Safety, Volume 4, Issue 1 (March 2018) – 11 articles

In this paper, the adequacy of the legacy API 521 guidance on pressure relief valve (PRV) sizing for gas-filled vessels subjected to external fire is investigated. Multiple studies show that in many cases, the installation of a PRV offers little or no protection—therefore provides an unfounded sense of security. Often the vessel wall will be weakened by high temperatures, before the PRV relieving pressure is reached. In this article, a multiparameter study has been performed taking into consideration various vessel sizes, design pressures (implicitly vessel wall thickness), vessel operating pressure, fire type (pool fire or jet fire) by applying the methodology presented in the Scandpower guideline. A transient thermomechanical response analysis has been carried out to accurately determine vessel rupture times. It is demonstrated that only vessels with relatively thick walls, as a result of high design pressures, benefit from the presence of a PRV, while for most cases no appreciable increase in the vessel survival time beyond the onset of relief is observed. For most of the cases studied, vessel rupture will occur before the relieving pressure of the PRV is reached. Full article

The speed-reducing effect of speed humps during darkness is important to ensure a consistent speed reduction and a decreased probability of accidents during darkness. This study examined the effects of speed humps, compared with a control location, on a residential road in Sweden with light-emitting diode (LED) street lighting and a 30 km/h posted speed limit. Hypotheses tested were that: (I) vehicle speed is higher during daylight than in darkness; (II) speed at speed humps is lower than at control locations during both daylight and darkness; (III) speed at humps is higher during daylight; (IV) vehicle speed at humps is lower when luminance or visibility of the humps is greater; and, (V) the road environment of speed humps is perceived as being similar by drivers. The results showed that vehicle speed at the control location was negligibly higher (+0.3 km/h) during daylight than in darkness. Speed humps reduced driving speed by 20% when compared with the posted speed limit and the effect was not significantly different between daylight and darkness. Speed reduction for the three speed humps varied between 9% and 29% as compared with the posted speed limit. In this study, the LED road lighting that was placed directly above or in front of the hump achieved the highest luminance. This study could not reveal any significant differences in vehicle speed attributable to light conditions per se. Full article

Safety concerns are among the most prevalent deterrents for bicycling. The provision of adequate bicycling infrastructure is considered as one of the most efficient means to increase cycling safety. However, limited public funding does not always allow agencies to implement cycling infrastructure improvements at the desirable level. Thus, bicycle trip planners can at least partly alleviate the lack of adequate infrastructure by recommending optimal routes in terms of safety. The presented study provides a systematic review of 35 bicycle routing applications and analyses to which degree they promote safe bicycling. The results show that most trip planners lack corresponding routing options and therefore do not sufficiently address safety concerns of bicyclists. Based on these findings, we developed recommendations on how to better address bicycling safety in routing portals. We suggest employing current communication technology and analysis to consider safety concerns more explicitly. Full article

Commercial aviation is currently one of the safest modes of transportation; however, human error is still one major contributing cause of aeronautical accidents and incidents. One promising avenue to further enhance flight safety is Neuroergonomics, an approach at the intersection of neuroscience, cognitive engineering and human factors, which aims to create better human–system interaction. Eye-tracking technology allows users to “monitor the monitoring” by providing insights into both pilots’ attentional distribution and underlying decisional processes. In this position paper, we identify and define a framework of four stages of step-by-step integration of eye-tracking systems in modern cockpits. Stage I concerns Pilot Training and Flight Performance Analysis on-ground; stage II proposes On-board Gaze Recordings as extra data for the “black box” recorders; stage III describes Gaze-Based Flight Deck Adaptation including warning and alerting systems, and, eventually, stage IV prophesies Gaze-Based Aircraft Adaptation including authority taking by the aircraft. We illustrate the potential of these four steps with a description of incidents or accidents that we could certainly have avoided thanks to eye-tracking. Estimated milestones for the integration of each stage are also proposed together with a list of some implementation limitations. We believe that the research institutions and industrial actors of the domain will all benefit from the integration of the framework of the eye-tracking systems into cockpits. Full article

In any consideration of the operating condition, the age of a particular aircraft is a major factor. Much attention is focused on planes which are aged, that is, aircraft with chronological age or accumulated hours of use beyond a threshold. Being aged is a state, and should be distinguished from aging, which is a process of degradation with use. The degradation process starts at first flight and continues through time, with the rate being affected by aircraft design, patterns of use, and maintenance procedures. In this paper, the cycles, block hours and failures were recorded, and failure rates with accumulated use were calculated. A pattern of increasing failure rates with accumulated use (age) is observable, with improvement (decline in rate) at times of planned maintenance. The evidence supports the hypothesis that aging, that is increasing rates of failure, begins early in the life of an aircraft. Early evidence of degradation is also a precursor for accelerated failure rates as use accumulates along the age trajectory. Full article

This study examines the available evidence of high reliability organisational (HRO) theory as a strategy to manage construction safety: (1) Background: High reliability organisations (HROs) have been under investigation by organisational scholars to understand how they function at an exceptionally high level with few or no accidents under challenging circumstances. The construction industry is a high risk industry and is also known for a high fatality rate around the world. This systematic review examines the available evidence of HROs as a strategy to manage construction safety; (2) Methods: A systematic review to summarise and critically appraise the literature on high reliability organisational theory, aimed at improving construction safety; (3) Results: Of 2724 articles found, fifteen studies met the inclusion criteria for qualitative synthesis and review. Six of the studies were from construction, four were from general HROs research, two were from health care, and three were from the aerospace, oil and gas, and nuclear industries; (4) Conclusion: Based on the available evidence, transferring the practices and principles of HROs to construction, the validation of proposed assessing tools and a consensus HRO definitions are the major issues identified. Full article

Management of occupational health and safety (OHS) risks is a crucial component of any business. Numerous investigations have shown that work-related injuries and deaths occur disproportionately in small-to-medium-sized enterprises (SMEs) and that this is clearly due to deficient management of OHS risks. The main goal of this work is to develop a base of indicators suitable for evaluating OHS risk management maturity in industrial SMEs. A preliminary model is then proposed for this evaluation, based on a small number of relevant indicators selected from a careful bibliographic review. The work begins with a critical review of the literature and analysis of known concepts, methods, tools and models of measurement of risk analysis maturity in order to extract relevant indicators. The most suitable indicators are then grouped to form the basis of a preliminary model for evaluating OHS risk management maturity in the SME setting. Our findings will help managers of SMEs make sound decisions in their quest to improve the OHS performance of their businesses. Full article

The accident levels in helicopter transportation vary between geographical regions and types of operations. In this paper, we develop some hypotheses regarding the factors that may explain this variation. The aim of this paper is to improve safety in helicopter transportation through better understanding of the causes leading to fatal accidents. We provide an analysis of three segments of helicopter transportation in Norway (i.e., offshore transportation; onshore ambulance/police, and onshore transportation). This analysis refers to international research on helicopter accidents. The number of fatal accidents per million flight hours in Norwegian offshore helicopter transportation was 2.8 in 1990–1999 and zero in 2000–2015. In Norwegian onshore helicopter transportation, the fatal accident rate was 13.8 in the period 2000–2012. Twenty-three onshore helicopters crashed to the ground; seven of these crashes were fatal, killing 16 people. It is reasonable to question why there is such a significant difference in accident rates between offshore and onshore helicopter transportation. We have approached this question by comparing how the different segments of helicopter transportation are organized and managed. Our analysis shows that there are major differences both at the “sharp” end (i.e., in actual operations) and the “blunt” end (i.e., rules, regulations and organization). This includes differences in regulations, market conditions, work organization (i.e., training, employment conditions, and qualifications of the crews), operations and technology. A central argument is that differences in the market conditions and requirements stipulated by the users explain some of these differences. The same differences can be found internationally. If we use best practice and expert judgments, there is an opportunity to improve helicopter safety through improving the socio-technical system (i.e., organizational issues, improved design, improved maintenance of critical components and more focus on operational factors). A reasonable goal is that the international helicopter transportation industry could reduce the accident level to less than one fatal accident per million flight hours (Considering the oil and gas industry internationally, this would reduce the average of 24 fatalities annually to 4 per year, thus saving 20 lives each year). Full article

Behavioral traps are accident-inducing operational pitfalls aviators may encounter as a result of poor decision making. The Federal Aviation Administration (FAA) identifies the existence of twelve of these negative pilot behaviors. These are: Peer Pressure; Get-There-Itis; Loss of Situational Awareness; Descent Below the Minimum En Route Altitude (MEA); Mind Set; Duck-Under Syndrome; Getting Behind the Aircraft; Continuing Visual Flight Rules (VFR) into Instrument Conditions; Scud Running; Operating Without Adequate Fuel Reserves; Flying Outside the Envelope; and Neglect of Flight Planning, Preflight Inspections, and Checklists. The purpose of this paper was to study the nature of their occurrence in the airline domain. Four Subject Matter Experts (SMEs) analyzed 34 National Transportation Safety Board (NTSB) accident reports. The SMEs were able to identify many pilot actions that were representative of the behavioral traps. Behavioral traps were found in all accidents with Loss of Situational Awareness and Neglect of Flight Planning, Preflight Inspections, and Checklists dominant. Various themes began to emerge, which played important roles in many accidents. These themes included Crew Resource Management (CRM) issues, airline management and fatigue. The findings of this study indicated that behavioral traps were prevalent in airline accidents including habitual noncompliance by pilots. Attitude management training is recommended. Full article

The largest cause of accidental death and placental abruption in pregnancy is automobile collisions. Lives can be saved by correct use of the three-point seatbelt during pregnancy. Human interaction is essential for correct use of seatbelts. The objective of this study is to investigate pregnant women’s use of correct shoulder section together with correct lap section as advised by obstetricians and highway experts and to identify the most common seatbelt misuse during pregnancy. An international web survey was conducted in five languages for this study. 1931 pregnant women reported their use of seatbelts and how they position the shoulder and lap sections of their seatbelts. Special attention was paid to distinguish between ‘partly correct’ and ‘correct’ seatbelt positioning. The questionnaire responses are used to determine the magnitude of every combination of the correct and incorrect shoulder and lap section of the seatbelt positioning during pregnancy. Results show that seatbelt usage in pregnancy is generally high in the world. However, the correct use of the entire seatbelt is very low, at only 4.3% of all respondents. 40.8% of the respondents use the shoulder portion of the belt correctly, whilst a 13.2% use the lap section correctly. The most common misuse is ‘across abdomen’ or ‘not using the seatbelt at all’, and both pose danger to pregnant women and their fetuses. Correct use of three point seatbelts is a challenge during pregnancy. We recommend that the media, medical community, and automotive industry provide targeted information about correct seatbelt use during pregnancy and accident databases include ‘correct seatbelt use’ information in crash statistics. Full article