Sometime during the late night or early morning hours of June 11 and June 12, 1962, John Anglin, his brother Clarence, and Frank Morris escaped from Alcatraz. The morning bed check revealed dummy heads made of plaster, flesh-tone paint, and real human hair. Despite near twenty years of investigation, the FBI never discovered if the men had successfully escaped or died trying.
Although it can't solve the mystery once and for all, new research from a Dutch team shows what conditions would have been necessary for a makeshift raft to make it to land and not get swept out to sea. Their model was originally created to study the impact of sea-level rise, but they realized it might help shed light on this decades-old mystery by combining their "high-resolution hydrodynamic simulation of the San Francisco Bay" with historical tide information from that night to plot different boat routes.
"We didn’t know exactly when the inmates launched their boats, or their precise starting point, and so we decided to release 50 ‘boats’ every 30 minutes between 20.00 and 04.00 from a range of possible escape spots at Alcatraz to see where they would end up. We added a paddling effect to the ‘boats’, as we assumed the prisoners would paddle as they got closer to land," says Fedor Baart, a hydraulic engineer at Deltares who is an expert on particle tracking.
Their model, which you can watch here, shows a narrow window for success. If they launched their raft anytime before 2300 (11:00 p.m.), they would be swept out into the ocean. Anytime after 1 a.m., and the tide would have pushed them back into the bay.
"In both cases they would have spent so much time in the water, they probably would have died of hypothermia, or they would have been picked up by the police because sunrise was at 0600," Dr. Rolf Hut explained to the BBC.
But between 2300 and 0100, or right around midnight, the trio would have had a chance if they paddled hard northward. The tides would have worked in their favor and they could have ended up at the marine headlands in the northern site of the Golden Gate Bridge.
It sounds like a slim chance, but an additional part of the model supports this possibility. The simulation shows that in the event that they did embark around midnight, any debris would be carried by the currents towards Angel Island, which is where the FBI found a paddle and some other personal belongings.