Applying science in Trakway design
Dale Robinson – Trakway veteran and Live’s MD talks fluid dynamics
Today I want to talk about how we use the laws of physics to inform our product design to keep your pedestrians, plant and property safe.
Let's keep it simple and remember those early Physics lessons at school...
It’s a fact that water molecules like to cling together. They form bonds with their counterparts and constantly pull towards each other, in physics this is ‘cohesion’. At the surface of water, the cohesion is even greater.
The image above demonstrates the water's surface tension. The needle will happily sit on top of the water until a force is applied to it and it breaks the surface tension. The needle will sink quickly because there is far less cohesion in the main body of the water than on the surface.
But why is there more tension at the surface?
Because there are no molecules above the water, this allows the molecules at the surface to form a stronger bond, in this case supporting the needle.
The molecules are also attracted to other materials by ‘adhesion’. You can see this effect on the inside of the glass where the water surface clings to the sides (below), this is called the ‘meniscus’, caused by ‘adhesion’.
Applying the science
How does this science inform how we keep pedestrians safe when designing Trakway?
On average, it rains in the UK for 133 days a year with nearly a metre of rainfall, so it isn’t a surprise that Live Trakway alone carried out 2500 UK contracts last year to counteract the risks of bad weather.
Using the laws of fluid mechanics above, we designed our trakway’s tread pattern to be as narrow as possible so that there is very little surface area for the water molecules to cling to. The tread pattern is made up of repeated narrow ‘fins’, flanked either side by ‘channels’.
The water molecules find it difficult to cling to such a small area because of the surface tension that holds the molecules together (water droplets). With the weight of these, the water struggles to stick to the narrow fin and falls either side of it into the channels and away from the panel surface (below).
This means that footwear or vehicle tyres are in contact with a dry tread, rain or shine.
Adding in more grip
The fins run across the width of the panel, creating high pedestrian or tyre friction when travelling with the run of the roadway. To ensure this grip is equal in preventing sideway slips, you can see in the picture above that we machine-cut cross-serrations into the fins to negate any sideway sliding, a great safety feature on cambers.
Depicted below, the underside of the panel uses the same principal, but at a larger profile. This helps keep the roadway in position and if we turn it over, it provides an even higher level of grip for heavy vehicles or for increased traction up steep inclines. The panels can also be pinned into place for really heavy-duty traffic.
Our family invented the Trak panel in 1966, kicking off the industry. Across Europe today, we operate the 5th generation of this invention - LionTrak. Through our engineering experience, we have a good understanding of fluid mechanics and this experience has enabled us to create one of the safest temporary roadway surfaces there is - forever improving, it hasn’t been equaled yet!
Next time, I'll be following up this post with the results of some independent Pendulum slip tests, which measure how our trakway products perform underfoot.
Thanks for reading this folks. Stay safe!