Mobotix Cams for Tunnel Boring Machine Project

Nearly everyone in the Pacific Northwest has heard of Big Bertha – the giant tunnel-digging machine that became stuck under the streets of Seattle while attempting to create the Alaska Viaduct replacement. It took months and cost millions in delays, to dig down to the cutting head and figure out what went wrong, and it took months more, before they were back in operation.

While it was too late for us to help Big Bertha, there were other giant tunneling projects happening in Seattle. JCM Northlink, the company that was awarded a $400M contract to dig the UW light-rail tunnel under Seattle, contacted RadiusVision to help them build and configuring a unique hi-res camera system to be deployed at the edge of the cutter head in their giant tunneling machine, so that they could see what was going on in real-time, and hopefully avoid Big Bertha’s fate.

The JCM Northlink system included a pair of hi-resolution 5-megapixel sensors, a pair of high-intensity compact LED floodlights, and a high-pressure water valve system to wash away cutting mud and debris from the protective glass so that it would be possible to see something other than mud, all under control of I/O extensions to Mobotix cameras. There’s very little free space behind the cutter heads of these giant machines, and the area is subject to intense vibration, so RadiusVision engineers had to build the control architecture into a small, waterproof, vibration-damped NEMA enclosure and add inline quick-disconnects for interface cables.

The very constrained space also required the construction of an environment-proofed multi-cable snake and high-speed micro-usb extension so that the NEMA controller could talk directly to the camera body, and so that all the pieces could be hand-fed and mounted one after the other during the installation process.

JCM wanted the ability to view and control the camera sensors and peripheral devices either from within the cabin or above ground, so RadiusVision engineers designed custom soft-keys for the Mobotix camera interface that permit separate control of camera, LED’s and pressure-wash system from anywhere within the network.

The system has been tested and delivered to JCM.