At the base of every towering wind turbine, thousands of precisely tensioned stud bolts hold the massive structure together. These critical components ensure stability but remain largely invisible. Despite their importance, the process of installing and maintaining them has long been a persistent bottleneck for the wind industry – slow, physically demanding, and lacking crucial data traceability.
Netherlands-based IntoMachines B.V. is tackling this challenge head-on, developing innovative tooling designed to make bolting operations faster, safer, and smarter.
The High Cost of Conventional Bolting
Bolting is one of the most repetitive and labor-intensive aspects of turbine assembly and maintenance. Precision is paramount; a single incorrectly tensioned stud can lead to serious structural issues.
- Time Consuming: Tightening a single flange with M72 studs can take up to three hours. On the critical path of turbine assembly, this translates directly into significant costs and potential delays.
- Labor Intensive Maintenance: Industry standards require checking 10% of bolts every one to two years. For large wind farms, this means thousands of manual checks, requiring skilled labor, specialized gear, and turbine downtime. Without data from the initial tightening, each check is like starting from scratch.
- Physically Demanding & Risky: Moving heavy hydraulic tensioning tools (often exceeding 30 kg) from stud to stud is strenuous, increasing fatigue and long-term injury risk for technicians. Working with high hydraulic pressures (up to 1,500 bar) also carries the inherent risk of hose bursts and hydraulic injection injuries.
The market feedback is clear: the industry needs bolting solutions that are faster, safer, less physically demanding, provide detailed data logging, and incorporate automation where possible, all without adding unnecessary complexity.
Understanding the Tensioning Process
To appreciate the innovation, let's recap the conventional process:
- Studs are inserted through flange holes, and nuts are fitted.
- A hydraulic tensioning tool is threaded onto the stud.
- Hydraulic pressure (via a pump and hose) stretches the stud by 1-2 mm.
- While stretched, the nut is tightened (approx. 150 Nm torque).
- Pressure is released, and the tool is removed, leaving the stud in pre-tension.
Accurate pre-tension is vital. Too much force risks snapping the stud; too little compromises the joint's integrity. Ensuring technicians follow procedures correctly is essential.
Introducing the QUANTUM Smart Tensioner
Developed by IntoMachines and TensionPro, the QUANTUM smart tensioner brings digital control and data logging to the field.
- Precision Presets: Engineers create exact tightening procedures (pressure, nut angle, multi-stage settings) which are loaded onto the pump.
- Simplified Operation: Technicians connect the tool, select the preset, and start. The system guides them step-by-step, confirming correct tensioning. Setup takes ~30 seconds.
- User-Friendly Interface: Only four push buttons on the pump and one on the tensioner – no complex touchscreens or delicate cables. Easy to operate even with gloves on.
- Robust Data Logging: Records pressure, nut angle, and bolt count for each stud. Includes functions to 'Loosen', 'Skip' (register unworked bolt), or 'Fail' (log damaged bolt).
- Verifiable Reporting: Generates a full report after completion, shareable via USB, email, or cloud. (An AI agent is also in development to automatically review reports for anomalies.)
- Increased Speed: An automatic nut tightening motor reduces tensioning time by 15%. A built-in START button on the tensioner eliminates handheld pendants.
Feedback from technicians highlights the speed and ease of use compared to older systems, with training taking only an hour online.
The Leap to Automation: The Autonomous Tensioning Robot (ATR)
To further accelerate the process and minimize technician risk, IntoMachines developed the Autonomous Tensioning Robot (ATR).
- Automated Movement: When paired with the QUANTUM system, the ATR physically moves the tensioning tool from bolt to bolt.
- Significant Time Savings: Consider a team using two tensioners taking three hours for an M72 flange. With ATR, one technician can remotely oversee multiple robots working in parallel, potentially reducing that time to under an hour. An entire tower could potentially be assembled in a single workday.
- Drastically Reduced Risk: Technician exposure to high-pressure hydraulics is minimized. The robot bears the physical burden and risk.
- Compact & Manageable: Weighing around 40 kg (for M72), the ATR can be installed by two people and fits behind the tower ladder.
- Major Offshore Benefits: Where vessel time is extremely costly (around $300,000/day) and crew limits are strict, the ATR offers huge potential. One technician overseeing 4-8 robots could cut bolting time in half, saving potentially $18,750 per flange operation.
The ATR is currently being prepared for use in nacelle/hub production sites, with field deployment planned for 2026.
Data-Driven Maintenance and Continuous Improvement
The data captured by the QUANTUM system offers long-term value beyond the initial assembly. By building a digital history for every stud, owners and service providers can:
- Track tensioning cycles over time.
- Identify which bolts remain within safe limits.
- Potentially extend maintenance intervals based on data, reducing costs.
Furthermore, these connected systems receive regular over-the-air updates, continuously improving performance and adding features without needing to leave the field.
Fixing the bolting bottleneck requires more than just incremental improvements. It requires smarter tools that enhance precision, ensure safety, capture critical data, and pave the way for automation. Innovations like the QUANTUM smart tensioner and the ATR represent a significant step forward, offering tangible benefits in speed, safety, cost, and long-term asset management for the wind industry.