GENERAL INFORMATION ON HAIL PROTECTION
WeatherSolve Hail Protection Systems are generally flat and are set to withstand whatever extreme loads might occur. Flat systems can be made stronger and are generally more economical. Both the Swivel and the Fixed Canopies are usually flat.The fixed systems can be removed for winter, but we recommend that if a system needs to be removed our Swivel Retractable system is used.
Traditional hail canopies as developed in Italy and France have a pitched roof. The fabric is hung loose with very few clips along the edges so the hail will spill out between the connection points.
The system requires a lot of poles and is difficult to make very resistant to other loads such as wind and snow.
- Pitched canopies catch the wind.
- Snow does not slide off unless the slope is over about 60 degrees, so the canopies are typically rolled up for winter.
- Infrequent clips holding onto bare fabric selvedges are very weak compared to cable in hem systems.
Newer pitched systems have stronger selvedge reinforcement and more tautly installed fabric. Note that if such a system is designed under the assumption that the hail is shed, and it doesn’t because the fabric gets loose or because the wind blows a sag into it – then that system will fail causing damage to the structure or to whatever you are protecting. Flat hail protection systems are either strong enough to support the hail above the ground, or elastic enough to let the fabric stretch to the ground(or trees) under load and spring back into place afterwards.
The swivel system is designed to be wide during the hail periods and narrow when access is needed in early spring for bee pollination or over winter when the trees are bare.
The canopy is converted from wide to narrow and back again by pulling on each end. A row 1000 ft (300 m) long is swiveled in a couple of minutes !
Note how the fabric pulls up tight and out of the way in the process of swiveling. The picture below shows the swiveling process.