Drunk Driving Essay Example for Free

Drunk Driving Essay Drunk driving is a primary cause of highway traffic accidents causing deaths and injuries with enormous monetary costs to society. The drunk driving was first recognized as a policy problem in the literature in 1904, approximately 5 years after the first highway traffic fatality in the United States (Voas and Lacey). In 1982, the National Highway Traffic Safety Administration started keeping statistics of alcohol related crashes through its Fatality Analysis Reporting System (FARS) (Stewart and Fell). In 1982, there were 26,173 alcohol related fatalities, which constituted 60% of all highway fatalities. In 2002, about 17,419 or roughly 41% of about 42,815 highway fatalities were estimated to be alcohol related which indicates a 19% change since 1982 (Stewart and Fell). Overall, alcohol related traffic fatalities have reduced by about 33% over the last two decades. Policies implemented to curb drunk driving in the last two decades seem to have an impact on alcohol related fatalities. FARS data shows a 62% decrease (1. 64 to . 61) in alcohol related fatality rate since 1982 (Stewart and Fell). The general decline in the alcohol related fatalities for the general population is believed to be due to a combination of deterrent based laws, increased alcohol awareness and decrease in alcohol consumption, increased publicity about prevention, and general car safety measures (Stewart and Fell). Starting 1980s, drunk driving has been conceptualized as a criminal justice issue. With the effect of Mothers Against Drunk Driving (MADD) and some other citizen activist groups, the issue has become a public policy problem in which drunk drivers are defined as sinful killers who drink and drive irresponsibly and claim lives of innocent victims. These efforts, according to Ross, created a dominant paradigm which focuses on the blameworthy driver. Thus, framing the issue as of a sin and drunk drivers as deviants has dominated the policymaking process and socially constructed the drunk drivers as a target group with negative connotations in public mind (Meier). Policymakers responded the demands by legislating stricter deterrent based measures to punish those criminal drunk drivers and deter drunk driving to save lives (Ross). Therefore, it is important to examine how drunk driving emerged as a policy problem and how deterrent based laws are introduced and accepted as a solution to the problem. This paper examines also the effects of MADD on legislation of drunk driving laws and effects of those laws on alcohol related fatalities. Background The struggle against drunk driving as a traffic safety problem began in late 1960s. Before 1960s, the federal governments influence on states drunk driving policies was minimal. The national character and seriousness of traffic safety problems prompted Congress to enact the Highway Safety Act and the Motor Vehicle and Traffic Safety Act, in 1966. In 1967, the Secretary of Transportation officially promulgated the first federal drunk driving standards in the National Uniform Standards for State Highway Safety Programs. One of the requirements of this program was for each state to utilize chemical tests for determining blood alcohol levels (BAC) and to enact BAC limits of no greater than . 10 % (Evans et al. ). If an individual is found to be driving with a BAC over a certain threshold they would be arrested for drunk driving. Those standards came with the threat of reducing highway funds for noncompliance. Although some states viewed the 1967 standards and the threats of reducing highway funds as interfering with their sovereign function, they complied with the new standards to participate in highway construction projects. By 1981 all states had adopted the specific standard of . 10 BAC or a lower level. In 1982, the Presidential Commission on Drunk Driving was created, and the Alcohol Traffic Safety Act of 1982 established a three-year program to provide highway grants for states that adopted certain anti-drunk driving measures (Evans et al. ). In 1983, the Presidential Commission on Drunk Driving recommended that states enact a uniform drinking age of twenty-one years. This approach was ineffective: only four states had done so by 1984. In response, Congress passed legislation requiring highway funding reductions for any state with a drinking age under twenty-one in 1984. That strategy was effective as the states soon began to establish twenty-one-year age limits. By 1986, all but eight states had adopted the twenty-one-year age limits. By 1989, all states had complied with this federal limit. Congress, by promising grants or threatening to withhold funding (carrot and stick from of coercive federalism), has taken an active role in formulating drunk driving policies and in encouraging the states to adopt them (Evans et al. ). On October 23, 2000 President Clinton signed Department of Transportation and Related Agencies Appropriations Act, 2001 that established the first-ever national drunk driving standard at . 08 blood alcohol content (BAC). According to this legislation, states that do not adopt . 08 BAC laws by 2004 would have 2% of highway construction funds withheld, with the penalty increasing to 8% by 2007. States adopting the standard by 2007 would be reimbursed for any lost funds. As of February 2004, 46 states plus the District of Columbia and Puerto Rico have adopted the national . 08 BAC standard. The federal BAC limit was the last, but not the least measure established to curb drunk driving. It was, indeed, the culmination of efforts targeting drunk driving which dates back to early 1980s (MADD). Although a variety of preventative policies including education campaigns, rehabilitation, and control of alcohol sales have been employed to reduce drunk driving, more emphasis has been placed on the use of punitive policy tools such as license revocation, increased fines, and mandatory jail time. Policies designed to change undesired behavior frequently frame drunk driving behavior as sinful or deviant, which suggests that drunk driving may constitute a morality policy. Indeed, drunk drivers are often depicted in the media and policy debates as irresponsible killer drunks. The politics around the issue of drunk driving as a morality policy may explain why punitive tools rather than preventive policies have been increasingly used in this policy area (Meier). Anti-Drunk Driving Policy Controversies Policies pertaining to alcohol have been regulated by local, state and the federal governments over the last century, including the prohibition at the turn of the twentieth century. At different times alcohol has been prohibited, permitted to operate without government control, regulated through licensing, or controlled by monopolies. This policy area is largely controlled by states through a wide range of policies regulating both the sale of alcohol and penalties for alcohol abuse. Although prohibition on drunk driving is a regulatory policy, it has a separate purpose. As Meier points out, rather than restricting access to alcohol, drunk driving policies are intended to punish individuals who abuse alcohol by drinking and driving (687). Over the last two decades states have adopted a variety of punitive policies to prevent drunk driving and its consequences. Since drunk driving is framed as sinful behavior, no one will stand up and support drunk driving. Advocates of drunk driving policies push for stricter measures to protect innocent victims and in such an environment, rational politicians will perceive that the demand for restrictive policies will be greater than it actually is and, thus, compete for more extreme policies because they always see there is a great support for being tougher on sin (Meier). These policies will be carried out through strict law enforcement by agencies, which will be awarded by the number of arrests made. Therefore, law enforcement agencies will also favor more extreme policies because such policies will create an environment that supports more resources for them (Meier). Furthermore, arresting killer drunks and saving innocent lives will increase their popularity in the eyes of public. In the absence of organized opposition, therefore, drunk driving policies shaped with the support of the public, politicians, and the bureaucracy-lead to adoption of coercive tools, which increases the cost of sinful behavior (Ross). As with most public policy issues, this one, too, has many sides. Just as anti-drunk driving movement supporters form alliances for specific efforts, adversaries also work independently and sometimes together depending on the current situation and how their alliances reflect common concerns. Organizations and individuals who appear to oppose the efforts of the anti-drunk driving movement are, in some cases, protecting a different interest or issue, such as business interests and, by extension, the economy (Baum). Despite the strength of the morality policy framework to predict what type of policy tools would be adopted in this policy domain, legislation of the federal . 08 BAC standard departs from this framework on -at least- one major point: there was an organized opposition to the legislation. Opponents of the national . 08 BAC limit consisted of interest groups representing alcohol and hospitality industries and a few non-profit groups defending motorists rights. Meier contends that highly salient morality policies permit little role for expertise and the lack of opposition results in avoidance of information that challenges the dominant position. Therefore, morality politics lead to adoption of poorly designed and rarely effective policies. In the case of . 08 BAC legislation, as with many other anti drunk driving policies, however, existence of such an opposition heated the debate around the effectiveness of that standard to prevent drunk driving. Studies evaluating the effectiveness of . 08 BAC limit and level of impairment at different levels of BAC were often cited by both sides of the policy (Meier 689-90). Opponents of the national . 08 BAC limit, however, differed in their solutions rather than in their conception of the issue. Both sides of the drunk driving debate agreed on the problem, but they disagreed on the solutions, which is closely related to the definition of the problem. Opponents and proponents of the legislation defined the problems in similar ways. For example, both sides distinguished good people who drink socially from a small minority of alcohol abusers, blameworthy deviants, who drink and drive irresponsibly. The alcohol and restaurant lobbyists could not and did not deny the existence of drunk driving problem. Furthermore, they accepted an obligation to contribute to the reduction of the problem (Baum). However, they defended that . 08 BAC limit would not affect those abusers but would punish the responsible social drinkers, which in turn negatively would affect alcohol sales. They argued that most fatal accidents involving BAC levels below . 10 were alcohol related, not alcohol caused. In almost all alcohol caused fatal accidents, drivers have had an average BAC level of . 17. Therefore, lowering BAC limit to . 08 would not prevent drunk driving. Instead, some other measures such as strict administrative license suspension, and frequent sobriety checks by law enforcement should be administered. Proponents of the . 08 BAC legislation, on the other hand, argued that everyones safe driving skills are dangerously impaired at this level, and nearly one-fourth of traffic fatalities caused by drunk drivers with a BAC level of . 10 or less (Meier 691-92). Anti-Drunk Driving Movement and MADD According to Reinarman, the anti-drunk driving movement did not spring from a rise in the prevalence of drunk driving or in accidents related to it, but from the fact that the injustices (or negative externalities) attributed to drunk driving have never been treated seriously by legislators and courts. Indeed, before 1980s drunk driving had been seen merely a traffic offense. The morality policy focus of the Reagan administration created the suitable climate in which the claims of MADD affected the public and legislators (Reinarman). MADD was founded as a non-profit victims rights organization concerned with advocating for and counseling victims and bereaved relatives, and monitoring courtrooms. Although many members of MADD are victims or bereaved victims of drunk drivers, general community activists (non-victim) have also been active in many chapters. A study on a national sample of 125 MADD chapters indicated that victimization alone does not cause activism (Weed). Moreover, victim and non-victim activists share similar social backgrounds and already participate in other voluntary associations, which reveals that MADD tends to be run by activists who have been victimized rather than victims who have become activists (Ross). Despite its inception as a victims rights organization, MADD has been blamed for becoming a neo-prohibitionist movement (Hanson). The goal of the organization, Hanson claims, is no longer preventing alcohol related accidents but preventing drinking. Moreover, MADD members are accused of seeking vengeance through harsh penalties either than rehabilitation and prevention. Reinarman points out that MADDs goals include the demand for justice or vengeance on the group that took lives of friends and children, which warrants harsh punishment whether deterrence is achieved. He also contends that in the case of drunk driving, the purpose of jail is generally social revenge, not accident prevention. Advocates of MADD, on the other hand, have always pointed out the public education programs, victim assistance, and legislative activism as their agenda items. Regardless of the objectives mentioned above, MADD has managed to make drunk driving a major public problem. Its approach to the problem assumes that the victim in an alcohol related accident is innocent; the drunk drivers behavior is willful and it is a crime which should be dealt in the criminal justice system; and harsh punishment is effective in reducing drunk driving by the threat of swift, certain, and severe penalties. By working against the alcohol industrys promotion of drinking in general, MADD has focused on the negative externalities created by the drunk driver -framing the issue as a deviant behavior (Ross). This strategy allowed the movement to gain support even from the alcohol industry itself. Starting from being a small group of women to a nationwide organization with over 600 chapters across 50 states, MADD has become the most influential citizen group fighting drunk driving. The organizations 2003-2004 annual report shows that its assets reached more than $28 million and revenues more than $53 million (MADD). As with other anti-drunk driving laws, MADD was the main actor behind the federal . 08 BAC legislation. With support of other non-profit organizations, MADD members brought the issue to the public attention. They lobbied key members of Congress, organized media campaigns, participated in press events and other activities, and published fact sheets and statistical information demonstrating the significance of the policy initiative (Ross). They not only contacted the president and obtained his support, but also reached both Democrat and Republican members of the Congress gaining bipartisan support, necessary for passage of the legislation. MADD saw the fight for . 08 BAC as a fight for public safety. Karolyn Nunnallee, the president of the organization, once said, The danger imposed by a drunk driver does not stop at State lines. Neither should the standards that define drunk driving (190). Conclusion Like many other public policy issues, drunk driving can also be defined and addressed in several ways with every definition proposing a different solution. Contrary to the dominant paradigm, for example, drunk driving can be considered as a public health issue. Then the solution would be rehabilitation of offenders rather than imposing sanctions on them. However, efforts of MADD and other grassroots organizations to define the problem in criminal justice terms by describing the problem as of a sin committed by irresponsible killer drunks against innocent victims succeed over other possible definitions of the problem as well as the solutions attached to them (Meier). Their success of the definition of the problem yielded social construction of the target group as deviants with negative connotations and weak political power who deserve sanctions either than rehabilitation. Although proponents of drunk driving policies have been successful in defining the issue in terms of sin that no one could stand for it, opponents were also successful to some extent in addressing the issue by questioning the effectiveness of deterrent based policies. They were able to frame the issue in such a manner that opposition became legitimate. Meier contends that when the opponents are able to change the social construction of the debate from sin to some other dimension, the redistributive nature of the policy becomes open and acknowledged (694). At this point, we can hold that the drunk driving issue was transformed from the politics of sin to the politics of redistribution when alcohol and hospitality industries considered that the stricter laws -as in the case of federal . 08 BAC legislation- would threat alcohol sales. They were not successful, however, in changing issue entirely from being a policy of sin and could not defend drunk driving, but emphasized the potential inefficiency of measures to curb drunk driving. Moreover, they could not sustain holding that position over time and once again the dominant definition of the problem prevailed yielding more punitive tools to deter drunk driving. MADD has been acknowledged as the driving force that transformed drunk driving into a public problem which warrants governmental action. Moreover, MADD as a citizen advocacy group is an important factor in shaping policies in American states. The results provided evidence for the effects of MADD not only on states adoption of anti-drunk driving laws but also adoption of traffic safety measures in general. Works Cited Baum, Scott. Drink Driving as a Social Problem: Comparing the Attitudes and Knowledge of Drink Driving Offenders and the General Community. Accident Analysis and Prevention. 32 (2000): 689-694. Evans, William N. , Doreen Neville, and John D. Graham. General Deterrence of Drunk Drivers: Evaluation of Recent American Policies. Risk Analysis. 11 (1991): 279-289. Hanson, David J. Mothers Against Drunk Driving: A Crash Course in MADD, 2002 http://www. alcoholfacts. org/CrashCourseOnMADD. html MADD. Saving Lives: Mothers Against Drunk Driving Annual Report 2003-2004, 2004. Meier, Kenneth J. (1994). The Politics of Sin: Drugs, Alcohol, and Public Policy. Armonk, NY: M. E. Sharpe. Meier, Kenneth J. Drugs, Sex, Rock, and Roll: A Theory of Morality Politics. Policy Studies Journal. 27 (4) (1999): 681-695. Nunnallee, Karolyn. Pro Con: Should Congress Pass . 08 Blood-Alcohol Concentration (BAC) Drunk Driving Standard? Congressional Digest. 11 (6-7) (1998): 178-191. Reinarman, Craig. The Social Construction of an Alcohol Problem: The Case of Mothers Against Drunk Drivers and Social Control in 1980s. Theory and Society. 17 (1988): 91-120. Ross, H. Laurence. Confronting Drunk Driving: Social Policy for Saving Lives. New Haven, CT: Yale University Press, 1992 Stewart, Kathryn and James Fell. Trends in Impaired Driving in the United States: Complacency or Backsliding? In Daniel R. Mayhew and Claude Dussault eds. Proceedings of the 16th International Conference on Alcohol, Drugs and Traffic Safety, Montreal, Canada, August 4-9, 2002. Voas, Robert B. and John H. Lacey. Drunk Driving Enforcement, Adjudication, and Sanctions in the United States. in R. Jean Wilson and Robert E. Mann eds. Drinking and Driving: Advances in Research and Prevention. New York, NY: The Guildford Press, 1990 Weed, Frank J. The Victim-Activist Role in the Anti-Drunk Driving Movement. The Sociological Quarterly. 31 (3) (1990): 459-473.

Causes Of Joint Failures Engineering Essay

Causes Of Joint Failures Engineering Essay This report emphasizes methods for determining, minimizing, and uniformly distributing the stress for cable joints and HV bushings. The analysis is intended to reduce the failures caused by high stressed, to provide maintenance cost reductions, and to improve service reliability. Predicting the remaining life of a joint is a major challenge to electric utilities, one that has long had the attention of design and maintenance engineers who manage overhead transmission lines. The recent joint failures reported by a few utilities follow the trend caused by aging joints and conductors. These problems are expected to increase over time because of higher line loadings under the current deregulated environment. Since typical inspection techniques have many limitations, it is currently difficult to isolate the components early enough to reliably avoid failure. If two electrical conductors are joined to form a stationary electric contact, i.e. an electric joint, the joint resistance does not remain constant but will increase during operating time. This long-term behaviour of the joint resistance can be influenced by different aging mechanisms like corrosion processes, interdiffusion, electromigration, fretting and stress relaxation. Especially in bolted aluminum joints at high current load, i.e. at high joint temperatures stress relaxation may play an important role in joint aging. Creep deformation of the conductor material decreases the joint force. The area and the number of a-spots decrease and may cause an increase of the constriction resistance which may occur suddenly, if mechanical vibrations act on the joint. In order to describe the factor of influence of creep on the aging behaviour of high current bolted aluminum joints, the relationship between the decreasing joint force and the joint resistance and the development of the joint force have to be determined. The relationship between the decreasing joint force and the joint resistance can be evaluated on the basis of the surface profile of the rough joint surfaces [7]. In order to extrapolate the development of the joint force beyond the time of experiments and to reduce the number of experiments with numerous types of joints geometry the development of the joint force is calculated. The calculation is performed by means of the Finite Element Method (FEM) based on material parameters of the conductors and the physical fundamentals of creep [8]. Due to the structural characteristics of bushings and cable ends. the electric fields near the grounding flange are highly concentrated. and have a strong axial component, resulting in corona and gliding discharge. The traditional way of improving this condition is to apply semiconducting paint or band on the insulating surface by the flange. The electric field is evened by decreasing the surface resistance of the insulating surface. However, the effect is not very good due to the thinness of the applied material. In addition, the applied material will aging or peel off in time, decreasing its effect to zero. Failure Mechanisms Causes of Joint Failures Joint failures are expected to increase with the increase demand for heavier loading operations. Some of the key contributors to joint failures include: inadequate cleaning of the conductor, complete absence of conductor cleaning, absence of corrosion inhibitor, improperly inserted conductor, incomplete die closures, and high load fault currents contributing to aging with thermal stresses. Installation and Quality Assurance Issues One of the main reasons for joint failures is improper installation. Misalignment of steel sleeve, crimping with wrong dye, no grease present in splice, and improperly cleaned conductor can greatly accelerate the failure process. Other factors that influence failures are internal crevice corrosion, releasing of compression force by thermal cycling, creep due to line tension, and fatigue cracking on bent joints. Corrosion Problems Corrosion is a major factor in the deterioration process of splice/connectors. Figure below is anexample of a failed field joint. Characteristics of a Joint Failure The final failure mode of connectors is either mechanical or thermal. Sometimes the steel sleevehas been installed off-center, resulting in one end of the conductor being barely inserted. This can result in a mechanical failure. A thermal failure is the result of high resistance heating or individual strands failing with the same consequence. These situations can either melt components or cause the joint to lose its connection. Failures generally show evidence of both mechanical and thermal failure in combination. Temperature and Resistance Relationship The degradation of a joint can be observed by changes in its resistance and temperature. The interface resistance is a very small part of the total joint resistance until there are signs of damage. Because of this effect, no noticeable heating takes place until late in the failure cycle. High temperature values are usually the result of high resistance measurements in a component. Resistance is a function, to varying degrees, of temperature. As an abnormally high resistance component begins to heat up, resistance increases, resulting in an even faster rate of temperature increase. This physical property of electrical conductors can quickly make a bad situation worse! In addition, as the component heats it may reach the material melting point. Often a complete structural failure results and the line drops. More often, however, the melted metal re-solidifies; as this happens resistance decreases, and thus temperature, may be reduced. This is only a 2-3 temporary phenomenon, but if the inspection is conducted at this point in the failure cycle, the data will certainly be misleading! Eventually both resistance and heating will again increase, and the material will again melt. This melting and re-welding can take place many times before total failure occurs, especially when copper alloy components are involved. Design of High Voltage Cable Joints General For the stress control, basically the following methods are known: Geometrical, where the contour of conducting elements is controlling the electrical field at the end of a high voltage cable. Resistive, where the resistance of a semiconducting material is used to reduce the electrical stress in high field regions. Refractive, where material with a high permittivity is used for pushing away the field from high stress regions. The first method which refers to the geometry of the joint, is more of a mechanical way of reducing or controlling stress. If we have to cables and there is a joint connecting them, what ever the stress distribution may be, it is possible to control both the parameters that are stress concentration and stress distribution. For example, if we have a straight joint exactly alligned with the cable shape, whatever stress it shows, we can reduce or vary the stress distribution, and stress concentration can be decreased by applying changes to the joint shapes such chamfering the joint a bit, and also by varying its size to a possible extent. While the resistive and refractive method is successfully used for medium voltage applications up to 72.5kV maximum, the geometrical field control method is the standard method for high voltage and extra high voltage applications. Controlling the field by a well defined contour still offers the best quality from design and production point of view. To install a pre-moulded joint they are normally slipped-over the prepared cable on site by using grease and special push-on tools. Another technology, widely used in the medium voltage range, is the cold shrink technology. With this technique a pre-moulded joint body is pre-expanded on a support tube, which can be removed while being placed around the cable on site. It has the advantage that no push-on tools must be used. Electrical Design One basic function of every termination or joint is to control the electrical field at the endof a cable or between two cables. This means that the electrical field is controlled by the contour of conducting elements integrated into the joint body. During design stage FEM (Finite Element Method) calculation programs are an important tool as the latest versions of these programs offer a vast range of possibilities such as: Calculation of the electrical field in any direction of the joint body Optimization tools for calculating the optimum shape of stress control elements Solving of coupled fields, like thermo mechanical stresses Models for non-linear behavior of materials, like stresses in polymeric materials Simulation of slip-on procedures Choice of Material Nowadays the materials used for high voltage joints are silicone rubber and EPDM. The basic requirements for an elastomeric material are as follows: Sufficient mechanical properties in order being expandable in the required range. Capability to withstand the required temperature range. Availabilty of material with constant quality and constant purity. Low ageing with respect to electrical and mechanical properties. According the requirements given above silicone rubber is an ideal and preferred material for cable joints. Therefore it can be concluded that silicone rubber is an excellent material for the use in cable accessories as it can fully cope with the electrical, mechanical and thermal requirements given by nowadays polymeric cables. Ageing An important aspect, which we still have to consider is the ageing factor of insulating material and interface. The ageing can be described by the life time law as follows: EN * t = const. Where, E = Electrical field in the insulation t = Time, where the electric field is applied N = Lifetime coefficient Stress Analysis For the Stress Analysis we have used a Finite Element Analysis (FEA) software in order to find the electric field distribution. We have done this by MAXWELL SV software. A little bit about the software first and then we proceed towards our analysis. USING THE SOFTWARE We have used a student version of MAXWELL SV software depending on the availability, which allows us to analyze a problem on the basis of 2D geometry. The resistive solution for reducing stress is of great importance as well. If another piece of metal is being used to joint two pieces of cable, it could produce more stress on the joint due to its own resistive and other properties. So, if the two pieces of wire are making contact through a third material, normally the third material is to be used as a jacket that overlaps two wires as shown below. In the above arrangement two cables have direct contact with each other and third material is making parallel circuit with two cables and is supporting electrical current through a joint. In the arrangement that involves a joint in series, the third material is making a series circuit with two cables and adding extra resistance to the joint with will increase the stress on the joint. On the other hand if we talk about the refractive part the situation could be explained as , if a single piece of sleeve is taken and we plot the rise in temperature due to sleeve. Exposed part of the cable will have low temperature as compared with the portion under sleeve and it will create difference of resistance at both ends of wire under sleeve, due to this difference thermal stresses on the ends of the two cables being joint. To reduce the stress it is recommended that sleeve should be good conductor to heat and the temperature of exposed part will be as same as the part under the shielded portion. SIMULATION BASED ANALYSIS For our simulation we have considered two cables joined together, where the joint between them is assumed to be a perfect one, and hence we can treat it as one perfect conductor. Therefore, the conductor can be a single copper cable as demonstrated in the results below. In reality when the cables are to be joined, the ends of the two separate cables must be stripped of its insulation. For modeling purposes this has been represented by a gap in the insulation between the conductor and outer sheath. This gap will initially be left empty to see the distribution with no insulation. In attempt to distribute the stress uniformly the gap will then be filled with a variety of material. The layer of the insulation at the joint is generally a lot thicker than the rest of the cable, and the simulations below make uses of this. The conductor has been assigned as a source of 500KV, and the outer sheath at ground potential. The insulating material for the two cables is XLPE. The results presented below show stress distribution in various scenarios where the geometry has been unchanged, and different insulation materials have been tested. Due to different properties of different insulating materials the stress distributions also vary. The first result presents the field distribution, where the gap has been left empty, to examine the initial stress with no insulation at all. Figure 1: Cable joint with no insulation at the joint XLPE Cable Insulation Outer Sheath (0V) Gap HV Conductor (500KV) In this situation the stress in the gap at the joint and surrounding insulation in very high. This would eventually result in failure of the joint due to the extreme stresses. Now that the initial stress has been determined, it is necessary to find how to minimize and uniformly distribute the stress. As mentioned previously the gap is now filled with a layer of a variety of materials. The layer at the joint is thicker than the insulation of a normal cable as to attempt to minimize and create a more uniform distribution of stress. Below the distribution for a variety of materials used to insulate the joint is presented. Figure 2: Field distribution for Silicon Insulated cable joint Joint Insulation Figure 3: Field distribution for FR4-Epoxy insulated cable joint Figure 4: Field distribution for Polyimide-Quartz insulated cable joint Figure 5: Field distribution for Polyethylene insulated cable joint Figure 6: Field distribution for Teflon insulated cable joint Figure 7: Field distribution for Polystyrene insulated cable Figure 8: Field distribution for Porcelain insulated cable Notice that there are two effects of using the thick insulation at the cable joint, first the concentration of the stress is brought down, and secondly the stress is distributed more uniformly. These are both important in ensuring the insulation is efficiently used, and maximizes the life span of the insulation. Notice that in the case of all but Polyimide-Quartz insulation the concentration is minimized somewhat, though the main effect is the uniform distribution of stress. On the other hand Polyimide-Quartz insulation greatly decrease the stress concentration, though the distribution is undesirable as the majority of the stress is concentrated at the conductor surface which will result in uneven wear of the insulation. Thus the optimal insulation will have even distribution of stress, and somewhat minimize the stress concentration. It was determined that the silicon insulation is best suited for this purpose. The distribution of the stress across the joint and surrounding insulatio n is very uniform, and the concentration is somewhat minimized as well. This result is consistent with industry practices as in general a thick layer of silicon is used at the joint for insulation []. Conclusion Cable Joints The Electric Stress has been determined for the general structure of a high voltage cable using finite element analysis, and a method suggested to create a more uniform, and less concentrated distribution of stress. The results obtained agree with what is currently standard practice in the high voltage industry. FINITE ELEMENT ANALYSIS Background Finite Element Analysis (FEA) was first developed in 1943 by R. Courant, who utilized the Ritz method of numerical analysis and minimization of variational calculus to obtain approximate solutions to vibration systems. Shortly thereafter, a paper published in 1956 by M. J. Turner, R. W. Clough, H. C. Martin, and L. J. Topp established a broader definition of numerical analysis. The paper centered on the stiffness and deflection of complex structures. By the early 70s, FEA was limited to expensive mainframe computers generally owned by the aeronautics, automotive, defense, and nuclear industries. Since the rapid decline in the cost of computers and the phenomenal increase in computing power, FEA has been developed to an incredible precision. Present day super computers are now able to produce accurate results for all kinds of parameters. What is Finite Element Analysis? FEA consists of a computer model of a material or design that is stressed and analyzed for specific results. It is used in new product design, and existing product refinement. A company is able to verify a proposed design will be able to perform to the clients specifications prior to manufacturing or construction. Modifying an existing product or structure is utilized to qualify the product or structure for a new service condition. In case of structural failure, FEA may be used to help determine the design modifications to meet the new condition. There are generally two types of analysis that are used in industry: 2-D modeling, and 3-D modeling. While 2-D modeling conserves simplicity and allows the analysis to be run on a relatively normal computer, it tends to yield less accurate results. 3-D modeling, however, produces more accurate results while sacrificing the ability to run on all but the fastest computers effectively. How Does Finite Element Analysis Work? FEA uses a complex system of points called nodes which make a grid called a mesh . This mesh is programmed to contain the material and structural properties which define how the structure will react to certain loading conditions. Nodes are assigned at a certain density throughout the material depending on the anticipated stress levels of a particular area. Regions which will receive large amounts of stress usually have a higher node density than those which experience little or no stress. Points of interest may consist of: fracture point of previously tested material, fillets, corners, complex detail, and high stress areas. The mesh acts like a spider web in that from each node, there extends a mesh element to each of the adjacent nodes. This web of vectors is what carries the material properties to the object, creating many elements. Introduction Bushings In todays competitive market, there is a need for the bushing manufacturing industry to improve bushing efficiency and to reduce costs; because high-quality low-cost products and processes have become the key to survival in the global economy. The reliability of equipment and facilities used in a power system is an essential precondition of the energy transmission security. High voltage bushing breakdown is one of the major contributors to the transformer failures. Since the electrical design of the HV bushings is the most important part of their manufacturing process, finding an algorithm for the electrical design of bushings in an optimum way is very important. Bushing failure is one of the leading causes of transformer failures. The electrical design of capacitive grading bushings is one of the important parts of manufacturing of these kinds of bushings. Capacitive grading bushings contain embedded in their insulation core concentric conductive foils, which are isolated from each other. By adjusting the diameter and length of these cylinders, the electrical stress and voltage drop in the core and along its surface can be influenced by variation of the ratio of the partial capacitances between the conducting cylinders, [1]. The grading of ac-bushing is achieved from the capacitances that are formed between the grading foils and thus determined by the permittivity of the insulating material. HIGH VOLTAGE BUSHINGS Bushings provide a point of interface such that the electric current can pass to and from the apparatus. The current is at some potential above ground and must be electrically insulated from the tank walls which are at ground potential. It can be thought of like a bridge where the potential is the length of the bridge and the longer the bridge the more support it must have such that it will not come into contact with the ground. The current path is the number of lanes. If the number of lanes are reduced on part of the bridge under heavy traffic flow, a multi-car pile up will occur. The two key factors are: 1) Insulating System to prevent a failure mode of over voltage. 2) Conductor Path to prevent a failure mode of over current. Over voltage will cause a flash over in the insulation and over current will cause overheating in the conductor due to I^2 * R losses. Figure 9: Diagram of typical high voltage bushings General Types: High-voltage bushings for use on transformers and breakers are made in several principal types, as follows: Composite Bushing.- A bushing in which insulation consists of two or more coaxial layers of different insulating materials. Compound-Filled Bushing.-A bushing in which the space between the major insulation (or conductor where no major insulation is used) and the inside surface of a protective weather casing (usually porcelain) is filled with a compound having insulating properties. Condenser Bushing.- A bushing in which cylindrical conducting layers are arranged coaxially with the conductor within the insulating material. The length and diameter of the cylinders are designed to control the distribution of the electric field in and over the outer surface of the bushing. Condenser bushings may be one of several types: Resin-bonded paper insulation; Oil-impregnated paper insulation; or Other. Dry or Unfilled Type Bushing.- Consists of porcelain tube with no filler in the space between the shell and conductor. These are usually rated 25 kV and below. Oil-Filled Bushing. A bushing in which the space between the major insulation (or the conductor where no major insulation is used) and the inside surface of a protective weather casing (usually porcelain) is filled with insulating oil. Oil Immersed Bushing.- A bushing composed of a system of major insulations totally immersed in a bath of insulating oil. Oil-Impregnated Paper- Insulated Bushing.- A bushing in which the internal structure is made of cellulose material impregnated with oil. Resin-Bonded, Paper- Insulated Bushing.- A bushing in which the major insulation is provided by cellulose material bonded with resin. Solid (Ceramic) Bushing.- A bushing in which the major insulation Is provided by a ceramic or analogous material. Bushing Failures Operating records show that about 90 percent of all preventable bushing failures are caused by moisture entering the bushing through leaky gaskets or other openings. Close periodic inspection to find leaks and make repairs as needed will prevent most outages due to bushing failures. Such an external inspection requires little time and expense and will be well worth the effort. High-voltage bushings, if allowed to deteriorate, may explode with considerable violence and cause extensive damages to adjacent equipment. Flashovers may be caused by deposits of dirt on the bushings, particularly in areas where there are contaminants such as salts or conducting dusts in the air. These deposits should be removed by periodic cleaning. Figure 10: Picture of High Voltage Bushing that has failed due to penetration of moisture One of the failures can also be a dielectric failure occurring with the paper insulation punctured through from the center draw rod, at a location about one third of the way down from the top terminal, to the grounded capacitance tap. HOW DOES THE BUSHINGS WITHSTAND THE STRESSES? The bushings must contain many layers of capacitors to grade the voltage down evenly from the potential at the centre conductor to ground potential. These capacitors are made up of many layers of paper and foil and usually filled with an insulating fluid such as oil. These layers of insulation can be checked by measuring the power factor of the bushing when the parent apparatus is out of service [2]. While the parent apparatus is in service, an infrared camera can be used to check for low oil levels. The oil level relates to the insulation quality of the grading capacitors. Infrared method will only work when the parent apparatus produces heat because it relies on the thermal mass difference between the fluid and the void at the top of the bushing. Bushings in transformers are ideal examples due to the heat produced by losses in the windings and core. The capacitor core of high voltage bushing is widely used to decrease the electric stress and to avoid field centralization where the high voltage lead drill through the tank wall of transformer. The floating potentials of capacitor core can be calculated with several methods[6], that are, the minimized energy algorithm, the partial capacitance algorithm and the electric charge conservation algorithm[6]. Some times dummy dielectric constant method are also used to solve the failure problems. When the electric flux line leaves higher dielectric constant region to lower dielectric constant region, if the ratio of higher dielectric constant to lower dielectric constant is much larger than 1, then it is nearly vertical on the interface in low dielectric constant material. Stress Analysis For the simulation we have tried two arrangements. First, the high voltage conductor is insulated by one large thick layer of silicone from the porcelain outer layer, which is held in place by two metal flanges at ground potential. Secondly, a capacitive graded arrangement where the conductor is insulated by several layers of silicone of varying axial length separated by thin layers of foil (form a large capacitor), again with two flanges at ground potential holding the structure in place. A voltage of 132KV is supplied to the conductor. The results presented below show the stress distribution where to distribute the stress uniformly the geometry of the structure has been altered. It is expected that with the two arrangements the distribution of the stress will vary greatly. Figure 11: Distribution of stress for first arrangement on bushing Figure 12: Distribution of stress for capacitively graded bushing arrangement In the first arrangement the electric stress is concentrated around the surface of the conductor, and the metal flange. While the other regions are under considerably less stress. The result is consistent with known theory. This is inefficient use of the insulation, as the wear of the insulation is not even. It is thus necessary to find a more desirable arrangement. Figure 12 shows the result of a capactively graded arrangement. Not only is the stress distributed more uniformly throughout the insulation, ensuring maximum efficiency and long life span, though the concentration is also reduced. This is the optimal design for high voltage bushings and is currently used in many high voltage applications. Again the result found is consistent with theory, as capacitive grading is vastly used to distribute stress uniformly. Conclusion High Voltage Bushings The Electric Stress has been determined for two different bushing arrangements using finite element analysis. The capacitive grading arrangement was found to be the best at distributing , and minimizing the concentration of stress. The results obtained agree with theory, and are applied throughout the industry.

Feasibility Report Essay examples -- essays research papers

Abstract   Ã‚  Ã‚  Ã‚  Ã‚  The purpose of this report is to determine whether it would be feasible for the Style Shop to add a computerized register to the store. The Merchandising Society is the largest club on F.I.T.’s campus. It provides the opportunity for its members to enhance their college experience at the Fashion Institute of Technology. Its members are dedicated to gaining exposure to the fashion industry first-hand through running a business, visiting companies worldwide, and volunteering services to the community. The club is responsible for operating a successful on-campus boutique, the Style Shop. The store offers the unique opportunity for FIT students, faculty and alumni to sell their original creations on a consignment basis. This not only allows students to earn recognition and profit, it enables Merchandising Society members to gain experience in buying, product development, marketing, finance, customer relations, management, visual merchandising, and website development. The Style Shop offers students the chance to develop a sharper awareness of group dynamics, build professional relationships, and actively participate in our college education. Currently the store uses a non-computerized register. There is no computerized inventory or bar codes used. Everything is done by hand. The addition of a computer would not only help keep track of all purchases by time, it would allow for the finance team to plan sales and monitor loss. The Style Shop uses a budget handed out by FITSA to fund purchases and stock for the store. This budget would be used to purchase a computer. It is highly feasible that the Style Shop purchases a computer and a register program. Introduction Purpose The purpose of this report is to determine the feasibility of adding a computerized register to the Style Shop team. Problem During the 2001/02 school year the Merchandising Society has over 180 active members. The store currently has no regulated computerized system. Inventory and tickets are all manually printed. By adding a computer to the store, inventory and sales could be more easily monitored. The computer would also serve as a ticket printer and finance station. Scope The addition of a computerized register would make the flow of goods in and out of the Style Shop easier. By adding a computer to the store each Merchandising Society member would h... ...h day. They will also be in charge of closing all curtains at night so that passers-by cannot see the computer in an empty store. Summer/Winter   Ã‚  Ã‚  Ã‚  Ã‚  When the Style Shop is not in operation the computer will be disconnected and stored in the Style Shop closet on the 7th Floor of the A-Building. This closet is only accessible to Style Shop Managers. Conclusion   Ã‚  Ã‚  Ã‚  Ã‚  The Style Shop is a growing student run boutique on F.I.T.’s campus. Each semester the store’s sales increase. The store needs a better way to track sales and inventory. By purchasing a computer Managers would be able to effectively track sales, inventory, and expenses. The total cost for the computer and register system is just under $2000.00. The money to purchase the computer/register would come out of the Style Shop budget given to the store by F.I.T.S.A. Recommendations   Ã‚  Ã‚  Ã‚  Ã‚  The Style Shop is an expanding establishment at the Fashion Institute of Technology. The addition of a computerized register would increase productivity within the store. It is recommended that the Style Shop use their budget and purchase a computer and a point of sale

Interview Skills Essay

1. List three key components involved in the communication process. †¢Sender (encoder). †¢Channel (Message). †¢Receiver (Decoder). 2. Identify three key characteristics of effective communication and briefly explain their impact on the communication process. Openness is a key characteristic of communication, as by listening with an open mind and showing genuine interest, the relationship and trust between the client and counsellor grows. Openness with body language is also important, as it lets the client know you are being honest and congruent. Empathy is another important characteristic, as by being empathetic you are concerned, understand, and care for the client thereby making a warm, friendly environment that is safe for the client to be able to talk freely. Thirdly, positiveness is important in communication. Using positive rather than negative messages, both verbal and non-verbal, shows the client that you respect them, their beliefs and believe in their ability to gain personal awareness and growth. 3. In the communication processes between a client and a counsellor, barriers may be present. List three specific communication barriers. †¢Environment. †¢Timing. †¢Perceptions. 4. Take one of the communication barriers given in your answer to the question above, and briefly describe how you would apply strategies to overcome these barriers. Environmental factors can be a barrier to listening as outside noise, telephones and even other people talking can distract you from getting a clear message and understanding of what the client is saying. To avoid this clients should be seen in a fairly soundproof room, with the windows and door shut to cut out excess noise. Also if possible, your phone should be on silent, so as not to distract either yourself or your client’s line of thought. 5. List two basic micro-skills of counselling and briefly describe how they can be used to facilitate the relationship between counsellor and client. To facilitate a good client and counsellor relationship, the use of active listening is very important so as the client feels they are heard, understood and respected. The counsellor needs to focus on what is being said, as well as how it is said, so they get a clear understanding. The counsellor also has to not let listening barriers distract them or the client. Barriers can include; judging, filtering, day dreaming or environmental factors. Paraphrasing is another micro-skill that builds a good rapport. By the counsellor picking the most important details and reflecting them back to the client, they are clarifying what has been said and the client knows that the counsellor is listening and understands what they are saying. Paraphrasing also help build trust and promotes sharing. 6. List one advanced micro-skill of counselling and briefly explain how it can be used in the counselling process. One advanced micro-skill of counselling is to challenge the client. This is used in the counselling process to assist making the client aware of faulty thinking, self-limiting and destructive behaviours and beliefs. It is very important though, to only use this micro-skill once the counsellor has built a good relationship with the client, and then, it should only be used where really necessary. Then with this new awareness, hopefully, the client is open to explore more positive beliefs, thinking and behaviours.

Einstein essays

Einstein essays Einsteins theories all came about from his curiosity as a child, he could not imagine what sitting on a beam of light would be like, and so he continued to imagine different possibilities until he came up with one that stuck true. His perseverance to find knowledge allowed the world to understand the universe better. And his theories about time travel have sparked many writers creativity. Another theory, led to the decimation of Hiroshima and Nagasaki. Picasso at the Lapin Agile is based on the idea of Einstein and Picasso meeting and debating their ideas. Then Elvis comes into the scene through time travel and reflects on the effects that the two had on the century. Although Einsteins ideas were amazing and great they led to the terrible invention of the atom bomb. Even today, we feel this regret as we enforce non-proliferation. Einstein himself was very interested in politics in Why Socialism? he wrote: Is it advisable for one who is not an expert on economic and social issues to express views on the subject of socialism? I believe for a number of reasons that it is.... we should be on our guard not to overestimate science and scientific methods when it is a question of human problems; and we should not assume that experts are the only ones who have a right to express themselves on questions affecting the organization of society (monthlyreview.org/598einst.htm) He had previously had a discussion with Freud on War when it was suggested by the League of Nations. Most of his political ideas are very idealistic as in accordance with the opinion of the day: human beings are not condemned, because of their biological constitution, to annihilate each other or to be at the mercy of a cruel, self-inflicted fate. As in Steve Martins play, Germaine comments in her prediction that: Cruelty will be perfected. This is in no doubt a reference to atom bo...

Weapons Of Mass Destruction Essays

Weapons Of Mass Destruction Essays Weapons Of Mass Destruction Essay Weapons Of Mass Destruction Essay Weapons Of Mass Destruction ARTCLE 1 The issue of weapons of mass destruction has always been one that intrigued me. I have believed for the longest time that more attention needed to be placed on the subject, and the effectiveness of our ability to control who, or whom has what. More and more nations are building and stockpiling these weapons for years, so when National Geographic came out with the article Weapons of Mass Destruction (an ominous new chapter opens on the twentieth century?s ugliest legacy), I was enthused to say the least. The inspiration for the article came about after a mock scenario by the United States military, which showed America?s vulnerability, and ill preparedness for such an attack. The information for the article suffered a setback after the events of September 11, and a dragnet was put over the world of WMD. Still the article proved to be very informative, and eye opening. The author, Lewis M. Simons did a good job of detailing particular problems besetting why weapons of mass destruction exist in the first place. The article attempts to convey the senses, of fear, pain, and hopelessness by way of gripping tales and pictures. One picture in particular was very good article, people, way, one, world, weapons, think, simon, job, cities, about, wmd, say, particular, forms, across, very, various, try, subject, sense, really, put, population, place, pain, out, mass, liked, least, lagos, it?s, including, hyderabad, good

George A. Custer - American Indian Wars

George A. Custer - American Indian Wars George Custer - Early Life: The son of Emanuel Henry Custer and Marie Ward Kirkpatrick, George Armstrong Custer was born at New Rumley, OH on December 5, 1839. A large family, the Custers had five children of their own as well as several from Maries earlier marriage. At a young age, George was sent to live with his half-sister and brother-in-law in Monroe, MI. While living there, he attended McNeely Normal School and did menial jobs around the campus to help pay for his room and board. After graduating in 1856, he returned to Ohio and taught school. George Custer - West Point: Deciding that teaching did not suit him, Custer enrolled at the US Military Academy. A weak student, his time at West Point was plagued by near expulsion each term for excessive demerits. These were usually earned through his penchant for pulling pranks on fellow cadets. Graduating in June 1861, Custer finished last in his class. While such a performance normally would have landed him an obscure posting and a short career, Custer benefited from the outbreak of the Civil War and the US Armys desperate need for trained officers. Commissioned a second lieutenant, Custer was assigned to the 2nd US Cavalry. George Custer - Civil War: Reporting for duty, he saw service at the First Battle of Bull Run (July 21, 1861) where he acted as a runner between General Winfield Scott and Major General Irvin McDowell. After the battle, Custer was reassigned to the 5th Cavalry and was sent south to participate in Major General George McClellans Peninsula Campaign. On May 24, 1862, Custer convinced a colonel to allow him to attack a Confederate position across the Chickahominy River with four companies of Michigan infantry. The attack was a success and 50 Confederates were captured. Impressed, McClellan took Custer onto his staff as an aide-de-camp. While serving on McClellans staff, Custer developed his love of publicity and began working to attract attention to himself. Following McClellans removal from command in the fall of 1862, Custer joined the staff Major General Alfred Pleasonton, who was then commanding a cavalry division. Quickly becoming his commanders protà ©gà ©, Custer became enamored with flashy uniforms and was schooled in military politics. In May 1863, Pleasonton was promoted to command the Cavalry Corps of the Army of the Potomac. Though many of his men were alienated by Custers showy ways, they were impressed by his coolness under fire. After distinguishing himself as bold and aggressive commander at Brandy Station and Aldie, Pleasonton promoted him to brevet brigadier general despite his lack of command experience. With this promotion, Custer was assigned to lead a brigade of Michigan cavalry in the division of Brigadier General Judson Kilpatrick. After fighting the Confederate cavalry at Hanover and Hunterstown, Custer and his brigade, which he nicknamed the Wolverines, played a key role in the cavalry battle east of Gettysburg on July 3. As Union troops south of the town were repulsing Longstreets Assault (Picketts Charge), Custer was fighting with Brigadier General David Greggs division against Major General J.E.B. Stuarts Confederate cavalry. Personally leading his regiments into the fray on several occasions, Custer had two horses shot out from under him. The climax of the fight came when Custer led a mounted charge of the 1st Michigan which stopped the Confederate attack. His triumph as Gettysburg marked the high point of his career. The following winter, Custer married Elizabeth Clift Bacon on February 9, 1864. In the spring, Custer retained his command after the Cavalry Corps was reorganized by its new commander Major General Philip Sheridan. Participating in Lt. General Ulysses S. Grants Overland Campaign, Custer saw action at the Wilderness, Yellow Tavern, and Trevilian Station. In August, he traveled west with Sheridan as part of the forces sent to deal with Lt. General Jubal Early in the Shenandoah Valley. After pursuing Earlys forces after the victory at Opequon, he was promoted to divisional command. In this role he aided in destroying Earlys army at Cedar Creek that October. Returning to Petersburg after the campaign in the Valley, Custers division saw action at Waynesboro, Dinwiddie Court House, and Five Forks. After this final battle, it pursued General Robert E. Lees retreating Army of Northern Virginia after Petersburg fell on April 2/3, 1865. Blocking Lees retreat from Appomattox, Custers men were the first to receive a flag of truce from the Confederates. Custer was present at Lees surrender on April 9, and was given the table on which it was signed in recognition of his gallantry. George Custer - Indian Wars: After the war, Custer reverted back to the rank of captain and briefly considered leaving the military. He was offered the position of adjutant general in the Mexican army of Benito Jurez, who was then battling Emperor Maximilian, but was blocked from accepting it by the State Department. An advocate of President Andrew Johnsons reconstruction policy, he was criticized by hardliners who believed he was attempting to curry favor with the goal of receiving a promotion. In 1866, he turned down the colonelcy of the all-black 10th Cavalry (Buffalo Soldiers) in favor of the lieutenant colonelcy of the 7th Cavalry. In addition, he was given the brevet rank of major general at the behest of Sheridan. After serving in Major General Winfield Scott Hancocks 1867 campaign against the Cheyenne, Custer was suspended for a year for leaving his post to see his wife. Returning to the regiment in 1868, Custer won the Battle of Washita River against Black Kettle and the Cheyenne that November. George Custer - Battle of the Little Bighorn: Six years later, in 1874, the Custer and the 7th Cavalry scouted the Black Hills of South Dakota and confirmed the discovery of gold at French Creek. This announcement touched off the Black Hills gold rush and further heightened tensions with the Lakota Sioux and Cheyenne. In an effort to secure the hills, Custer was dispatched as part of a larger force with orders to round up the remaining Indians in the area and relocate them to reservations. Departing Ft. Lincoln, ND with Brigadier General Alfred Terry and a large force of infantry, the column moved west with the goal of linking up with forces coming from the west and south under Colonel John Gibbon and Brigadier General George Crook. Encountering the Sioux and Cheyenne at the Battle of the Rosebud on June 17, 1876, Crooks column was delayed. Gibbon, Terry, and Custer met later that month and, based on a large Indian trail, decided to have Custer circle around the Indians while the other two approached with the main force. After refusing reinforcements, including Gatling guns, Custer and the approximately 650 men of the 7th Cavalry moved out. On June 25, Custers scouts reported sighting the large camp (900-1,800 warriors) of Sitting Bull and Crazy Horse along the Little Bighorn River. Concerned that the Sioux and Cheyenne might escape, Custer recklessly decided to attack the camp with only the men on hand. Dividing his force, he ordered Major Marcus Reno to take one battalion and attack from the south, while he took another and circled around to the north end of the camp. Captain Frederick Benteen was sent southwest with a blocking force to prevent any escape. Charging up the valley, Renos attack was stopped and he was forced to retreat, with Benteens arrival saving his force. To the north, Custer too was stopped and superior numbers forced him to retreat. With his line broken, the retreat became disorganized and his entire 208-man force was killed while making their last stand. Selected Sources PBS: George A. CusterCuster in the Civil WarBattle of the Little Bighorn