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To address the transportation sector's contribution to climate change problems across North America (NA), passenger rail is an attractive solution. However, NA passenger rail traditionally relies on diesel motive power, which has been associated with causing health problems of noise, vibrations, and emissions. High costs of overhead and (or) third rail infrastructure have mostly precluded electrification. This paper examines the impact of battery size on fuel cell stack efficiency for hydrogen fuel cell – battery hybrid (hydrail) railway propulsion systems using dynamic simulations as opposed to existing simulations in the literature that rely on static efficiency values. The journey of the British Rail Class 156 diesel multiple unit is simulated over the round trip from Trehafod to Treherbert (UK) using a series hybrid architecture powertrain. Dynamic simulations at incremental battery masses were used to assess fuel cell efficiency, maximum power, and overall hydrogen consumption. Battery mass is employed as a proxy for power and energy capability of the battery. Results suggest that hydrail passenger railway systems work well, with hydrogen fuel cells handling most load dynamics. Hybridization with batteries works best and reduces fuel cell stack size and hydrogen consumption, with overall 64% stack efficiency. [ABSTRACT FROM AUTHOR]

Culverts are important components of highway infrastructure. They are structurally designed to support earth and live traffic loads. Corrugated steel pipes (CSPs) are widely used as culverts in North America in different geometries. However, due to the corrosive nature of the stormwater passing through the culverts, it is common to find CSPs with partially or entirely lost inverts. Dependent on site, depth of cover and embedment conditions, invert deterioration would not necessarily result in culvert failure. This paper presents the results of a laboratory testing campaign that evaluates the structural capacity of two circular CSPs and their equivalent arch CSP through the application of a vertical static loading. The circular pipe samples had a length of 6 ft (1.82 m) and a diameter of 60 in. (1.52 m). The same length arch pipe sample had a span of 71 in. (1.8 m) and a rise of 47 in. (1.19 m). The invert of the arch and one of the circular CSPs were cut to simulate heavily corroded culverts in service. The pipe samples were embedded under two feet (0.6 m) of cover using one foot (0.3 m) of sand and one foot (0.3 m) of coarse aggregates on top, simulating a base course layer of pavement. The results of testing showed that the invert-cut circular CSP was highly dependent on its ring stiffness. While, the invert-cut arch CSP took advantage of its arch geometry and was able to resist the applied load without significant loss in the sample pipe's horizontal dimension. [ABSTRACT FROM AUTHOR]

Resilient design requires information about a structure's response to a variety of exposures such that systems can be implemented to prevent unacceptable losses. For the case of critical infrastructure like bridges, losses associated with structural damage and traffic closures from fire events can be substantial. Despite this, there are no specific code requirements for bridge fire safety in different national jurisdictions, particularly in North America and Europe, and only minimal guidance available for establishing the fire resistance requirements of bridges. Research into the fire safety of bridges is ongoing but knowledge gaps persist that limit practitioners' ability to conduct performance-based fire designs using the latest state of existing research. This paper provides a first-stage state of the art review of bridge fire research conducted to date in effort to summarize key findings and make available the most relevant information for researcher and practitioner use. The key research themes considered as subdivisions are fire hazard and risk assessment, bridge fire scenario modelling, and the structural response of steel and composite steel-concrete, cable-supported, concrete, and fiber reinforced polymer bridges to fire. The authors conclude the study with identified knowledge gaps and priority research areas. [ABSTRACT FROM AUTHOR]