Press 4: Log Loading System (automation improvements) With little room to manouvre the logs into position when loading them onto the loading chains, issues were being created with the logs being placed on the chains on one side and the guide rails on the other. This would cause problems when the loading chains tried to traverse the logs. Curved mirrors have now been mounted directly above each guide rail. This will give the fork lift truck drivers a better view when loading the logs onto the loading chains. The guide rails used to try to keep the logs on the loading chains were adjudged to be too close together, leading to the loading issues we currently see. To improve this, the distance between the guide rails has been widened, to allow more room to manouvre the logs onto the loading chains, and hopefully preventing skewing of the logs when running the pre-load cycle. The location of the control desk for manually loading is situated in a location where it’s almost impossible to see what’s happening. In the past, we had situations where the log hasn’t loaded correctly onto the pusher chain and this has resulted in damage to the shock absorber assembly when the manual command to push the log was executed. This resulted in major damage and downtime to production in repair work. The only means of monitoring what’s happening in the manual loading sequence is through a small viewing window situated too far away from the manual control station. Furthermore, the condition of the remote control station is in a pretty poor state, and doesn’t provide the necessary information needed to ensure a correct ‘manual’ load sequence has been completed successfully, and more importantly, completed safely, and without the possibility of injury to others. As mentioned in the previous slide, the existing manual control station – although giving the operator a means of loading the logs onto the log loading system, there is little information presented on the ‘on-board’ PV500 operator panel. The final deciding factor in deciding to go ahead with this improvement project is the time taken for the operator to set the station up, in order to carry out the manual functions necessary to perform a manual load. Prior to the implementation of these project changes, a screen was available on the main operator press panels (both left and right hand side operator panels), but had no means of carrying out manual functions. Instead, it only provided information relating to pusher arm position and sensor status. This screen has now been completely re-engineered to give better information, as well as full manual loading functionality that effectively mimics the existing remote loading station. The new screen offers the following functionality: The option to turn on or off control of the on-screen command buttons. Full control of all manual movements to allow safe loading of the new log in the event of an automatic loading failure. The option to switch between the pusher arm measuring device – encoder or laser. Feedback for pusher arm position and more importantly the actual log measurement taken during a manual load operation – the latter being a crucial addition in the prevention of slithers. Last week (21st February, 2020), at around 9.00pm, we experienced a slither after a billet cut. When I first joined HYDRO, the issue of slithers was a pretty regular occurrence and due to an incorrect Konstant in the software for the physical position of the measure PEC for snapshotting the position of the pusher value, that’s then used to calculate the effective length of the newly loaded log. This problem has since been resolved and has been correct for the past three years. Periodical checks to ensure this Konstant remains correct are carried out on a regular basis, as if the value is incorrect then we will have major issues with slithers. The system however still had a serious flaw – and this was to do with when loading in a log in manual mode. In manual load mode, the old software would NOT calculate the effective length of the new log, but rely on operator input to manually key in the length of the new log. IF THIS VALUE IS INCORRECT – AS SEEMS TO HAVE BEEN THE CASE LAST WEEK, THEN THE SOFTWARE CAN’T CALCULATE WHERE THE END OF ONE LOG FINISHES AND THE START. OF THE FOLLOWING LOG BEGINS. THIS RESULTS IN A PERFECT CASE SCENARIO WHERE SLITHERS CAN AND WILL BE FORMED. It’s easy to blame sensors - as is usually the chosen diagnosis as to why we get slithers, but it’s also seldom the actual cause of why we get the slither. Previously, and prior to the new software modifications, if the new log was loaded manually, then it was up to the operator to input the actual log length of the newly loaded log. For some reason, the value entered would ALWAYS be 7400mm – without an actual measure being taken of the true log length! As log lengths from the cast-house can vary from 7350 – 7490, this immediately creates chaos within the software. The software can accurately calculate the overall log train length, but relies on correct information to monitor where the joins are within the log train. Entering an incorrect log length when loading in manual will give an error in position, of where the actual physical position is between two logs, and that calculated by the software. In this example above, if we have a true log length of 7420, but a value of 7400 is entered, then the software thinks the point at which the two logs touch is 20mm out from the actual join positions. As the manually entered log length approaches the ‘active log’ – the expiring log being cut, at the front of the log train, the software calculates, based on the value entered by the operator, whether or not it is allowed to make one last cut. As it thinks that the join line between expiring and next log is further back, it will execute an illegal cut!! …………AND THIS IS HOW WE END UP WITH A SLITHER!!!! 7407 On a manual log load, the software will capture the position of the pusher arm value and from this, calculate the effective length of the newly loaded log. This will be automatically entered into the system in position L4 of the heater screen. This in effect removes the need for manual intervention and shouldn’t require any operator input when performing a manual log load. PLEASE NOTE: The function for operator over-ride is still in place. This is in the event there is a failure in the PEC sensor that triggers the log measurement reading. In this case, a measure of the newly loaded log should be taken, before the manual value is keyed in.