Requirement:

Application of sprinkler systems to a range of Poly Tunnel types, inc. single span and multi-span structures.

The overall aim (as per Outdoor Beds case study) was to meet or exceed minimum requirements set by HDC recommendations of sprinkler performance (HDC Factsheet 16/05), and generally improve on performance of sprinkler systems that were originally applied to the structures.   

System Application:

As structure type varied, there were TWO application types considered:

1. In tunnel structures with high sides, or multi-span structures, the use of the MP-Rotator was adopted.  This allowed for the application along high sided leg rows of 180° sprinklers distributing one way across the width of the bay these units are dedicated to.  This application sees the lateral pipe laid to one side of the structure, supporting the sprinklers on risers, and does not impede day to day work being carried out in the tunnel areas.

2. In tunnel structures with curved sides, the application of "overhead" sprinklers supported on laterals with droppers in the traditional fashion, BUT, concentrating on the importance of height and spacing, as well as running pressures specified to get the best performance out of the sprinklers applied.

Overview:

The results of BOTH application types have seen a move to all tunnelled and other covered areas being considered for said applications.  Following numerous tests (HDC specified) which are now complete, as well as adopting a routine maintenance schedule on site: the checking of pressures, cleaning of filters, visual inspection of sprinklers, etc, the grower has taken an appreciation to the understanding of hydraulic performance, with improved crop yields, reduced labour costs on "hand watering" and water savings.