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Moje diplomová práce se zabývá provozním testováním vybraných konstrukcí kolejového svršku „in situ“. Pro účely měření byly vybrány dva úseky bez a s podpražcovými podložkami, na kterých se prováděla měření. Tato měření byla následně zhodnocena. Výsledkem je posouzení o vhodnosti či nevhodnosti pražců s podpražcovými podložkami pro železniční dopravu., The masters thesis is about operational testing on selected constructions of a railway track „in situ“. There were selected two sections with and without under sleeper pads on a railway track for measurement. These measurements were evaluated then. The result is an assessment of the suitability or unsuitability for under sleeper pads for a rail transport.

Práce je zaměřena na měření a analýzu dynamických účinků ve výhybkách. V rámci práce byly vytipovány dvě výhybky v různém stádiu opotřebení, pozornost byla zaměřena především na oblast srdcovky výhybky, kde dochází k největším dynamickým účinkům. Cílem práce je srovnání výhybek z hlediska dynamického chování a stanovení vlivu opotřebení na dynamické účinky. Součástí práce je sestavení metodiky měření a návrh vhodného matematického aparátu pro vyhodnocení dynamických dějů ve výhybkách., This thesis is focused on measurement and analysis of dynamic effects on railway turnouts. Two turnouts with different wear condition were chosen. My attention was focused mainly on the crossing part of the turnout, where the highest dynamic impacts occur. The point of the thesis is comparison of the crossing part of turnouts in term of dynamic behaviour and assessment of influence of the wearing depth on dynamic effects. A part of the thesis is proposal of methodology of the measurement and convenient mathematical apparatus for analysing of dynamic effects on crossings.

Moje diplomová práce se zabývá provozním testováním vybraných konstrukcí kolejového svršku „in situ“. Pro účely měření byly vybrány dva úseky bez a s podpražcovými podložkami, na kterých se prováděla měření. Tato měření byla následně zhodnocena. Výsledkem je posouzení o vhodnosti či nevhodnosti pražců s podpražcovými podložkami pro železniční dopravu., The masters thesis is about operational testing on selected constructions of a railway track „in situ“. There were selected two sections with and without under sleeper pads on a railway track for measurement. These measurements were evaluated then. The result is an assessment of the suitability or unsuitability for under sleeper pads for a rail transport.

DTNH2215C00029, On behalf of NHTSA, the National Association of State EMS Officials had the Institutes for Behavior Resources develop a publicly and freely available website tool based on a biomathematical model of fatigue that applies to typical shift configurations/lengths among EMS personnel. The purpose of this webtool is to help agencies create and evaluate work schedules that minimize fatigue

This edition of Traffic Tech briefly describes two forthcoming NHTSA reports on fatigue among emergency medicals services personnel. The first report, The Emergency Medical Services Sleep Health Study by Patterson et al., describes a major study into EMS fatigue. The second report, Developing a Webtool for Fatigue in Emergency Medical Services Scheduling by Devine et al., describes a webtool specifically designed to improve scheduling to help solve the sleep fatigue problem.

Ten years of research on physiological stress in air traffic control specialists (ATCS's) is reviewed. Data were derived from 20 tasks involving the experimental variables of workload, shift-rotation patterns, and automation., Laboratories at the Civil Aeromedical Institute consisted of a survey of the quantity and quality of sleep in working ATCS's, a restudy of ATCS's several years after the first study to appraise stress change, and experimental attempts to evoke a differential response to two different qualities of stress. Stress was distinctly related to imposed workload as well as to working conditions. Differences in stress levels in ATCS's on different shift-rotation patterns were minimal. Automation gave rise to increased total stress accounted for by an increased workload incident to the changeover period from annual to computerized control techniques. A stress index was developed to facilitate comparison of physiological stress at the different air traffic control (ATC) facilities and among ATCS's. Anxiety level measurements vary minimally from facility to facility indicating little impact of ATC work on the physchological state of ATC's., These and other measures show that it is clearly inappropriate to describe ATC work, as is commonly done in the popular press, as being unusually stressful.

Three groups, each comprising five healthy, male, paid volunteers (ages 21 to 30), were studied for 11 days. Baseline data were collected for 3 days, during which subjects adhered to a day/night routine. On the fourth day each group took a 'flight' in the altitude chamber., Following the flight day, subjects in the first group (Group I) slept from only 0230 to 06000; subjects in the next group (Group II) had their day extended by 6 hours and began a new routine of sleeping from 0430 to 1200 for the remainder of the study; subjects in the third group (Group III) had their day compressed by 6 hours and slept from 2030 to 2400 only that fourth night and then began a new routine of sleeping from 1630 to 2400 for the final 7 days of the study., According to the physiological and biochemical measurements, there was little difference between the two 6-hour-change groups (Groups II and III), both of which required longer rephasal times than did the group that experienced sleep loss but no time change (Group I) The psychomoter performance test indicated the greatest change in the group whose day was shortened by 6 hours (Group III). The Multiple Task Performance Battery (MTPB) indicated the greatest deficit in performance for Group III and the best postshift performance for Group II.

Data obtained from sleep logs maintained for a period of 5 weeks by 185 air traffic controllers indicate that on a weekly basis there is no significant difference in the amount of sleep obtained by controllers working the 2-2-1 rotation pattern and that obtained by those on the 5-day rotation pattern. Controllers working the 2-2-1 rotation pattern slept significantly less prior to the midshift than they did before the evening and day shifts., On both the 2-2-1 and 5-day rotation patterns, the most sleep obtained was on the evening shift followed by the day shift and midshift respectively. Approximately half the controllers indicated satisfaction with their present shift rotations; however, preferences indicate that they would prefer to work a shift rotation that excluded the midshift. Age and experience do not appear to be related to pattern of sleep or amount of sleep obtained. 'Fatigue', 'weakness', and 'somnolence' were complaints most often expressed on the midshift on both rotation patterns.

Physiological and biochemical measurements were made on 22 air traffic controllers at O'Hare tower during five days of the heavy traffic evening shift (1600-2400) and five days of the light traffic morning shift (0000-0800)., Pulse rates were higher on the evening shift than on the morning shift. Converging approaching traffic was more excitatory than departing diverging traffic on the evening shift; there was no differential response on the morning shift. Galvanic skin response indicated that adaptation to the morning shift was incomplete in five days. Fibrinogen levels in controllers' blood was not elevated above the expected level for their age group., Controllers had a higher total plasma phospholipid concentration than populations of normal people, schizophrenics and combat pilots. Phosphatidyl glycerol was significantly higher in controllers' plasma than in the normal population but less than in the combat and schizophrenic populations. Findings from urine analyses that are reported separately by Hale, et al., have been summarized in this report. Urine chemistry shows that catecholamine excretion is related to the number of aircraft operations. Corticoid excretion rises late in the morning shift and recovery from morning shift work is incomplete during the off-duty rest period.

From six enroute and six terminal air traffic control facilities selected on the basis of differences between shift rotation schedules and high IFR traffic volume, 300 journeymen and assistant controllers were selected as volunteer subjects to complete a biomedical inventory daily for a period of 90 consecutive days. The inventory elicited information relating to health, morale, behavioral habits, and side effects of medications.

This bibliography was developed as part of a research task concerning the impact of shift work on employee job satisfaction, productivity, perceived job difficulty, and subjective health. Some selectivity was exercised in the choice of references for inclusion: the search covered the years 1950 through 1982; there was an emphasis on human versus animal studies; and the focus of the selected article or study had to be on the effects of an actual alteration in sleep/work hours. The latter criterion involved the exclusion of a large number of citations concerning the assessment of circadian effects on physiological responses and performance., However, an included reference by Holly et al (1981) provides a rather extensive bibliography that is more specifically focused on circadian influences on physiological and psychological variables. Since time zone changes during flight are equivalent to rapid shifts in work/sleep hours, and since this is an area of interest to the FAA, references on this topic were included. Of the citations, approximately 8% are from the 1950's, 20% from the 1960's, and slightly over half from the 1970's., The most productive year was 1981 (nearly 10% of the references), when several books on the shift topic were edited and published. Significant improvements in the quality of the research analyses have been observed over this same time period, with the increased use of multivariate techniques illustrating the highly complex nature of individual responses to alternating work schedules. However, it is also apparent that there has been some duplication of effort and investigators need to be more aware of the available world-wide literature.

Biochemical and physiological indices of stress showed that the level of stress of 16 air traffic controllers at the Houston Intercontinental Airport Tower was indistinguishable from that of control populations. While the level of stress was lower than that among O'Hare Tower controllers, both groups showed about the same degree of adaptation., Day work (heavy traffic load) at Houston was characterized by elevated levels of all stress indicators as compared with the mid-shift (light traffic); epinephrine excretion increased significantly during the last half of the mid-shift as compared with the first half. Urinary stress indicators (17-ketogenic steroids, epinephrine, norepinephrine) were all significantly elevated during day sleep as compared with night sleep, indicating less effective rest during day sleep.

The State-Trait Anxiety Inventory (STAI) was used to assess the anxiety of air traffic controllers who had experienced difficult and easy work shifts. Eighty volunteers completed the STAI before and after two or more eight-hour work shifts. Controllers relatively high in anxiety proneness tended to report higher levels of anxiety in association with control work than those relatively low in anxiety proneness. The mean A-state score after shifts was higher than the mean score before shifts. It was also determined that the increase in anxiety during shifts was greater for difficult shifts.

STAI scores of adult men and women within the age range of 25 through 59 years were generally equal to or slightly less than scores of the college undergraduate normative group. This suggests that the previous use of undergraduate norms to evaluate A-Trait and A-State scores of ATCSs did not underestimate the levels of work-related stress associated with their work. Smith's* conclusion that there is little evidence to support the notion that ATCSs are engaged in an unusually stressful occupation is not changed by the findings of this study., Although A-State scores increased from before work to after work in the subsample of FAA employees surveyed in the present study, neither the absolute levels of work stress nor the change in stress induced by work were noticeably different from those levels and changes reported by ATCSs who rated their work shifts as difficult. (*Smith, R.C. 'Stress, Anxiety, and the Air Traffic Control Specialist: Some Conclusions from a Decade of Research'. FAA Office of Aviation Medicine Report no. AM-80-14, 1980)

Stress in 23 air traffic controllers (ATCS) at Atlanta Air Route Traffic Control Center (ATL) on the straight 5-day shift rotation schedule was compared with stress in 23 ATCS's on the 2-2-1 shift rotation schedule at Fort Worth Air Route Traffic Control Center (FTW). Stress in six other FTW ATCS's on the 5-day schedule was compared to stress in their 23 cohorts on the 2-2-1 schedule. Stress estimates were made from urinary levels of 17-ketogenic steroids (st), epinephrine (e), and norepinephrine (ne).

A total of 2,366 employees of the Airway Facilities (AF) Service responded to a detailed questionnaire concerning job satisfaction and such factors as salary, shift schedule, workload, and geographic location., In general, AF employees reported satisfaction with employment by the AF Service, particularly in the areas judged most important by them: salary, job security, independence and personal responsibility, and achievement. Dissatisfaction was focused on various aspects of working conditions, such as shift rotation, management effectiveness, promotion opportunities, and paperwork. Detailed analyses of responses as a function of such variables as age, grade level, location, and AF program were also presented. The findings were discussed in terms of the implications for improving the job-related attitudes of AF personnel.

The report presents suggestions for the design of an air traffic control (ATC) incident-reporting system aimed at maximizing the amount of corrective feedback to the ATC system. The approach taken is system-oriented rather than controller-oriented. Included is a discussion of a philosophy of corrective and punitive action relative to controller involvement in an incident. Recommendations and examples of format are included for the design of incident-report forms and incident chronology and of a checklist to be used in periodic appraisal of controller performance. Emphasis is given in format design to use of systems and human function, rather than regulatory and procedural terminology. Implementation and data-analysis techniques are also discussed.

Stress in controllers on the straight five-day shift was determined at Houston Intercontinental Tower in 1970. In 1971 controllers on the 2-2-1 rotation were studied at the same tower. Controllers generally prefer the 2-2-1 to the straight five-day schedule because of the long week end associated with the 2-2-1. Management is concerned that the 'quick turnaround' on the 2-2-1 is a stressor that could compromise job performance., Physiological and psychological assessments showed no significant stress differences on the two schedules. On neither of the schedules did the controllers' stress levels differ from the general polulation., It was concluded that the stress differences on the two rotation patterns were too slight to be of real significance and a choice between them would have to rest on managerial considerations rather than biomedical ones.

DTRT57-05-D-30103, FA2R/DL411, Although the current crew rest and duty restrictions for commercial space transportation remain in place, the Federal Aviation Administration (FAA) continues to review the regulation on a regular basis for validity and efficacy based on input from scientific and operational communities. A previous report completed by Clemson University, in cooperation with the Volpe Center and Aerospace Corporation review the scientific literature pertaining to crew rest and duty restrictions and provided recommendations for those involved in commercial space transportation. This report extends the review to include the impact of shiftwork on commercial space transportation. Included in the review is an overview of shiftwork and recommendations for commercial space transportation.

Three groups of subjects completed Composite Mood Adjective Check Lists (CMACL) before and after selected shifts at two air traffic control (ATC) facilities as part of a multi-discipline study of stress in ATC work., At one facility, a high traffic density tower (HDT), 22 air traffic control specialists (ATCS) were sampled before and after five evening (1500 to 2300) shifts and five night (0000) to 0800) shifts. At a second facility, a moderate traffic density tower (MDT), 16 ATCSs were assessed on three day (0800 to 1600) and three night (0000 to 0800) shifts. In addition, four non-ATC individuals involved in monitoring the MDT ATCSs for other aspects of the general stress study served as controls., It was found that all subjects, both ATCSs and controls, showed a considerable increase in feelings associated with fatigue and tiredness as a function of working an eight-hour shift. These effects were generally more pronounced for night shifts. There were no differences between subject groups on the variables predicted to be most sensitive to variations in stress. Findings are discussed in terms of expected work effects and the lack of significant stress variations.

From six enroute and six terminal air traffic control facilities selected on the basis of differences between shift rotation schedules and high IFR traffic volume, 300 journeymen and assistant controllers were selected as volunteer subjects to complete a biomedical inventory daily for a period of 90 consecutive days. The inventory elicited information relating to health, morale, behavioral habits, and side effects of medications.

Fifteen male paid volunteers (ages 20 to 28) were studied in three groups of five each. The first 4 days of the experiment they slept nights (2230 to 0600( and worked days. On the fifth night, they slept only 3 hours (2100 to 2400) before starting a 10-day period in which the wake-sleep cycle was altered by 12 hours. According to the subjective fatigue index, the total fatigue for the awake periods was not significantly changed; however, the times within days for greatest fatigue were altered and 9 days were required for a complete reversal of the daily pattern. from shortest to longest mean rephasal times, these were; heart rate, norepinephrine, epinephrine, potassium, sodium, internal body temperature, and 17-ketogenic steroids., Performance data based on the Civil Aeromedical Institute Multiple Task Performance Battery suggest the following, 1.There was evidence of diurnal variation during the preshift period., 2.There were decrements on the day of the shift following the short sleep period., 3.Performance during the first 3 days following the shift was relatively high for most of the day but was relatively poor in the final session of the day., 4.Performance on the fourth through sixth postshift days was average or above average for the experiment with relatively small variations among the five test sessions per day., 5.Performance on the seventh through ninth postshift days was below average for the experiment and showed some evidence of a return to a diurnal cycling pattern with a new peak period of performance that reflected the 12-hour shift in the wake-sleep schedule.

This paper summarizes a decade of research evaluating possible stress effects of work on Air Traffic Control Specialists (ATCSs).Studies were conducted at a variety of large and small air traffic facilities. A visit of several days to each facility was part of an interdisciplinary research effort involving physiological and biochemical, as well as psychological, assessments., The principal psychological measure was the State-Trait Anxiety Inventory (STAI). The STAI and other questionnaires were adminstered at the beginning and end of three to five different work shifts scheduled at a facility. The findings showed that controller groups scored significantly below college student norms on both the A-state (current anxiety level) and A-trait (anxiety proneness) measures of the STAI. Results with mood adjective checklists were similar. The findings also showed that anxiety levels (1) increased across an 8-hr work shift and (2) were higher on shifts rated 'difficult' than they were on 'easy' shifts. The establishment of adult norms for the STAI was undertaken to provide a better comparison for ATCS data., Results of those efforts indicated that ATCSs had lower anxiety scores than the normal adult population. Moreover, A-state scores increased from the beginning to end of work shifts for employees in a variety of non-air-traffic jobs (e.g., engineers), just as they did for ATCSs. Thus ATCSs are well within normal limits on every indicator of psychological states used in these studies and appear to experience less anxiety than is the average in other work settings.

Two types of shift rotation in the same air traffic facility were investigated in order to determine the relative advantages and disadvantages of nonrotating shift work (steady shift) and rotating shift work. The rotating shift work chosen for comparison was a 2-2-1 pattern often preferred by air traffic controllers, and which consists of a schedule of progressively earlier work periods throughout the workweek, with 9 to 14 hours off duty between 8-hour work periods, and an extended off-duty period of 80 hours between workweeks., Objective differences, as judged by urine biochemistry, between workers on the two shift patterns are minimal and insignificant statistically. Generally, however, greater fatigue was reported in connection with the 2-2-1 rotation than with the steady shift, both preshift and postshift. When prework to postwork changes in subjective fatigue were compared for the two shift patterns, no statistically significant differences were noted. Within the 2-2-1 schedule, there was (i) significantly greater excretion of catecholamines on the day watch as compared to the evening watch; and (ii) significantly greater preshift fatigue reported on day shift than evening shift., Despite the observed differences between and within the steady and rotating shift patterns, employee participation in shift pattern choice may have contributed greatly to worker contentment and willingness to accept the observed stressors. Keywords: Shift Work, Air Traffic Controllers, Biochemistry, Fatigue, Employee Participation.