Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Torpedo explosive force
Posted by:
Forest
()
Date: November 21, 2002 04:53AM
For comparison the pressure at the bottom the Mariana Trench is a little over 15,000 psi, and the maximum pressure inside a (firing) rifle cartridge is around 50,000 psi, or so. The values you quote are obviously far greater.
Of course, Brisance is not the same as the total effectiveness of the explosion. My understanding is that Brisance is closely related to the rapidity of the explosion. Some benchmarks for this are:
TNT detonates at 6900m/s.
RDX detonates at 8750m/s.
HMX detonates at 9100m/s. (unknown until post-war)
Mixes of these explosives detonate at intermediate velocities. For example, a 50/50 mix of TNT and RDX (called Hexolite 50/50) detonates at about 7,650m/s, almost halfway between the respective velocities for TNT and RDX.
Adding aluminum to the mix reduces the velocity slightly, reducing brisance, but enhances the explosive effect by prolonging the pressure wave. Oxygen freed from the NO2 groups gives much more heat if it reacts with aluminum than with the freed carbon.
Torpex, a mix of about 41% TNT, 41% RDX, and 18% aluminum (it varied) detonates at about 7,200m/s, just above that of plain TNT. Compared to Hexolite, the aluminum in the Torpex reduces the velocity but sustains the pressure longer.
HBX-1 is virtually the same thing as Torpex, but with some stanbilizer worked in. This was done after they figured out during the war that Torpex was giving off hydrogen gas.
Amatol, another popular but less effective explosive mix, was substituted frequently in depth charges when TNT production came up short. Amatol 50/50 (50% TNT and 50% ammonium nitrate) detonates at about 6,300m/s, inferior to plain TNT. Still, I'm sure it sank many submarines, given the frequent use.
Hope this helps.
Of course, Brisance is not the same as the total effectiveness of the explosion. My understanding is that Brisance is closely related to the rapidity of the explosion. Some benchmarks for this are:
TNT detonates at 6900m/s.
RDX detonates at 8750m/s.
HMX detonates at 9100m/s. (unknown until post-war)
Mixes of these explosives detonate at intermediate velocities. For example, a 50/50 mix of TNT and RDX (called Hexolite 50/50) detonates at about 7,650m/s, almost halfway between the respective velocities for TNT and RDX.
Adding aluminum to the mix reduces the velocity slightly, reducing brisance, but enhances the explosive effect by prolonging the pressure wave. Oxygen freed from the NO2 groups gives much more heat if it reacts with aluminum than with the freed carbon.
Torpex, a mix of about 41% TNT, 41% RDX, and 18% aluminum (it varied) detonates at about 7,200m/s, just above that of plain TNT. Compared to Hexolite, the aluminum in the Torpex reduces the velocity but sustains the pressure longer.
HBX-1 is virtually the same thing as Torpex, but with some stanbilizer worked in. This was done after they figured out during the war that Torpex was giving off hydrogen gas.
Amatol, another popular but less effective explosive mix, was substituted frequently in depth charges when TNT production came up short. Amatol 50/50 (50% TNT and 50% ammonium nitrate) detonates at about 6,300m/s, inferior to plain TNT. Still, I'm sure it sank many submarines, given the frequent use.
Hope this helps.
