Sports technology - artificial grass
With the advent of artificial pitches in the 1980s grass seemed to have had its day, but new hybrid technology is giving it a new lease of life.
When England beat Calcutta'Cup rivals Scotland
Sports technology - artificial grass
With the advent of artificial pitches in the 1980s grass seemed to have had its day, but new hybrid technology is giving it a new lease of life.
When England beat Calcutta'Cup rivals Scotland at Twickenham earlier this month in the RBS Rugby Six Nations, both teams could be sure that the playing surface was in immaculate condition.
The pitch, maligned over the years, was re-laid last summer but rather than opting for a traditional grass surface, the stadium's owners, the Rugby Football Union, opted for a hybrid pitch. This combines the strength and robustness of an artificial pitch with the pleasing aesthetics and forgiving properties of a grass surface.
In 1970 former England football manager Terry Venables published a novel 'They used to play on grass', which predicted the end of grass as a playing surface, saying that plastic pitches would become the norm.
That forecast fell short of the mark and although artificial pitches are used in some lower league football and rugby stadia, the majority of clubs spurned the plastic offerings. That was until Desso Sports Systems developed Desso Grassmaster, a hybrid pitch concept that has rapidly gained favour among the top football clubs with Wembley Stadium as well as the grounds of Tottenham Hotspur, Arsenal, Manchester City and Liverpool already benefiting from it.
The hybrid system consists of a 100 per cent natural grass surface into which artificial fibres are injected 20cm deep, every 2cm across the pitch. This results in approximately 20 million artificial fibres reinforcing the natural grass.
The ingenuity of the system is found below the surface. The natural grass roots grow around the artificial fibres, anchoring the field. The system offers stability and reinforcement, ensuring a uniform surface in perfect condition at all times. With the protection from the artificial fibres, the natural grass can recover faster.
"The old pitch was the old 1910 allotments, with 4in of fibre-sands on top with five-metre drains," says Keith Kent, head groundsman at Twickenham. "The contractors dug out 18in of soil - 9,000 tonnes in total, and installed undersoil heating and irrigation under the new surface.
"The artificial grass, which makes up just 3 per cent of the surface, stabilises the pitch because the roots wrap around it while bigger sand particles can also be used."
An additional benefit is the excellent drainage. "The pitch draws water at 123mm an hour, so if the England v Poland football game [World Cup qualifier in Poland controversially postponed last year after heavy rainfall] had been here, we would have played," Kent adds.
Rugby playing surface
"Twickenham had some issues with the original playing surface. It had only minor upgrades during the past few years and Keith and his guys had done a fantastic job with what they had to work with," Alex Stead, Desso's UK sale manager, says. "With the added pressure of additional fixtures and the changing climate we have seen they needed additional assistance and a surface that would give them more stability and a better playing surface."
Under the heavy pounding that a pitch suffers from 30 marauding rugby players, durability is a vital attribute. The root system and the fibres are at such a depth that the whole area will be stable, ensuring that there are no divots to mar the surface. "Sometimes a scar might form between the rows of fibres, these are set at 2cm distance all over the field, it is hard to get in between," Stead adds. "A small amount of soil might be taken off the top but no divots. One of the beauti