a tension sensor 124 can be placed above each of the chains instead of the flight tips the tip of the flight bar 20 will only contact the wear strip intermittently as a result the tension sensor 124 will only produce intermittent signals to eliminate transient load spikes and to allow for the odd missing flight bar 20 the tension sensor 124 collects a rolling average reading over 20 or so flight bars as each flight bar tip passes along the load sensor even at a constant chain tension the signal varies due to the changing geometry of the system the tension sensor 124 records the peak signal value as each flight bar 20 passes over the wear plate 132 if the rolling average peak reading is too low then the tension means moves the joint 48 to stretch the chain or vice versa the tension means is initialized by establishing a required peak signal value by stopping the conveyor with a flight bar under the sensor fitting a temporary load transducer to the chain itself and then moving the joint 48 to tension the static chain when the chain is at the required tension the tension sensor 124 stores the signal and it is this signal value that the tension sensor 124 maintains while the conveyor is running the above overview is a simplified version of the sensor signal management system and applies to steady chain load increase or decrease during the coal cutting cycle the tension sensor 124 must also deal with special events such as starting a full conveyor or the rapid unloading of a conveyor like when the shearer stops cutting collecting a rolling average signal cannot respond quickly enough to deal with these events so advance action must.