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The vehicle–track interaction and the resulting dynamic response of the vehicle involve a number of complex nonlinear problems. Large vertical loads act through a small contact patch leading to very high contact pressures. Transverse loads acting through this contact induce a relative velocity between wheel and rail expressed in non-dimensional form as a creepage. The wheel and rail profiles determine the contact patch shape and affect the ability of the vehicle to run stably. If the yaw stiffness of the axles is too low, the vehicle will become unstable at a relatively low speed; conversely, if the yaw stiffness is too high, the curving behaviour will be adversely affected. The vehicle suspension, especially the secondary suspension, also affects the ride comfort of passengers. Finally, it is shown how the speed profiles of accelerating and decelerating trains can be calculated from basic assumptions about the train power, adhesion and rolling resistance.

What is the role of ethics and values in justice and the role of justice in ethics and values? How do we do them? These questions, ever-present and often unacknowledged, undergird efforts to survive, practice mutual aid, and work to prevent and address harms produced through disasters and environmental change.

Emerging from the teachings of Reverend Richard Krajeski and to honor his call, a group of his mentees, collaborators, and co-conspirators organized a special session at the July 2020 Natural Hazards Workshop, Just Dialogue: An Intergenerational Conversation on Justice, Sustainability, and Abundance. Enough is abundance, as Dick Krajeski, a longtime leader in the hazards community, was known for saying. In this way, he reminded us that that when we live as if we already have enough, we live sustainably and in ways that help lift oppression and reduce inequality and injustice. The session brought together people from diverse and intersecting places of Dick’s life for an intergenerational conversation about hope and healing, and invited the Natural Hazards community to engage in a just dialogue to which we bring our whole, true selves (open and vulnerable) to ask – what are the questions for the Natural Hazards community to be questioning, and to be asking, to motivate change and to move our systems of research and practice toward more equitable futures for all?

The railway track system is the platform by which loads from moving trains are transferred to the underlying soil or supporting infrastructure such as bridges. The most common type of railway track system is ballasted track, which has been in use for over a century. Ballasted track has proved versatile. It can be constructed using locally available materials and with modifications to the rails and sleepers, crossings transferring trains from one route to another can be created. The structure of a ballasted track system consists of two main parts. The upper portion, termed the superstructure, comprises the rails, fastenings and sleepers. It is formed of components whose shape, stiffness and strength are designed and closely controlled. Below the superstructure is the substructure, which comprises the ballast and sub-ballast. Although the materials used in the substructure may have been specified, their engineering properties and geometric placement are less well controlled. In this chapter, we will explore how a typical ballasted track system transfers load to the ground and the ways in which the track form deteriorates, requiring maintenance and eventually renewal.

This chapter is an autoethnographic account of my journey from a working-class childhood and youth to becoming an academic in a large UK university. Using the techniques of poetics (Bachelard, 2004), the chapter focuses on several pivotal periods in my life, where I encountered a sequence of events that were to influence my journey towards transformation. Back in my early 20s, I knew that I wanted to change and to grow in new directions; however, infused with a particular heritage, set of experiences and cultural values – none of which embraced, recognised or understood learning and university as a possibility – I struggled to make sense of my feelings of frustration and being stranded. This is where my strange fascination with the airport, music, daydream and the notion of flight emerged (see Bachelard, 2011; Seres, 1993). Here, the nebulous and seemingly futile ache for an alternative and better future emerged as a potent hope and journey towards transition.