Green Buffers named Swedish Steel Prize 2023 finalist

Making safe travel safer

Travelling by railway is safe. Yet in the EU and in Canada alone around 350 to 400 significant train collisions occur every year (Source: UIC Safety Public Report) – not counting collisions related to shunting operations. Fatal accidents are rare, but the costs involved due to damage and derailments are considerable. 

”The existing train safety standard is based on technology from the 1960s or 1970s. Compare that to how the safety standard for cars has developed – no one would accept to travel in a car like that today,” says Roger Danielsson, Founder & CEO of Green Buffers. He and his colleagues saw room for improvement.

Replace primitive systems

Existing crash management systems for trains are primitive. Many of today’s uncontrolled collisions and derailments are a consequence of the coupling links between the carriages being too stiff. In a collision they simply cannot manage the dynamic energy in time. 

In Europe, for example, existing systems are based on a specific collision speed of 36 km/h. But in reality, the impact from a collision is distributed unevenly throughout the train, with the first wagon taking most of the impact. Today, even minor accidents result in derailments and in entire coaches having to be removed and recycled.

Zero derailments goal

Based in Avesta, Sweden, Green Buffers have developed an energy dissipation system that makes train travel safer for passengers and more economical for operators. Inspired by the automotive industry, it uses high-strength steel profiles to dissipate the energy from a train collision in a controlled way. The profiles are located in the coupling interfaces throughout the entire train set. Roger explains:

“If you bring to mind a train collision you often see that the wagons in the front have been derailed. That is what we avoid. We distribute the energy in another way than it has been done before. Using a modular structure we spread out the energy with lightning speed for the duration of half a second.”

How it works

The patented solution optimizes the energy distribution throughout the entire train set with all the energy absorbers efficiently working together. In a collision they are gradually incorporated, step by step, force vs. stroke, so that the energy-absorbing profiles are involved simultaneously and for a longer working time. The overall kinetic energy is the same – but by averting the initial peak force and minimizing all other peak forces, it is distributed in a controlled manner. 

“The steel does the work. It folds like an accordion and absorbs the impact of the shock as it does so. By combining units with different dimensions the energy is absorbed along the entire train, keeping it in place and saving lives and reducing costs.”

The sustainable edge

A Green Buffers system consists of twelve deformable units. It can be implemented on existing platforms without the need to change the design of new trains or to rebuild existing ones. All dedicated energy-absorbing materials can be easily recycled. The use of Strenx® 700 MC steel reduces the weight of train sets and their overall energy consumption. And replacing deformed steel profiles is a far greener option than removing and recycling entire train wagons. “Unlike with cars, practically all collisions that occur with trains are frontal. This gives our system enormous significance”, says Roger. 

For future improvements sensors in every interface can provide information on force vs. time, compression strokes, and energy absorption. Green Buffers’ goal is clear: Zero uncontrolled derailments related to train accidents.