates. Further discussion with Captain Alfred Wilkinson Johnson, Commander, Air Force, Atlantic fleet aboard USS Shawmut, confirmed that near-miss bombs would cause more damage than direct hits by causing an underwater concussive effect against the hull.”
“Sinking of the Ostfriesland. NBS-1s dropped six bombs in quick succession between 12:18 p.m. and 12:31 p.m., aiming for the water near the ship. There were no direct hits but three of the bombs landed close enough to rip hull plates as well as cause the ship to roll over. The ship sank at 12:40 p.m., 22 minutes after the first bomb, with a seventh bomb dropped by the Handley Page on the foam rising up from the sinking battleship. Navy studies of the wreck of the Ostfriesland show she had suffered little topside damage from bombs and was sunk by progressive flooding.”
Before ww2 this issue was often overlooked in all major navies. Prewar doctrine for the IJN, USN, and RN, all leading carrier powers, believed that armoured warships could not be sunk by bombs alone. The sinking of the light cruiser Konigsberg in Bergen harbor by Skuas equipped with 500lb. bombs was considered an aberration cause she was stationary target in shallow water harbor where the concussive effects of the near miss bombs were magnified.
It’s well known what IJN dive-bombers achieved in the early war stages, but few know that this success came as a shock surprise to IJN. Standard 250kg GP bomb carried just 133lb of explosive, designed by Kure arsenal, it supposed to be used against the wooden decks of American carriers, which it could pierce with ease and penetrate into carrier’s vitals resulting fatal damage to the vessel, in the same time, these bombs were not supposed to be capable of sinking such heavily armored vessel as battleship outright, nor were they intended to. When used against ships with armoured decks, their function was to suppress the exposed gun positions, damage communications and wreck the upper works, all of which would allow the real killer – torpedo-bombers, to make their own vulnerable attack approach with immunity. Vals used 250kg GP bombs against battleships at PH solely because their primary target, USN carriers were not present. Used against medium-armoured ships like CA, it was hoped that these bombs could be effective enough to sink such warship, but only if an overwhelming number of hits was attained. Isolated hits on CA, or up to 4-5 direct hits should not normally sink such a ship, at least nobody expected that. The fact that the Vals actually sank, quickly and decisively, heavy cruisers Dorsetshire and Cornwall in the Indian Ocean in April 1942 absolutely shocked IJN naval specialists who did not believe that bombs alone could sink any ship larger than a destroyer. Surprisingly fast IJN expert team lead by Commander Obata had figured out that fatal damage was caused by “hydroshock effect” of numerous near-miss hits, later in 1942 IJN initiated two projects in experimental centre in Migure where they tried to develop “Ii-tan” type HE bombs, specially designed hydro-shock bombs to be used by Rikko units.
Just about any deck armor is sufficient to force the HE/GP ordnance to explode. The damage caused is then typically limited to the target's upper works. Bomb hits upper deck and it’s enough to trigger the fuse. That way, the bomb explodes before reaching the armor deck, and usually does not damage the engineering spaces or magazines. Armored decks were impervious to penetration by HE bombs. However, as events showed, armoured ships subjected to attack by 500- 1000lb HE bombs saw some damage above the armor deck, while near misses breeched any underwater protection. It’s hard to figure out how many ships were sunk exclusively by bomb near-misses, but I think it’s not that necessarily for making the point clear, when warship came under serious air attack it usually got some direct hits along with near-misses, more important is what damage reports claim as a major damage factor, and quite often it turns out that underwater explosions did most of the battle-damage. HE ordnance that could do only limited damage topside sometimes breeched hull below waterline and was as effective as torpedo that way. Read any USN carriers damage reports, Lex, Yorktown, Big E they all were seriously damaged by near-misses. In some cases, near-misses were the only way to damage fast, maneuverable vessel with narrow hull like, for example, CL Yubari. On 10th Marh 1942 Yubari survived furious USN air attacks, she evaded 67 bombs and 12 torpedoes, no direct hits were scored, however she was damaged. A couple of days she was again “missed” by B-17s at Rabaul and departed for battle-damage repairs at Truk, no direct hits were scored on her. During Guadalcanal campaign a lot of ships were heavily damaged or sunk by near misses in shallow waters, on 11th october 42, SBD pilot Lt.Cdr John Eldridge attacked IJN destroyer Natsugumo and got a close near-miss. Underwater explosion caused uncontrollable flooding and the ship capsized 40 minutes later. One, single near miss by 1000lb bomb was enough to sink 2400t. ship, note that Asashio class DD were capable to withstand several direct 1000lb hits. 6 days before her sinking Natsugumo was escorting her sister Minegumo back to Shortlands, Minegumo was near-missed by two 500lb. bombs in shallow waters, although both bombs exploded quite far from the ship, there was serious flooding and the top speed went down to 13 knots.
It’s hard to analyze damage reports of all ships sunk during the war, so I took only IJN heavy cruisers damage reports. All 18 warship were lost due
Fatal damage caused by torpedoes – 10
Fatal damage caused by own torpedoes explosion – 3
Fatal damage caused by near-misses bombs – 3
Fatal damage caused by artillery fire – 1
Fatal damage caused by direct hit bombs – 1
IJN cruisers sunk by bomb underwater explosions
Kinugasa – 1 x 500lb direct hit (gun mount disabled) + 7 x 500lb near misses (fatal damage)
Aoba – 1 x 500lb direct hit, 1 x 2000lb near miss in shallow waters and she was just hull after that.
Tone – 3 x 500/1000lb direct hits (medium system damage), 7 x 500/1000lb bomb near misses (flooding – fatal damage), ship beached with main deck above the waterline.
Many IJN light cruisers were heavily damaged by near-misses, and for example CK Oyodo got 6 500/1000lb near misses during the final attack on her on 28 july ’45, no direct hits, and sunk.
Here is an interesting report on the subject. It’s way scientific, a lot of formulas, but still worthy to look at.
The Response of Surface Ships to Underwater Explosions. By Warren D. Reid
http://dspace.dsto.defence.gov.au/dspac ... 0%20PR.pdf
“An underwater explosion detonated nearby a ship can in many situations, be devastating to the combat readiness of the vessel. Damage to a vessel may occur in the form of dished hull plating or more serious holing of the hull. However some damage may not be obvious and could occur as a result of shock-wave loading of equipment and systems aboard the vessel. Equipment damage may incapacitate a vessel. Much research effort has been expended in the study of underwater shock, especially during the period after World War II, where it became obvious that many navy vessels could be disabled easily by a non-contact underwater explosion.”
