by the present Kennington loop) car ends were marked "A" or "B" (later, when axles were designated by letters, the "B" car ends became "D" to match the adjacent axle), and it was not permitted to couple cars together if the ends to be coupled bore the same letter. It was found necessary to provide a turntable at Golders Green depot (near the other end of the line), for use when there was an imbalance of car directions. The former South Ferry station on the New York City Subway solved the railcar door hazard by using gap fillers that extended out to the railcar door when the train triggered a switch on the tracks. The older station was closed in 2009, but was reopened between 2013 and 2017 as a result of damage to the newer station caused by Hurricane Sandy. References External links Railway track layouts Tram loops