Abstract: A slip form apparatus for the in place formation of a continuous concrete pipe in an open trench. The concrete material is supplied under high pressure to obtain a good and uniformly compacted pipe. The apparatus is automatically moved forward along the trench only when a properly compacted continuous pipe is being formed within the apparatus. Provided in the construction of the apparatus is the ability to temporarily stop the movement and formation of the pipe and then subsequently continue with the formation of the pipe without having to remove the apparatus from the trench. Also utilized in conjunction with the apparatus is a unique deployment arrangement for an inflatable film means located at a stationary position behind the apparatus to automatically supply support for the wet cementitious material as the pipe is being formed along the trench.

Abstract: A slip form apparatus for the in place formation of a continuous concrete pipe in an open trench. The concrete material is supplied under high pressure to obtain a good and uniformly compacted pipe. The apparatus is automatically moved forward along the trench only when a properly compacted continuous pipe is being formed within the apparatus. Provided in the construction of the apparatus is the ability to temporarily stop the movement and formation of the pipe and then subsequently continue with the formation of the pipe without having to remove the apparatus from the trench. Also utilized in conjunction with the apparatus is a unique deployment arrangement for an inflatable film means located at a stationary position behind the apparatus to automatically supply support for the wet cementitious material as the pipe is being formed along the trench.