There is no offi­cial wind rat­ing on our tun­nels. The cater­pil­lar tun­nel is designed to be a move­able struc­ture. Therefore, it is inher­ent­ly not made to with­stand high winds.

A tun­nels abil­i­ty to with­stand wind is based on at least 6 factors:

1. Soil type
2. Water Saturation
3. Bracing
4. Anchoring Selection
5. Wind Direction
6. Customer Installation

Soft soils have less grip on the anchor­ing mate­ri­als, while more com­pact soils hold better.

Related to soil type is ground sat­u­ra­tion. How wet is the soil at the time of said wind event? Saturated soil will be more like­ly to let go of the anchors.

The stan­dard cater­pil­lar tun­nel is sta­bi­lized by a nylon purlin strap. Accessories that increase rigid­i­ty while main­tain­ing the cater­pil­lar attribute of move­able are: Solid Center Purlin, Wind Bracing, and Spring Wire.

Anchoring options that exist for cater­pil­lar tun­nels are rebar, cement­ed ground posts, and Earth Anchors. Rebar is the most eco­nom­i­cal indus­try stan­dard effec­tive in mod­er­ate winds. Cemented ground posts elim­i­nates the Caterpillar Tunnel strength of tem­po­rary, but pro­vides a rock sol­id foun­da­tion. Earth Anchors are an expen­sive ground screw option that holds like con­crete but is eas­i­ly removed and reused.

Tunnels have also been report­ed as hav­ing prob­lems with the plas­tic being blown to one side from broad­side winds. Spring wire is a solu­tion to aid in pre­vent­ing this occurrence.

Customer instal­la­tion is the final fac­tor. Assuming all instruc­tions are fol­lowed and instal­la­tion is cor­rect, the stan­dard tun­nel can with­stand light winds and mod­er­ate gusts.

With all that said, our stan­dard tun­nels have with­stood winds up to 50+ miles per hour. In the cas­es where sim­i­lar winds have dam­aged tun­nels, the six fac­tors must be analyzed.

The pru­dent grow­er would do well to eval­u­ate these six fac­tors in light of their bud­get, short and long-term farm plan, and spe­cif­ic grow­ing context.