• Myth confirmed? The fate of the Alcatraz escapees

      Three man brave the cold water of the San Francisco bay in a dingy made of stolen raincoats. It is june 12th, 1962 and the trio has just committed the most daring, and by now the most famous, prison break in recorded history. Digging a hole through the concrete behind the ventilation covers in their cels using stolen spoons, the escaped from Alcatraz: the heavy guarded prison on an island in the San Francisco bay. Onze out of their cells, Clarence AnglinJohn Anglin and Frank Morris moved to the northern edge of the island and entered the water in their dingy. Never was ever heard of them again.

      Did they make landfall? Did they drown? Nobody knows for sure. The mythbusters tested if it was possible to reach the shore, by recreating the events of that night, including the ride in the raincoat-made dingy. Their conclusion: myth plausible.

      When Delft University of Technology colleague Olivier Hoes showed me his implementation of 3Di model for the San Francisco bay, I immediately thought about the mythbuster episode. Olivier originally used 3Di to study the effect of sea level rise, but this was, in my opinion, the ultimate chance to re-analyse the events of that night in 1962. 

      I looked up old tital records. Olivier used those to calculate the water-flow around Alcatraz that night. Fedor Baart, a simulation expert at Deltares used that to analyse the potential flow-paths of the escapees.

      And we confirm: myth plausible! We calculated a worst case and a best case scenario. In the worst case the peddling of the escapees is futile: only the tidal movement is considered. In that case, the escapees are either swept into the pacific if they entered the water before 23.00, or they are pushed deep into the bay and discovered if they enter the water after midnight. Only in the time window between 23.00 and midnight do they get close enough to the shore to have a chance to survive. 

      In the best case, the escapees peddle northwards with a speed of almost 1 km per hour, an almost olympian effort. In that scenario, they most likely survive and make it to the north side of the Golden Gate bridge: exactly the same location at which the mythbusters made landfall.

      Fedor Baart made two really nice visualisations, shown below. In each visualisation 50 virtual boats are released every hour from the location where the escapees entered the water. The first visualisation describes the worst case scenario (ie. no peddling) and the second describes the best case scenario (peddling northwards with almost 1 km per hour)


    • In the news

      Our work was picked up by the BBC, and just as last time with my "Umbrella Raingauge" work, other news outlets followed suit. Here is a list of news sites that have mentioned / published our work: (will update as more become available)

      • The BBC: published it on their site here and interviewed me for the UK radio (listen here) and the BBW World Service.
      • The Washington post published this cool feature.
      • Local CBS SF Bay Area came over and interviewed Fedor and me and made this cool short item.

      A lot of Dutch news outlets also run the story, including national TV news of the NOS and the newspaper Volkskrant. For a complete list see the dutch version of this page here.