Abstract: The appliance comprises on a carriage 3 running inside the pipes 1,2, two struts 8 manipulated by two jacks 14 in order to make two shoes 13 and an arch 21 pivot against the inner face of the pipe 1 already laid, as well as a jack 26 for jointing the pipe 2 to be laid into the pipe 1 after having made it bear against the arch 21 which keeps it centered during the jointing.Application: to the laying of concrete pipe sections for drainage mains.Reference: FIG. 1.