Shields Magnetics Lifting Magnets are currently in use with the seismic retrofitting of the Bay Bridge in San Francisco. The Bay Bridge is undergoing the retrofitting in the hopes of bringing it up to current transportation standards. Following the 1989 Loma Prieta Earthquake, in which the East Span of the bridge was damaged, it was determined that the work was highly necessary. The lifting magnets are being used to hold beams and girders in position both above and under water. Lifting magnets are specifically suited to this type of application since their field of reach is immediate upon contact. Unlike their counterparts, the magnetic sweepers, the lifting magnets do not have a “depth of reach” and possess great strength at the surface but not peripherally.