A carpet becomes better and more and more popular
|Premiá (2nd Division B in Spain) play their home matches on artificial turf.
Modern techniques have managed to negate many poor weather conditions - for example under soil heating for frost and snow, drainage systems for heavy rain, sprinkler and under soil watering systems for dry pitches. But even these cannot cope with the worst that weather extremes can supply. What grass needs most of all is sunshine and rainwater but these days some stadia have been built with such huge steep-sided stands or roofs that some parts of the pitch never even see the sun.
The first artificial turf was laid in the 1960's at the Houston Astrodome and other artificial pitches appeared in American baseball and American football stadia over the following decade. Football clubs looked on with interest and some followed. Dr. Eric Harrison is Chairman of the European Standards Committee on Sports Surfaces and consultant to FIFA: "In the early eighties in the UK a small number of clubs dug up their grass pitches and laid artificial turf, notably Luton Town, Queens Park Rangers, Preston, Oldham and Stirling Albion, but the fans certainly didn't like the game it produced and most players hated it. The bounce was unpredictable - mainly too high, the ball travelled too fast across the surface and, worst of all, any player going in for a sliding tackle was likely to end up with third degree burns. Finally the stability of the pitch could be quite variable because, like a carpet, it would sometimes stretch and ruckle making the playing surface uneven."
Within a year or two the English and Scottish Football Leagues put a moratorium on artificial turf and banned it for sanctioned play.
Currently, the Laws of the Game do not specify anything about the surface of the pitch at all and this is generally left to individual associations and leagues - at the moment no top-level league has sanctioned artificial turf pitches. However, they are appearing in minor and amateur leagues and are ideal for countries where severe heat or cold make grass pitch maintenance a nightmare.
|FIFA President Joseph S. Blatter touches the artificial pitch that was installed at the National Stadium in Monrovia (Liberia) as part of FIFA's Goal development programme.
Photo: Sando Moore
Artificial turf is manufactured very much like a carpet - in fact turf-makers tend to be based in towns where carpet-making is a major industry. The materials commonly used are nylon, polypropylene or polyethylene tufted into a woven synthetic base approximately four metres by 80 metres.
Meanwhile there is much preparation work to be done. The old pitch must be dug out and down to a level to lay the base. The depth and material of this base will vary from country to country so there is no recommended norm - it depends on what local materials are available and also weather conditions. But, generally, in a temperate climate such as northern Europe, the base layer will consist of graduated processed stone, then two layers of asphalt - typically a base course and a 'wearing' course (unbound bases consisting of combinations of sand stone or lava rock have also been utilised). The purpose of the base is not only to provide a totally flat and supportive layer on which to lay the carpet but also the most permeable support possible to allow rain to drain away. The carpet rolls are then laid on this in sections across the base layer and glued together at the joints. Now tons of infill consisting of rubber or a sand and rubber mixture are laid on the surface to a depth of about 35mm to 50mm, leaving up to 15mm of grass fibres above the level of the infill.
This grass and sand mixture is an interesting one. Sand is chosen because it is fine granules of stone; it must be river sand, which is round granules and not like sea sand which is basically broken shells and thus very sharp. The sand supports the artificial grass fibre blades.
But sand alone has two disadvantages. Firstly, it is energy absorbing. Anyone who has ever run on sand knows that it is extremely hard work - your feet sink in and every step requires more energy than on a more supportive springier surface. Secondly, over time, it becomes compacted and hardens which makes it unpleasant to play on and often is the cause of injuries. Rubber, on the other hand, is light and springy and gives the bounce that a player needs when running. The rubber granules are generally made up from recycled rubber and ground down into small particles.
Every year brings further refinements and improvements and when the day comes when an artificial pitch is as good as grass, then the advantages will be incalculable, certainly at the top level.