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We describe a simple experiment involving spheres rolling down an inclined plane towards a bottleneck and through a gap. Results of the experiment indicate that flow rate can be increased by placing an obstruction at optimal positions near the bottleneck. We use the experiment to develop a computer simulation using the PhysX physics engine. Simulations confirm the experimental results and we state several considerations necessary to obtain a model that agrees well with experiment. We demonstrate that the model exhibits clogging, intermittent and continuous flow, and that it can be used as a tool for further investigations in granular flow.

A coordinated effort between the pipeline regulatory entities in the United States and Canada is paramount for reducing energy congestion across the border. The interconnected nature of the pipeline infrastructure in North America and the growing demand for energy in the US are clear drivers for cross border coordination and collaboration. Regulatory agency cooperation by the Canadian National Energy Board (NEB) and the US Pipeline and Hazardous Materials Safety Administration (PHMSA) recognizes this dependency and the continued safe operation and expansion of the pipeline infrastructure. To achieve these goals, much is dependent on the adequacy and effectiveness of safety and specification consensus standards covering a wide range of pipeline transportation activities. Pipeline regulations in the US and Canada rely largely on the partial or complete incorporation of industry standards by reference. The US and Canadian national pipeline regulations are compared in this paper in design and construction areas, noting the important differences.

The media and sections of the public have shown recently an acute interest in Pipeline operational performance incident statistics. Published data for North America shows that 99.999% of crude oil and petroleum products shipped by pipelines reach their destination safely. Some pipeline operators claim even better performance, 99.9996 % being one example. However, should failing to deliver 4 barrels of product for every million shipped be a legitimate cause for concern? If not how about the more general case of 1 per one hundred thousand? Is pipeline performance being singled out unreasonably when compared to other threats to public and environmental wellbeing such as medical malpractice or industrial waste contamination? Evidence from Canada and elsewhere, indicates that, during their hospital stay, an appreciable number of patients, one in every 18, experience adverse events, such as medication error, injurious falls, infections, and other medical misadventures. Errors (mostly minor), in fulfilling pharmaceutical prescriptions show an even higher error rate — 1 in 4 in one recent study, yet the public appears to be unperturbed. A common thread is determining what constitutes an acceptable level of risk whether individual or societal, voluntary or involuntary. Besides providing a broader context for pipeline risk, the paper explores the origin and intent of the environmental screening standard of 1 in 10−6, as well as the concept of setting risk tolerance to be as low as reasonably practicable — ALARP. The question of why there may be a reticence for many Pipeline Regulators to set, as other industries have, a prescriptive value for ALARP is considered.

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