High Tunnel Emergency Safety Update

Last weekend, several farmer veterans with newly installed High Tunnels were struck by severe storms. One of the major suppliers of High Tunnels does not provide lock washers with their kits and they do not recommend them in the instructional material provided. The arches, purlins, and cover vibrate on windy days and especially during high wind. This vibration causes the nuts on the structure to loosen and in some cases fall completely off of the bolts. Once the nuts are loose it allows for significant movement allowing the bolts to shear completely off. We heard this report and added a lock washer on every bolt in the ground posts, arches, baseboards, and ribbon boards. The storms that impacted the other farmer veterans in North Texas hit us that evening. Winds were in excess of 50 mph and we had no problems with the tunnel or the bolts keeping it all together. I don't know if this would have resolved the problems experienced in North Texas however, we thought you should know what our experience was and let you make the decision for your operation.