Apparatus for and a method of laying a pipe line

An apparatus for use in laying a pipe line which is composed of individual pipe sections arranged end-to-end, comprising:

• trench means for forming an open trench and for supporting the walls thereof, a receptacle located at the rear of the trench forming means for receiving the individual pipe sections, said receptacle having a sealed opening between the interior and exterior of the receptacle thereby permitting the pipe sections to be arranged end-to-end and the receptacle moved in the direction of advancement as the pipe line is extended, a plate component and a hollow unit on said receptacle each respectively capable of defining part of the sealed opening, said hollow unit being adapted to extend the interior of the receptacle while maintaining the sealed opening, whereby the plate and the hollow unit are usable individually and successively to accommodate a pipe section provided with an access tube projecting outwardly from its exterior periphery.

A method of laying a pipe-line composed of pipe sections arranged end-to-end;

• said method comprising excavating an open trench, introducing a pipe section into a receptacle located in the trench, arranging the pipe section in end-to-end relationship with a pipe section previously-installed and projecting through a sealed opening into the interior of the receptacle, displacing the receptacle to follow-up the advancement of the trench and repeating said sequence and whenever the pipe section to be introduced is provided with an access tube projecting outwardly from its exterior periphery carrying out the following additional steps:
• utilizing a hollow unit to extend the interior of the receptacle and engage on the exterior of the previously-installed pipe section to form part of the sealed opening, removing or displacing a plate defining part of the sealed opening to permit the tube of the newly-introduced pipe section to pass into the interior of the unit as the receptacle is displaced, relocating the plate to re-establish a seal with the pipe section inwardly of the receptacle relative to its tube and removing or displacing the unit to expose the tube of the pipe section.