For roughly forty years, from the late 1940s until after the fall of the Iron Curtain, West Berlin was connected by railway to West Germany via Marienborn and Helmstedt, with military Duty Trains operated by Britain, France, and the United States, which also operated Duty Trains between Frankfurt and Bremerhaven (the endpoints for the US Berlin trains). This group is dedicated to preserving their history and to sharing anecdotes and old friendships.