From the seat to the system: Re-designing a tram drivers' workstation combining technical and contextual aspects.

Through the detailed account of a design case-study, the paper aims to demonstrate how the activity-oriented approach promotes a systems perspective in ergonomics interventions. Specifically, by presenting an activity-oriented re-design of a tram drivers' workstation, it is shown: (i) how technical and contextual aspects were jointly considered, (ii) how their combination affects workers' activity in a non-trivial manner, and (iii) how this system level view helped generate feasible and sustainable design solutions. First, the activity-oriented theoretical lens is briefly presented, followed by the analysis of the tram driving activity, emphasizing on drivers' efforts to compensate for the original work-system design flaws. Next, key elements of the re-design process are presented, through a concept map, combining technical and contextual aspects, coupled with an account of stakeholder debates and resolution processes. The paper ends with a discussion on the lessons learned, concerning the adopted approach for design interventions in real work situations.

Subway-Related Trauma: An Urban Public Health Issue with a High Case-Fatality Rate.

BACKGROUND: Between 1990 and 2003, there were 668 subway-related fatalities in New York City. However, subway-related trauma remains an understudied area of injury-related morbidity and mortality. OBJECTIVE: The objective of this study was to characterize the injuries and events leading up to the injuries of all patients admitted after subway-related trauma. METHODS: We conducted a retrospective case series of subway-related trauma at a Level I trauma center from 2001 to 2016. Descriptive epidemiology of patient demographics, incident details, injuries, and outcomes were analyzed. RESULTS: Over 15 years, 254 patients were admitted for subway-related trauma. The mean (standard error of the mean) age was 41 (1.0) years, 80% were male (95% confidence interval [CI] 74-84%) and median Injury Severity Score was 14 (interquartile range [IQR] 5-24). The overall case-fatality rate was 10% (95% CI 7-15%). The most common injuries were long-bone fractures, intracranial hemorrhage, and traumatic amputations. Median length of stay was 6 days (IQR 1-18 days). Thirty-seven percent of patients required surgical intervention. At the time of injury, 55% of patients (95% CI 49-61%) had a positive urine drug or alcohol screen, 16% (95% CI 12-21%) were attempting suicide, and 39% (95% CI 33-45%) had a history of psychiatric illness. CONCLUSIONS: Subway-related trauma is associated with a high case-fatality rate. Alcohol or drug intoxication and psychiatric illness can increase the risk of this type of injury.

End-of-Life in the railway sector: Analysis of recyclability and recoverability for different vehicle case studies.

The railway system represents one of the most resource-efficient answer to our ever-growing demand for transport service and the development trends for the following years forecast a substantial increase in this sector. Considering the European Union, rolling stock realizes a significant share of both goods and passengers carriage while it is responsible for a derisory quota of environmental impact and energy consumption involved by transportation. Contrary to the low environmental impact, the amount of End-of-Life (EoL) waste generated by rolling stocks in relation to the number of vehicles is notable, much greater than in the case of road vehicles. As railway vehicles are constituted by many heterogeneous components, the EoL rolling stock is a precious source of materials, whose recycling brings measurable economic benefits and needs to be appropriately debated. The paper presents calculation of recoverability/recyclability rate for different typologies of vehicles representative of railway transport; calculation is performed on the basis of primary data and according to the recyclability and recoverability calculation method issued by UNIFE in the context of Product Category Rules (PCR). The typologies of railway vehicles taken into account are electric metro, diesel commuter train and high-speed electric train. The analysis envisages also to replicate the calculation in case innovative materials and manufacturing technologies are adopted in the construction of car-body structure. Results show that recyclability/recoverability rates are abundantly over the quota of 90% for each one of the three trains, these latter being made in major part of metals that benefit from very efficient recovery processes. The adoption of innovative materials and manufacturing technologies for car-body structure involves a scarce reduction of recyclability and recoverability rates (about 2% and 0.2% respectively) due to the introduction of components and materials characterized by critical dismantlability and low efficiency recovery processes; recoverability results less affected by lightweighting because post-shredding thermal recovery treatments are roughly independent with respect to dismantlability. A sensitivity analysis based on different dismantling scenarios reveals that the effectiveness of dismantling has a moderate influence on recyclability/recoverability rate (the variation does not exceed 3%). The low variability of recyclability/recoverability rate can be explained by the following reasons: predominance of metals in trains material composition, efficiency of metals separation processes close to 100%, post-shredding recycling processes of metals characterized by recovery factors equal to the ones of post-dismantling recycling processes.

[The impact of harmful occupational factors on the morbidity rate of workers of the railway-car repair plant].

The rail transport is the one of the leading sectors of the national economy. More than 50% of the employees of the enterprises of the railway complex work under the unfavourable impact of hazardous and dangerous substances and occupational factors. In the literature issues of working conditions and health of employees of railway carrepairing plant are hardly highlighted. The aim of the study is the evaluation of the morbidity rate shaped under the influence of harmful occupational factors for the elaboration of preventive measures. In the work there were used generally accepted methods of hygienic studies, analysis of morbidity rate with temporary disability (TD), according to records of periodic medical examinations, occupational prevalence. The railway car-repairing plant was established to be characterized by the complex of harmful factors of the working environment and labor process: noise, local vibration, industrial aerosols of complex composition, chemicals, low light, hardness of the labor process. The levels of incidence with temporal disability in the studied groups, depending on the work seniority in the harmful labor conditions, significantly decrease with the experience from 5 to 9 years and increase with the experience more than 10 years. Executed in-depth analysis as of the both morbidity rate and TD, as well results of periodic medical examinations of workers of main shops shows that overall indices of the morbidity rate and TD are significantly higher than in the comparison group; levels of the morbidity rate and TD in the observed groups significantly decline depending on the length of service in hazardous working conditions with a length of the experience offrom 5 to 9 years and increase with the increase in the length of experience of 10 years or more. In the structure of morbidity and TD leading positions are occupied by diseases of the respiratory system, musculoskeletal system and connective tissue, circulatory system and digestive system, diseases of the eye and its appendages. The health damage risk coefficients in the studied groups of workers and the average losses of working time due to the morbidity with TD per 1 employee in all shops are higher than those in the comparison group. The level of the occupational morbidity rate is very low. Harmful working conditions contribute to the development of general and occupationally related diseases.

A practical approach to glare assessment for train cabs.

The assessment of glare is a key consideration in the design of a railway driver's cab. However, unlike assessment of other factors, such as forward visibility, there are no standardised approaches for performing assessments of glare. This paper describes an approach for assessing the impact of glare in a full size mock-up of a railway cab. While it is unrealistic to evaluate every possible lighting condition that may potentially occur in the vehicle cab in service, a pragmatic and practical approach is taken to provide a good level of indicative information about the cab design's likely glare performance. This involves assessing internal light sources, such as internal lights and illuminated controls, and simulating external light sources (e.g. the sun, other trains' headlights) by illuminating the cab mock up windscreen, side and door windows with a single light source manually located in a sequence of discrete positions and orientations and assessing the resulting glare impacts. The paper describes a structured process for assessing and recording the impact of glare and recommending mitigations.

Activities, postures and comfort perception of train passengers as input for train seat design.

Working in the train is a part of new ways of working. However, the ideal working position is unknown. Moreover, the ideal position for leisure and relaxing is also unknown. This article defines what activities train passengers mainly perform and which corresponding postures are seen. Based on the observations on actual train rides, four main activities could be identified: Reading, Staring/sleeping, Talking and Working on laptop. Working on laptop was the activity with the longest duration and talking had the shortest duration. Associated with these four activities, a top eight of different postures were observed. Except for headrest comfort, comfort scores were not significantly different between activities. The top eight corresponding postures combined with comfort scores showed that per activity different postures were observed and the comfort scores varied in relation to the combination of posture and activity. Nearly for all activities, the majority of passengers preferred adjustability options to fit the seat to the performed activity.

Ultrasonic attenuation in pearlitic steel.

Expressions for the attenuation coefficients of longitudinal and transverse ultrasonic waves are developed for steel with pearlitic microstructure. This type of lamellar duplex microstructure influences attenuation because of the lamellar spacing. In addition, longitudinal attenuation measurements were conducted using an unfocused transducer with 10 MHz central frequency on the cross section of a quenched railroad wheel sample. The dependence of longitudinal attenuation on the pearlite microstructure is observed from the changes of longitudinal attenuation from the quenched tread surface to deeper locations. The results show that the attenuation value is lowest and relatively constant within the quench depth, then increases linearly. The experimental results demonstrate a reasonable agreement with results from the theoretical model. Ultrasonic attenuation provides an important non-destructive method to evaluate duplex microstructure within grains which can be implemented for quality control in conjunction with other manufacturing processes.

Numerical study for a new methodology of flaws detection in train axles.

Train loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20 years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coupled thermo-mechanical simulations allow visualization of the ultrasonic field guiding the definition of the optimal NDT setup. The geometry of the axle and of the elements mounted on it is accurately reproduced; moreover the press fit effect caused by the wheel and the bearing rings is implemented. The current NDT techniques for railway axles require removing wheels and other components from the axle. The presented scheme uses non-contact ultrasonic generation and detection allowing non-contact in-service inspection of railway axles at trackside station. The numerical results are promising and encourage us to test the new approach experimentally.

Measurements of Young's and shear moduli of rail steel at elevated temperatures.

The design and modelling of the buckling effect of Continuous Welded Rail (CWR) requires accurate material constants, especially at elevated temperatures. However, such material constants have rarely been found in literature. In this article, the Young's moduli and shear moduli of rail steel at elevated temperatures are determined by a new sonic resonance method developed in our group. A network analyser is used to excite a sample hanged inside a furnace through a simple tweeter type speaker. The vibration signal is picked up by a Polytec OFV-5000 Laser Vibrometer and then transferred back to the network analyser. Resonance frequencies in both the flexural and torsional modes are measured, and the Young's moduli and shear moduli are determined through the measured resonant frequencies. To validate the measured elastic constants, the measurements have been repeated by using the classic sonic resonance method. The comparisons of obtained moduli from the two methods show an excellent consistency of the results. In addition, the material elastic constants measured are validated by an ultrasound test based on a pulse-echo method and compared with previous published results at room temperature. The measured material data provides an invaluable reference for the design of CWR to avoid detrimental buckling failure.

Management of personal safety risk for lever operation in mechanical railway signal boxes.

Despite increased implementation of computer control systems in managing and regulating rail networks, mechanical signal boxes using lever operation will be in place for years to come. A rolling risk assessment programme identified a number of levers in mechanical signal boxes within the UK rail network which potentially presented unacceptable personal safety risk to signallers. These levers operate both points and signals and the risk is primarily the weights which have to be moved when pulling and pushing the levers. Operating difficulties are often compounded by the design and condition of lever frames, the linkages to the points/signals, maintenance regimes, the workspace and the postures and strategies adopted by signallers. Lever weights were measured as from 15 kg to 180 kg at over 160 boxes, using a specially designed and constructed device. Taken together with examination of injury and sickness absence data, interviews and field observations, and biomechanical computer modelling, the measurement programme confirmed the potential risks. A risk management programme has been implemented, comprising lever weight measurement, training of operations staff, a structured maintenance regime and renewal or redesign for boxes/levers where, after maintenance, a criterion weight level is still exceeded. For a feasible management programme, the first alert (or 1st action) value for further assessment is 55 kg, a second action level requiring specified maintenance is 80-99 kg, and a third action level requiring the lever to be signed out of use is 100 kg.

[Improvement of sanitary and epidemiological safety of rail transport--a requirement of the new legislation of the Russian Federation].

Brief analysis of the legal framework in recent years, both in the sphere of technical regulation, and in the field of sanitary and epidemiological welfare of the population is presented in this article. The necessity of inclusion in the technical regulations for the safety of railway rolling stock and elements of railway infrastructure the requirements for sanitary-epidemiological safety and hygiene regulations has been proved. Fragments of technical regulations for railway equipment and infrastructure elements, including the basic requirements for the sanitary-epidemiological security are presented. The position of authors in the processing of the regulatory framework in the field of sanitary-epidemiological welfare of population in standardization documents in accordance with the requirements of federal law "On technical regulation" has been reflected.

Development of design principles for automated systems in transport control.

This article reports the results of a qualitative study investigating attitudes towards and opinions of an advanced automation system currently used in UK rail signalling. In-depth interviews were held with 10 users, key issues associated with automation were identified and the automation's impact on the signalling task investigated. The interview data highlighted the importance of the signallers' understanding of the automation and their (in)ability to predict its outputs. The interviews also covered the methods used by signallers to interact with and control the automation, and the perceived effects on their workload. The results indicate that despite a generally low level of understanding and ability to predict the actions of the automation system, signallers have developed largely successful coping mechanisms that enable them to use the technology effectively. These findings, along with parallel work identifying desirable attributes of automation from the literature in the area, were used to develop 12 principles of automation which can be used to help design new systems which better facilitate cooperative working. PRACTITIONER SUMMARY: The work reported in this article was completed with the active involvement of operational rail staff who regularly use automated systems in rail signalling. The outcomes are currently being used to inform decisions on the extent and type of automation and user interfaces in future generations of rail control systems.

Spatial assignment of emissions using a new locomotive emissions model.

Estimates of fuel use and air pollutant emissions from freight rail currently rely highly on aggregate methods and largely obsolete data which offer little insight into contemporary air quality problems. Because the freight industry is for the most part privately held and data are closely guarded for competitive reasons, the challenge is to produce robust estimates using current reporting requirements, while accurately portraying the spatial nature of freight rail impacts. This research presents a new spatially resolved model for estimating air pollutant emissions (hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter less than 10 µm in diameter, sulfur dioxide, and carbon dioxide) from locomotives. Emission estimates are based on track segment level data including track grade, type of train traffic (bulk, intermodal, or manifest) and the local locomotive fleet (EPA tier certification level and fuel efficiency). We model the California Class I freight rail system and compare our results to regional estimates from the California Air Resources Board and to estimates following U.S. Environmental Protection Agency guidance. We find that our results vary considerably from the other methods depending on the region or corridor analyzed. We also find large differences in fuel and emission intensity for individual rail corridors.

Generalized railway tank car safety design optimization for hazardous materials transport: addressing the trade-off between transportation efficiency and safety.

North America railways offer safe and generally the most economical means of long distance transport of hazardous materials. Nevertheless, in the event of a train accident releases of these materials can pose substantial risk to human health, property or the environment. The majority of railway shipments of hazardous materials are in tank cars. Improving the safety design of these cars to make them more robust in accidents generally increases their weight thereby reducing their capacity and consequent transportation efficiency. This paper presents a generalized tank car safety design optimization model that addresses this tradeoff. The optimization model enables evaluation of each element of tank car safety design, independently and in combination with one another. We present the optimization model by identifying a set of Pareto-optimal solutions for a baseline tank car design in a bicriteria decision problem. This model provides a quantitative framework for a rational decision-making process involving tank car safety design enhancements to reduce the risk of transporting hazardous materials.

Improving a workstation in an existing cab by means of a participatory approach: the case of subway operators' workstations.

A study was conducted to identify possible solutions for redesigning a subway cab in order to improve the posture of drivers working in a restricted space. The approach used included the participation of a working group comprised of operations, maintenance, and engineering managers as well as several drivers. After 6 meetings in which different simulation techniques were used, the working group proposed changes for increasing the available space inside the cab and three seat designs. The involvement of the actors from the three departments affected by the changes, as well as the operators, throughout the process, was a determining factor in the advancement and acceptance of the projects. The fact that 400 cars are currently in service and must be modified means that it will take several years to implement the modifications in the entire fleet.

Human-factors engineering for smart transport: design support for car drivers and train traffic controllers.

The theme Smart Transport can be described as adequate human-system symbiosis to realize effective, efficient and human-friendly transport of goods and information. This paper addresses how to attune automation to human (cognitive) capacities (e.g. to take care of information uncertainty, operator trust and mutual man-machine adaptations). An introduction to smart transport is presented, including examples of best practice for engineering human factors in the vehicle ergonomics and train traffic control domain. The examples are representative of an ongoing trend in automation and they show how the human role changes from controller to supervisor. Section 2 focuses on the car driver and systems that support, or sometimes even take over, critical parts of the driving task. Due to the diversity of driver ability, driving context and dependence between driver and context factors, there is a need for personalised, adaptive and integrated support. Systematic research is needed to establish sound systems. Section 3 focuses on the train dispatcher support systems that predict train movements, detect potential conflicts and show the dispatcher the possibilities available to solve the detected problems. Via thorough analysis of both the process to be controlled and the dispatcher's tasks and cognitive needs, support functions were developed as part of an already very complex supervision and control system. The two examples, although from a different field, both show the need for further development in cognitive modelling as well as for the value of sound ergonomics task analysis in design practice.

Application of a human error framework to conduct train accident/incident investigations.

Accident/incident investigations are an important qualitative approach to understanding and managing transportation safety. To better understand potential safety implications of recently introduced remote control locomotive (RCL) operations in railroad yard switching, researchers investigated six railroad accidents/incidents. To conduct the investigations, researchers first modified the human factors analysis and classification system (HFACS) to optimize its applicability to the railroad industry (HFACS-RR) and then developed accident/incident data collection and analysis tools based on HFACS-RR. A total of 36 probable contributing factors were identified among the six accidents/incidents investigated. Each accident/incident was associated with multiple contributing factors, and, for each accident/incident, active failures and latent conditions were identified. The application of HFACS-RR and a theoretically driven approach to investigating accidents/incidents involving human error ensured that all levels of the system were considered during data collection and analysis phases of the investigation and that investigations were systematic and thorough. Future work is underway to develop a handheld software tool that incorporates these data collection and analysis tools.

Impact of railroad ballast type on frontal plane ankle kinematics during walking.

Five healthy male subjects walked on a control surface (level concrete), and two sloped rock surfaces (walking ballast-rock about 1.9 cm across; main line ballast-rock about 3.8 cm across) while their rearfoot motion (defined throughout as ankle inversion/eversion as seen from the frontal plane) was measured to determine if the different walking surfaces caused different ankle kinematics. The ballast was placed in 5m long trays that were tilted 7 degrees in the transverse plane. Rearfoot motion was measured while the subjects walked the length of the respective surfaces wearing work boots. A repeated measures ANOVA and a subsequent multiple comparison test revealed that the rearfoot range of motion was significantly greater walking on the main line ballast than walking on either the walking ballast or the level concrete. Meanwhile, the mean range of rearfoot motion for walking ballast was not significantly different from that resulting from walking on concrete. Variability was more than twice as great walking on main line ballast than walking on level concrete. Rearfoot angular velocities walking on level concrete and walking ballast were not significantly different, but both were significantly less than walking on main line ballast. Results suggested that rearfoot motion could be reduced if railroads placed walking ballast where trainmen have to walk as part of their jobs.

Digital redesign of anti-wind-up controller for cascaded analog system.

The cascaded conventional anti-wind-up (CAW) design method for integral controller is discussed. Then, the prediction-based digital redesign methodology is utilized to find the new pulse amplitude modulated (PAM) digital controller for effective digital control of the analog plant with input saturation constraint. The desired digital controller is determined from existing or pre-designed CAW analog controller. The proposed method provides a novel methodology for indirect digital design of a continuous-time unity output-feedback system with a cascaded analog controller as in the case of PID controllers for industrial control processes with the presence of actuator saturations. It enables us to implement an existing or pre-designed cascaded CAW analog controller via a digital controller effectively.