One of the highlights of TPI’s Midwinter Conference was the opportunity for people to have an up-close and personal tour the University of Phoenix Stadium, home of the NFL’s Arizona Cardinals. This multi-purpose facility is located in Glendale, AZ.
With its retractable roof and field, it is an engineering marvel of design and technology. It was the first fully retractable natural grass playing field in North America and uses Tifway
419 that’s nestled in an 18.9-million-pound tray kept outside the stadium when not in use.
The field features Stabilizer Solutions StaLok Fiber, which is a synthetic fiber that mimics grass roots and helps reinforce the root zone of the natural turf. Tifway 419 Bermudagrass sod is overseeded with both perennial ryegrass and Kentucky bluegrass at a rate of 100 pounds of seed per acre (varieties are Paragon GLR and Midnight, respectively).
Two days before a game, the field is moved inside where the interior building temperature is 62ºF (16.6 ºC). It goes back outside a couple of days after each game. The Stabilizer Solutions fiber is tilled into the soil at TPI member farm, Evergreen Turf in Chandler, Arizona (the exclusive turfgrass sod supplier to the University of Phoenix Stadium) at a rate of 2,000 lbs/ac; it is tilled in to a depth of four inches. The 63,400-seat stadium (expandable to 72,200) opened on August 1, 2006 after three years of construction.
Field Fun Facts (Source: University of Phoenix Stadium website)
The roll out playing field travels at a speed of 11.5 feet/
minute (1/8 mph); it takes approximately 75 minutes to
travel approximately 741 ft.
The turfgrass resides outside of the stadium except for football
and soccer events.
Excavation took the field down to 26 feet below the present
grade. When it was completed, the field lied 39 feet below
the main concourse level because 13 feet of berming was
added around the stadium.
The site has the stadium situated along a slight northwest to
southeast axis for maximum sun exposure for field in the
outboard position.
The field is 234 ft. wide x 403 ft. long and 39 inches tall.
Field tray rests on 13 rail tracks and moves in and out of the
stadium on 546 steel wheel assemblies (42 rows).
76 – of the wheel sets are powered by a 1- horsepower
motor (total = 76 hp).
The field will support approximately 94,000 square feet
(over 2 acres) of natural grass.
The tray has a fairly sophisticated irrigation system that
works on timers and can be customized. The water drains
through a one-inch deep mat and several pipes that lead to a
main drainpipe underneath the field tray. A few inches of
water remain in the tray while the field is in play to keep the
grass moist.