Dynamics of railway freight vehicles

This paper summarises the historical development of railway freight vehicles and how vehicle designers have tackled the difficult challenges of producing running gear which can accommodate the very high tare to laden mass of typical freight wagons whilst maintaining stable running at the maximum required speed and good curving performance. The most common current freight bogies are described in detail and recent improvements in techniques used to simulate the dynamic behaviour of railway vehicles are summarised and examples of how these have been used to improve freight vehicle dynamic behaviour are included. A number of recent developments and innovative components and sub systems are outlined and finally two new developments are presented in more detail: the LEILA bogie and the SUSTRAIL bogie

The effect of energy and time efficient driving strategies on longitudinal heavy haul train dynamics

Railway operators are continually investigating ways to reduce the cost of heavy haul train haulage operations. Two main components that influence the cost of a haulage trip are energy/fuel usage and journey time. But other costs are more difficult to measure such as train and wagon wear, fatigue damage and derailment likelihood. Past research and train driving training resources recognise that generally energy efficient driving strategies provide the best train handling and therefore the lowest cost of train operation. However, more energy efficient strategies tend to be slower in order to reduce the amount of braking required. While slower journey times result in lower energy usage it has the disadvantage of reducing the capacity of the rail network and rolling stock utilisation and hence increases cost in this area. Evaluating the total cost of a train driving strategy involves many parameters. The paper presents a method used to determine the total cost of a number of train driving strategies used on an Australian heavy haul line. The results are used to show the various cost relationships between energy, time and longitudinal dynamics during typical heavy haul train operation. The paper also highlights ways cost analysis can be used to further reduce train operation costs

Energy, time and longitudinal train dynamics costs using energy optimised driving strategies in heavy haul trains

There are many costs and overheads in operating a rail haulage service. Insights into how to reduce some of the operational costs can be obtained by focusing on costs that are affected by the driving strategy. Two main costs affected by the driving strategy relate to time and energy. There also exists a train dynamics cost which is influenced by longitudinal in-train forces. The cost optimisation of a heavy haul rail operation involves many factors such as train design, track design and scheduling. However an above-rail operator may only have control over the driving strategy and the train configuration with the other factors forming the operational limits. This paper investigates the train dynamics cost, energy cost and time cost of a heavy haul train using an energy efficient driving strategy. In the view of the conference theme “Rail’s Digital Revolution”, comparison is also made with operational data to provide insights into and estimations of possible cost reductions in areas of energy, time and longitudinal train dynamics. It was found that operational control strategies of empty trains exhibit minimal energy and dynamics, but reducing journey times could reduce the empty journey cost by 25%. Loaded journeys had higher possible cost reductions of up to 33%. To realise these cost reductions improvements to the track and rollingstock would be required to permit higher operational speeds. Longitudinal dynamic costs generally increased with faster journey times, but overall the longitudinal dynamics costs were low when compared to the time and energy costs. The study confirmed that energy-time efficient strategies generally produced good train handling. However in some instances, control strategies with higher energy usage produced better train handling

Rail Short-wavelength Irregularity Identification based on Wheel-Rail Impact Response Measurements and Simulations

Long and short-wavelength dip defects unavoidably exist on railway track top surface. Several manual measurement methods and AK track measurement car were used to measure and to identify these types of defects in a selected track section. The paper considers rail dip irregularities in detail when measured, the dip can be considered as two components. The first one is the large, long dip profile, which can be measured by the survey leveling. The other is a small short dip profile, which is superimposed on the large profile and can be measured using the dip gauge. The corresponding measurement and processed data from AK car were analysed and compared with the manual measurements. It has been found that the severities as indicated by the AK car for the short-wavelength dips in the bandwidth of 0.1 ~ 1.0m were in agreement with those measured by the dip gauge. Simulation analyses were also carried out in order to fully understand wheel-rail impact behaviours due to dip defects using the VAMPIRE package and the CRE-3D VTSD model. There was good agreement between the simulation results and the measurements from the AK car, and the simulations show that the impact accelerations are principally caused by the small dip profile

Effective use of Zoom technology and instructional videos to improve engagement and success of distance students in engineering

Taylor, BA ORCiD: 0000-0002-8229-3964CONTEXT Distance engineering education is a familiar and well-accepted mode of study in Australia, especially for regional areas, due to improvements in technology and convenience of learning opportunities. Many students choose distance mode over face-to-face because of flexibility around work and family commitments. But still, there are a lot of challenges to maintain student engagement and to make learning by distance as effective as on-campus studies. Moreover, most of the distance students choose to study and want to engage with academics outside standard working hours which challenges work-life balance. Online support tools such as Zoom allow students and academics to connect through virtual tutorials from any convenient location, which is an effective use of technology to improve student engagement and their success rate while minimising the inconvenience of after-hours commitments for academics. PURPOSE The aim is to study the effectiveness of using Zoom technology to offer evening tutorial sessions to improve the success of students studying foundation engineering units by distance mode at a regional university, while maintaining a manageable workload for academics. APPROACH A course Moodle site gives information about the learning behaviors of students. For example, data can be collected on how many students watched a lecture or the most frequently watched parts of lectures. In this study, student engagement with the course was measured by closely observing the number and types of posts to the Q&A Forum on the Moodle site for the years 2016 and 2017 and the number of students attending Zoom virtual tutorials when introduced in 2017. RESULTS Data collected from the Moodle site over the 2016 and 2017 course offerings showed levels of engagement were maintained with the learning resources (Q&A Forum in 2016 and additionally the Zoom virtual tutorials in 2017). Also, a similar response rate was recorded for the course evaluation questionnaire but satisfaction scores improved in many areas. The introduction of Zoom virtual tutorials resulted in higher student satisfaction and a reduction in instructor workload of approximately 25%. CONCLUSIONS By offering online Zoom tutoring sessions, the number of questions and answers posted on the Moodle has reduced significantly and reduced the workload of academics. This has been achieved without reducing the engagement levels of students or altering the grade distribution

Rail short-wavelength irregularity identification based on wheel-rail impact response measurements and simulations

Long and short-wavelength dip defects unavoidably exist on railway track top surface. Several manual measurement methods and AK track measurement car were used to measure and to identify these types of defects in a selected track section. The paper considers rail dip irregularities in detail when measured, the dip can be considered as two components. The first one is the large, long dip profile, which can be measured by the survey leveling. The other is a small short dip profile, which is superimposed on the large profile and can be measured using the dip gauge. The corresponding measurement and processed data from AK car were analysed and compared with the manual measurements. It has been found that the severities as indicated by the AK car for the short-wavelength dips in the bandwidth of 0.1~1.0m were in agreement with those measured by the dip gauge. Simulation analyses were also carried out in order to fully understand wheel-rail impact behaviours due to dip defects using the VAMPIRE package and the CRE-3D VTSD model. There was good agreement between the simulation results and the measurements from the AK car, and the simulations show that the impact accelerations are principally caused by the small dip profile