SUBSIM Radio Room Forums - View Single Post - Hit power of torpedoes : US to IJN calculation

keltos01 · 03-23-09, 04:05 AM

explosives data :

TNT
Trinitrotoluene, commonly known as TNT, is a constituent of many explosives, such as Amatol, Pentolite, Tetrytol, Torpex, Tritonal, Picratol, Ednatol, and Composition-B. It has been used under such names as Triton, Trotyl, Trilite, Trinol, and Tritolo.

Formulag/ccmKj/KgPower*
C7H5N3O / 61.64 / 870 / 1

Torpex
TORPedo EXplosive aka TPX. A mixture of 37-41% TNT, 41- 45% RDX (Cyclonite, Cyclomethylene Trinitramine), 18% aluminium.
Torpex is attractive because of the increased explosive energy and higher detonation velocity of RDX as compared to TNT and the prolongation of the pressure wave by the aluminium. On a weight basis, Torpex is conservatively estimated to be about 50% more effective than TNT as an underwater explosive against ships. However, Torpex is more sensitive than TNT and RDX is expensive and difficult to make safely.
Formulag/ccmKj/KgPower*
? / 1.81 / ? / 1.61

In the late 1940s Torpex was replaced by HBX, then H-6 in the 1960s and by PBX in the 1970s.?1.81?1.61Wet gun-cottonWet gun-cotton is not affected by shock, failing to explode when penetrated by rifle bullets, or when loaded in shells, upon shock of discharge; is comparatively insensible to sympathetic explosion, and is not exploded by heat.???0.5

*= Explosive power compared to TNT

http://www.dutchsubmarines.com/speci...MineExplosives

Warheads
The second major development, new warheads, involved the switch from TNT to Torpex as the high explosive. Torpex is a mixture rather than a pure chemical compound as TNT is. The components are TNT 41%, RDX (Cyclonite, Hexogen) 41% and aluminum powder 18%8. Torpex is attractive because of the increased explosive energy and higher detonation velocity of RDX as compared to TNT and the prolongation of the pressure wave by the aluminum. On a weight basis, Torpex is conservatively about 50% more effective than TNT as an underwater explosive against ships. Torpex is, however, more sensitive than TNT and RDX was expensive and difficult to make safely. The process of converting to Torpex torpedo warheads (and depth charge loadings) began with an order for 20 million pounds in early 19429. The first Torpex loaded warheads10 followed late the same year. The 640 pounds of Torpex in a Mk.14 warhead was at least the equivalent of 960 pounds of TNT11 almost twice the destructive power of the original Mk.14.

The reaction of the submariners to Torpex is apparent from an entry for 19 March 1943 in the fourth war patrol report of USS Wahoo: "0515H; Fired one torpex torpedo at medium sized freighter identified as KANKA MARU, 4,065 tons, range 750 yards, 120 port track, speed 9 knots. Hit. After part of ship disintegrated and the forward part sank in two minutes, and 26 seconds. These Torpex heads carry a [sic] awful wallop."

____________________
7 Quoted in Theodore Roscoe "United States Submarine Operations in World War II", Annapolis: US Naval Institute Press, 1949 p.262. In addition to these problems Westinghouse seems, albeit with Navy concurrence, prematurely to have turned their attention to the all electric Mk.19 and allowed the Mk.18 to languish.
8 Torpex ranges from 45% TNT, 37% RDX, 18% Al to 41% TNT, 41% RDX, 18% Al
9 Interestingly, the US Army was willing to produce cyclonite, RDX, for the Navy's use in Torpex, but was reluctant to use it for Army munitions because of safety concerns.
10 Torpex and TNT warheads were interchangeable. If there was a substantial change in weight, some adjustment to the depth gear was required.
11 Comparisons with Japanese torpedoes often neglect the difference in high explosives. Japanese torpedoes used Type 97 high explosive, which is not significantly more powerful as an underwater explosive than TNT.

http://www.geocities.com/Pentagon/1592/ustorp3.htm

tomas : Generally speaking, RDX, explosive mixed with TNT to form Torpex, is rated by itself as giving a detonation wave of 8700m/s, while TNT yields 6900m/s. By itself, RDX is therefore about 21% more powerful than TNT.Adding aluminium powder to the explosive increases the generation of heat and increases the brisance by allowing the explosive to convert itself into gas pressure more rapidly. Brisance is the ability of the explosive through heat, shock and pressure to destroy structures it is in contact with.

Bill Jurens :Also, keep in mind that due to scaling laws, even a relatively large difference in charge weight only increases the damage radius a relatively small amount. In air, the radius of equivalent overpressure is proportional to the cube root of the charge weight, so doubling the damage radius (using overpressure as a measuring stick) requires multiplying the charge weight by eight. The situation in water is much more complex, but basically quite similar. In a nutshell, changes of even 15%-20% in charge weight tend to have relatively little effect on the amount of damage observed.

The Type 89 torpedo is equal in explosive weight to the Type 92 : 300 kg, but the one uses type 91 explosive, the second type 97 explosive.

Obviously only two torpedoes are necessary to sink a 10000T+ ship.

Since the Type 95 mod 1 has 405 kg Type 97, and the Type 96 has 550 kg Type 97, I would expect them to be a one torpedo kill shot most of the time.

What could be the result of only 60% hits out of fired torpedoes I wonder ?

keltos

03-23-09, 04:05 AM	#22
keltos01 Silent Hunter Join Date: Feb 2008 Location: Milan Italy Posts: 4,999 Downloads: 114 Uploads: 18	explosives data : TNT Trinitrotoluene, commonly known as TNT, is a constituent of many explosives, such as Amatol, Pentolite, Tetrytol, Torpex, Tritonal, Picratol, Ednatol, and Composition-B. It has been used under such names as Triton, Trotyl, Trilite, Trinol, and Tritolo. Formulag/ccmKj/KgPower* C7H5N3O / 61.64 / 870 / 1 Torpex TORPedo EXplosive aka TPX. A mixture of 37-41% TNT, 41- 45% RDX (Cyclonite, Cyclomethylene Trinitramine), 18% aluminium. Torpex is attractive because of the increased explosive energy and higher detonation velocity of RDX as compared to TNT and the prolongation of the pressure wave by the aluminium. On a weight basis, Torpex is conservatively estimated to be about 50% more effective than TNT as an underwater explosive against ships. However, Torpex is more sensitive than TNT and RDX is expensive and difficult to make safely. Formulag/ccmKj/KgPower* ? / 1.81 / ? / 1.61 In the late 1940s Torpex was replaced by HBX, then H-6 in the 1960s and by PBX in the 1970s.?1.81?1.61Wet gun-cottonWet gun-cotton is not affected by shock, failing to explode when penetrated by rifle bullets, or when loaded in shells, upon shock of discharge; is comparatively insensible to sympathetic explosion, and is not exploded by heat.???0.5 = Explosive power compared to TNT http://www.dutchsubmarines.com/speci...MineExplosives Warheads* The second major development, new warheads, involved the switch from TNT to Torpex as the high explosive. Torpex is a mixture rather than a pure chemical compound as TNT is. The components are TNT 41%, RDX (Cyclonite, Hexogen) 41% and aluminum powder 18%8. Torpex is attractive because of the increased explosive energy and higher detonation velocity of RDX as compared to TNT and the prolongation of the pressure wave by the aluminum. On a weight basis, Torpex is conservatively about 50% more effective than TNT as an underwater explosive against ships. Torpex is, however, more sensitive than TNT and RDX was expensive and difficult to make safely. The process of converting to Torpex torpedo warheads (and depth charge loadings) began with an order for 20 million pounds in early 19429. The first Torpex loaded warheads10 followed late the same year. The 640 pounds of Torpex in a Mk.14 warhead was at least the equivalent of 960 pounds of TNT11 almost twice the destructive power of the original Mk.14. The reaction of the submariners to Torpex is apparent from an entry for 19 March 1943 in the fourth war patrol report of USS Wahoo: "0515H; Fired one torpex torpedo at medium sized freighter identified as KANKA MARU, 4,065 tons, range 750 yards, 120 port track, speed 9 knots. Hit. After part of ship disintegrated and the forward part sank in two minutes, and 26 seconds. These Torpex heads carry a [sic] awful wallop." ____________________ 7 Quoted in Theodore Roscoe "United States Submarine Operations in World War II", Annapolis: US Naval Institute Press, 1949 p.262. In addition to these problems Westinghouse seems, albeit with Navy concurrence, prematurely to have turned their attention to the all electric Mk.19 and allowed the Mk.18 to languish. 8 Torpex ranges from 45% TNT, 37% RDX, 18% Al to 41% TNT, 41% RDX, 18% Al 9 Interestingly, the US Army was willing to produce cyclonite, RDX, for the Navy's use in Torpex, but was reluctant to use it for Army munitions because of safety concerns. 10 Torpex and TNT warheads were interchangeable. If there was a substantial change in weight, some adjustment to the depth gear was required. 11 Comparisons with Japanese torpedoes often neglect the difference in high explosives. Japanese torpedoes used Type 97 high explosive, which is not significantly more powerful as an underwater explosive than TNT. http://www.geocities.com/Pentagon/1592/ustorp3.htm tomas : Generally speaking, RDX, explosive mixed with TNT to form Torpex, is rated by itself as giving a detonation wave of 8700m/s, while TNT yields 6900m/s. By itself, RDX is therefore about 21% more powerful than TNT.Adding aluminium powder to the explosive increases the generation of heat and increases the brisance by allowing the explosive to convert itself into gas pressure more rapidly. Brisance is the ability of the explosive through heat, shock and pressure to destroy structures it is in contact with. Bill Jurens :Also, keep in mind that due to scaling laws, even a relatively large difference in charge weight only increases the damage radius a relatively small amount. In air, the radius of equivalent overpressure is proportional to the cube root of the charge weight, so doubling the damage radius (using overpressure as a measuring stick) requires multiplying the charge weight by eight. The situation in water is much more complex, but basically quite similar. In a nutshell, changes of even 15%-20% in charge weight tend to have relatively little effect on the amount of damage observed. The Type 89 torpedo is equal in explosive weight to the Type 92 : 300 kg, but the one uses type 91 explosive, the second type 97 explosive. Obviously only two torpedoes are necessary to sink a 10000T+ ship. Since the Type 95 mod 1 has 405 kg Type 97, and the Type 96 has 550 kg Type 97, I would expect them to be a one torpedo kill shot most of the time. What could be the result of only 60% hits out of fired torpedoes I wonder ? keltos __________________ "Honorable Builder of Sinking Ships" Last edited by keltos01; 03-23-09 at 10:51 AM.