Conveyor belts are made to the most exacting standards. Humidity, temperature, pressure and time are all closely managed.
However, it seems very little control is applied to the splices conducted onsite. Without these splices the belt cannot be installed.
While companies are finding ways to install even longer lengths of belting to reduce the amount of splices needed, some splicing is usually still required.
That splice is the conveyor belt’s Achilles heel because it will always be a weak spot.
In the belt, the steel cords carry the tension loads. In the splice, it is the rubber fill between the cords that takes the load. Failure will occur through fatigue of that rubber infill. Any lessening in the bond between rubber and the tension materials will hasten that failure. Once the splice fails the belt cannot operate.
Part of the problem is how splicers are trained and the way they are treated. Another issue is the lack of attention paid to quality assurance. Often the only paperwork is the invoice.
In many cases this boils down to unskilled people doing non-quality assured work on mission-critical equipment.
On the personnel front, it seems little wonder conveyor belt installers and repairers find it hard to recruit people interested in becoming splicers. It does not sound like the sort of job most high-school career guidance counsellors would get badgered about.
Consider the job description. Hard, sweaty, dirty manual work requiring a high degree of skill that is often carried out in extreme conditions. In some regions, the ambient temperature can exceed 50C – all while working on a piece of black rubber. Not to forget the need to work under a cover because ultraviolet light can hurt the splice and to use a dehumidifier because moisture can be harmful to the adhesion.
There is certainly little glamour attached to the job. Even though the required skill level is high and the consequences of failure great, conveyor splicers are often considered on a par with trades assistants.
Fenner Dunlop has made some inroads into addressing this. It has set up a nationally accredited, 14-week conveyor belt splicing course, which was initially run at a training school in Mackay, Queensland. The school has since been moved to its major facility in the Perth industrial suburb of Kwinana.
Metso vice-president conveyor and lining services Henning Volzke knows first-hand the problems conveyor businesses have in getting skilled staff. He had to recruit his splicers from India.
However, Volzke said that outside of Germany, he knew of no other country that considered conveyor belt splicing to be a trade.
Delmec Consultants principal Doug Ellis has been involved with conducting quality assurance and quality control audits on
BHP Billiton and Rio Tinto conveyor systems for the past decade.
He told Australia’s Mining Monthly one of the biggest problems was that attention to splicing had deteriorated.
“I think that when mining companies moved to core business they lost what experts they had within the corporations and they had some very good people,” he said. “But they’ve all retired.”
Ellis said another problem was that most mine engineers did not understand conveyor belts.
“It seems there are many engineers who
still believe that conveyor belts are delivered to the site as complete endless lengths – forgetting that the lengths have to be joined.”
But Ellis believes the biggest problem is that there is not enough effort put into quality assurance of the splicing process.
“Very few mines have accurate procedures for QA or for the acceptance of completed splices, except ‘Is it finished?’ and ‘Can the plant be restarted now?’
“Frequently, the only paperwork is an invoice. Rarely is there an investigation into why a splice failed and there are a number of reasons why a splice may fail.”
Although Ellis acknowledges the work done on the training front, he thinks it needs to go further.
“In some countries, such as Japan, they have three levels the guys go through,” he said.
“They start with fabric belts, work up to steel cord belt and then go on to be a master splicer.”
