A catheter includes a tip electrode with a shell and a support member to provide a plenum chamber. The plug is formed with a U-shaped passage for a safety line to wrap around and secure the support member (with the shell affixed thereto) to the catheter. Additional passages are formed in the plug to accommodate components such as irrigation tubing, lead wire and thermocouple wire pair. A method of manufacture provides distal installation and/or anchoring of the safety line, lead wire and thermocouple wire pair in the support member prior to sealing the support member and mounting the shell.