Schaeffler’s OPTIME Helps Prevent Unplanned Downtime at UK Limestone Plant


  • OPTIME wireless condition monitoring sensors are installed at the Tarmac Tunstead limestone plant to continuously monitor critical machines and auxiliary units.
  • A total of 150 OPTIME sensors monitor a range of rotating equipment at the plant including pumps, motors, fans, blowers and feed conveyors.
  • OPTIME provides early warning of any potential issues, allowing maintenance to make repairs in a structured, planned way before the equipment breaks down.
OPTIME wireless condition monitoring sensors are installed at the Tarmac Tunstead limestone plant to continuously monitor critical machines and auxiliary units.

Schaeffler’s OPTIME wireless condition monitoring solution is helping prevent unplanned downtime of machines and auxiliary equipment at the Tarmac Tunstead limestone plant near Buxton, Derbyshire. The site benefits from the early detection of equipment failures, as the OPTIME app keeps the maintenance team informed on the condition of the machines at all times, without them having to take manual readings.

Tarmac, a CRH company, is a producer of sustainable building materials and construction solutions. Tarmac Tunstead is home to one of the largest limestone quarries in Europe. Limestone is heated in kilns to extremely high temperatures to induce a chemical reaction that produces calcium oxide or quicklime. Quicklime is used in iron and steel manufacturing and for the production of aerated concrete blocks. It can also be processed into hydrated lime, which is used in a wide range of industries including construction and civil engineering, food and agriculture, chemical manufacturing, and water.

                       The Tarmac Tunstead site is home to one of the largest limestone quarries in Europe.


Prior to installing OPTIME, for more than 10 years the plant has relied on route-based condition monitoring services provided by Schaeffler UK. Every two months, a Schaeffler field service engineer would visit the site to take vibration measurements on a variety of critical plant and equipment to identify any deterioration of rolling bearings and other general mechanical components such as gears and fan blades. Although this approach worked very well, it relied too much on time-based maintenance and was more ‘reactive’ than ‘proactive’. The maintenance team was also ready to embrace the latest condition monitoring technology and to take more ownership of the data rather than rely on data analysis reports from Schaeffler every two months. They preferred a condition monitoring solution that could provide measurement data on a continuous basis, which would help prevent unplanned failure of auxiliary units such as pumps, fans and motors, which otherwise could quickly shut down an entire production line and incur high costs.

Easily scalable, wireless solution

Working together with the customer and understanding the needs of the application, Schaeffler’s experts recommended OPTIME, an easily scalable wireless condition monitoring solution consisting of wireless sensors, a gateway (routers with SIM cards) and digital services based on proprietary Schaeffler algorithms.

In 2021, a total of 50 OPTIME sensors – a mix of OPTIME 3 and OPTIME 5 sensors – were installed on 25 machines. Schaeffler helped identify which machines and equipment would be most suitable for monitoring. The site’s maintenance team then installed the OPTIME sensors themselves.

                    OPTIME sensors monitor a variety of rotating equipment such as motors, pumps, fans and blowers.
                     Photos: Schaeffler

Simon Hackney, Reliability Systems Engineer at Tarmac Tunstead comments: “We find the OPTIME sensors easy to set up and the gateways work within an environment where we don’t have a reliable mobile phone signal. The notification and alarm system are good at identifying any issues. The OPTIME app and web platform is easy to use and navigate, while we also have the option of asking Schaeffler to analyse any measurement results. Schaeffler has provided full support throughout the whole process. We initially installed OPTIME in one area of our plant but have since rolled the sensors out to different areas where we feel they would be of benefit.”

The plant has rolled out OPTIME to its hydration plant and to the nearby Hindlow quarry. A total of 150 OPTIME sensors have now been installed, which monitor a wide variety of machines and rotating equipment, including electric motors, pumps, fans, blowers, gearboxes, compressors, feed conveyors and general bearing assemblies – in both indoor and outdoor areas. The plant is open to the elements, so the OPTIME sensors must withstand these harsh, dusty environments.

OPTIME is an end-to-end solution that comprises all the necessary hardware and sensors, as well as data collection from the machines. This data is then sent to the Schaeffler Cloud, which is where Schaeffler algorithms are applied. The data analyses are automatically sent to the Tunstead maintenance team via the OPTIME mobile phone app. If any issues are detected, alarms are sent, allowing maintenance to check those issues on their daily walk-around. Automating the data measurement process using OPTIME hasn’t meant replacing any labour at the plant either; OPTIME works alongside the engineers, telling them where they should focus their attention.

Numerous benefits

Now provided with continuous measurement data from OPTIME, the plant is building a comprehensive history of data on how the machines and equipment operate over time and which maintenance or repairs they need to perform next – making maintenance more efficient.

Hackney continues: “The OPTIME system continuously monitors our equipment so that if we do notice any changes in the trends, we can complement this information with other condition monitoring techniques such as ultrasound or handheld vibration analysis, as required, to confirm what we are seeing. We then take the appropriate action.”

Cost savings have also been made. For example, some large fans at the plant were being balanced by an external third-party every four to six weeks. Rather than continue to pay for these services, the plant now waits for the OPTIME data to advise them when the fans need balancing, extending the time interval between servicing – moving from a time-based maintenance approach to a predictive one.

As Simon Hackney concludes: “We have identified issues through OPTIME and repaired the plant in a structured, planned way, preventing the equipment breaking down and causing unplanned downtime. We are still learning reaction times [what priority/severity to assign to an alarm] when we do see issues, but are confident this will develop over time.”

OPTIME is part of the Schaeffler Lifetime Solutions portfolio, which offers a comprehensive range of products, services and solutions for industrial maintenance. It is designed to support maintenance engineers over the entire lifetime of a machine.


Laura McKenzie
UK Communications & Branding Manager
Schaeffler (UK) Ltd
Unit 308, Fort Dunlop, Fort Parkway
B24 9FD
[email protected]


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