Sprinkler heads around the edge of the pitch have a soft rubber cap on them which sits flush with the turf and eject when in operation as shown in the photo above.
The brains of the irrigation equipment sits in two other locations the solenoid that controls the individual sprinkler sits directly below the sprinkler head in the pitch 40cm below ground with all the electrical cables built in to it. We do have to change the solenoids every few years as they get contaminated with lime scale from the hard water around Cambridge and this prevents the solenoid from shutting down which means the sprinkler continues to run instead of shutting off and would cause water logging if not dealt with.
The control panel for the overall setting of the system is located elsewhere and each pair of irrigation heads has a separate setting we can water from a minute to 2 hours per head.
Supporters will have noticed that we generally water for 1 minute before kick –off and 1 minute at half time this is generally a management and player decision as this quickens the pace of the ball across the surface and is seen generally across most stadiums within the current game.