Anglesea Outfall Replacement Project, Australia: The pipe string is towed out to sea and pulled back to the mainland by the HDD-rig.

Beatrice Offshore Windfarm, Scotland: Innovative installation technology on the Scottish North Sea coast.

Case 1: Shortly before the start of the tourism high season, a collapsing cliff in Australian Anglesea cuts off ​​the sealink of a water treatment plant. Fast action is needed. The project environment does not make things easier. In the immediate surrounding area is not only Port Philip Bay, visited by about 4,000 ships a year, but also Point Addis, a 10 kilometer long underwater national park. Unique and sensitive coral reefs worthy of protection are not to be affected by the necessary shore-approach operation. Nothing must enter the biosystem that does not belong there.
Using a Herrenknecht HK250C HDD-rig, Australian drilling contractor Dunstans Construction Group first drills a pilot hole. After sealing, it is reamed from the rig side. The 700 meter long pipe string with a diameter of 355 mm is then towed out to sea and pulled back to the mainland by the HDD-rig. Reconnection in the shortest time: three months after the old connection is cut the new line is put into operation. There is nothing to stop Australian summer fun on the coast near Melbourne.

Case 2: As if made for the Direct Pipe® method: in very rough wind and weather on the Scottish North Sea, two 440 meter long cable conduits are installed underground between the coast and an offshore wind farm. The trick is to have the smallest possible distance between the seabed and the protective pipe. The maximum overburden is 8.3 meters. On this basis, the installed power cables can be cooled by the sea water. With the Direct Pipe® method, potential frac-outs can be safely avoided. The cool mission is crowned with successful project completion: the connection of the wind farm to the power grid operated by National Grid.

Learn more:
Speedy pipeline connection in Australia
Beatrice Offshore Wind Farm Landfall

See also:
Beatrice Offshore Wind Farm

Crossings under railway lines require the greatest precision when installing pipelines.

Case 1: In order to maneuver with absolute precision under cramped conditions while minimizing the impact for residents, Dutch contractors A. Hak Drillcon B.V. and Visser & Smit Hanab B.V. choose Herrenknecht's Direct Pipe®-method. In the Netherlands , it is used to cross under a railway line at depths of up to 30 meters. Things move quickly: with top advance rates of up to 230 meters per day, the 1,400 meter wide section is fully completed in just 16 days. Immediate subsequent mission: the successful crossing beneath the Hartel Canal in the port of Rotterdam.

Case 2: A total of 9 obstacles make the Freeport Texas a gigantic undertaking. A very diverse obstacle course: in addition to the Dow Barge Canal, various roads, multi-track railways and a flood protection levee have to be crossed under. For contractor Michels, appropriately flexible equipment is key. To put the entire pipeline more or less effortlessly into the ground with the necessary force, a 750 tonne Pipe Thruster is connected to the 1,000 millimeter diameter AVN machine. Using the Direct Pipe®-method, this powerhouse can deliver the required thrust non-stop. As a result, the ambitious mission in a sensitive urban environment is quickly accomplished with maximum power and safety.

Learn more:

The Netherland's North-South Route

See also:
REM Directional Moves From Traditional Excavation to Directional Drilling
Direct Pipe boring Hartelkanaal Europoort

Bundaberg, Australia: Successful crossing of the Burnett River

Hetlingen, Germany: Supreme discipline in the pipeline business: crossing rivers, as here on the banks of the Elbe

Long distance crossings for oil and gas pipelines can extend to more than 2,000 meters. Since drilling and installation work runs under the riverbed, this can result in quite large vertical and horizontal curves. For the pipeline installer, one of the core tasks of the pending installation is to work with extreme precision from the beginning to reach the exit point and ensure maximum safety throughout the process in the heavily pressurized environment. To meet all requirements in this special discipline, Herrenknecht is doing real pioneering work with its customers.  

To expand the gas supply infrastructure in Greater Hamburg, the Elbe has to be safely crossed at a 1,500 meter wide location. During the pipe jacking process, the AVND machine from Herrenknecht (diameter 3,025 millimeters) overcomes massive boulders and sometimes very adhesive clay layers. In addition, the fluctuating tide at water pressures of up to 4 bar complicates the drive. To keep up the pace under these circumstances, the heavily worn cutting tools on the cutting wheel have to be replaced by new ones because of the arduous alignment conditions. After 4 months of precise long-distance tunnelling, celebrations are in order: the two opposite banks of the Elbe are connected by a 2,400 millimeter pipeline.  

State-of-the-art horizontal directional drilling technology is also suited for crossing wide river sections. As demonstrated in Klaipeda. In three steps the Lithuanian supply network is connected to the LPG terminal in Lithuania's largest seaport. In view of massively high frictional forces underground, it is necessary to proceed rapidly with the pipe infeed of the 8 2/4" and 28" gas pipelines with a total of 4 boreholes of different lengths. In order to cover the extraordinary distance of the longest section at 2,300 meters, 50 meters below the water surface, the contractor relies on reinforcement from Herrenknecht's powerful Pipe Thruster. The length and size of the pipelines require high push and pull forces of up to 500 tonnes. With this powerhouse, all drilling and subsequent pipe insertion is completed within the specified 18 months.

Learn more:

All Around Issue 2
Teamwork ensures swift pipe jacking under the Elbe
Powerful pipeline installation technology

See also:
TAP’s trenchless river crossings

Icy conditions: Crawler Rig in an extreme situation

Case 1: In winter a pretty icy wind can blow in Scandinavia. When installing two sewage pipes and a drinking water pipeline in Sweden, the drilling team and the technology are facing a temperature drop to minus 20 degrees Celsius. An <<HK150C>> Crawler Rig designed for arctic temperatures is needed and accordingly equipped in Schwanau. 

The operation in water and centimeter thick ice is quite something. The 700 meter long pilot hole is completed after only two days of drilling, but then the weather changes radically: the thermometer drops by 25 degrees. A two-week battle against centimeter thick ice begins for the experts on site. Day and night, up to four boats are in action on the lake as icebreakers. The boats have to break through the ice to retrieve the cutterhead, swap it for a reamer and attach the pipeline, which is also frozen in the ice. The effort is worth it – the 28-inch line is safely installed in time for Christmas.

Case 2: In the French town of Saint-Jean-Cap-Ferrat on the Mediterranean, a Crawler Rig is also used, although in somewhat more pleasant temperatures. Here, the topography of the drilling location makes this crossing extreme: the drill site right next to a coastal road is very small and directly on the rocky, steeply cut coastline. Even the access to the jobsite can only be reached via very narrow, winding alleyways, no crane can help. The flexibly maneuverable caterpillar tracks of the Crawler Rig prove their worth in this endeavor too. As corals live on the seabed, various protective measures are taken. At 22 degrees the drill string penetrates steeply into the rocky stretch of coast, while the rig stands solid as a rock. The muck is removed with compressed air and by the beginning of the holiday season the job on the Côte d'Azur is done.

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Saint-Jean-Cap-Ferrat
Norrtälje

The Herrenknecht Slant Directional Drilling Rig can be used for depths of up to 2,000 meters, as here in Russia.

Innovative machine technology: versatile rigs that drill into the ground with a 90° entry angle.

Case 1: In the Russian tundra, the innovative SDD method was used with an entry angle of 45⁰ to bring underground bitumen to the surface. In a single step it is possible to drill down quickly to 980 meters and then deflect the drill string horizontally. This allows the insertion of filter tubes into the embedded oil sand layers to then extract the oil by means of the SAGD method (Steam-assisted gravity drainage).

Case 2: For the "Greenbrothers" in Zevenbergen in the Netherlands, everything revolves around ideal conditions for growing eggplants. Heating should be as climate-friendly as possible, preferably with renewable geothermal energy. The principle is very simple: a well raises the warm water from a depth of 1,535 meters. Then, after the heat has been extracted, the cold water is pumped down a second well back into the reservoir.

See also:
VSH Zevenbergen