Twitter 上的 Adelphia Gateway:"Horizontal Directional Drilling (HDD) is on-going at multiple sites. “Pullback” is the last step in #HDD pipeline installation where the prefabricated #pipeline section is pulled through the bored hole.
![2: Pipeline installation using HDD: (a) Pilot hole; (b) Reamer; (c)... | Download Scientific Diagram 2: Pipeline installation using HDD: (a) Pilot hole; (b) Reamer; (c)... | Download Scientific Diagram](https://www.researchgate.net/publication/339244035/figure/fig2/AS:992778481856512@1613708243594/Pipeline-installation-using-HDD-a-Pilot-hole-b-Reamer-c-Pull-the-pipe-back.jpg)
2: Pipeline installation using HDD: (a) Pilot hole; (b) Reamer; (c)... | Download Scientific Diagram
![What is HDD? | Trenchless Boring for Underground Cables Pipes Conduits Water Sewers Storm Cables Ducts Fibre Optic Telecommunications Electricity What is HDD? | Trenchless Boring for Underground Cables Pipes Conduits Water Sewers Storm Cables Ducts Fibre Optic Telecommunications Electricity](https://www.hddrilling.co.za/images/page_pics/horizontal_directional_drilling_gauteng_kwazulu_natal.jpg)