Nov 29 2010
The damaged segments of the five lane double deck toll Bay Bridge that links Oakland and San Francisco has been repaired by removing a 3200Â ton, 1100 m, portion of it and by slotting a 3600 ton segment into the gap.
This work had to be executed 50 m above the ground and accomplished within three days. Syrinx Industrial Electronics was offered an agreement to devise a central sensing system for this scheme for furnishing a visual display of the bridge parts being replaced.
According to Gerry Bryant, Countapulse Controls’ managing director, nearly 31 Leuze laser distance sensing units and 16 pressure sensing devices were utilized for this purpose for use in exacting conditions. The ODSL 96B laser devices supplied a visible display for monitoring the calibrated readings instantly. He added that this in turn helped in exempting the requirement of personnel to change, between the main laptop and the portions of the bridge where sections have been replaced.
The sensors have been embedded in a fixed plate position by robust magnets. While replacing, the bridge was pushed nearly 300 mm upwards at four and then drifted horizontally using hydraulic winches. The position and height of the numerous winches were transferred to 4mA to 20 mA signals employing distance sensors. The horizontal 30 m motion was also monitored by means of these sensors.
The ODSL 96B is equipped with RS485 output and its unique electronics transforms this data to an appropriate 4mA to 20 mA signal. This functionality provided accuracy throughout the whole calibration range up to 50 m. Syrinx has also fabricated eight evaluation boxes in which all the pressure and laser sensors were joined. This provided the calibration grid that has been coupled to the laptop, which was then linked to a monitor for visualizing the motion processes.