Crane is a very important equipment at any project site or industry for handling all loads. SLI is a device that continuously monitors the crane parameters such as the boom angle, and the operating radius, and displays them to the crane operator. This ensures that he is aware of the parameters, and is in the position to avoid any overloading or eronous operation of the crane. Thus SLI is an important aid to the operator which ensures crane safety and prevents accidents at all times.