Double effectiveness of near-miss on ship (close underwater exposition)

[artik]

When the bomb lands in water but very close to ship it effectiveness should be in general much higher than direct hit because it explodes underwater generating a significant shock-wave that actually sinks the ship.

So if you aim well you can be able to sink a ship with lower amount of ammunition (as it was actually in real life)

[gyrene81]

   oh this is going to be good.



too early to really rip into this one right now, i'll wait and see who else chimes in on.

[LCADolby]

Dambuster style!

[gyrene81]

since no one else is chiming in to tell him where he's wrong...

When the bomb lands in water but very close to ship it effectiveness should be in general much higher than direct hit because it explodes underwater generating a significant shock-wave that actually sinks the ship.

So if you aim well you can be able to sink a ship with lower amount of ammunition (as it was actually in real life)

whatever nick toons channel you got that information from is wrong.

the effectiveness of shockwave damage is not going to be higher than a direct hit. assuming the bomb actually detonates in the water, it needs to have enough explosive energy and explode close enough to do more than splash water; the potential is to cause leaks by popping rivets, breaking welds, damaging the prop and/or shaft, and/or damaging the rudder.

it would take more explosive energy in the water to match the damage caused by a direct hit.

[Arlo]

Maybe he's confusing bombs and torps. Magnetic detonation under the keel gave a torp more kick. Armor penetration through the deck gave a bomb more kick.

[artik]

whatever nick toons channel you got that information from is wrong.

Sources: http://en.wikipedia.org/wiki/Billy_Mitchell#1st_Provisional_Air_Brigade

Quoting:

Mitchell took command on May 27 after testing bombs, fuses, 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 inflict more damage than direct hits; near-misses would cause an underwater concussive effect against the hull.

Actually this was confirmed in tests as bombs that hit did less critical damage than bombs that actually exploded nearby and caused underwater damage.


Of course it is really depends on were do you hit.

For example in Midway the hits that exploded on the deck were more damaging as created a huge fire that run out of control. And of course if the hit causes ammunition detonation is much more devastating (Perl Harbor/Arizona), however if the bomb hits the structures above they may severely damage the ship but not sink it on the other hand underwater explosion causes leaks and actually send the ship to the bottom of the sea.

[macleod01]

Artik,

I have always heard that the water cushioned the explosion, hence why the Dambusters was such a hard task, a near miss wouldn't damage the Dams. After searching youtube, I have found this attack on Japanese ships. You will see at 1.25 some very close misses that the Japanese Destroyer (It looks like one, may be mistaken) sails quite safely out.
https://www.youtube.com/watch?v=UNWlNNONplM

[danny76]

The explosive has to be actually touching or extremely near to the surface of the target in order to benefit from the 'tamping' effect of the water

Water between the surface of the target and the ordnance will only serve to deaden the impact.

[Arlo]

So it's not a 'near miss' that's being described but a 'subsurface hit.'

[Zacherof]

So what your saying is you want to compensate for your lack of aim?

The way I look at it is your going to use the same amount of bombs.

Bomber MO is generally aim, and "walk" the bombs onto target

[gyrene81]

Sources: http://en.wikipedia.org/wiki/Billy_Mitchell#1st_Provisional_Air_Brigade

Quoting:

Actually this was confirmed in tests as bombs that hit did less critical damage than bombs that actually exploded nearby and caused underwater damage.


Of course it is really depends on were do you hit.

For example in Midway the hits that exploded on the deck were more damaging as created a huge fire that run out of control. And of course if the hit causes ammunition detonation is much more devastating (Perl Harbor/Arizona), however if the bomb hits the structures above they may severely damage the ship but not sink it on the other hand underwater explosion causes leaks and actually send the ship to the bottom of the sea.

and not one bit of your resource shows that it takes "less ordnance" to sink a ship. i read the entire article and the actual consensus is that damaging the hull of a ship will sink the ship faster than hitting the superstructure. they used 2,000lbs and bigger bombs with fuses that made them work like depth charges, smaller bombs had as much effect as hitting the decks. end of story.

[Windycty]

Well sound travels much faster under water that it does above. So, the shock wave of an underwater explosion would be more intense. I wouldn't make it destroy the ship but maybe make some of the guns disabled for 2 min and then they come back online. Like if the crew was stunned but then they come around and resume defending the ship.

[EagleDNY]

If you read the history of the united states navy in WW2, there are plainly many examples of ships having sprung plates, flooding damage, etc. from near misses with bombs.   In the early war years, many of the US Destroyers were old WWI 4-pipers and a near miss could spring enough plates to make the flooding a significant problem, but on the later destroyers this wasn't much of a problem unless the ship had sustained a lot of other damage.   Since AH2 does not simulate flooding damage (as is plain since you can hit a CV with a torpedo and it just keeps right on going at full speed) - simulating sprung plates and flooding damage on small combatants doesn't seem like it should be much of a priority.

[Ack-Ack]

This is an interesting report from the 5th AF on skip and masthead bombing during the Bismark Sea Battle.

This is just an excerpt.

"Reports of the Bismark Sea Battle were studied and a number of individuals participating in the battle were contacted. From all the information that can be gathered the mission was carefully planned and coordinated. B-17's led the attack and were given pursuit protection by P-38's. The B-17's bombed from about 7500 feet, apparently causing considerable confusion among the vessels attacked, as well as scoring several direct hits starting fires on the vessels. This attack was followed by a strafing attack by Beaufighters. The Beaufighters followed the B-17's so close that pictures taken of vessels by them show bombs dropping directly in front of the Beaufighters. B-25C-l's then attacked, strafing and skip bombing. This is as nearly an accurate account of the initial attack as can be determined. Flights and elements within the squadrons became separated and returned to their bases individually or in pairs or threes with whatever type plane or squadron they could get together with. Planes were refueled, reloaded and returned to the attack. From then on there were no coordinated attacks, but the convoy was under continual attack until it was destroyed (about 3 days) and survivors in life rafts and boats were eliminated by strafing."

Full report here: Report of Masthead Bombing - South West Pacific Area

The conclusion of the report is that masthead bombing was far more effective than skip bombing as it almost always resulted in a hit on the ship being attacked.  Also surprising how effective the 5th AF was in level bombing against maritime targets, contrary to popular belief that level bombing was ineffective against ships.


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