Biedermann, Lippok book London swimming berths

World 200m freestyle record-holder Paul Biedermann and European short-course champion Silke Lippok secured their places at the Olympic Games with victory at the German trials on Friday. After a disappointing time in the morning\'s heats, Biedermann won Friday night\'s 200m freestyle final in a convincing time of 1min 46.70secs to claim seventh place in the world rankings. \"I\'m very relieved, because I really wanted to qualify,\" said Biedermann. The 25-year-old is the world record-holder having clocked 1min 42.00sec at the 2009 world championships when he beat superstar Michael Phelps. Teenager Lippok also made sure of her London place by winning the women\'s 200m freestyle final in 1min 57.83sec. In the morning\'s heats, the 18-year-old clocked 1min 57.61sec to go under the Olympic qualifier time (1min 57.83secs) before victory in the final confirmed her London place.  Meanwhile, Britta Steffen, the 50m and 100m freestyle Olympic champion, is in fine form having clocked 53.65sec in the 4x100m relay for her Berlin-based team SC Neukoelln on Thursday ahead of Saturday\'s individual race. It was her fastest time since setting the world 100m freestyle record in 2009 when she broke her own mark and took gold in Rome at the 2009 world championships in 52.07sec. \"I am now the fourth fastest in the world, it\'s very nice,\" she said. Despite her impressive display, Steffen must still swim under the Olympic qualifying mark of 54.57secs and finish in the top two to book her London place in Saturday\'s individual final. \"If I can do that time again, I\'ll be satisfied,\" said Steffen, who struggled for form at last year\'s world championships in Shanghai.