We’ve received orders this week to remove and replace two more of a competitor’s axle weighbridges that weren’t up to the job.
After struggling to get them to remain within calibration or, in one case, to even get it close to being calibrated, the decision has been taken to remove them and replace them with Axtec systems.
Both of them had the same issue; a load cell mounting design which although ideal in many applications is far from suitable for an axle weighbridge installation. Nothing inherently wrong with the load cell or its mounting but it was never designed to be placed under a weighing platform that is being driven across by heavy goods vehicles.
Both weighing platforms were installed in areas where they would be heavily trafficked by non-weighing vehicles heading for the exit gate. The load cell mountings in those circumstances basically just wore out simply by having vehicles drive across the platform and as a dynamic axle weighbridge is supposed to have vehicles driven across it, it is clear that the load cell and mounting design were just not intended for that type of application.
Coupled with the fact that one of the systems had never had any high tolerance concrete approaches laid, it was hardly surprising that the system was virtually impossible to calibrate.
We recently installed a system in East Anglia and, as part of the training procedure, we showed the customer the effect of changing a single 0.5mm shim under one load cell. The change in weighing accuracy was dramatic and illustrated starkly how varying the level of the platform relative to the surrounding area could affect the result obtained.
|Axtec's Civils team will get the approach levels perfect|
The same is true if the approach levels aren’t laid to the correct tolerance. Getting the levels wrong can seriously affect the accuracy of weighing and whereas correcting the height of the platform can be done using shims, correcting poor approach areas is much more difficult.
They basically need to be dug up and re-laid at some expense and disruption to the operation.
We realised many years ago how important the levels and height of the platform are. Which is why we have our own civil’s teams to make sure they approaches are right and design a platform that can have the shims changed in seconds if necessary.
Coupled with the fact that the Axtec platform has been purpose designed to have vehicles driven across it, at speed when not weighing, means that once installed it will provide many years of service.