Swen Weiner, General Manager of Herrenknecht in Abu Dhabi

Q. Is trenchless technology well-known and accepted in the Middle East?

Swen Weiner: Acceptance and level of utilization depends strongly on the region or country you look at. For Middle East, I would say that trenchless technology is commonly well-known and established as state-of-the-art technology, in particular for sewer construction. Contractors are quite independent, engineers and consultants are familiar with trenchless methods. This is the result of 30 years of hard work to get engineers and contractors convinced about the technology and the benefit they can get out of it. 

Q. And in Africa?

Weiner: In some North African Countries like Egypt, Algeria or Morocco, trenchless technology is also quite common. In other regions of Africa, we still have to invest in Business Development Activities to get the technologies and its wide range of application in to the minds of planners and consultants. We have to start with the basics of tunneling machines and possibilities in regards to tunnel alignment, installation depth and ground conditions. We have to continue our educational efforts to make clients and consultants more aware of the benefits of “going trenchless”. For the Kpone Independent Power Project in Tema, Ghana, Herrenknecht is proud of having delivered an AVND2000 tunneling machine, which is in operation since April this year to install a water intake and a brine outlet tunnel to assure cooling of the power plant. In difficult rock conditions, and with drive lengths up to 1,100 meters this project is a challenge for all involved parties, but will make the public aware of what can be achieved with trenchless technology.

Q. How do such reference projects influence future projects?

Weiner: Project owners often go for open-trench methods when they tender a project as, at a first glance, open-trench solutions often seem cheaper than investing in tunneling equipment. People tend to trust in technologies they know well, even if there are more reasonable and beneficial alternatives. With a rising number of projects executed with trenchless technology, clients and consultants become more and more aware of trenchless possibilities. Projects with high public interest even increase this effect, of course.

Q. What is the main application field of trenchless technology in the MENA region?

Weiner: The main topic in the region are sewage disposal and flood protection. The cities and industrial zones need innovative sewerage and drainage systems. The realized Strategic Tunnel Enhancement Program (STEP) in Abu Dhabi is an example fora sustainable deep sewer system comprising a main sewer, supply tunnels (link sewer) and pump stations. Further projects such as the Inner Doha Re-sewerage Implementation Strategy (IDRIS) Project are planned or being constructed to be ready for future urban development and anticipated population growth. In Doha, two Herrenknecht EPB machines have been in operation for the so-called Abu Hamour Southern Outfall Project. A comprehensive drainage system covering an area of 170 km² aims to ensure improvement in the southern section of the city populated by half a million people.

Q. What about water supply?

Weiner: For the improvement of water supply for the growing population, a large number of desalination plants has been built in coastal areas. In particular in Algeria and Morocco, Herrenknecht has supplied the machine technology to construct marine intake and outfall tunnels for various desalination plant projects. In Egypt near Ismailia, where large diameter pipe jacking has already been quite common for more than 20 years, the New Suez Channel was crossed several times with Herrenknecht Tunneling and HDD equipment to ensure water supply for population and irrigation at the other side of the Channel.

Q. What kind of technology is required for such projects?

Weiner: Generally, we think of remote-controlled micro-tunneling machines in diameters up to 3m. But there is a rising demand for high-capacity, large diameter tunnels where segmentally lined tunnels are a good alternative due to the possibility of relatively long drive lengths. Project-specific machine adaptations, e.g. for works in rock conditions, under high groundwater pressures or for subsea recovery in case of outfall installations are our daily business. Based on 35 years of experience in trenchless technology, Herrenknecht is nowadays the global technology specialist. Contractors around the world use our equipment to install hundreds km of tunnels and pipelines every year, while more and more extend the range of application possibilities. Long-distance pipe jacking, the possibility of curved alignments and great installation depths open new perspectives for construction projects that have to be considered, especially from the budget point of view. And cost is what counts for clients.