Naval Mine Research Articles

Preliminary Calculations for Minehunter's Genset Foundations

The requirements for the foundations of naval vessel engines are based on classification rules devised by classification societies or/and military standardization rules. A class guideline was published, defining the requirements, acceptance criteria and machinery seating methods. There is also a schedule of basic calculation procedures for cast resin or rubber chocks which facilitates the process of machinery foundation design, preloading force calculation, the establishment of boundary conditions etc. In case of naval vessels, typical procedures do not meet tactical requirements due to potential explosion loads. Since minehunters are mainly deployed at sea, handling active, naval mines, the shock resistance calculation for the entire machinery, including the Genset, is required. The paper presents preliminary MatLab calculation methods which can be used to analyse the type, number and location of rubber or elastomer chocks. The procedure consists of input data such as UNDEX pressure and technical data of the Genset used in the Polish Navy. Calculation results include the analysis of the dynamic interaction between the Genset and the foundation, as well as the damping effect generated by the UNDEX (UNDerwater EXplosion) shock pulse.

Design and implementation of underwater laser imaging test aquarium

A test aquarium was built to perform and simulate different marine environment to optimize laser imaging of submerged targets. The setup can be used to study many parameters as required (i.e., the correlation between the detection angle, the target surface topology and color, water turbidity due to clay and mud, and laser type at different depths, and backgrounds). A theoretical model of the detection process was tested using MATLAB simulation. The system was able to simulate light extinction of the real deep and shallow aqua environments due to plankton chlorophyll. The used dummy targets are approximately 1/500 of the real submarines and naval mines. These targets were illuminated by several laser wavelengths in order to identify the targets with different color and shapes. The setup permits to test the efficiency of different target camouflage versus optical detection.

Navigating free‐floating minefields via time‐varying Voronoi graphs

Despite their illegality, untethered free‐floating naval mines are increasingly employed as part of maritime area‐denial operations. By ignoring international treaties, these mines require less effort to acquire and deploy, and result in a far more dynamic‐threat environment. In order to assist commanders during breach operation planning, we develop several algorithms that generate a minimum‐risk journey through a field of drifting mines. Using Voronoi graphs to capture a series of static snapshots of the operational area, we present a practical methodology for building a fully connected time‐varying graph . Vertices are defined as specific times and locations, and edges ℰ define the continuous movement of a ship with simple parametric equations. The length, acceleration and risk of each edge is calculated and employed by a threat‐additive A* search to quickly find a plausible, minimum‐risk journey through a given minefield within a specific time frame. Using real‐world data for a modern‐day port and minefields of variable density, we find navigable paths that incur acceptable risk in less than 2 minutes on average. We also introduce several methods for reducing the size of and the time required for its generation.

Relationship Between Basic Physiochemical Properties of Seawater and Magnitude of Underwater Electric Field

Abstract Passive defense systems which minimize chance of vessel detection have to be utilized due to application of naval mines. Passive defense and signature minimization can be regarded as not only magnitude reduction but also as its shaping. Electric field magnitude at a given depth is a function of an electric field source but also it depends on physicochemical properties of seawater — temperature and salinity. In this paper results of underwater electric field simulations are presented. Cases of various depths, temperatures and salinities are shown. Computational results are compared to underwater electric field measurements performed with portable sensor.

International regulations related to naval mines and protection of navigation

The free movement of people and goods is one of the fundamental values of the European Union. Nowadays, the security environment out of Territorial waters is changing its characteristics. The statute of any military action in the Exclusive Economic Zone (EEZ) becomes more sensitive than ever. The use of naval mines is demanding adequate responsibility so that to correspond to trends in maritime security. It is vital, the perception for laying off mines at sea to be placed impartially between international legislation and military morale inspired by inherent civilization values, adequate to requirements of Geneva Conventions and United Nations Convention on the Law of the Sea (UNCLOS-82) in respect with human rights. The Convention relative to the laying of automatic submarine contact mines (Hague VIII) is an example that there are some needs for regulation of the use of naval mines at sea. Moreover, the significance of the Hague VIII Convention released in 1907 is more or less melting. UNCLOS-82 doesn`t treat the use of naval mines in details, so there is certain vacuum in regulation of those security aspects. The existence of sound and transparent principles is extremely important for building firm trust and mutual understanding between coastal states.

The Design and Implementation of Under-Water Laser Imaging Test Aquarium

A test aquarium was built to perform and simulate different marine environment to optimize laser imaging of submerged targets. The setup enable to study the correlation between the detection angle, the target surface topology and color, water turbidity, and laser type at different depths and backgrounds. A theoretical model of the detection process was tested using MATLAB simulation. The system was able to simulate light extinction of the real deep and shallow aqua environments due to plankton chlorophyll as well as the effect of clay and mud water turbidity. The used dummy targets are approximately 1/500 of the real submarines and naval mines. These targets were illuminated by several laser wavelengths in order to identify the targets with different color and shapes. The setup permits to test the efficiency of different target camouflage versus optical detection.

The Concept of Microprocessor Registration System of Energy Consumption of an Underwater Vehicle

Abstract The article, on the basis of the underwater vehicle ‘Głuptak’ intended to combat naval mines, outlines the general concept of the microprocessor system of registration of change of electricity stored in batteries for the underwater vehicle at the implementation time of the set task. Registration system the amount of energy allows you to optimize the implementation of the working time of the underwater vehicle drive system in conditions of interference type underwater sea current.

Risk evaluation and games in mine warfare considering shipcounter effects

Mines are believed to have suitable cost performance because cheap weapons prevent opponents from freely engaging in activity in mined areas for a comparatively long time. Mine warfare (MW) can be regarded as combat between a minefield planner and mine countermeasure (MCM) forces. The minefield planner equips influence mines with mine counter-countermeasures (MCCMs), which increase the difficulty of their removal. One of the MCCMs is a mine shipcounter, which provides a mine detonation fuse that triggers with some delay after the mine sensor detects vessels. In this paper, we develop a mathematical model of the MCM operation against scattered naval mines with shipcounters and analyze MW as a two-sided warfare game between the minefield planner and the MCM forces. The MCM forces must make a clever choice between mine-hunting or sweeping operations because, depending on the MCM operations, the shipcount has different effects on the removal of mines or on the damage risk to civilian ships transiting in a channel. First, we evaluate the performances of hunting and sweeping considering the mine shipcount; second, we consider a simple game with the minefield planner and the MCM forces as players and analyze rational strategies for these decision makers in MW.

Acoustic monitoring of coastal dolphins and their response to naval mine neutralization exercises.

To investigate the potential impacts of naval mine neutralization exercises (MINEX) on odontocete cetaceans, a long-term passive acoustic monitoring study was conducted at a US Navy training range near Virginia Beach, USA. Bottom-moored acoustic recorders were deployed in 2012–2016 near the epicentre of MINEX training activity and were refurbished every 2–4 months. Recordings were analysed for the daily presence/absence of dolphins, and dolphin acoustic activity was quantified in detail for the hours and days before and after 31 MINEX training events. Dolphins occurred in the area year-round, but there was clear seasonal variability, with lower presence during winter months. Dolphins exhibited a behavioural response to underwater detonations. Dolphin acoustic activity near the training location was lower during the hours and days following detonations, suggesting that animals left the area and/or reduced their signalling. Concurrent acoustic monitoring farther away from the training area suggested that the radius of response was between 3 and 6 km. A generalized additive model indicated that the predictors that explained the greatest amount of deviance in the data were the day relative to the training event, the hour of the day and circumstances specific to each training event.

Chester McKinney: A legacy of high frequency sonar development at Applied Research Laboratories, The University of Texas at Austin

Following the Korean War, improvements in high frequency, high resolution sonar were needed in order to successfully prosecute naval mines. Chester McKinney led an effort at Applied Research Laboratories (formerly Defense Research Laboratories), The University of Texas at Austin (ARL:UT), to make progress in this important area of research; and began a lifelong passion for Chester to pursue both basic and applied research in high frequency acoustics as applied to mine countermeasures. This research has been performed over many years by numerous scientists and engineers at ARL:UT and continues today. Based on this research, both experimental and operational high frequency, high resolution sonars were constructed, tested, and employed. This paper will explore some of these important sonar developments as well as some of the underlying physics. These developments span from analog implementations of CTFM sonars, pulse sonars, beamformers, and signal processing to early implementations of digital sonars and digital signal processing. Key parts of sonar research will be traced from the AN/UQS-1 to the AN/SQQ-14, AN/SQQ-16, AN/WQS-1, and the Data Collection Test Bed Sonar (development model for the AN/SQQ-32).

Treating Pilonidal Disease: You Do Not Need to Detonate a Naval Mine to Catch a Fish.

Treating Pilonidal Disease: You Do Not Need to Detonate a Naval Mine to Catch a Fish.

Naval mines: Legal considerations in armed conflict and peacetime

AbstractThe purpose of this article is to examine the key elements of the legal framework in which naval mines are used both across the spectrum of conflict and during peacetime. The article will also consider the legal issues associated with the use of mines by States in international armed conflict, and address the distinct legal issues which arise in non-international armed conflict, where the emergence of an increasing presence of non-State armed groups has been a hallmark of the late twentieth and early twenty-first centuries. The obligations placed upon States in peacetime, and under the law of neutrality, when the use and presence of naval mines is a relevant factor will also be analyzed.

Numerical analysis of penetrometers free-falling into soil with shear strength increasing linearly with depth

Dynamic penetrometers have been used for offshore oil and gas industry applications such as pipeline feasibility studies and anchoring systems, and military applications including naval mine countermeasures and terminal ballistic studies. The main challenge of using dynamic penetrometers is the interpretation of their test results in order to deduce the mechanical properties of the penetrated soil via empirical or theoretical relations. Recently, a robust numerical method based on the Arbitrary Lagrangian–Eulerian (ALE) technique has been developed for analysing dynamic penetration problems and used to investigate a smooth penetrometer free falling into a uniform layer of clayey soil. Numerical as well as experimental results indicate that the penetration characteristics, including the impact energy, total time, and total depth of penetration, depend on the mechanical properties of the soil including its stiffness and strength parameters as well as the geometry of the penetrometer and its initial impact energy. In this study, the ALE method is employed to study the effect of shear strength increasing with depth (a common condition of seabed deposits) on the penetration characteristics of a free falling penetrometer. Conducting more than two thousand numerical simulations has shown that there is an approximate quadratic relation between the final embedment depth of a FFP penetrating into a non-uniform clay soil and the combined kinetic energy on contact with the soil and subsequent loss in potential energy of the penetrometer.

Research on the asphericity error elimination of the invariant of magnetic gradient tensor

Real-time, point-by-point localization of magnetic targets such as ferrous unexploded ordnance can be achieved by the cube magnetic gradiometer system designed by the Naval Surface Warfare Center. The localization method uses the Frobenius norm of the magnetic gradient tensor to calculate the location of the magnetic target. This method assumes that the potential field of the Frobenius norm of the magnetic gradient tensor is a prefect sphere. But the Frobenius norm of the magnetic gradient tensor has an asphericity parameter, and its potential field is an ellipsoid, which can cause asphericity error. Since the current localization method can be affected seriously by the asphericity error, an improved method is proposed in this paper to eliminate the asphericity error. The improved method is based on a new invariant, which does not contain asphericity parameter. The new invariant can be obtained by the combination of the Frobenius norm and eigenvalues of the magnetic gradient tensor. In detail the procedure is as follows: first, the magnetic gradient tensor of the center point of the regular hexahedron's six planes can be measured by the cube magnetic gradiometer system, then these eigenvalues can be calculated and combined according to a certain relationship to eliminate the asphericity parameter, then the new invariants of the six planes can be obtained, and the spatial gradient of the new invariant can be calculated from the six new invariants, then the localization of the magnetic target can be calculated from the spatial gradient of the new invariant. This improved method can overcome the asphericity error effectively, and it can be used for real-time, point-by-point localization and detection of unexploded ordnance. Simulation experiments show that the localization error of the improved method is much smaller than that of the original method, the average relative error can be reduced by 10.9%. The improved method can be deployed on the highly maneuverable platform. The platform motion will not be constrained, and the improved method will be made more effectively in detection and localization of the magnetic targets. Thus the improved method can be widely applied in naval mines localization, mineral exploration, ferrous resources exploration, moving magnetic target tracking, and other fields.

소나와 무인기뢰처리기 정보를 활용한 기뢰전 체계 설계 방안

기뢰는 수중에 설치되어 수상함과 잠수함을 공격하기 위한 폭발물로서, 기뢰전은 해군의 여러 가지 성분작전 중에서 매우 중요한 작전 중 하나이다. 본 논문은 기뢰전 일반 개념에 대한 이해로부터 기뢰탐색작전 및 소해작전의 소개와 본문에서 소개 할 몇 가지 기능을 통한 전반적인 기뢰전 체계 설계 방안을 제안한다. 기뢰전 체계의 기능으로는 소나 영상정보로부터 아다부스트 기법을 활용하여 기뢰영역을 탐지하는 기능과 기뢰탐색작전 및 소해작전의 수행 시 각각의 진행률을 계산하는 기능, 소나로부터 수신한 기뢰 표적으로 무인기뢰처리기를 유도하는 기능 등이 있다. The naval mine is the explosives that are installed in the water in order to attack surface ships or submarines. So mine warfare is a very important component of naval operations. In this paper, first, understanding of the general concept about mine warfare. Second, introduce the mine hunting progress and mine sweeping progress. And then, suggest the system design method of mine counter measure warfare using several functions. The functions are mine area detection algorithm for side scan sonar image using Adaboost algorithm, and calculation to mine hunting progress rate and mine sweeping progress rate. And techniques that lead the mine disposal vehicle(MDV) to mine.

Corrigendum to: New methods for interpretation of magnetic vector and gradient tensor data I: eigenvector analysis and the normalised source strength

Acquisition of magnetic gradient tensor data is likely to become routine in the near future. New methods for inverting gradient tensor surveys to obtain source parameters have been developed for several elementary, but useful, models. These include point dipole (sphere), vertical line of dipoles (narrow vertical pipe), line of dipoles (horizontal cylinder), thin dipping sheet, and contact models. A key simplification is the use of eigenvalues and associated eigenvectors of the tensor. The normalised source strength (NSS), calculated from the eigenvalues, is a particularly useful rotational invariant that peaks directly over 3D compact sources, 2D compact sources, thin sheets and contacts, and is independent of magnetisation direction. In combination the NSS and its vector gradient determine source locations uniquely. NSS analysis can be extended to other useful models, such as vertical pipes, by calculating eigenvalues of the vertical derivative of the gradient tensor. Inversion based on the vector gradient of the NSS over the Tallawang magnetite deposit obtained good agreement between the inferred geometry of the tabular magnetite skarn body and drill hole intersections. Besides the geological applications, the algorithms for the dipole model are readily applicable to the detection, location and characterisation (DLC) of magnetic objects, such as naval mines, unexploded ordnance, shipwrecks, archaeological artefacts, and buried drums.

Reply to Comment on “Underwater Explosion (UWE) Analysis of the ROKS Cheonan Incident” by K. S. Kim

On choosing two net explosive weights (NEW) (250 kg and 136 kg) to primarily focus on: 250and 136-kg net explosive weights—the case of a DPRK torpedo and the case of an ROK LCM—were researched by the MCMJIG (2010) with the conclusion that the UWE source had to be a 250-kg NEW according to the evidence. During the course of our research we have been led to have serious doubts on the authenticity and veracity of this evidence provided by the MCMJIG (including chemical residue and the torpedo submitted as proof). Coupled with the often overlooked or ignored fact that at least two antisubmarine warfare (ASW) warships—the ROKS Cheonan (PCC-772) itself and the ROKS Sokcho (PCC-778); the PCC class series 761–785 were specifically designed for ASW)—were in the area at the time of the UWE incident and both failed to detect either a DPRK sub or a torpedo travelling through the water, this makes it extremely unlikely that a torpedo fired from a DPRK sub is the culprit. Another important fact is that there is ample evidence of the Cheonan having serious navigational problems (i.e., partially running aground) leading up to the incident. Now there is sufficient evidence that there was some sort of underwater explosion (UWE) from seismoacoustic analyses. The only two plausible UWE source possibilities are a mine or a torpedo. Of course it could also theoretically be a hybrid, i.e., a torpedo launched from a mine. However, if it is not a DPRK launched torpedo, then it has to be a mine. A friendlyfire torpedo has also been raised as a possibility, but that involves many more players and would be much more difficult to cover up, especially in a very wired country such as the ROK. Our premise is that the most likely source of this UWE is a ROK littoral ‘‘land control mine’’ (LCM) naval mine. This premise is the basis of our hypothesis, but of course it cannot be definitively concluded due to the lack of access and transparency regarding this incident. Various net explosive weight (NEW) variables were hypothetically tested in this paper, with 250 kg being pointed out for being the NEW asserted by MCMJIG and 136 kg being pointed out for being the NEW for the ROK LCM naval mine. In the case of the 136-kg NEW of the ROK LCM, the variables fall within the allowable parameters and we are asserting this as the most likely UWE source. In the case of the 250-kg NEW DPRK torpedo, the variables fail to fall within the parameter limits. On the question of the pertinent equation to use: there seems to be some confusion regarding the equations. The commentator stated that we had to use Eq. (3) of the SWISDAK (1978) report. However, the third equation is a ‘‘correction equation’’ that may be utilized but is not necessary in every situation where the surface, bottom, or both could potentially influence the bubble. The basic equations of the bubble pulse period and the maximum gas bubble radius (SWISDAK 1978) are as follows:

Multiobjective planning for naval mine counter measures missions

Near-optimal scheduling and allocation for DoD missions is complicated by many factors, including multiple measures of effectiveness, mixed-initiatives, heterogeneity of systems and non-uniformity of homogenous systems; these factors contribute to a complex planning problem with non-linear, combinatorial, and continuous components that is further complicated by information uncertainty. In Navy, mine counter measure missions, planning entails components of the vehicle routing problem with time windows and flexible flowshop scheduling with pre-emptive maintenance. We present a multiobjective mine counter measures problem formulation and describe the non-dominated scheduler, a scheduling programme that parametrically explores continuous dimensions of the decision space, stochastically samples from exponentially large decision spaces, and uses surrogate metrics to bound computational complexity. This provides mission commander with a non-dominated set of alternative plans. This scheduler has been integrated into existing tools and is being evaluated by the US Navy for extension and integration into next-generation mine warfare decision aids.

New methods for interpretation of magnetic vector and gradient tensor data I: eigenvector analysis and the normalised source strength

Acquisition of magnetic gradient tensor data is likely to become routine in the near future. New methods for inverting gradient tensor surveys to obtain source parameters have been developed for several elementary, but useful, models. These include point dipole (sphere), vertical line of dipoles (narrow vertical pipe), line of dipoles (horizontal cylinder), thin dipping sheet, and contact models. A key simplification is the use of eigenvalues and associated eigenvectors of the tensor. The normalised source strength (NSS), calculated from the eigenvalues, is a particularly useful rotational invariant that peaks directly over 3D compact sources, 2D compact sources, thin sheets and contacts, and is independent of magnetisation direction. In combination the NSS and its vector gradient determine source locations uniquely. NSS analysis can be extended to other useful models, such as vertical pipes, by calculating eigenvalues of the vertical derivative of the gradient tensor. Inversion based on the vector gradient of the NSS over the Tallawang magnetite deposit obtained good agreement between the inferred geometry of the tabular magnetite skarn body and drill hole intersections. Besides the geological applications, the algorithms for the dipole model are readily applicable to the detection, location and characterisation (DLC) of magnetic objects, such as naval mines, unexploded ordnance, shipwrecks, archaeological artefacts, and buried drums.

New Methods for Interpretation of Magnetic Gradient Tensor Data

SummaryRecent technological advances suggest that we are on the threshold of a new era in applied magnetic surveys, where acquisition of magnetic gradient tensor data will become routine. In the meantime, modern ultrahigh resolution conventional magnetic data can be used, with certain important caveats, to calculate gradient tensor elements from total magnetic intensity (TMI) or TMI gradient surveys. Until the present, not a great deal of attention has been paid to processing and interpretation of gradient tensor data. New methods for inverting gradient tensor surveys to obtain source parameters have been developed for a number of elementary, but useful, models. These include point pole, line of poles, point dipole (sphere), line of dipoles (horizontal cylinder), thin and thick dipping sheets, sloping step and contact models. A key simplification is the use of eigenvalues and associated eigenvectors of the tensor. The scaled source strength, calculated from the eigenvalues, is a particularly useful rotational invariant that peaks directly over compact sources, 2D sources and contacts, independent of magnetisation direction. New algorithms for uniquely determining the location and magnetic moment of a dipole source from a few irregularly located measurements or single profiles have been developed. Besides the geological applications, these algorithms are readily applicable to the detection, location and classification (DLC) of magnetic objects, such as naval mines, UXO, shipwrecks, archaeological artefacts and buried drums. As an example, some of these new methods are applied to analysis of the magnetic signature of the Mount Leyshon gold-mineralised system, Queensland.