A panel for supporting the sidewalls of an excavation includes a plate, longitudinal members and vertical members. Each longitudinal member includes a first leg extending along the length, substantially parallel to and spaced laterally from the plate. The first leg of each longitudinal member being located adjacent and secured to the first leg of another member. A second leg, integral with the first leg, extends along the length, away from the first leg and toward the plate, the second leg being secured to the plate. Axially spaced vertical members are welded to the plate and to the longitudinal members.