Submarine Service Research Articles

Capital reserve calculation analysis of operational risk in submarine cable service portfolio

This study analyzes the amount of capital reserves required for the Submarine Cable Service PT AAA to mitigate the risk of delays in completing work without disrupting the company's cash flow. Data used in this paper is the operational loss of delay work in the Submarine Cable Service portfolio from 2016 to 2019. The method and analysis used in this paper are the Monte Carlo simulation to calculate Operation Risk Variance (OpVar) by analyzing the distribution of severity and frequency. The result of the study shows that delayed work is the risk that has the most influence on the company's cash flow. PT AAA needs Rp 2.16 billion per event as capital reserve PT AAA to mitigate the risk of work delays in the Submarine Cable Service portfolio. Risk mitigation needs to minimize the potential loss are choosing the right partner in the operational process, scheduling the cable repair process, and securing the amount of capital reserve that has been counted.

Mortality of Enlisted Men Who Served on Nuclear-Powered Submarines in the United States Navy.

To describe the long-term mortality experience of a cohort of enlisted men who served on nuclear-powered submarines in the United States Navy and breathed recirculated filtered air for extended periods of time. In this historical cohort study we estimated standardized mortality ratios (SMRs) and used within-cohort Poisson regression analyses to address healthy worker biases. Three thousand two hundred sixty three deaths occurred among 85,498 men during 1,926,875 person-years of follow-up from 1969 to 1995. SMRs were reduced for most cause-of-death categories, prostate cancer had a twofold elevation. In within-cohort comparisons, prostate cancer mortality did not increase with duration of submarine service, but ischemic heart disease mortality increased 26% per 5 years of submarine service. Long periods of submarine service do not increase mortality in most cause-of-death categories. Increased mortality from ischemic heart disease likely reflects the effects of tobacco smoke.

Submarine medicine: An overview of the unique challenges, medical concerns, and gaps

Submariners face many challenges. For example, they “live where they work” and can be called to duty anytime. They have limited access to open space, natural settings, fresh air, fresh food, sunlight, privacy, exercise, and outside communication. They support a wider range of missions than occur aboard most other Navy vessels. At sea or on shore, submariners work long hours under conditions with little margin for error. They may traverse remote or disputed areas of the ocean far from rescue assets, and must remain vigilant for potential encounters with hostile forces, onboard fires, anomalies in the breathing atmosphere, leaks, undersea collisions, or radiation exposures. If any of these factors cause casualties, the Independent Duty Corpsman (with intermittent advice from shore-based medical personnel), must be ready to provide aid as long as necessary. The challenges of submarine service led to the growth of the unique field of submarine medicine, which has maintained an excellent record of health and safety. This review introduces the field of submarine medicine as practiced in the U.S. Navy, describing its major concerns, giving an overview of the operation of a submarine medical department, and identifying several medical gaps that researchers are working to fill. Submarine medicine already has a stellar record in terms of radiation and atmospheric safety and has made strides in fatigue management. Ongoing work will deliver improved psychological screening and support tools. This report summarizes developments in these and other areas of submarine medicine.

Revisiting the U.S. Navy Submarine Service Psychological Casualty Rate in World War II

Conclusions concerning how many World War II U.S. Navy submariners should be classified as psychiatric casualties have long been based on a pioneering study by two navy physicians, Commander Ivan Duff, MD, and Captain Charles Shilling, MD, that was first made public in the Journal of the American Psychiatric Association shortly after the war. This article seeks to show that, despite the longevity of the resulting published figures, there were serious problems in their approach and conclusions. The data set of the study was far from comprehensive, which, in turn, led to erroneous calculations generating a minuscule number—approximately two cases per 1,000 submariners—that in turn necessitated explanatory overreach. Reasons for the approach taken in the original work, and subsequent longevity of acceptance and celebration of the results produced, are then examined through the lens of confirmation bias.

Identifying Predictors of Pressurized Submarine Escape Training (PSET) Attrition.

Pressurized Submarine Escape Training (PSET) physically prepares submariners to safely escape a submarine at depth. Failure to complete PSET is not a submarine service disqualification. Serious medical incidents are rare, but the safety record tradeoff has been low throughput. From 2009 to 2015, only 34% of students screened completed PSET. Students may be medically screened out of the training altogether (disqualified), or dropout during the physical training (attrite). Training records from 12,122 U.S. Navy students were used to identify factors contributing to training disqualification and attrition. Multivariate logistic regression model predictors included demographic and screening items. Association to PSET disqualification included cold/congestion/cough (ORadj 12.34), limited duty status (ORadj 4.29), Physical Readiness Test failure (ORadj 3.37), pneumonia or bronchitis in last 2 years (ORadj 3.17) and nervousness or anxiety in tight spaces (ORadj 2.37). Basic Enlisted Submarine School students were more likely to be disqualified and attrite than other submariner groups, and black/African American (ORadj 1.53) students were more likely to attrite than white students. Only cold/congestion/cough (ORadj 1.52), trouble swimming (ORadj 1.53), and screening during cold/flu season (ORadj 1.28), were associated with training attrition. Recommendations to modify screening requirements are listed in conclusions.

Altered Sex Ratios in Offspring of U.S. Submariners Urban Legend or Fact - Do Submariners Have More Daughters?

There is a widespread and long-held belief in the submarine community that submariners father more daughters than the general population. The U.S. Sex Ratio at birth (males/females) has remained around 1.05 since the early 2000s. Limited evidence exists that certain environmental exposures including chemicals, heavy metals, radiation and g-forces may influence sex ratio at birth. A reduction in male births in a population has been associated with lower male fertility. A 1970 single site study showed a higher ratio of female offspring in personnel serving aboard U.S. Navy nuclear submarines than the general population. A 2004 study concluded that this was probably not true. However, this study was small, and did not evaluate the difference between children conceived during sea duty versus shore duty. They did note a higher chance of female offspring correlated with a longer time in the community, as well as an increased ratio in sonar technicians. These findings warrant further investigation. An electronic survey was e-mailed to submariners, after receiving required IRB and Navy approvals. Participants were asked birth year, year they entered submarine service, and how many children they had. For each child they were asked sex, child's birth year, mother's birth year, and whether they were on sea duty or shore duty at the time of conception. Those who were on sea duty at the time of conception were asked what their job was, where they were stationed and what type of submarine they were on. Those who were on shore duty at the time of conception were asked whether they were in contact with submarines on a regular basis, whether they were officer or enlisted, and what region they were stationed in for shore duty. Four thousand eight hundred responses were received with a total of 6,958 children included in the analysis. Respondents had a SR of 0.95 compared to 1.05 U.S. population in 2015 (p < 0.0001). Submariners on sea duty had a SR of 0.88 compared to 1.02 on shore duty (p = 0.007). Those who had regular submarine contact on shore duty had a SR of 0.72 compared to 1.17 in those who did not (p < 0.001). Geographical location during shore duty did show differences that were statistically significant (p = 0.018). Geographical location during sea duty did not show significant differences. No significant differences were seen for paternal age, maternal age, job during sea duty, type of submarine assigned to or time in community. The submariners surveyed reported greater numbers of daughters than the general population, especially when on sea duty or in regular contact with submarines during shore duty. Further study should be done to confirm results and explore possible etiologies of differences in sex ratio.

Metabolic syndrome and its components among Korean submariners: a retrospective cross-sectional study.

Metabolic syndrome (MetS) is a cluster of inter-related risk factors for cardiovascular disease and diabetes. Although submariners tend to be exposed to unhealthy environmental factors, such as a confined work environment, physical inactivity, and circadian disruption, little is known regarding whether the risks of MetS and its components are associated with submarine service. The present study aimed to evaluate the risks of MetS and its components among submariners. A total of 5090 subjects (513 submariners and 4577 non-submariners) were included in the present study. We calculated the age-standardized and age-specific prevalences of MetS. The associations between submarine service and the risks of MetS and its components were evaluated using logistic regression analysis after adjusting for age, service rank, and lifestyle factors. The age-standardized prevalences of MetS were 17.6 and 15.1% among submariners and non-submariners, respectively. Compared to non-submariners, submariners had higher risks of MetS (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.02, 1.68), low high-density lipoprotein cholesterol (OR 1.73, 95% CI 1.36, 2.20), and impaired fasting glucose (OR 1.46, 95% CI 1.21, 1.76). When we stratified the subjects according to physical activity, an increased risk of elevated blood pressure associated with submarine service was evident only in the subgroup with moderate or vigorous physical activity (P for interaction = 0.006). Submariners had higher risks of MetS and some MetS components, compared to non-submariners. These findings suggest that special efforts are needed to prevent and manage MetS among individuals who are expected to be exposed to submarine environment.

Presentation and management of traumatic pneumothorax in the deployed setting

AbstractPneumothorax is a potentially life-threatening complication of traumatic chest injury. Rapid assessment, recognition and management in the deployed pre-hospital and hospital environment is essential, as complications such as hypoxia and cardiovascular collapse require urgent intervention. This article aims to describe the evidence for presentation, management and occupational aspects of traumatic pneumothorax, which can prevent selection into specialist roles such as diving, submarine service and aviation.

Analysis of factors related to failure in the pressure test: a six-year experience in Taiwan

The Republic of China Navy instituted the pressure test as one of the selection tools for diving troops and submarine crews. We analyzed factors associated with failure in the pressure test. This was a retrospective cohort study designed to investigate pressure test failure in Navy recruits between January 2010 and August 2015. The recruits received pressurization in a hyperbaric chamber to a simulated depth of 112 feet of seawater (fsw) at a rate of 25 fsw/minute. Data describing trainee demographics, disease history, causes and depth of failure, as well as type of injury, were extracted from case notes and facility databases for statistical analysis. Of 3,608 trial cohorts, there were 435 failures, with an overall failure rate of 12.06%. About 95% of these failure trials were within a simulated depth of 60 fsw. Fifty-seven (57) failures did not record causes of failure. Among the other 378 failures, the most commonly identified causes were ear barotrauma (365 trials, 96.56%) and sinus barotrauma (10 trials, 2.65%). Statistical analysis revealed that recent upper respiratory tract infection, allergic rhinitis, and cigarette smoking were all significantly associated with higher incidence of middle ear barotrauma. Our results suggest that pressure testing to a depth of 60 fsw is effective in disqualifying personnel entering diving and submarine service. Recent infection of the upper respiratory tract, allergic rhinitis and cigarette smoking are risk factors for middle ear barotrauma, resulting in failure of the pressure test.

Book Review: The Silent Deep: The Royal Navy Submarine Service since 1945. Peter Hennessy and James Jinks

Book Review: <i>The Silent Deep: The Royal Navy Submarine Service since 1945</i>. Peter Hennessy and James Jinks

The association between submarine service and multimorbidity: a cross-sectional study of Korean naval personnel

ObjectiveWe aimed to estimate the prevalence of multimorbidity (≥2 chronic health problems) among Korean submariners and to evaluate the association between submarine service and multimorbidity and disease burden.Study design and...

Risk factors for dermatitis in submariners during a submerged patrol: an observational cohort study

ObjectiveThe aim of this pilot study was to determine risk factors, including Staphylococcus aureus nasal carriage, for dermatitis in submariners during a submarine patrol.Participants and methods36 submariners undertaking a submerged...

The silent deep: the Royal Navy submarine service since 1945. By Peter Hennessy and James Jinks

The silent deep: the Royal Navy submarine service since 1945. By Peter Hennessy and James Jinks

The Submarine Service: Cross-Connect Open to the Allied System

The Submarine Service: Cross-Connect Open to the Allied System

The assessment of bone mineral content and density of the lumbar spine and proximal femur in US submariners.

The submarine environment is unique in that there is limited space and no sunlight, which may negatively affect skeletal health and lead to accelerated bone loss, osteoporosis, and fractures. The primary purpose of this study was to determine whether there was an association with submarine service, specifically time spent at sea, and bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine and dual proximal femur (total hip and femoral neck) measured by DXA. This is a cross-sectional study of 462 submariners 20-91years old. Variables included in the analysis were age, height, race, alcohol intake, tobacco use, fracture history, conditions, and medications known to cause bone loss and osteoporosis and submarine service. Of the submarine service predictors, only serving onboard a diesel submarine was determined to be independently associated with a reduction in BMD of the total hip and femur neck, while no submarine service predictor increased the odds of having low BMD. In submariners 50+ years old, the age-adjusted prevalence of osteopenia was 15.7% (lumbar spine) and 40.4% (femur neck), while the prevalence of osteoporosis was 4.8% (lumbar spine) and 4.2% (femur neck), rates that did not differ from NHANES 2005-2008. In submariners <50years old, 3.1% was below the expected range for age. The proportion of submariners 50+ years old that met the FRAX criteria for pharmacological treatment was 12%. Intermittent periods of submergence that can range from a few days to 3+ months do not appear to compromise skeletal health differently than the general population.

A Bosphorus Submarine Passage and the Reinvention of Neurosurgery

One of the major themes characterizing the emergence of modern neurosurgery has been the concept of technology transfer and the application of a broad spectrum of revolutionary elements of technology from both physical and biological science. These transference applications are now apparent in modern neurosurgery as it is practiced on all continents of the globe. More than 3 decades ago, these ideas that now have come to fruition were in states of formulation. This article describes and further documents one such fertile cauldron of ideas and practical realities--the United States Navy Nuclear Submarine Service and its role and affect on the life and professional career of an academic neurosurgeon who was active in areas of progress as modernity was established for the early 21st century.

An Unusual Pattern of CPAP Usage

An Unusual Pattern of CPAP Usage

The Submarine: A Cultural History from the Great War to Nuclear Combat, by Duncan Redford

This book is distinctively different from the usual run of books about naval history in general or of the submarine service in particular. From the start it adopts a ‘cultural’ approach to the submarine, rather than an operational one, that is perhaps surprising given the fact that the author is himself a former submariner. The book starts with a review of reviews—naval ones, that is—and especially the fleet reviews of 1897 for Queen Victoria and of 1977 for Queen Elizabeth II. There were no submarines present in the first and lots in the second. Comparing these two reviews with others, the latest being at the time of the Trafalgar bicentenary, Duncan Redford sets the scene for a detailed consideration not so much of the way in which the submarine developed technologically and operationally but more as an element in the public and service imagination. He shows the ways in which different audiences ‘constructed meaning’ (a term frequently used in this book) for the submarine and how that meaning changed as technology developed and the context shifted. His major point is that conceptions of the submarine reflected a slow transition from their being considered ‘underhand, unfair and damned unEnglish’ craft that only the strategically and morally weak would use to their fullest effect, to being accepted, eighty years later, as crucial elements in a fleet that served the highest purposes.

Understanding Good Coping: A Submarine Crew Coping with Extreme Environmental Conditions

The present study is based on in-depth interviews with 12 Israeli submarine crew members. The study examines various aspects of coping with submarine service and its unique characteristics from the crew members’ points of view. Content analysis reveals the following salient themes: First, positive perception of submarine service: positive thinking, optimism and sense of humor, accompanied by cynicism. Second, the submarine team is characterized by high moral standards, high team spirit and a sense of the importance of the service. Third, social relationships are characterized by avoidance of conflicts, while maintaining a good atmosphere and high social cohesion. Fourth, crew members perceived separation from home, friends and daily life as the most difficult aspects to deal with. Fifth, they perceived the submarine as dangerous place but reduced aspects of danger by developing a sense of trust in their submarine and in their ability to control potential dangers. Study results are discussed in light of relevant theories. This study is unique in that it was a rare opportunity to get a glimpse into the unknown world of an Israeli submarine crew which is mostly secret and not open to researchers.

Democracy in a Drum: Social Relations on American Submarines During the Second World War

Describing life on a us submarine war patrol, one veteran submariner enlists the reader to, 'imagine yourself crammed inside a cold, clammy, inescapable steel cylinder with eighty-five smelly souls for a period of thirty-to-sixty days'. l For most people it is not an inviting image, and yet submarine service during the Second World War evokes a certain glamour. As a fighting unit submarine crews were seen as in some ways unique...