Smart Trolley

Design of a smart trolley to address safety issues in current rail trolley equipment.

About RSS Infrastructure

RSSI logoFounded in 2012, RSS Infrastructure (RSSI) rapidly established itself in the rail sector with a comprehensive range of services, particularly for supplying Contingent Labour. Operating from Birmingham, Doncaster, and Cwmbran offices, RSSI provide solutions across a broad range of infrastructure activities in Rail, including Construction & Civils, Overhead Line Electrification (OLE), Safety-Critical Resource & Recruitment, Signalling, Track Warning Services, Vegetation Management and Welding Services.

RSSI are involved in a vast number of infrastructure projects across the UK. They are passionate about improving workers' safety and constantly review their policies and practices to maintain their strong reputation for safety and innovation. By working with customers to understand their challenges, RSSI can improve safety and increase productivity. RSSI recognises its customers' business demands and focuses on safety, exceptional service, and consistent delivery.


Each day, hundreds of rail trolleys are used on sites around the country, but their misuse has resulted in several incidents in recent years. Trolleys can be overloaded, leading to damage and injury, and the safety mechanism can be undermined, resulting in a runaway trolley.

The trolley compromised the visibility of the track ahead, meaning workers could not see if ballast was present between sleepers, causing leg and ankle injuries. Runaway trolleys can reach speeds of 25-30mph or more, posing a danger to site workers, plant, and property. There have been incidents where a runaway rail trolley has struck a railway vehicle causing significant damage and delays and workers have suffered severe eye and mouth injuries from being struck by trolley handles.

Rail trolleys’ technology have hardly changed since the 1930s, but RSSI identified safety improvements they could make by introducing modern technology, materials, and safety features.


Peter Thompson, Rail Director at RSSI, considered the problems track workers face when using rail trolleys and identified a range of features to improve the trolleys' safety, such as making them remote-controlled, electric (battery-powered) and geared so that they couldn't roll away and gather speed. Thompson approached DIGI-RAIL to explore the possibility of collaborating to improve rail trolleys.

A diagram of the new smart trolley design, showing a railway trolley with the new safety features: additional lighting, a digital scale with overweight alarm, fail-to-safe motorised movement, and the replacement of the manual handle with a wired controlle

After detailed discussions with RSSI, DIGI-RAIL carried out initial designs for an intelligent rail trolley, including motor calculations, battery requirements, controllers, and a complete vehicle dynamics simulation including the acceleration rate and top-speed. The DIGI-RAIL team added several other safety features, such as lighting, a fail-to-safe mechanism for motor control, over-weight detection, and a location-reporting device. The new trolley design addressed the two fundamental safety issues of overloading and runaway, resulting in a safer system.

In the project discussions, both parties agreed that it was essential to create a retrofit kit to upgrade existing trolley stock to improve safety quickly and at a lower cost, thereby mitigating the prohibitive cost of brand new rail trolley stock while still offering the Smart Trolley’s enhanced safety features to the workforce. DIGI-RAIL’s design blueprints for a retrofit system do just that.

Plot showing the electrical power [W] required to accelerate to a specific desired velocity for different vehicle dynamics. δa is a coefficient which captures a number of mechanical characteristics.
Plot showing the electrical power [W] required to accelerate to a specific desired velocity in a different number of seconds. Pf shows the electrical power required to move the trolley once it reaches the desired velocity, Pa shows the electrical power ne


The smart trolley design significantly improves the safety and functionality of rail trolleys, which should reduce the number of incidents of overloaded and runaway trolleys and the resulting damage and injuries. Further, the ability to inexpensively retrofit existing trolleys with these features greatly increases the scope of these benefits.

Additionally, the prototype trolley design, constructed and improved by DIGI-RAIL, includes calculations for different vehicle characteristics such as acceleration, range and capacity. These design options enable the products to be task-specific and vary the weight and cost, thereby enabling RSSI to select the most valuable combinations of features before prototyping begins, including the rail trolley and future products.

Collaborating with an experienced rail business provided DIGI-RAIL with insight on how rail trolleys are used (and misused), enabling them to focus on the critical areas of importance.

Peter Thompson

Peter Thompson

Rail Director at RSS Infrastructure

“RSS Infrastructure were delighted to work with DIGI-RAIL on this project. It was a true collaboration that sparked many additional ideas and improvements on the original concept whilst always keeping in mind the practical aspects such as engineering, production and costs. The DIGI-RAIL team were fully committed to the development of the smart trolley concept. After my initial presentation, DIGI-RAIL did their research to ensure that there was a genuine business case for this product. The concept of a retrofitted kit to improve existing rail trolley stock at a reasonable cost shows the DIGI-RAIL team's commercial acumen. They deal in real-world problems and solutions that are both practical and affordable. This project was a true collaboration taking the knowledge and experience of both parties to create something greater than they could individually.”