Taking a train during a heat wave? Watch out for ‘sun kinks’. As tracks heat up, they expand and buckle. That's forcing rail operators to adapt as the climate heats. Grist Matt Simon Jul 09, 2024  There is a gap between the rails, and this gap is meant for such expansion,” said Dev Niyogi, who studies urban climate extremes at the University of Texas at Austin. Still, in a severe heat wave, the rail can swell until the underlying ties can no longer contain it. Then the rail gets visibly wavy, morphing into what’s known as a sun kink. That’s a serious hazard for trains, which can derail on misaligned tracks. In extreme cases, the track can violently buckle, going from a straight shot to grotesque curves almost instantly. So if it’s excessively hot out, rail services will slow their trains as a precaution, which provides less of the mechanical energy that can lead to buckling. Amtrak, for instance, restricts speeds to 80 miles per hour if the rail temperature hits 140 degrees. That was partly the reason behind Amtrak delays in the Northeast Corridor, which runs between Washington D.C. and Boston, during a brutal heat wave last month. (Amtrak did not respond to multiple requests to comment for this story.)  As extreme heat waves get worse, more tracks will turn into sun kinks — disrupting commuter rail service that reduces carbon emissions and slows that warming. In 2019, a study estimated that the U.S. rail network could see additional delay costs totaling between $25 billion and $45 billion by the year 2100, in a scenario that assumed greenhouse gas emissions decline in the next 20 years.  Compared to a tree falling on top of a track and blocking traffic, or a switch breaking, heat is a much larger, harder problem for rail operators to deal with. “Heat waves tend to be regional, so the impacts can be huge,” said Jacob Helman, one of the author’s of that 2019 study and a senior climate consultant at Resilient Analytics, which provides infrastructure vulnerability assessments. “It can impact the entire Northeast Corridor over the course of five days.”As climate change drives hotter and longerheat waves, companies are reevaluating their operations and adapting new technologies. Railroads already use remote sensors to determine the temperature of their rails, but are getting still more sophisticated as heat waves intensify......read on       https://mail.google.com/mail/u/0/?tab=wm&ogbl#drafts?compose=DmwnWrRrlrGjJPcPRzdQcsHRwgkKBGKPPMQwTXZvZqKHBlKtScmmWGHhnGtbXvWdXZNkGTsNmvwG