Modern US torpedoes

[Ed Rotondaro]

Hi:

I was reading up on US torpedoes and was curious as to what their warheads are composed of these days. Does anyone know? has torpex been replaced with a more powerful explosive? If I recall, navy bombs use Octol as their explosive filler.

[William Miller]

Ed,

The warhead on the newest USN torpedo, the Mk 48 Mod 5 ADCAP, is based on the explosive compound "PBXN-103". For underwater explosive effectiveness this compound has a RE (Relative Effectivensss) value of roughly 1.8 to 1.85 (where TNT = 1.0). The older Torpex warheads, while much better than TNT, had a RE of from 1.4 to 1.5.

[Ed Rotondaro]

Ed,

The warhead on the newest USN torpedo, the Mk 48 Mod 5 ADCAP, is based on the explosive compound "PBXN-103". For underwater explosive effectiveness this compound has a RE (Relative Effectivensss) value of roughly 1.8 to 1.85 (where TNT = 1.0). The older Torpex warheads, while much better then TNT, had a RE of from 1.4 to 1.5.

William:

Thanks for the quick reply! I'll see what I can find out about PBXN (I'm at work and our firewall tends to block searchs on weapons).

[William Miller]

Ed,

After a quick look through Janes Underwater Weapons Systems and my military explosives handbooks, it appears that the current Mod 5 torp likely uses a PBXN-109 derivative, not the PBXN-103 used in prior versions. From what I can tell there are only minor differences between the two explosives; 109 being even more stable/insensitive than 103 (which was quite stable) over a longer shelf life apparently being the primary advantage.

Here is a online link on explosives that offer a fair amount of detail, and covers PBXN-109 (but not the earlier 103):
http://www.globalsecurity.org/military/systems/munitions/explosives-compositions.htm

[Ed Rotondaro]

Ed,

After a quick look through Janes Underwater Weapons Systems and my military explosives handbooks, it appears that the current Mod 5 torp likely uses a PBXN-109 derivative, not the PBXN-103 used in prior versions. From what I can tell there are only minor differences between the two explosives; 109 being even more stable/insensitive than 103 (which was quite stable) over a longer shelf life apparently being the primary advantage.

Here is a online link on explosives that offer a fair amount of detail, and covers PBXN-109 (but not the earlier 103):
http://www.globalsecurity.org/military/systems/munitions/explosives-compositions.htm

William:

Thanks for the additional details and the link. From what I've found, the PB means polymer binded and it helps reduce sensitivity in certain types of explosive compounds. The basic explosive is still RDX (Cylconite, a very complex molecule).

[old_pop2000]

PBXN-103 is commonly termed plastisol. It contains plasticized nitrocellulose. Detonation velocities exceed 8000 meters per second or 26 246.7192 feet per second. Mark 46 has 96 pounds of plastisol. Mark 48 has 650 pounds of plastisol.

official name is Explosive, plastic-bonded, cast PBXN-103.

There is also PBXW-106

Both explosive use a polymer with glass beads in the binding.


Hope that helps:D