Original sentence: An accident at a Swiss station was caused by buffer-locked wagons in the 1980s.The bufferlock could be caused on the very sharp turnouts by the older rounded buffers.The newer buffers has rectangle shape and they are wider than taller.They are not so flat, so they rarely cause buffer locking
Edited sentence: An accident at a Swiss station in the 1980s was caused by bufferlocked wagons.Bufferlock could be caused on the very sharp turnouts by the older, rounded buffers.The newer buffers are rectangular and they are wider than they are tall.They are not so flat, so they rarely cause bufferlocking