The horizontal drilling machines from Herrenknecht AG pave the way for fast and easy installation of pipelines and tubes. And now there are also electrically powered versions available. In its machines, the company relies on HELUKABEL for the wear-resistant cables with higher current carrying capacity, and on EKD Systems for the tailor-made energy chains.
The substructure of the drilling rig can move back and forth several meters.
The world population continues to grow, and with it the need for better performing infrastructure. Reliable distribution networks for water, energy and communication are particularly important in urban areas. A large part of these networks runs underground through tunnels and pipes. Their installation is becoming increasingly expensive and time-consuming, especially in densely populated areas where planned routes run under buildings or other obstacles.
Such challenges are nothing new for Herrenknecht AG. The company, based in Schwanau, Baden-Württemberg, is a global leader in tunnel boring technology and is currently involved in various construction projects worldwide. The company's portfolio includes various types of drilling methods. For example, so-called Horizontal Directional Drilling (HDD) enables fast, cost-effective and environmentally friendly installation of pipelines and tubes for oil, gas, wastewater, district heating or internet cables under rivers and roads.
The HDD method uses a steerable drill head that starts by making a borehole from the start to the end point. The borehole is then enlarged in several steps until the required size is reached. During the final step, the prefabricated pipe is inserted. The main advantages are the elimination of the need to dig a trench and therefore the minimal impact on the environment.
The HK300TE is an HDD drilling machine powered exclusively by electric motors and was launched on the market by Herrenknecht in 2022.
Electric drives replace diesel hydraulics
Previously, horizontal drilling machines (also known as rigs) were powered by diesel generators. These had several disadvantages, as Stefan Pabst, Head of Process Engineering at Herrenknecht, explains; “Diesel engines are very energy-intensive, have low efficiency and are relatively noisy. The latter is a particular problem in residential areas.” Therefore, as in many other areas, the trend is towards electric drives.
The HK300TE is an HDD drilling rig powered entirely by electric motors and was launched on the market by Herrenknecht in 2022. With a tractive force of 300 tonnes and a torque of 120,000 newtons, it is identical to diesel engines in every respect, but it is significantly more energy-efficient, emission-free and quieter. “This means, for example, that it can be operated for longer periods of time because it causes less disturbance to residents. Tunnels can therefore be completed more quickly and efficiently,” Pabst notes. “In addition, the speed, forward pressure and torque of the rigs can be set much more precisely.” And there is another advantage: “The different emission standards for diesel engines that exist in many countries do not apply to these machines, which means they can be deployed more flexibly.”
“HELUKABEL has become more of a partner than a supplier.” – Stefan Pabst, Head of Process Engineering, Herrenknecht.
The environment in which tunnel boring takes place is tough with adverse weather conditions, humidity, dust, debris and dirt. High-quality cabling is essential to ensure that the electric motors operate reliably and at full power. “To achieve the required performance, we need high current loads,” explains Jens Holzwarth, Electrical Engineer for Process Engineering at Herrenknecht. “Electromagnetic compatibility (EMC) must also be guaranteed to prevent disruptions to operations.” Weight and space requirements were also important factors during the design, as the rigs are transported on trucks and therefore need to be as compact and light as possible.
“To achieve the required performance, we need large currents” – Jens Holzwarth, Electrical Engineer for Process Engineering, Herrenknecht.
Long-term and solution-oriented partner
With these requirements, Herrenknecht turned to HELUKABEL. The expert in electrical connection technology has been a reliable supplier and partner in the development of new machines for the company for around 15 years. The TOPFLEX series of drive cables, which connect frequency converters to electric motors, was one of the cables selected for the HK300TE. “They have the required load capacity and are shielded to prevent electromagnetic interference,” explains Michael Huser, Head of Regional Sales at HELUKABEL. The HELUTHERM series of single-core cables, which are mounted between the distributor and the motor, is also used. The experts at HELUKABEL developed a special shielded cable with adapted sheathing material for outdoor use. The scope of delivery also includes data cables for measuring the temperature of the motor.
The main drive of the HDD drilling machine is the carriage, which provides the necessary torque and forward pressure for drilling. The carriage can move back and forth over several meters and thus presses the rotating drill rod into the rock or soil. Each cable that connects this component to the rest of the machine must be built into a flexible energy chain to ensure reliable protection against damage from the moving carriage. The energy chain is a custom development by EKD Systems GmbH, a subsidiary of HELUKABEL. “A ready-made plastic chain would not be strong enough for this demanding application, so the design department decided to make one out of steel,” explains Stefan Pabst. Thanks to the high level of expertise in the development of custom constructions at EKD Systems, it was no problem to optimally adapt the energy supply for use in the HDD machine.
Michael Huser, Area Sales Manager at HELUKABEL
“Together with Herrenknecht, we have developed a special shielded cable that is suitable for outdoor use.” – Michael Huser, Head of Regional Sales, HELUKABEL
One total supplier
Cables and energy chains from a single source offer Herrenknecht considerable advantages. As Holzwarth emphasises; “We can trust that all components complement each other optimally. And if we get stuck, we have an expert who knows what he is talking about and can answer our questions about electrical connection technology. Over the years, HELUKABEL has become more of a partner than a supplier. And we are convinced that this successful collaboration will continue in the future.”
You can find this and many other interesting articles in the current issue #14 of HELUKABEL's customer magazine, POWER. Read it here!
Nederlands