A famous prison-break mystery gets a new wrinkle as scientists examine a hydraulic model that gives the escapees a brief window for a survivable run.
Alcatraz, with its location on a craggy island in the middle of the San Francisco Bay, was supposed to be an unescapable jail. In June of 1962, prisoners John Anglin, Clarence Anglin and Frank Morris slipped away from the island, never to be seen again. Even after a nearly two-decade investigation, the FBI was never able to figure out if the men died in the attempt or survived and successfully disappeared on dry land.
The ingenious escape involved plaster dummy heads, holes in walls, homemade paddles and an inflatable boat crafted from over 50 raincoats. We will likely never know the prisoners' ultimate fate for sure, but a team of Dutch scientists has figured out a way the escapees could have survived the treacherous trip across the water, and it all comes down to timing.
Scientists from the Delft University of Technology studying sea-level rise in the San Francisco Bay built an advanced hydraulic model of the bay. The computer model was originally designed to look into modern-day flood risks for industrial facilities.
Armed with the model and historic tidal information for the time of the escape in 1962, the team launched 50 virtual boats from various spots on the island at various times and watched to see where the craft ended up. The virtual boats also had an added "paddling effect" to simulate the prisoners presumed use of homemade paddles on approach to land.
"The simulations show that if the prisoners had left before 23.00, they would have had absolutely no chance of surviving. The strong currents would have taken them out to sea. However, if they left between 23.00 and midnight, there is a good chance they reached Horseshoe Bay north of the Golden Gate Bridge," said Fedor Baart, a hydraulic engineer who assisted with the project.
The scientists give a nod to a well-known "Mythbusters" episode that examined the escape and also determined the most likely landing place for the prisoners was Horseshoe Bay. "Of course, this doesn't prove this was what really happened, but the latest and best hydraulic modelling information indicates that it was certainly possible," said researcher Rolf Hut.