According to this report, three elements were important in passing the bridge
-lowering of the funnel
-sailing at low tide
-sailing at high speed for Squat-effect
Sorry, it's in German..
http://www.ln-online.de/news/schleswig_holstein/2682429
edit: here's a rudimentary translation, thanks to Babelfish..
article (http://66.196.80.202/babelfish/translate_url_content?.intl=us&lp=de_en&trurl=http%3A%2F%2Fwww.ln-online.de%2Fnews%2Fschleswig_holstein%2F2682429)
Also, Wikipedia has recently added this event in their article on Squat effect..
http://en.wikipedia.org/wiki/Squat_effect