Riding the Rails with Envu

Smart Weeding System Revolutionises Railway Weed Control

Maintaining the vast network of railways that crisscross the United Kingdom is no small feat. For decades, weed control on the tracks has been a complex and challenging task. Traditionally, it involved the use of multi-purpose vehicles (MPVs) for herbicide spraying; but, with the fleet being used for all seasonal treatments there was limited opportunity for downtime; so, a solution was needed to relieve the pressure.

Enter Envu's Smart Weeding System (SWS), a revolutionary approach to weed control that provides greater efficiency, reduced herbicide use and environmental protection.

Adrian Marston, Rail Contracts Manager at Envu, emphasises the importance of Envu’s innovation, stating, "We recognised the need for a more efficient and environmentally-friendly approach to weed control on our railways. The Envu trains are a game-changer, and their impact will be felt across the industry."

 

The Challenges of Traditional Railway Weed Control

To ensure UK trains continue to run safely, in excess of 16,000 miles of track need to be cleared of weeds every year. 

Traditionally weed control has involved two herbicide applications; a residual herbicide treatment between March and early June, followed by a contact herbicide application covering June to September. Spraying was either ‘on’ or ‘off’ regardless of the weed cover. While rail authorities have always respected sensitive areas and employed people to hand-spray sections, when ‘on’ MPVs weren’t selective.

 

The Envu Smart Weeding System

“The Envu Smart Weeding System represents a giant leap in weed control technology,” explains Adrian. “The trains detect weeds using cameras that can distinguish between different plants using their chlorophyl. The cameras send a signal to the calculation module which then operates the correct solenoid valve to target the detected weed, the level of chlorophyl can then be adjusted to only target large plants.

“The SWS consists of modules mounted on standard freight wagons hauled by locomotives at both ends.”

The first wagon contains energy and storage modules. The energy module has a 60KVA generator to power the SWS independently of the locomotive. There are seven IBCs worth of storage which can carry liquid as well as granular products. The exterior of the module is equipped with cameras and spotlights for weed detection.

The second wagon contains the mixing module, a hydraulic system with four 1,000 litre tanks, six dosage pumps, and four delivery lines to ensure homogeneous mixing of herbicide, together with the control and office modules. With two operator seats, CCTV, spray controls, and amenities, as well as a workshop with spare parts and personal protective equipment, operators are well-equipped.

The final wagon has two 25,000 litre water tanks to provide the water for the hydraulic system plus another camera and spotlight arrangement for weed detection. In addition, this camera and spotlight arrangement provides bi-directional operation.

 

Efficiency and Precision

“One of the key advantages of the train is its precision and efficiency,” says Adrian. “Ultimately, it’s about the sustainable use of herbicides, with the spot treatments using only the minimum herbicide possible and GEOfencing protecting environmentally critical sites and waterways.

“The spray nozzles are strategically arranged to provide comprehensive coverage across the tracks, ballast shoulders and bank sides. The adjustable upper nozzles are an innovative feature, allowing operators to adapt accuracy as the terrain changes.

“The SWS operates within speed ranges of 20 and 33mph, with the lower speeds allowing the operator to manually respond to variations in topography. This level of control ensures that herbicide is applied exactly where needed.

“Herbicides and water can be replenished from either side of the train, increasing flexibility over when and where the SWS can be filled.”

 

Environmentally Friendly and Safe

The Envu SWS incorporates several features to minimise its environmental impact and ensure safety, as Adrian explains:

“One of the most challenging aspects of the project was programming the protection of sensitivity areas.  This required input from a wide range of organisations including The Environment Agency, Natural Resources Wales, Scottish Heritage and the regional water authorities.

“Whether a site is of historical or ecological importance, protection is critical. The SWS uses GPS and GEOfencing systems to ensure total accuracy and we’ve incorporated a ‘fail safe’ so if the train loses connectivity, it will automatically stop spraying.

“A CCTV system ensures that there are no hazards, such as people, on the track during operation, enabling operators to start and stop the spraying accordingly.

“Operators are fully trained in the use and application of herbicides and hold BASIS certificates,” he adds.

 

Innovation and Future Possibilities

The SWS is equipped with an advanced weed detection system that employs bright spotlights and an array of cameras to identify weed presence and density. This system sends electronic signals to the calculation module, triggering the precise application of herbicide. A touch screen interface provides operators with real-time information on tank levels, nozzle usage, train speed and direction.

Additionally, the system transmits records to a database, including data on weed density and herbicide usage. This not only aids in planning, but also demonstrates compliance with regulatory restrictions.

Adrian concludes, "The Envu Smart Weeding System represents a paradigm shift in weed control on the railways. It's a win-win for operators, consumers and the environment. We're not just reducing herbicide use; we're revolutionising the way we approach this critical aspect of rail maintenance.

“It’s taken extensive collaboration to get here, and I’d like to thank all those who have worked on the project."

Looking ahead Adrian sees opportunities to refine SWS. “Technology is advancing all the time,” he acknowledges. “In the agricultural sector - where some of this technology originated – much work is being done to enhance weed recognition.  I envisage that the future could involve specific products being used for different plant types, and improvements made in how we plan areas and manage vegetation on specific sites.”

With its precision, efficiency and environmental benefits, this technology is a testament to the power of collaboration and innovation in addressing complex challenges while safeguarding our environment. The future of weed control on the railways has arrived.