How to Make a Trip-Wire Alarm

Select a location to set the trip wire. You need to find a location where anyone approaching you will have to walk. As they pass by, their feet will catch the line and trip the alarm. The location should be where the line will be unseen at a casual glance.

Take one end of the trip line and attach it to a fixed location. This location can be a tree, root or rock. It just needs to be stable enough so that it will not move when the trip line pulls on the alarm by a passing foot.

Stretch the line across the pathway and secure it to the alarm. The alarm may be a string of noisy cans or it could be a siren that will sound when the line activates the alarm. The alarm should be self-contained but be loud enough to notify you that someone has passed by it. For this application, a series of tin cans illustrates the principles.

String tin cans across a web network hung between two trees. When the alarm activates, the cans will make noise as they hit each other.