Fuzing bombs for skip-bombing.

[Maxrobot1]

The dud rate for aerial bombs in WW2 has been estimated at around 10% and a recently posted video by "WW2 US Bombers"
View: https://www.youtube.com/watch?v=H1p25U0OZW8 has comments regarding U.S. bomb tail assemblies sometimes separating during the drop and causing the bombs to tumble and "Keyholing" of striking the ground broadside instead of nose first.
This is blamed for some bombs not going off.
When the USAAF developed skip bombing in the Pacific, did they uses special fuzes? I think they did not install tail fins too.
Anybody have ideas?
Watching the video, I had no idea that the Germans saved the fuzes they removed from our duds.

 

[SaparotRob]

Me neither.

 

[Greg Boeser]

Bombs fused for skip bombing had a 4-5 second delay fuse. This would give the aircraft enough time to clear the target before the bomb went off. The bomb would either penetrate the side of the ship, or strike the side then sink before detonating. The resulting overpressure could crack the keel of the ship.

 

[Thumpalumpacus]

Just winding up my physics brain, at 100' ASL there's not a lot of time for the tail to separate or the bomb to tumble, so the bomb is still going to hit roughly horizontal and then skip.

I'm not aware of any removal of tail-fins on the bombs for this sort of delivery. It could be that some separated upon waterstrike, but I've also heard reports of bombs skipping along about the pace of the airplanes and presenting a danger to them.

I think that a tailless bomb would be less likely to skip accurately, but I ain't sure.

 

[hw97karbine]

AT-11 trainers skipping bombs in training:

As you can see these dummy bombs remain more or less nose first but you can't rely on that in practice, not to mention the risk of the bomb detonating on the first impact with the water. A delayed fuze was the most feasible option for such a scenario.

Here is an example of a Japanese fuze designed for such use: JapaneseType 4 "Skipping-Bomb" Tail Fuze - Inert-Ord.net

Note it is an "all ways" fuze that is initiated by the first impact with the water regardless of the orientation of the bomb.

 

[alsaad]

US used AN M112 series fuzes for skip and dive bombing. Fuzes had 7-11 sec delay and were extremely sensitive if unexploded. Bombs had regular box tail assembly.