An apparatus and method for supporting pipe main repair tools in an excavation while repairs are being made requires only exposure of the top surface of a buried main and utilizes an anchoring system installed in or above the excavation and an elongate support member that spans the excavation in a generally horizontal position above the pipe main and supports an elongate tubular seal tube against the exposed surface of the pipe main. The elongate support member is secured and supported at opposite ends on the ground surface on opposed sides of the excavation by a pair of parallel laterally spaced shoring members firmly engaged on opposed sides of the excavation, or by a pair of parallel laterally spaced anchor plates firmly engaged on the ground surface on opposed sides of the excavation. The bottom end of the elongate tubular seal tube is engaged on the exterior of the pipe main and an adjustable clamping assembly mounted on the support member supports the seal tube in selective radially extending positions relative to the longitudinal axis of the pipe main. A jack mechanism between the seal tube and the adjustable clamping assembly on the support member forces the seal tube downward to seal against the pipe main. Various tools may be passed through the interior of the seal tube to perform operations on the pipe main.