It took years to float a train over Lake Washington. Here's how it works

<p>Opening the light rail across Lake Washington over the weekend was an historic moment.</p> <p>Trains go across bridges regularly, but never before has there been a train over a floating bridge.</p> <p>Engineers worked on the challenge for years.&nbsp;</p> <p>We&rsquo;ll hear why it&rsquo;s so complicated and how engineers pulled it off from University of Washington professor Travis Thonstad.</p> <p>We can only make Seattle Now because listeners support us. <a href="https://www.kuow.org/donate/seattlenow">Tap here</a> to make a gift and keep Seattle Now in your …