Esor Pipejacking called in to tricky pipeline project
Esor Pipejacking is acting as sub-contractor in a project involving a search for a pilot
hole used in the laying of a Sasol gas pipeline.
The horizontal directional drilling pilot hole had been made by a previous contractor
as part of the deviation of the existing 8¨ Uncle Charlie’s to Lawley pipeline where the
conduit crosses under the Klipriver near Nancefield, Johannesburg.
The pilot hole was found to be in very close proximity to the southern bank of the river and the main contractor, Frontier Pipe Lines (Pty) has enlisted Esor’s assistance in exposing the pilot hole. The existing hole will be reamed and the steel gas pipeline installed along the remaining length of the drill path.
Esor’s task in locating the hole is by no means easy. It lies approximately 12m below ground and only 14m from the river bank. The first decision was to sink a 12m-deep shaft by drilling and grouting micro piles onto the shaft perimeter. In addition, six dewatering holes were drilled down to a depth of 14m and pumps installed.
The shaft excavation, which is ongoing, has proved to be a major task. This is owing to difficult rock formations and large volumes of water, and involves the use of a mini bobcat excavator, which was lowered into the shaft using a 35 tonne crane.