This animation illustrates how a standard Polychem chain and flight scraper system is assembled and installed.
On the weekend of April 1, the star of a re-enactment of a famous prison escape at Philadelphia’s Eastern State Penitentiary became the escape tunnel itself, excavated by archeologists with images projected on-screen by Envirosight, LLC. Using its ROVVER robotic crawler and QuickView zoom camera, the Envirosight team was guided by archeologist Rebecca Yamin of John Milner Associates to pinpoint a remaining section of the 97-ft tunnel and send back amazing color images.
On April 3, 1945, 12 prisoners including infamous bank robber Willie Sutton escaped through the tunnel and out to the street in the early morning hours. Most were captured immediately, while Sutton and others remained at large for up to seven weeks.
The unique tunnel vision was the first ever captured of the secret passageway that led the 12 men to temporary freedom, with many similarities to the film Shawshank Redemption.
“Our equipment is typically used for pipeline inspection, so this was a fun way to use our ROVVER and QuickView with tremendous historic benefits,” said Richard Lindner, president, Envirosight.
The ROVVER is a robotic-wheeled vehicle that travels through pipelines, operated with pinpoint accuracy by a remote pendant. It has an illuminated zoom camera that tilts and pans, capturing vivid color video. The QuickView is a zoom camera on an extension pole that descends 18 ft and casts bright illumination. The controls are all operated from a safe distance, with video transmitted to large LCD monitors. Both were operated from the back of an Envirosight Outpost portable inspection unit truck positioned near the tunnel excavation hole, with two LCD monitors displaying the images for the hourly tour groups.
According to Eastern State Program Director Sean Kelley, “The condition and even existence of the tunnel, thought to have caved in or been filled in over time, was unknown until the excavation and underground inspection by the Envirosight equipment.”
Families, school children and the Philadelphia media were among the first to see the live tunnel video, which showed wooden planks used for support thought to be stolen from the prison’s workshop, wiring for lighting and even some metal pieces and other items thought to be digging tools. The tunnel was designed and dug by inmate trusty and plasterer Clarence Klinedinst, who reportedly flushed the dirt down the toilet and concealed the hole in his cell with a laundry basket. Klinedinst did plaster work in the prison and had access to tools and supplies. It took him a full year to dig the tunnel.
As part of the historical weekend, actors recreated the escape scene for the public, as they held up pictures of their criminal counterparts and gave a brief history of each prisoner. Then, in the spot outside the wall where the 12 had emerged from the tunnel, the “prisoners” jumped to the sidewalk and were chased by police actors, who rounded up most of them to the cheers of the crowd.
“Seeing the small size of this tunnel, which we estimated at 24 in. in diameter, we can now imagine what the 12 desperate prisoners were feeling and seeing as they plunged into it,” said Jake Wells, Envirosight marketing manager.
One of the tour group’s favorite images on the screen was a shot of the ROVVER crawler inside the tunnel, climbing over dirt mounds toward the wooden bracing, as the QuickView illuminated the area and sent back the image. Another LCD monitor showed close-ups of what the ROVVER was seeing—zoomed images of the bracing, wire and possible tools. The Envirosight equipment also recorded and stored all of imagery for the Eastern State Penitentiary historical archives.
“The kids were transfixed by the whole thing,” Wells said. “They seemed fascinated by the robotic crawler because they could relate it to remote toy cars, though the ROVVER is designed for much more rugged environments.”
The city of Philadelphia uses Envirosight inspection equipment for its underground infrastructure and sewer system.
“It’s incredible that equipment used for pipe inspections can show us exactly what the prisoners were experiencing in that tunnel and capture and preserve a piece of history for us,” Kelley said.