The Mark 9 Torpedo Exploder Mechanism A

Parallel to the evolution of explosives, initiation devices have gone through important technological advances since the decade of the forties in an attempt to obtain the following objectives:

Philosophical Transactions of the Royal Society A-Mathematical Physical and Engineering Sciences, 2014

International Journal of Impact Engineering, 2009

The response of a lightweight torpedo when subjected to an underwater explosion (UNDEX) is an important criterion for multidisciplinary design. This paper investigates the effect of structural stiffeners on the performance of a lightweight torpedo. The finite element package ABAQUS was used to model the UNDEX and the fluid-structure interaction (FSI) phenomena, which are critical for accurate evaluation of torpedo stress levels. The pressure wave resulting from an underwater explosion was modeled using similitude relations and it was assumed to be a spherical wave. Various explosive weights and explosion distances were explored to determine the critical distance both for an un-stiffened and a stiffened torpedo. Once it was established that the stiffened torpedo performed better under explosive pressure loads, various configurations were studied to determine the optimal number of ring and longitudinal stiffeners. A final configuration was obtained for the torpedo that had minimum weight and was least sensitive to small manufacturing variations in the dimensions of the stiffeners. This paper presents details of the torpedo and fluid models and the finite element analysis method for FSI.

arXiv (Cornell University), 2020

We report on an unpublished and previously unknown manuscript of John von Neumann and contextualize it within the development of the theory of shock waves and detonations during the nineteenth and twentieth centuries. Von Neumann studies bombs comprising a primary explosive charge along with explosive booster material. His goal is to calculate the minimal amount of booster needed to create a sustainable detonation, presumably because booster material is often more expensive and more volatile. In service of this goal, he formulates and analyzes a partial differential equation based model describing a moving shock wave at the interface of detonated and undetonated material. We provide a complete transcription of von Neumann's work and give our own accompanying explanations and analyses, including the correction of two small errors in his calculations. Today, detonations are typically modeled using a combination of experimental results and numerical simulations particular to the shape and materials of the explosive, as the complex three dimensional dynamics of detonations are analytically intractable. Although von Neumann's manuscript will not revolutionize our modern understanding of detonations, the document is a valuable historical record of the state of hydrodynamics research during and after World War II.

1993

High Power Microwave technology has matured to the point where practical Elec- troMagnetic Pulse (1) weapons are becoming technically feasible, with applications in Electronic Combat, Offensive Counter-Air, Combat Air Support and in Strategic Air Attack. The current development of conventional ElectroMagnetic Pulse devices allows their use in non-nuclear confrontations. This paper proposes a doctrinal foundation for the use of such devices in warhead and bomb applications. † Carlo Kopp is currently working on a PhD in Computer Science. He is also a practising computer industry consultant who has specialised in computer systems, communications and operating systems software. He has prior industry R&D experience both as high speed electronic design engineer and systems integrator. As a Defence Technology Analyst writing for Australian Aviation journal in Canberra, he has produced technical fea- tures on modern military aviation since 1980. His other interests include the strategy, tac...

There are many possible paths to explore when solving a problem," he says, "and it is satisfying to narrow down these possibilities into one final theory." [14] A combined team of researchers from the University of Ottawa and National Research Council Canada has developed a new way to generate rapid strong magnetic fields using laser pulses. [13] Conventional electron accelerators have become an indispensable tool in modern research. [12] An outstanding conundrum on what happens to the laser energy after beams are fired into plasma has been solved in newly-published research at the University of Strathclyde.

Choice Reviews Online, 2014

Pure and Applied Geophysics

This paper focuses on events linked to controlled underwater explosions of World War 2 (WW2) ordnances which were included in the Reviewed Event Bulletin (REB). Data used for the study were provided by seismic stations of the International Monitoring System (IMS) in 2020. Examined events were triggered by devices of different charge size and took place in several locations in Europe. There were also other, previously detected WW2 ordnance underwater explosions which could be compared to events in 2020. It is shown that these relatively small underwater explosions listed in the REB, with good coupling to the ground, are located by the IMS network within 20 km from the ground truth. Charge size of explosive material was related to event magnitude. Results were compared to magnitudes published for underwater explosions of larger sizes. The conclusion is that an in-water explosion will result in seismic waves with amplitudes equivalent to the amplitudes of seismic waves from an in-groun...

Abstract: This paper draws a parallel between the archetypal bombard of the fifteenth century and the ballistic design of the cartridge for the modern 40mm grenade While the design of the former was presumably derived by purely empirical reasoning, more formal ballistic considerations have arrived at a remarkably similar solution to a twentieth century problem.

ANNALES · Ser. hist. sociol. · 33 · 1, 2023

In 1984–1986, Zvonimir Kralj, diver and keeper of the Piran Aquarium, recovered the Enigma cipher machine with codebook and several other items from the wreck of the German minesweeper R 15 sunk off the west coast of Istria between Savudrija and Umag. The article describes and defines the device and outlines the technical characteristics of the minesweeper of the 6th Minesweeper Flotilla (6. Räumbootsflottille) of the German Kriegs- marine, which was hit by the British torpedo boat MTB 409 on the night of April 16–17 1945, and sank about 3 nautical miles northwest of Umag. An examination of the preserved parts of the cipher machine revealed that it was a naval Enigma M4 with four rotors and a reflector C. An X-ray microtomography showed the serial number of the machine M 15648 and the last configuration, left to right: C/γ (Gamma), III, VI, IV. The external position of the Gamma rotor (»P«) indicates that the Enigma was not set in a mode compatible with the M3 model, which corresponds to the cipher keys for the last two months of the war.