Inventor of the Portable Train Weigher (PTW)
In 1995, Weighwell invented the Portable Train Weigher (PTW). Today, it remains a trusted and proven solution across the rail industry.
The Origins of Innovation
In 1988, at the age of 22, Paul Horsfall founded Weighwell Engineering Ltd. The company began by servicing and maintaining weighing equipment, from laboratory scales to fixed train weighbridges.
Encouraged by early successes, including collaborations with ABB Transportation and the development of a Portable Bogie Weighing System, Paul realised that train weighing could be done differently. This vision led to the invention of the patented Portable Train Weigher (PTW), the first portable train weighing system of its kind.
By 1995, that idea had evolved into a working prototype. Following several years of development and testing, Weighwell officially launched the PTW at Railtex 1997.
Immediate Success
The system’s success was immediate. As a result, it earned Millennium Product status from the Design Council and received a SMART award from the Department of Trade and Industry.
Unlike traditional fixed train weighbridges, the PTW did not require permanent modifications to the track. Instead, it allowed engineers to bring the rail scale to the train, a new concept that offered precision and portability without the need for costly installation. Consequently, the PTW quickly became a highly valued asset for rail companies worldwide.
Today, thousands of PTW units are installed across more than 40 countries. Although the product has evolved significantly, its core purpose remains the same: to deliver quick, accurate and reliable train weighing with minimal disruption.
// From design to function
How the PTW Delivers Results
All train wheels feature a flange that helps them remain aligned on the track. Paul invented an assembly that lifts the wheel tyre while keeping the flange securely within the rail head. This innovative approach also includes entry/exit ramps and an integrated loadcell.
Precision Weighing
By weighing through the flange instead of the tyre, this system achieves greater precision, providing a detailed insight into a rail vehicle’s load distribution.
Entry & Exit Ramps
These ramps guide the train wheels onto the system. An advantage of our portable rail scale is that it operates without disrupting regular train movements.
The PTW is engineered for versatility and suits a wide range of rolling stock and railway networks. Its adaptability relies on two key features:
Track Gauges
Thanks to its poles, the PTW can support various track widths. Whether standard, broad or narrow gauge, our system ensures seamless integration.
Rail Profiles
The PTW works with multiple rail profiles using rail keys. This approach ensures secure placement and delivers reliable weight measurements on any rail type.
Since its invention, the PTW has evolved significantly to meet the changing needs of both our customers and the wider rail industry. Below are some of the key milestones in its development:
Innovation Through the Years: Milestones in PTW Design
The First PTW (1995)
The journey began in 1995 with the invention of the first Portable Train Weigher. At 600mm in length, this innovative rail scale set a new standard for portable train weighing.
Heavy Duty PTW (1997)
In 1997, we introduced the Heavy Duty (HD) PTW as a robust solution to support increasing axle loads of up to 40 tonnes. The original HD unit measured 656mm in length.
The PTW 500 (2010s)
Responding to market feedback, we developed the PTW 500 to replace the 600mm model. Its shorter 500mm length allowed for easier installation between rail fastenings.
Latest HD PTW (2020s)
More recently, we redesigned the patented HD PTW with a compact 556mm length. This improved durability whilst making it even easier to install between rail fastenings.
PTW 500DS (2020s)
At 500mm, the patented PTW 500DS supports both static and in-motion weighing. Importantly, its smoother, “flange-friendly” design improves both precision and versatility.
// Redefining precision
Our Latest Innovation
Our latest innovation represents a major advancement in PTW design.
With the introduction of a patented in-built loadcell ramp, train wheels now transition more smoothly onto the system. This updated, “flange-friendly” approach improves vehicle movement while incorporating additional features:
Expanded weighing area
The 500DS load cell is now over 20% longer, which helps with more accurate vehicle positioning.
Increased sensitivity
The redesigned loadcell delivers more precise measurements thanks to improved sensitivity.
Enhanced durability
The 500DS assembly is over 60% stronger, reducing flexing and improving consistency.
Together, these enhancements reaffirm the PTW as the go-to solution for portable train weighing.
// What sets us apart?
Built on proven expertise and trusted for decades
From its pioneering invention in 1995 to today’s latest innovations, the Weighwell PTW has fundamentally changed how rail vehicles are weighed. Many rail operators find that the PTW, though portable, fits so seamlessly into their workflow that it effectively becomes a permanent installation.
Backed by decades of experience, installations in over 40 countries, and an unwavering commitment to quality, Weighwell continues to be the trusted name in portable train weighing solutions.
