Sky News has reported of too many slips on the lawns of Wimbledons Tennis courts:
When I read this it was too perfect to be true, I love sport and I love analysing slips, what a brilliant combination! Let’s have a look as to how this could have occurred and what can be done. I will list possible causes, remember that slip prevention has one overriding and all important factor; friction, it’s all about friction, get the right level of friction (bearing in mind that if it was 100% you would not be able to move) then everyone is safe and happy.
Water contamination is one of the greatest causes for slips, it rapidly fills grips and cavities creating a smooth hydroplaning effect that can override many efforts put in to reduce risk. Could Wimbledon have a water problem? Possibly, grass is a natural substrate; it naturally holds inherent moisture and can hold it on its surface. Wimbledon chief executive stated in a press release “exactly the same meticulous standard as in previous years and it is well known that grass surfaces tend to be lusher at the start of an event.”
“The factual evidence, which is independently checked, is that the courts are almost identical to last year, as dry and firm as they should be, and we expect them to continue to play to their usual high quality.”
“Although a number of players have withdrawn injured, only one player has attributed this to slipping over on court”, source http://www.bbc.co.uk/sport/0/tennis/23067270
One would expect that they have done due diligence on surface moisture and I would expect it to be on the low side of the problem.
All the journalists have shown their lack of slip knowledge, they have all asked about surface water but what about surface coatings? Many artificial and natural substances can be coated; they are coated for protection, treatment, durability, friction prevention etc. It is normal for commercial lawn mowers to be coated with liquid graphite based coatings; these prevent grass cuttings building up inside the machine enabling faster cutting and less cleaning. The graphite creates a superb low energy surface, a low energy surface dramatically lowers friction levels – low friction levels results in major slip risks. Could the graphite have been applied too liberally and has contaminated the playing surface resulting in top class players being injured? Without analysing the surface who knows, but, it should be strongly considerd.
Don’t forget something as simple as footwear, modern sports shoes often have low levels of grip, it’s all about weight so thinner soles result in less weight but thinner soles provide less chance for a good quality shoe impression.
Without being given access to the courts (unlikely, but it would be welcome and I am sure my wife would love to come along and help) then the reason why so many have slipped may not be conclusive. Testing would be difficult, I am normally a big fan of Pendulum testing as it relies on firm scientific principals, as grass is a living thing it varies substantially, I would probably do a combination of Pendulum and DIN51130 testing using conventional grass turf from the locale testing with a section from a court (imagine requesting that to the Lawn Tennis Association!) with reliance on a mixture of shoes from injured competitors. I would certainly consider whether over liberal use of liquid graphite on the mowing equipment is the cause, but, just saying, that is all…