Reliable Monitoring in Hard-to-Reach Dam Structure in Germany

Monitoring structural behaviour within deep, enclosed dam infrastructure presents significant technical challenges. At a dam operated by Harzwasserwerke GmbH in Germany, vertical shafts extending up to 50 metres into the structure required long-term geodetic monitoring. These shafts are not only difficult to access but are also permanently damp, creating a harsh environment for instrumentation. 

Additionally, the shafts are sealed with heavy concrete slabs, raising concerns about whether wireless signals could successfully transmit data to the surface. Ensuring reliable communication without frequent maintenance interventions was critical, as regular physical access to the shafts is both complex and undesirable. 

As Florian Schäfer from Allsat (trusted Senceive distributor) who oversaw the installation on-site, explains: "The exciting and unknown aspect for us was whether the data would even get out of the shaft with this massive concrete cover. The sensors operate wirelessly, and we wanted to ensure stable communication between the sensors and the gateway."

Working closely with the dam operator, Allsat advised on and supported the implementation of a wireless monitoring solution tailored to these challenging conditions. 

Eight Senceive wireless NanoMacro Triaxial Tilt Sensors were installed within the vertical shafts to continuously measure structural movement. These sensors capture high-precision tilt data across both horizontal axes, enabling the calculation of vertical deflection curves over time. This data is integrated with environmental factors such as reservoir water levels and temperature to provide a comprehensive understanding of structural behaviour. 

To overcome the challenge of signal transmission through thick concrete coverings, repeater sensors were strategically installed beneath the slabs to maintain a stable communication pathway between the sensors and the gateway located at the dam crest. Measurement data was transmitted reliably and without interruption. 

The sensors’ fully encapsulated IP69K-rated design ensured reliable operation in the shafts’ permanently humid conditions, eliminating the risk of moisture ingress and reducing the need for maintenance. 

Florian Schäfer highlights the importance of this robustness: "The environment there is incredibly humid and the weather is challenging. Senceive sensors are completely IP69K rated. Nothing can get in. No other system is suitable for such areas." 

With a battery life of up to 15 years, the sensors enable long-term monitoring without the need for frequent access. An essential advantage in deep shaft environments.

The system has demonstrated reliable, uninterrupted data transmission despite the challenging structural and environmental conditions. Measurement data is consistently delivered to the gateway, enabling continuous monitoring and analysis of the dam’s structural performance. 

The robust sensor design has proven highly effective in damp environments where other technologies may fail or require frequent servicing. By eliminating the need for regular maintenance visits, the solution significantly reduces operational effort and risk. 

The success of this installation has reinforced confidence in Senceive’s wireless monitoring technology. Harzwasserwerke GmbH has already implemented multiple systems and continues to expand its use, with additional installations planned. 

Furthermore, the FlatMesh communications platform infrastructure allows for future expansion, enabling additional sensors, such as crack or joint monitoring devices, to be easily integrated as monitoring requirements evolve. 

 
This project demonstrates how Senceive’s wireless tilt sensors provide a dependable solution for long-term dam monitoring in hard-to-reach and extreme environments. By combining precision measurement, robust construction, and reliable wireless communication, operators can achieve continuous insight into structural behaviour with minimal maintenance intervention.