History
In 1999 Winstone Aggregates commissioned a new plant to be built at the old Hunua Quarry site in the Hunua Gorge. The plant was finished in Oct 2000 and final hand over was in early 2001. Applied Conveyor was not involved in the initial contract for supply of conveyor belt. Early into the hand over we were called in to supply Fenner Dunlop belt because of its proven reputation for superior quality, and many of the other Winstone plants were using Fenner Dunlop belt with excellent results.
Situation
The original belt supplied was 4ply PN150 5×2 ‘N-Grade’ of either Korean or Taiwanese manufacture. This belt lasted a little over 3months in this harsh primary application. It was replaced by a 4ply PN150 8×2 with a breaker strip. This was either a locally manufactured or Korean belt. This lasted 5months before being replaced with an Fenner Dunlop Quarrymaster II PN630/4 6×2 covers. This belt lasted 8months before it needed replacing. At this point we sat down with Winstone management and looked at the whole situation. While the design checks confirmed a 4ply PN150 was well within the operating tensions, the rock being conveyed presented other problems. We came to the conclusion we needed a belt that was flexible enough to go around the 400mm Head and 320mm Tail drums without stressing the splice, yet have high impact and extra cut and gouge resistant rubber covers. The belt we chose was Apex Fenner Rockmaster PN800/4 XCG covers. This belt has the extra cut and gouge covers with ample top and bottom cover thickness and a heavy ply fabric with extra skim cover to handle the impact. In addition to the savings below there is reduced downtime for belt replacement and onsite costs for re-splicing in the case of items 1(8 splices) and item 2(5 splices) all at $1200 per splice. As of the 31/1/04 Apex Fenner Rockmaster has done 24months and will be changed out in March 2004 (26months). This does not take into account the extended production hours and increased tonnage this belt has carried.
