A tool assembly configured for location on a section of a pipe is operable to both isolate a section of the pipe and perform an intervention into the pipe while maintaining pressure integrity. The tool assembly includes a clamp, a cutting tool and an isolation tool. In use, the clamp sealingly secures the tool assembly to the pipe, the cutting tool performs an intervention operation on the pipe, and the isolation tool isolates the section of pipe in order that repair or replacement of equipment can be effected.

A drill press comprises a hollow pillar with a base, a holder for a drill slidably mounted on the pillar and a clamp integral to the pillar for clamping the base to a work piece so that the drill is guided to the work piece. The clamp is a G clamp with a jaw held by an arm which engages a screw thread shaft housed in the pillar so that rotating the shaft raises and lowers the arm and the jaw.