Weighbridge Mothballing – Protecting Your Assets

At a time when a number of weighbridge systems and/or sites are temporarily closing due to a downturn in business, Brian Fisher, regional service manager with Avery Weigh-Tronix, urges operators to look to the future

Naturally, all quarry operators hope that closure of a weighbridge is merely a temporary measure and that it will be reinstated when the industry picks up again. Tempting though it may be, it is not a good idea to simply walk away from a weighbridge system and hope that it will be okay. Closing the system down properly will save money in the long term.

If a site is being closed, operators should consider whether it is worthwhile moving the weighbridge to another site to allow the asset to continue working. Such a decision could improve productivity elsewhere by increasing traffic flow and reducing queuing. If this is not an option, operators should talk to their maintenance provider about the best way to proceed, otherwise they could face an unexpectedly large bill when it comes to reinstating it.

The biggest problem faced by a disused weighbridge is the build up of mud, slurry and water, and the potential risk of a nearby lightning strike. Both could affect the load-cells, cabling and indicators, and result in the weighbridge being rendered inaccurate and in need of repair. Load-cells in particular are costly items to replace.

To save money on repairs in the long term, it is well worth the operator calling in his or her service provider to decommission the weighbridge. They will remove the load-cells and any cabling for safe storage so that these can be reused at a later date. When removing the cabling, it also pays to plan for recommissioning. As the cables are taken out, the service provider should leave draw wires in place so that it is easier to pull them back into place in the future.

Having removed the load-cells, the supplier should raise the structure of the weighbridge using packing material to maintain its height. This is important for two reasons. First, it ensures that the weighbridge remains structurally sound, particularly if the site is still operational and traffic continues to travel across it. Secondly, it ensures that the steel structure is lifted clear of the pit floor so that it is not sitting in mud, slurry or water.

If the weighbridge is pit mounted it is worth carrying out a full inspection of the pit to ensure that the drainage system has not become clogged up, and that water and debris can drain away freely. It is worth noting that most weighbridges are constructed from galvanized steel, so there is a danger of rusting if the structure is left sitting in water, particularly its protective coating has worn away.

Although the weighbridge may not be used in the immediate future, the pit walls should still be inspected for any bulging and seepage, especially if traffic will still be crossing the structure.

Finally, having removed the more costly components for storage, it is worth inspecting the weighbridge site visually on a regular basis. How often this inspection should take place is open to interpretation, but if the site is still being used the chances are that, over time, mud and slurry will continue to collect in the pit even though the actual weighbridge is not operational. Again, the best advice is to ask the service provider.

In conclusion, it pays to take care when decommissioning a weighbridge. It is a significant investment that is worth looking after. If a service provider is called in, they should have the expertise required to ensure that the weighbridge can be recommissioned in the future with minimal cost. Even if this is not seen as an option, it is important to preserve such assets whatever the future brings.