Article code: 43-060
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PanStadia International Quarterly Report: Volume 4 No 3, July 1997.


[TURF TECHNOLOGY]


ONE STADIUM, TWO FIELDS


The Giants
Stadium in New
York has an AstroTurf
pitch and a natural
turfgrass
field.



The New York Giants, the New York Jets, rock concerts and the New York/New Jersey MetroStars. What do they all have in common and what sets the MetroStars apart?

They are all tenants of Giants Stadium, owned and operated by the New Jersey Sports Authority. The distinguishing factor is that the MetroStars require a natural grass playing surface whereas the field in Giants Stadium is AstroTurf.

This presented a unique problem for the Empire Soccer Club, the owner of MetroStars. How could they meet the natural grass requirements of Major League Soccer in a venue housing an artificial playing field?

Pilot Studies

In December 1995 the MetroStars Soccer Club authorised a study by the Clark Companies of Delhi, NY to explore the possibilities of installing a permanent natural grass field in the Giants Stadium. A research conference was organised by John Hilson of the Clark Companies and was hosted by the State University of New York at Delhi Turfgrass Division in January 1996. It discussed the myriad possibilities available in natural grass systems. Clark Companies returned to the MetroStars with the opinion that there was no grass reinforcing system that, even combined with climate control, could stand up to the rigours of Giants Stadium.

The MetroStars then made the decision to hire Clark Companies to construct a temporary grass field in Giants Stadium for the 1996 season. The field was constructed in the spring and removed before the NFL preseason schedule. While successful, this was not seen as a permanent solution to the problem. Investigation continued into developing a more permanent and cost effective solution, rather than to continue building and discarding temporary fields year after year.

Discussions towards the end of 1996 centred around the use of a modular natural grass field. The ITM system is one such transportable natural field. It consists of square, interlocking plastic modules - commonly called grass squares - containing a prescribed growing medium and turfgrass. In December 1996, Scott Clark heard from Bryan Wood of Systematrix that a new, high-density mould for manufacturing the polyethylene plastic modules had just been completed.

The ITM System

As negotiations ensued, the new module began testing. In February 1996 Charlie Stillitano - the vice president and manager of MetroStars Soccer Club - and Clark Companies struck a deal. Giants Stadium would host the first commercial installation of the ITM system.

The agreement translated into an adventure for everyone involved. The modules had to be manufactured, shipped, filled with the sand and soil medium, turfed and rooted, and be ready for the first MetroStars home game in just ten weeks. even with a well-established system, meeting the deadline would have been tough. With the young, redesigned system being installed on an unprecedented scale, it presented a real challenge. It all had to be done in February, March and April - a time when Mother Nature hammered the northeast of America with harsh winter weather.

The first batch of 336 modules - each 48 inches by 48 inches by 11 inches deep - was moulded and shipped directly to Giants Stadium where John Hilson and his crew from Clark Companies waited. The crew unwrapped and aligned the empty modules in a staging area in the stadium's parking lot then locked the side of the modules in their upright positions for the root zone component loading phase of the project.

Crews filled the modules with a root zone mix of sand and organic matter over a graded, pea stone aggregate designed to provide efficient drainage. Excess water flowed at eight inches per hour through channels moulded into the modules' pallet-style bases and out of the stadium through the existing drainage system. The design allowed the root zone to be ventilated with forced air from below for aeration. This also enabled the turf to be cooled in summer and warmed in winter.

Once the modules had been filled, the sand and organic profile was compacted and then turfed with rolls of Kentucky bluegrass which had been shipped in. Crews were able to complete 500 to 600 modules a day. Over 6,100 modules would be needed before the project was completed.

It became obvious that the turf in the ITM modules would not be rooted deeply enough to allow for play by the MetroStars' opening game on April 10th and so a temporary grass field was installed in the stadium. However, by the end of April, the root system in the modules was sufficiently developed and the decision was made to remove the temporary field. The ITM field was installed following the MetroStars' game of May 4th and before their game of May 9th.

All Change

Once the changeover began, the modules were separated and moved into the stadium on forklift and flatbed trucks. This took about 80 hours. Like a tiled floor, the modules were installed on top of a 40 mm plastic liner and plywood layer that covered the stadium's synthetic playing surface. The sides of the modules were then folded down to allow a soil-to-soil compression joint with adjacent modules. The final result was a solid, seamless natural turfgrass field.

Come summer, when concerts are scheduled, the grass squares will be removed from the area of the field where stages will be constructed while the rest of the field will be covered with Terraplas protection system. For NFL football games this autumn, the entire field will be dismantled and stored in a lot outside the stadium. Both the New York Giants and Jets will evaluate the performance of the grass squares this year for a possible permanent conversion to natural grass for next year's home games.

Rapid Progress

The ITM system has come a long way in a relatively short time. Inventors Tom Ripley, president of Greenway Services, and Dr Henryk Indyk, formerly of Rutgers University, began working on the concept of grass squares in 1990. They soon developed a design consisting of connecting metal trays.

Dr James Beard and Arthur Millberger studied the design during a research project and concluded that the modular system would be an effective way of converting synthetic playing surfaces to natural turf. A successful installation of portable grass modules in the Pontiac Silverdome for World Cup soccer in 1994 bore out their conclusion.

About the same time, Ripley and Indyk installed a new plastic and wood version of modular turf at Baltusrol Golf Club as a practice tee for the US Open in Springfield, New Jersey. That also proved successful. Modular turf was ready for the next level.

GreenTech took control of all domestic and international patent and trademark rights for the ITM module. Bryan Wood of Systematrix in England joined GreenTech as European distributor and consultant and took on the time-consuming, frustrating process of developing a high density polyethylene module.

In addition to serving the MetroStars in the Giants Stadium, the ITM system is currently being tested at several other venues and research authorities to develop standards and specifications for the system's various applications. For football, those include quickly repairing worn sections of a field with fresh, mature turf or replacing entire end zones to save repainting them. For golf, tees can be rotated or changed. Other uses include cricket squares, horse racing, tennis courts, playgrounds and system gardens. Greens could be constructed from concrete pads topped off with the ITM system. This would allow for drainage and aeration of the turfgrass as well as providing a means of controlling or re-using chemical run-off so that it doesn't affect the environment.

With the success at Giants Stadium and the other test venues, turf managers will have a new, flexible tool for effectively accommodating a wide range of activities. Managers can rely on a hard surface for turf-torturing events like rock concerts and tractor pulls, then turn the venue around and serve up the soft natural grass field that most athletes prefer.