It’s an icy January morning. An inconspicuous white container stands in the middle of the test site near the car park of TUM‘s Garching Research Centre. Only the screw foundations on the sides, which are screwed deep into the ground, indicate from the outside that something exciting is hidden here: the potential winner of the 2025 edition of the “Not-a-Boring Competition“, organised by the Boring Company, a tunnelling and infrastructure company.
Over the past 12 months, the team of 19 TUM students has made significant improvements to the tunnelling machine that won the first two rounds of the 2021 and 2023 competition: The control electronics are now integrated in the first tunnel segment directly behind the drill head, the “power pipe”, which should enable the full torque of the four electric motors that serve as the drive to be utilised. The project manager of the TUM team, Felix Blanke, is confident of victory: “With the experience gained from the first two rounds and the improvements we have been able to implement, we expect to be the first to achieve the target of 30 metres of drilling distance.”
Connectivity solutions from LAPP, the global market leader for integrated solutions in the field of cable and connection technology, play a central role in the improvements to the cutterhead. Because the electronics are now largely housed in the first tunnel tube, the mechanical stresses in the harsh field environment are enormous. “Reliability and robustness are an absolute necessity here,” says Jens Zaigler, electrical engineering expert on the TUM project. “It has to work without restriction, because once we have started drilling, we can no longer access the drill head. It was therefore clear to us that we would use cables and connectors from LAPP again.”
Who is faster than a snail?
“Can you beat the snail?” That’s the question that the “Not-a-Boring Competition” has been focussing on since 2021. The background: a snail is around ten times faster than a conventional tunnel boring machine. Student teams from all over the world are tasked with showing that innovative technology can do better. Felix Blanke explains: “Of course, it’s not just about the fierce competition and academic research spirit. Among other things, the Boring Company is also looking for solutions that they can implement themselves to work more effectively. It’s also a good opportunity to recruit skilled labour.”
In the new round, which will be held in Texas in March 2025, the demands on the machine are higher than ever before. The winner is the team that manages to the first to drill through 30 metres of sticky clay with their tunnel boring machine. “Our first machine was designed to drill through hard rock – now the conditions are completely different. The muddy clay soil doesn’t make it any easier for us, on the contrary, we really had to come up with something here.” The TUM team’s solution: a foam is pumped to the cutting teeth of the drill head via a rotary feedthrough, which mixes with the sticky soil to form a fluffy mass and prevents the drill head from sticking.
The torque decides
In addition, extensive improvements have been made to ensure that the full torque of the drive can be utilised. A hydraulic device presses the drill head into the drilling tunnel and can speed of up to one metre per minute. However, the effective drilling speed depends on how quickly the drill head can remove material – and this is where the torque is crucial. Jens Zaigler explains: “The four electric motors that we have been using since the first round can theoretically produce around 11,000 Newton metres together. That would be more than enough to achieve a considerable drilling speed. So far, however, we have only been able to get around 3,000 newton metres out of it. We want to improve that this time with the further developments.” In the previous solution, the entire power electronics were installed outside the drill head and the drill tunnel, so ten long cables were required to transport the control signals and energy – “and this simply led to difficulties in synchronising the four motors with each other, which resulted in a drop in performance,” says Jens Zaigler. With the new power pipe concept, the student team has found a solution to this problem: The power electronics are mounted close to the drill head so that the signal path for synchronising the motors is much shorter, which, together with new frequency converters, increases the efficiency of the system
Connection solutions from LAPP guarantee reliable operation
From the outside, only a single power cable, the LAPP ÖLFLEX® ROBUST, and a single data cable, the ETHERLINE® ROBUST from LAPP, now run through the tunnel pipe into the power pipe, thus enabling communication via the Ethernet/IP fieldbus system between the control system in the control cabinet and the actuators and sensors in the power pipe and the drill head. The ÖLFLEX® SERVO power and control cable from LAPP connects the frequency converters in the power pipe to the electric motors in the drill head in order to supply them with power and transmit motor values. The connectors for the cables also come from LAPP, including the particularly robust and compact EPIC® POWER LS 1 connectors, which are installed to reliably connect the servo cables to the electric motors.
Jens Zaigler fulfilled an apprenticeship as an electronics technician before studying at TUM, so he was already familiar with LAPP’s connection solutions. When he took over responsibility for electrical engineering for the 2025 competition, it was clear to him that the team would continue to source connection technology from LAPP: “It’s simply the gold standard in the industry. And I know that LAPP not only fulfils the necessary requirements for standard certificates with its products, but also tests them beyond this on its own initiative. And it is precisely this reassuring certainty that everything is sound that we need here,” explains Jens Zaigler.
Ideal solutions for all challenges
Due to the new concept, the cables near the drill head are exposed to high mechanical loads and must be able to withstand strong vibrations, among other things. With the solutions from LAPP, we are simply on the safe side,” says Jens Zaigler: “With Cat.7, the ETHERLINE® ROBUST data cable offers an exceptionally high data transmission rate and is ideally matched to the Ethernet/IP bus system used. It therefore ensures stable and reliable communication and is also extremely resistant thanks to its TPE insulation. The electrical engineer already knew from his training that the ÖLFLEX® SERVO is ideally suited for use in harsh environments. Thanks to the additionally shielded wire pair, the cable can safely transmit the motor values in just one cable, which reduces complexity and cabling costs. And the compact and robust EPIC® connectors also offer reliable and fast installation. “This is important, because every second that we are faster increases our chances of winning,” emphasises Jens Zaigler.
On course for victory again with LAPP
In his 18 years as an Account Manager at LAPP, Markus Schreiber has been involved in and supported many exciting user projects. He acts as the contact person for the student team and is enthusiastic about their work: “The tireless commitment with which the students plan, test and implement innovative developments on a voluntary basis within a very short space of time inspires respect. It’s inspiring for me to work with young people who show such energy and commitment. The fact that we at LAPP are once again involved in this project with our connectivity solutions continues to make us proud. Especially the fact that our focus on quality and reliability is a key success factor – the two victories of the TUM team so far are great proof of this.”
Project manager Felix Blanke is also enthusiastic about LAPP: “In the first rounds, LAPP not only supported the TUM team with components, but also with advice. This laid a solid foundation for us, so that this time we were able to get started independently and fully rely on the connection technology supplied and the quality of LAPP.” The LAPP online shop was an essential basis for this. Markus Schreiber explains: “This is another factor that characterises LAPP: The online shop not only offers all relevant technical data, but is also clearly structured according to application areas. This means that users are guided quickly and accurately from their problem to the right solution, which our customers often praise. For the tunnel boring machine, the TUM team selected the components in the shop and sent us a list that proved to be 99% suitable after our internal tests. And of course we were happy to help with the rest.” Felix Blanke from the TUM team appreciated the simple and accessible selection option, as this gave the team more time to focus on improving and further developing the drilling system. “I’m glad that in LAPP we have such a customer- and quality-orientated partner for our connectivity solutions. This gives me the certainty that we have the best possible chance of winning in March – and we are aiming for nothing less.”
