Group 33 Engineering

Secunda HDD for 2 x 400mm water pipelines in Rock.

2023 started off with a bang!!!

The project consisted of 2 crossings with varying ground conditions from hard to rock formations. We established our American Auger DD-10 and Straightline Rock Eye Hammer.

We completed both crossings with the second crossing already having a tie-in point built. We achieved the crossing with great accuracy ending up exactly where the tie-in point was opened for the new HDPE pipe.

The void between the bore and pipeline was grouted after the installation of the new HDPE water lines.

Need our accurate and competitive HDD Services? Contact us today! www.group33.co.za

HDD Eldorado Park (River Crossing) 170-meter crossing.

Our longest HDD crossing for the year started off in Eldorado Park where we were tasked with installing a 450mm HDPE pipe over a distance of 170 meters in one continuous pull.

The area was a wetland and included a river crossing. Our time period for the installation of the new pipeline was relatively short as we wanted to complete the crossing before the rainy season. The new pipeline was to replace an old overhead steel pipeline that was leaking fresh drinking water at many of the pipeline joints.

We established our American Auger DD-10 which has a maximum pullback/thrust of 45 metric tons with 18 982NM of torque. For this project, we reached a peak pullback of 7 tons (15%) and a peak torque of 4 500NM (23%).

The ground conditions were non-reactive clay which can be incredibly difficult to drill in if the incorrect combination of chemicals are used, clay tends to stick to the HDD tooling which results in balling of the tooling which increases both torque and the pullback tonnage, which could cause the new pipeline to get stuck which renders the bore completely useless with the loss of equipment and new product pipe, and inevitably breaks equipment which delays the project.

Initially, we expected this crossing to take 12 days from pilot bore to pipeline installation, however, we installed the new HDPE pipe in 5 days. We maintained approximately 1.5 meters of cover from the depth of the riverbed (approximately 3 meters deep) and maintained approximately 1.8 meters from NGL after the riverbed until we reached the launch pit.

It's that time again!!!

Group 33 Engineering will be closing for our annual builders break on Tuesday the 13th of December 2022 and opening on Monday the 09th of January 2023.

It's been a year filled with growth, we have built so many relationships, thank you to all our clients.

Wishing you a Merry Christmas and a prosperous New Year!!!

For urgent quotations over our builder's break, send us an email.
📧 [email protected]

Lenasia 160mm water and sewer crossings HDD soft and boulder ground conditions.

Our good client required our services in Lenasia again, the scope of work entailed HDD for 25mm house connections (water) over 3 crossings, 1 160mm water crossing, and a 160mm sewer crossing.

We completed the water crossings including the HDPE Butt Welding of the 160mm product pipes, however upon an investigation of the 160mm sewer crossing, it was decided that we would attempt to drill but due to the boulder formations at this particular site, we could not guarantee that we would be able to drill to the required level.

During the pilot bore our HDD head was thrown off level and we decided to not continue drilling to save our client both time and money.