HE Shell Detonation Question

[rexford]

If a Sherman fires a 75mm HE shell at infantry 300m away and the projectile nose does not touch the ground as the round impacts the ground and starts to bounce, will the HE shell explode if it set for quick fuze?

For ricochet fire to work with fuze set for delay, it would seem that the projectile nose would not impact the ground.

The question came up when someone said that if an IS-2 fires 122mm HE fragmentation at an ATG and the round impacts flat firm ground at less than 1° impact angle, the round would not explode since it is not retarded and the nose will not impact the ground.

Help on this would be appreciated. Thanks.

[StellarRat]

Based on what I read on this page it seems that only delay fuses will work for ricochet fire. http://www.poeland.com/tanks/artillery/fuzes.html

I think the shell wouldn't explode near the gun in your example, however somewhere down range I imagine the nose will hit something solid and it would explode. It did say that you could observe shells ricocheting, so I assume this means that they are not detonating as soon as they impact in all cases. And it said that the ground had to be hard and the angle low for ricochets to work. I know that bombs can have concussion fuses in the back to make sure they detonate if they stop suddenly, but I don't think shells are as fancy.

[ June 18, 2002, 09:48 PM: Message edited by: StellarRat ]

[Michael Emrys]

Originally posted by StellarRat:

I know that bombs can have concussion fuses in the back to make sure they detonate if they stop suddenly, but I don't think shells are as fancy.

This leads to a question I wanted to raise anyway. How common were base fuses on HE shells in the WW II era? I'm pretty sure that naval AP and semi-AP shells had them. What about on the land?

Michael

[offtaskagain]

I think the german Pzgr 39 had them, as they had a small explosive filler.

[rexford]

Michael Embrys wrote: "One reason I ask is because some projectiles use base or tail fuses. These obviously would not strike the ground (or other surface) and I always assumed that the deceleration of the projectile caused the fuse to initiate."

For base or tail fuzes to work does the round have to be decelerated or will a change in direction (such as bouncing off the ground) do?

Robert Livingston noted that Sherman 75mm HE had a graze fuze so impacts on shoulder or ogive would be sufficient to set round off. Low angle fire at high velocity with close to medium range ground target would result in shoulder impact. Would base or tail fuze HE detonate if it hit ground at low angle and bounced upward?

[Michael Emrys]

Originally posted by rexford:

Michael Embrys wrote: "One reason I ask is because some projectiles use base or tail fuses. These obviously would not strike the ground (or other surface) and I always assumed that the deceleration of the projectile caused the fuse to initiate."

If you meant me, the name is Emrys. And anyway, that's not what I wrote...but no matter.

For base or tail fuzes to work does the round have to be decelerated or will a change in direction (such as bouncing off the ground) do?

Robert Livingston noted that Sherman 75mm HE had a graze fuze so impacts on shoulder or ogive would be sufficient to set round off. Low angle fire at high velocity with close to medium range ground target would result in shoulder impact. Would base or tail fuze HE detonate if it hit ground at low angle and bounced upward?

I guess it depends mainly on how sensitive the base fuze is. Even a ricochet will cause some shock and deceleration of the shell. I would expect (though I might be mistaken) a base fuze to be pretty sensitive since otherwise it might not detonate at all. This would be true even if it has a built-in delay. Interesting question worth pursuing.

Michael