World Rugby is pushing the synthetic turf industry to produce synthetic turf rugby fields with a pile-height of 50mm that comply with their quality standards. As 50mm is becoming the norm for football, this move would allow fields to become multipurpose thereby stimulating the growth of rugby.
Reducing the pile-height and, subsequently, the infill height, means that the quality of the shockpad will become more important than ever. Marc Douglas of World Rugby explains: “We have always recognised that the 60 mm requirement is a bit of a barrier for people to include rugby when designing a field and for a number of reasons. As we are promoting the one-turf strategy we felt that by removing or reducing one of the additional requirements that rugby has, would be useful.
“Another reason for this was something that has come up fairly recently and forced us to escalate and speed it up, is the issue of microplastics. We recognised that a 60 mm pile height requires a substantial amount of performance infill. That’s why we said that if we can reduce the pile height we can reduce the performance infill amount, which will be good from an environmental perspective.”
World Rugby tasked Cardiff Metropolitan University to do some tests. “The field was dressed to make it look like 60 mm, 55 mm and 50 mm carpet. The infill height for the sand was left as it was. Infill height for the performance infill ranged from 39mm to 34mm to 29 mm. We took 14 forward players from the Cardiff University team and they were allowed to wear any footwear they wanted. They undertook collective and individual scrums: scrums as a pack, against the machine and as a live scrum against another pack. They scrummed individually in their own position against the machine as well, so that we could look at the individuals more closely.”
Before the scrums the AAA was used to measure energy restitution, shock absorption, vertical deformation and rotational resistance. Only significant performance variation was identified between the three dressings for energy restitution.
“As you would expect, the rotational resistance was higher on the shorter pile. Overall, the 29 mm differs more from the other two than the other two differ from each other. There was very little difference between any of the issues or any of the different mm measures on any of the surfaces. Player perception showed some statistical difference. Pile density has the largest outcome effect, with the higher density having higher grip. Infill depth also shows differences, with lower density having higher grip.
“Going forward we have started the process of asking permission to investigate stakeholder reactions and changes. This involves consultation with our unions, Preferred Turf Producers and Accredited Test Institutes, to make sure they are happy with any changes. I asked permission from our regulations committee a couple of weeks ago to move forward with the project and that should happen in the next couple of weeks.”