Little Paxton Quarry – Scene of a Quiet Revolution
Situated in the UK in the beautiful Cambridgeshire countryside lies a 127 hectare (1.27 km2) biological site of Special Scientific Interest and a hugely popular local nature reserve. These flooded former gravel pits are of national importance for wintering wildfowl including large numbers of herons, coots and moorhens. Amazingly, immediately adjacent is a flourishing sand and gravel quarry owned by Aggregate Industries. The fact that such harmony between heavy industry and nature is possible is an achievement in itself but what makes this whole situation even more remarkable is that the quarry is the scene of a quiet revolution of its own.
The first unusual aspect is that although Aggregate Industries own the central plant conveyors, all of the field conveyors are owned and maintained by Leicestershire-based conveyor specialists, MES International. A few years ago, the Little Paxton quarry had been ‘mothballed’. When Aggregate Industries decided to re-open the quarry, they approached Leicestershire-based conveyor specialists and Dunlop Service Partner, MES International. A contract was agreed whereby MES build, own and maintain the site’s six field conveyors. In addition, MES were also contracted to provide maintenance services for the main plant conveyors, which continued to be owned by Aggregate Industries. In return, MES are paid on a rate per ton basis. In order to maximize reliability and reduce unplanned stoppages for belt and splice repairs and replacements, MES replaced the low-grade imported belt supplied by a previous contractor with 1.8 km of 650mm wide single-ply Dunlop X3 belting. The change to Ultra X impressed everyone so much that MES were encouraged by Aggregate Industries on-site management to change the other field conveyors over to Ultra X. At the same time, they are also replacing their own plant conveyors with Dunlop Ultra X3. So far, three have already been changed.
The many benefits, as testified by both the quarry and MES management teams include much greater reliability and strength of the splice joints. With the previous 500/4 multi-ply belts, the splice joints would usually lasted a maximum of 3 to 4 months being having to be re-made. By comparison, the finger splice joints made when the first Ultra X3 belt was installed more than 18 months previously have never required attention of any kind. Engineers also found that belt tracking was much easier and more responsive. The Ultra X belts are able to pull greater loads with only a single rather than double drive drum, without slipping, even in wet, cold conditions. As a result, the hourly output, which was previously circa 170 tons, normally less in the winter, has increased to over 200 tons per hour all year round. The site is now delivering over 50% more than the contracted volume.
Silence is Golden
Because the quarry is bordered by a nature reserve, peace and tranquillity are essential not only for wildlife but also for its many human visitors. Not surprisingly, the quarry operators are subject to strict regulation and monitoring, including noise pollution so they were naturally delighted to find that when the first Ultra X3 conveyor belts started to run the noise level dropped by at least 50%. Additional environmental benefits include a substantial reduction in carbon footprint and waste. Firstly, the belts have only been transported from The Netherlands (550km) rather than more than 9000km from China. Secondly but equally significant is the fact that the Dunlop belts are likely to provide up to four or five times longer operational lifetime before needing to be replaced compared to the low-grade Asian import belting that was previously being used on site.
The undoubted success of Dunlop’s single-ply revolution is certainly not an isolated case. However, the catalyst for the success in Little Paxton has clearly been that the conveyor contractors are paid on the basis of productivity rather than effectively being ‘rewarded’ for each repair, failed component and prematurely replaced conveyor belt, as is the case with conventional ‘maintain and repair’ contracts. The reduced costs, the increased productivity and environmental benefits should hopefully mean that Aggregate Industries and MES have created a winning formula that can be mirrored across every industry.
Bob Nelson