Navy Vessel Research Articles

Investigation on the Structural Damage of a Double-Hull Ship, Part I – Ship Collision

Marine structure is designed to be able to resist various load conditions during its operational period. However, in design process, analysis of accidental loads, such collision and grounding, has not been included for both merchant ship and navy vessel. These loads are spontaneous and several remarkable casualties may occur after collision and grounding taking place. The aim of this paper is to investigate structural damage on the target ship during collision and grounding considering on failure process and damage extent. This work is divided into two parts which in the Part I, ship collision is discussed, and the Part II deals with interaction of ship structure with sea bottom in grounding. In the Part I - Ship Collision, condition of the side structure is observed, including the inner hull after impact which is considered as the key to determine safety condition of ship cargo. A passenger ship is modelled in this work and designated as the struck ship which will be struck by the striking ship in collision process. Resistance capability of the double-hull structure against side collision is evaluated. Virtual experiment is conducted by nonlinear finite element method in order to calculate several dynamic collision scenarios which are built based on physical parameter, namely target location. Based on calculation results, damage on the side hull is found to be highly influenced by relative height between two ships prior collision. Crashworthiness criteria are summarized and result tendency indicates that in the mentioned location, the striking ship produces larger tearing on the lower part of the struck ship. Contribution of each collision scenario on the resultant force is presented in later part in order to observe structural behaviour of each determined location in encountering side collision.

Ship Adaptive Course Keeping Control With Nonlinear Disturbance Observer

This paper investigates a scheme to reject the unknown bounded time varying external disturbance for a ship course keeping control system. A mathematical model of a steering system is derived considering nonlinear features that could affect the control design process. The feedback linearization approach is adopted to simplify the nonlinear system. The adaptive sliding mode control algorithm and nonlinear disturbance observer method are developed for course keeping maneuvers in vessel steering and for providing robust performance for the environment disturbance and rudder dynamics. Furthermore, the overall stability conditions of the presented controllers are analyzed by Lyapunov’s direct method. Finally, the effectiveness of the controllers is illustrated by the simulation results on a navy vessel with twin rudders.

Glacier sediment plumes in small bays on the Danco Coast, Antarctic Peninsula

AbstractGlacimarine sedimentary environments provide information about climate and oceanographic evolution in the Antarctic Peninsula. This study focuses on the generation of sediment plumes from glaciers. In February 2013 and 2014, two Chilean Antarctic Institute (INACH) Scientific Expeditions were carried out on board the Chilean Navy vessel Aquiles. Five relatively small bays were visited: Curtiss Bay, Recess Cove, Beaupre Cove, Paradise Harbour/Oscar Cove and Salvesen bay. Hydrography and turbidity profiling was carried out up to 100 m depth using an SBE19 Plus-V2 CTD-T. In general, the results showed sediment plumes at two levels: an upper plume from the surface up to 10 m deep and a deeper plume at 40–100 m. These plumes were identified by higher turbidity concentrations and their association with colder water tongues. The deeper plume tended to remain below the 1027.5 kg m-3 isopycnal and extended ~4 km from the glacier, maintaining its shape with a gradually decreasing particle concentration. This longitudinal extension was favoured by ebb tides. The characteristics of the sediment plumes may be influenced by the heat input from water masses. The contribution of the sediments from these small bay systems could play an important role in regional sedimentary processes.

Ship forward speed loss minimization using nonlinear course keeping and roll motion controllers

Ship forward speed can be significantly reduced by the added resistance generated by the effect of wave motion. Controlling the ship motions using the actuators available can reduce this speed loss. The use of ship rudder for both steering and roll reduction is considered here with the aim of reducing speed loss. The added resistance due to the wave effects is calculated by the extended radiated energy method and the added resistance in calm water, caused by steering, is also included. In order to judge the speed loss that occurs, a performance index is proposed to quantify the percentage of speed loss. A control system based on the sway–yaw and the roll dynamics is proposed to reduce the ship speed loss. The controller comprises two sliding mode controllers developed using ship dynamic models. Finally, an example of the control of a navy vessel with two rudders is presented to demonstrate the effectiveness of the proposed solution.

Sleep Duration in Rough Sea Conditions.

Environmental motion can affect shipboard sleep of crewmembers. Slamming and similar harsh motion may interfere with sleep, whereas mild motion and sopite syndrome may enhance sleep. If sleep needs vary by sea condition, this factor should be considered when assessing human performance at sea. The goal of this study was to assess sleep duration in different sea conditions. Crewmembers (N = 52) from a U.S. Navy vessel participated in the study while performing their normal daily schedule of duties. Sleep was assessed with wrist-worn actigraphy. Motion sickness and sopite syndrome were assessed using standardized questionnaires. In rough sea conditions, crewmembers experienced increased severity of motion sickness and sopite syndrome compared to their ratings during calmer sea conditions. Crewmembers slept significantly longer during sea state 5-6 compared to sleep on days with sea state 4 (25% increase) and sea state 3-4 (30% increase). Specifically, daily sleep increased from 6.97 ± 1.24 h in sea state 3-4, to 7.23 ± 1.65 h in sea state 4, to 9.04 ± 2.90 h in sea state 5-6. Although the duration of sleep in rough seas increased significantly compared to calmer sea conditions, causal factors are inconclusive. Accumulated sleep debt, motion-induced fatigue, and sopite syndrome all may have contributed, but results suggest that motion sickness and sopite syndrome were the predominant stressors. If sleep needs increase in severe motion environments, this factor should be taken into account when developing daily activity schedules or when modeling manning requirements on modern ships.

Contractors as a Second Best Option: The Italian Hybrid Approach to Maritime Security

Initially based mainly on the use of Navy Vessel Protection Detachments (VPDs) paid by shipowners, Italian maritime security legislation also allows for the use of Privately Contracted Armed Security Personnel (PCASP) when VPDs are not available. Hence, Italy has adopted a hybrid antipiracy approach that entails two different forms of private sector involvement: the financing and partial control of public military forces by the maritime industry and the provision of armed security by PCASP, an option that includes Private Military and Security Companies (PMSCs). This opening to the commercial sector is significant as one of the first of its kind in a state that has adopted a tight monopoly over the provision of armed services and can be explained as the interplay between the willingness to respond to the needs of the maritime industry and a long-standing resistance against loosening state control over the use of force.

Assessment of a Novel Watchstanding Schedule on an Operational us Navy Vessel

One watchstanding schedule used in the US Navy is the modified 6-hr on/18-hr off, a 6-hr watch followed by an 18-hr non-watch period. In this four-section watchbill, rather than standing the same 6-hour period each day, two 3-hr watches are “dogged”, resulting in a day shorter than 24-hrs in length. We assessed the 6-hr on/18-hr off schedule to determine its affordance of rest/sleep and psychomotor vigilance, comparing it to a 3-hr on/9-hr off schedule. Results show the 3-hr on/9-hr off schedule is superior, affording 0.63 more hours of rest daily (p=0.054), 0.89 more hours of sleep daily (p=0.024), and decreased variability in psychomotor vigilance (i.e., reaction time and lapses) compared to the standard schedule (p<0.05). Variability of daily rest and sleep is also reduced (p<0.05). Subjective assessments between the 3-hr on/9-hr off and seven other watch schedules showed that participants preferred the 3-hr on/9-hr off schedule. The 3-hr on/9-hr off schedule yields better sleep hygiene, more stable performance and is well-accepted by crewmembers.

Improving Life Cycle Quality of Navy Vessel through Integrated Management Approach

The life cycle management of navy vessels quality is presented, and the quality of various phases in the navy vessels life cycle is academically described. On the management of phase quality, taking shipbuilding as an example, the definition of the phase quality is provided, requirements of comprehensive quality management are discussed, which include the total-staff participation, the whole process of management, comprehensive approach and concept of quality. On the integrated quality management of the navy vessels life cycle, the mode that staffs participating in the various stages of life cycle, and integrated requirements of ship design, modeling & simulation environment are proposed. Technical support and realization of the quality management of navy vessels life cycle are presented, which has laid the foundation for the realization of the quality management of navy vessel.

Application of Video Image Interpretation Technology in the Angular Distortion Measurement System

A new video image interpretation technology applied mainly to the angular distortion measuring system of navy vessel is developed in this paper. The video interpretation system incepts two video signals coming from two CCD of photoelectric self-collimation parallel optic equipment. Real-time video image processing and interpretation, as well as dynamic miss distance are achieved by using concurrent working mode, and the relatively distortion of vessel can be obtained by combining the two measurement results.

Extended radiated energy method and its application to a ship roll stabilisation control system

Large roll motions induced by sea waves can severely affect the ability of surface ships to perform their missions. The additional resistance caused by ship motions reduces ship speed, especially in moderate to high sea states. In addition, with increasing needs for energy savings and emissions reduction, the effect of added resistance on surface ship performance and control quality must be considered when a ship roll stabilisation control system is designed. As an application, a fin stabiliser system is developed with an advanced proportional-integral-derivative (PID) controller base using a genetic algorithm. A navy vessel is considered for demonstration purposes. Linear roll motions are controlled using active fins.

The rediscovery of HMS Investigator: Archaeology, sovereignty and the colonial legacy in Canada’s Arctic

HMS Investigator, the British Navy vessel that discovered the North-West Passage in 1850, helped to stake Britain’s claim to Arctic territory. Her crew’s colonial attitudes towards the Indigenous Inuit inhabitants of the region have been perpetuated in archaeological interpretations of the ship’s impact on local Inuit communities and in media coverage of the rediscovery of the ship by archaeologists in 2010, which framed the ship as a symbol of Canada’s Arctic sovereignty. As climate change continues to fuel international debates about the control of Arctic resources and to negatively impact the Arctic archaeological record, Arctic archaeology promises to become increasingly political. In the Canadian Arctic, a range of collaborative projects that bring together archaeologists and Inuit community groups to better understand the human history of the north have made important steps towards decolonizing our discipline and could ripple outwards to support Inuit demands for a voice in international debates about Arctic sovereignty. Should we choose, these projects could also work to change the way the past is mobilized and presented beyond archaeological circles, contributing more directly to social justice on a broader scale.

Marine biosecurity: The importance of awareness, support and cooperation in managing a successful incursion response

Shipping is almost certainly the most prevalent human-mediated transport vector for non-indigenous species (NIS) within the marine environment. The Royal Australian Navy (RAN) has long acknowledged the importance of sound environmental management and in recent years has taken a proactive approach to addressing risks associated with marine biosecurity. primarily as a result of biofouling on Navy vessel returning from overseas operations. This paper describes two case studies that highlight the effectiveness of the RAN marine biosecurity management framework in identifying an unwanted marine species on Navy vessels, and the successful biosecurity management program that ensued. In particular, the early detection and identification of a suspect NIS, the quick response to the discovery and the collaborative approach adopted between the RAN and the Government regulatory agency (Western Australian Department of Fisheries) charged with coordinating the incursion response serves as a model for how future incursion responses should be reported and managed.

The Importance of Remembering in Relation: Juxtaposing the Air India and Komagata Maru Disasters

In 1914, a ship named the Komagata Maru arrived off the coast of British Columbia carrying 376 would-be immigrants, mostly Sikh men from India desiring to settle permanently in the burgeoning colony of Canada. A public sentiment of concern about “Hindoo Invaders” and a discriminatory immigration policy caused the ship to be anchored for two months in the Vancouver harbour, during which time passengers were occasionally denied food and water. The ship was finally forced back to sea under threat from the weaponry of a Canadian navy vessel. At a first glance, this event seems to have little in common with the 1985 bombing of Air India Flight 182, a terrorist act commonly believed to have been committed by Sikh separatists fighting for an independent Khalistan, or Sikh homeland, in India. Yet in Anita Rau Badami’s novel Can You Hear The Nightbird Call? and Uma Parameswaran’s poem “On the Shores of the Irish Sea,” the Komagata Maru and Air India disasters are explicitly linked. In this paper, I explore the reasons these authors might want to encourage a wider public to remember these two events in relation. How might remembrance of one refract and reframe memories of the other? Ultimately, I turn to recent state-sponsored efforts to memorialize and offer reconciliation for the Air India and Komagata Maru atrocities to demonstrate how failing to remember these events in relation makes it is easier to cloak the overt racism underpinning both and to thus maintain the veneer of “Canada” as a haven for racial diversity. By contrast, if public memorials of one event were designed in such a way as to explicitly make links to the other, I argue, a wider public might come to recognize how the unresolved injustice of the Maru incident is deeply implicated in the cascading torrent of violent atrocities that contributed to the bombing of Air India Flight 182, a connection virtually impossible to draw from current state-sponsored efforts to memorialize either event.

함승조원의 거주성 향상을 위한 함정 환경진동기준 분석고찰

The shipboard working environment of navy vessel is very inferior to the ground working environment. For this reason, the crew of a navy vessel suffer from an occupational disease such as lumbar pain, hearing loss, etc. Although standard for navy vessel's environmental vibration is applied, the criterion of the environmental vibration is too high. So it doesn't help to improve habitability of crew. In this study, for improving its habitability of crew, the current vibration level of navy vessel was examined and the standard of navy vessel's environmental vibration was investigated.

One of Morgan's Men: Memoirs of Lieutenant John M. Porter of the Ninth Kentucky Cavalry (review)

Reviewed by: One of Morgan's Men: Memoirs of Lieutenant John M. Porter of the Ninth Kentucky Cavalry Stephen E. Towne (bio) One of Morgan's Men: Memoirs of Lieutenant John M. Porter of the Ninth Kentucky Cavalry. Edited by Kent Masterson Brown. (Lexington: University Press of Kentucky, 2011. Pp. xix, 300. $32.50 cloth) Historians of John Hunt Morgan's Civil War cavalry command have known of John M. Porter's memoir for many years as an archival document, but Kent Masterson Brown's ably annotated edition makes the work accessible to a wider audience. Porter, born in Butler County, Kentucky, in 1839, penned his memoir shortly after the end of the war, when his memory of events, names, and places was relatively fresh and his ardor for the Confederate "Lost Cause" still burned brightly. The memoir survives as a typescript undertaken in later years by unknown hands. Porter enlisted in the Rebel armed forces in early November 1861, and saw action in Kentucky, Tennessee, and northern Mississippi. Captured at the capitulation of Fort Donelson in February 1862, he gained release from Union captors by claiming he was a civilian. Making his way through the South, he found and joined John Hunt Morgan's cavalry command. Porter participated in the notable cavalry raids in Kentucky and Tennessee of 1862 and 1863 as a junior officer of the Ninth Kentucky Cavalry Regiment (CSA). Ordered to make a secret foray in the spring of 1863 into northern Kentucky with his cousin, Captain Thomas Henry Hines, to scout routes for Morgan's main body to follow later, Union troops surprised his small command and scattered it. Porter escaped, but was captured a few days later. Federal military authorities soon sent Porter to the Johnson's Island military prison on Lake Erie near Sandusky, Ohio. Turning from an account of derring-do and battlefield gallantry, Porter's tale becomes a story of miserable prison life buoyed by the hope of escape. An attempt to tunnel out failed, as did the attempt by Confederate [End Page 467] agents operating out of Canada to release the thousands of Rebel officers on the island by capturing shipping on the lake and attacking the U.S. Navy vessel that guarded the island. Porter's memoir makes clear that the inmates "were expecting [the Canada-based agents] and were prepared to do all in our power to aid in our escape" (p. 186). He languished in the prison for nineteen months. At last, Federal officials sent Porter and three hundred other Rebel officers through the lines and released them to Confederate authorities in February 1865. Porter chronicled his attempts to rejoin his regiment and continue the fight amid the collapsing Confederate military effort during that spring. When the Rebel armies surrendered, Porter and other Kentuckians returned home to begin life anew. Porter and his cousin Hines practiced law together until the former's death in 1884. Historians of Morgan's operations have employed the Porter memoir to good effect, as it provides many useful details on the raids and battles Morgan's forces fought. However, historians must be careful to weigh Porter's words carefully, as his zeal tilts the scales heavily in favor of a whitewash of his own actions and those of others in behalf of the Lost Cause. On one side, Porter is quick to condemn "Yankee" perfidy, the disloyalty of African American slaves who provided information to their U.S. army liberators, prison officers at Johnson's Island who (he claimed) deliberately made prisoners suffer from hunger and cold, and "traitorous" Kentuckians who supported the Union. On the other side, the Confederates were generous, warm, and loving; their exploits were "brilliant," and he excuses his deception that gained him release after Fort Donelson, the common practice of wearing U.S. Army uniforms over their Confederate ones, and the expropriation (theft) of horses as a permissible practice in time of war. Brown's editorial efforts are, with a couple exceptions, well done. For example, sharper copyediting in the endnotes would have noted that Morgan's Great Raid into Indiana and Ohio was in July, not June, of 1863. Notwithstanding these minor flaws, this edition of...

Real-Time Strain Monitoring of a Navy Vessel During Open Water Transit

In this work we describe the installation of a real-time, fiber-optic strain monitoring system aboard a US Navy vessel undergoing sea trials. The system is lightweight, unintrusive, corrosion resistant, and provides dynamic strain response measurements from direct current (DC) up to 360 Hz. Also described are the data acquisition and subsequent analysis. The goals of the study were to demonstrate a fiber-optic strain monitoring system under real world conditions and to better understand the source of deck cracking above an area housing mission-critical components. The results of the two-day trial indicate that there exist large stresses in the deck plate during normal ship operation. Based on the results, it is clear that ship maneuvers, slewing of the radar located on the deck plate, and insolation-related effects are not the primary source of the observed stress.

Outbreak of Acute Respiratory Disease Caused by Mycoplasma pneumoniae on Board a Deployed U.S. Navy Ship

We identified 179 cases of acute respiratory illness including 50 cases of radiographically confirmed pneumonia over the course of 4 months on a deployed U.S. Navy vessel. Laboratory tests showed Mycoplasma pneumoniae to be the etiological agent. This report represents the first published description of a shipboard outbreak of this pathogen.

Orthopaedic Care Aboard the USNS Mercy During Operation Unified Assistance After the 2004 Asian Tsunami

On December 26, 2004, a 9.0-magnitude earthquake occurred off the northwest coast of Sumatra, Indonesia. The subsequent tsunami caused unprecedented destruction throughout the Indian Ocean basin1. In eleven nations, millions were injured and/or displaced and, although estimates vary, as many as 300,000 lives may have been lost2-4. Within days after this natural disaster, hundreds of humanitarian organizations and thousands of military troops from several countries mobilized to offer assistance5-7. The U.S. military response came in the form of Operation Unified Assistance, a mission of humanitarian aid and disaster relief8. Within days, the U.S. Navy carrier strike group led by the USS Abraham Lincoln and the expeditionary strike group led by the USS Bonhomme Richard were sent to provide aid to heavily damaged areas. Numerous U.S. military aircraft were also dispatched to facilitate the safe movement of personnel, food, medicine, and drinking water9,10. In addition to providing immediate relief services, the U.S. Navy deployed a hospital ship to the region. The USNS Mercy departed San Diego, California, on January 5, 2005, en route to the Aceh province of Sumatra, Indonesia. The mission of the USNS Mercy was to conduct medical humanitarian aid and disaster relief operations in support of the government of Indonesia to reduce suffering and improve public health. The Mercy crew of health-care providers included medical and surgical staff from the U.S. Navy and officers from the U.S. Public Health Service. To augment the Navy Medical Corps, approximately 100 civilian volunteer physicians, nurses, and technologists from the non-governmental organization Project HOPE were included11, making this the first mission in history to utilize civilian medical personnel aboard a U.S. Navy vessel. From February 5 through March 16, 2005, the USNS Mercy provided …

Lessons Learned from Indonesia: An Outline

The U.S. response to the December 26, 2004 tsunami in Indonesia heralded modifications of our responses to previous natural disasters, modifications that were highly successful and should be refined and repeated. These included seamless hand-off of responsibility from a line response unit to medical; the use of civilian medical practitioners working closely with military and public health service personnel aboard a Navy vessel; close prior communication and planning with the local medical, governmental, and U.N. establishment ashore before the arrival of the military medical unit; and with both line and medical units working closely in support of established ashore U.N. agencies instead of performing independent actions. The success of this total approach was unquestioned, and the lessons learned should be utilized fully in planning future disaster responses, both foreign and domestic.

The measure and decision of technical risk in the development of naval vessels

The risks in development of navy vessels were explored. The resources of technical risk in the design and development of vessels were mentioned. It was pointed that technical risk dominated the other risk components. Based on the writers' understanding and experience from risk analysis and risk management to the development of a navy vessel, four measure indexes of technical risk were presented. The decision criteria and the rules corresponding to the indexes were established by the statistic information.