Extensive construction work on the rail connection between Germany’s two largest cities began on Friday evening, meaning fewer train services on the Hamburg-Berlin route and longer travel times for long-distance passengers until December 14. Two of the four lines between the northern port city and the German capital will be suspended during the roughly four-month construction period, according to the rail operator Deutsche Bahn. All remaining long-distance trains will be diverted westwards via the town of Stendal, making the journey longer, and instead of twice an hour, they will only run once…